Ultrasound: Weighing the Propaganda Against the Truth

-- Beverly L. Beech, 1999 Midwifery Today #51    (Please read this overview article.)

“It should not be forgotten, however, that numerous studies on rats, mice and monkeys over the years have found reduced foetal weight in babies that had ultrasound in the womb compared with controls. Nor should it be forgotten that in the monkey studies (Tarantal et al., 1993) the ultrasound babies sat or lay around the bottom of the cage, whereas the little control monkeys were up to the usual monkey tricks. Long-term follow up of the monkeys has not been reported. Do they reproduce as successfully as the controls? And, as Jean Robinson has noted: "Monkeys do not learn to read, write, multiply, sing opera, or play the violin." Human children do, and perhaps we should consider seriously whether the huge increases in children with dyslexia and learning difficulties are a direct result of ultrasound exposure in the womb.”

 

“Furthermore, when a woman is scanned her baby’s ovaries are also scanned. So if the woman had seven scans during her pregnancy, when her pregnant daughter eventually presents years later at the antenatal clinic, her developing baby will already have had seven scans. Do women really know what they consent to when they rush to hospital to have their first ultrasound scan, then trustingly agree to further scans?”

 

Comment: Low systemic amounts of vitamin C  (ascorbic acid, AA) predispose one to bruising; a gentle bump causes injury; high AA protects against bruises; high amounts accelerate healing from injuries.

Related harms: Animal studies show experimental use of ultrasound to perforate the membrane of the blood brain barrier, predisposing to future meningitis and neural inflammation by infections. The experimenters’ claim the effect is transitory, but this is questionable.

Long Term Susceptibility: It is hard to show foetal ultrasound exposure predisposes to later vaccine-related neural inflammation and susceptibility to meningitis, but this is a credible possibility. Neural development retardation and other cognitive abnormalities have been shown to be related effects of foetal ultrasound.

Beware: Ultrasound, Scurvy and Vaccination together are factors producing increased harmful effects.

Countermeasures: Take or eat at least several grams of AA per day and >10 grams per day the week of the ultrasound. Eliminate all unneeded (medically unnecessary) ultrasounds.  Lower ultrasound intensity-levels and durations where possible.

Conclusion: Combine borderline scurvy (low vitamin C and ultrasound; the injury is greater and the healing is negligible.  Scurvy magnifies ultrasound injury by a factor proportional to the amount of malnutrition. There is no AA measurement or vitamin C supplementation in ultrasound protocols.

 

Whatever happened to “do no harm”?  Do not believe ultrasound is safe.

Introduction:

The application of ultrasound is big business; in some cases the charges for ultrasound are nearly the same as for all other prenatal treatment. Ultrasound provides intra uterine visibility that may be desired, if promoted, by both doctors and patients. It is popular both with patients and doctors and it is very profitable  for practitioners and provider organizations.

Its safety to the baby is highly suspect; ultrasound use has lead to developmental retardation in foetus and postpartum of monkeys. The supporting, Tarantal et al 1993, study is by a serious researcher and is well cited by many other concerned authors, but it is not found online.

 

There exist economic motivations to keep our scientific consensus oblivious of ultrasound’s multiple harms.  Research funds have been allocated towards increasing the marketability of the machines. To great financial success.

One company sold $275 millions worth of machines in one year. (2010) There are conflicts-of-interest (practitioner profits) in providing more and more unnecessary ultrasound procedures. The autism epidemiological statistics have changed from ~1/4000 to ~1/100. The societal and insurance costs of mental disabilities are huge: Medical, medical insurance, permanent disabilities, family expenses, social security, special training, lost productivity, lost income, lost taxes.

Public funds for studies of ultrasound safety or dangers have been withheld/blocked/under-funded with little safety improvements for more than 40 years, despite the increasing dangers. Still under funded and unable to prove the obvious, despite the increased power levels of the newer ultrasound machines. Where are the follow up experiments to the Tarantal study made in 1993?

Increasing Amounts of Harm and some Therapeutic benefits

The result is that more iatrogenic disabilities are produced at ever increasing ultrasound power levels.  Part of the autism epidemic is likely to be due to ultrasound cellular destruction/disruption, aggravated by low AA systemic levels.

  In my own case, a single ultrasound tooth cleaning resulted in deep tooth pain for a period of 3 months, accompanied by a progressive slow loss of the sense of balance, which continues to slowly worsen. 

For the therapeutic benefits vs. harms physical mechanisms summary and overview see Dr. John Srbely: http://www.sonicrelief.com/learn/whitepaper.pdf

Cell disruption/destruction can be therapeutic. http://www.foxnews.com/health/2012/04/17/ultrasound-beam-can-destroy-prostate-cancer-without-side-effects-study-finds/  Outcomes are better than other treatments like radiation or surgery.

History of Little Concern

Some of the first midwife-concerned studies of adverse foetal ultrasound affects are dated around 1990-1992. Ultrasound machines are now more than 5-50 times more powerful today, 23 years later.  People trained in using these machines have poor level of understanding of the energies that they apply and the physics of how they do harm.  Everyone assumes they are safe, without proof, and proofs of the intrinsic unsafenesses, where known, are not taught. Everyone seems oblivious of the dangers.

Propaganda based on cited-articles’ selection and selective omissions to support an agenda or make false appear true are found on the web pretending to be “science based”. Selective omissions obscure the underlying proven physics, chemistry, and cellular mechanisms and the basic scientific studies of harms actually produced. Science is being ignored by people who claim to represent science, as will be shown below.

Good faith studies where critical variables are not controlled or are unknown are also not valid science. Citing such defective articles in meta-studies is also not scientific; it may be good advertising. But to claim a sponsored, selection biased, flawed meta-study to be “science based” is fraud.

 

Ultrasound Cellular Disruption:

Cellular, animal, and human ultrasound damage studies have shown various permanent and sometimes cell-killing, gene scrambling injury to membranes, to tissues, to teeth, to DNA, to mitochondrial and organelle bodies. Ultrasound causes disruptions with subtle, permanent or slow-to-heal nervous system malfunctions causing disabilities. Genetic damage has been proven. Multi generation effects of ultrasound cellular disruptions are not well enough studied. Health regulators are not connecting the links between known dangers and clinical practices.  Safety margins are not well understood or enforced.  Doctors, patients and regulators are oblivious.  Our genetic pool in countries that practice modern medicine is in danger.

Disruption is not Understood by many

Fully characterizing the conditions and the details of the harms requires a research team including physicists, chemists, biochemists, cellular-microbiologists, electron microscopists, biologists, medical pathologists, all of the highest degree of skill and competence.  Such teams are highly expensive to maintain and have many competing tasks of interest.  It does not help that when a relevant study is done and published that it is in an obscure scientific journal that is not monitored by public health administrators. 

 

Much of what has been learned about the harms from ultrasound when applied to various living forms remains unknown to the popular medical consensus.  Except to the parents and to the practical medical professions, such as midwifery and nursing, who see the tragic results.  The midwives have expressed their concerns and have been largely ignored by the better-funded medical research establishment whose practitioners have classified the harms as “unproven” and the dangers as “unknown” in meta-studies and “science based” propaganda articles.  Regulators, notorious for job switching between government and industry, have failed to ask for or to provide adequate funds for ultrasound safety research. 

Physics of Disruption

Ultrasound energy is physical motion (high frequency vibration) with measurable physical attributes of intensity/amplitude, with vibration-frequencies above audible and having various waveform (pulse) envelope shapes.  Sound energy waves can be reflected, concentrated, and can be focused or diffuse. Sound waves can bounce off of bone structures and form amplified standing waves of higher intensity, much higher than safe levels in areas of focus. Tissue/air and tissue/liquid boundaries are locations for cavitation.

 

Ultrasound can and frequently does cause cavitation, which produces micro sized bubbles that collapse into pinpoint centers of super high pressure and temperature. The high temperatures cook cells’ micro components, DNA, RNA, bioactive molecules, hormones, enzymes, organelles, and mitochondria.

 

From the physics, it is clear that ultrasounds’ disruptive harm is proportional to intensity and duration.  [Incident-energy] multiplied by [Exposure-time]. Disruptive effects also depend on other sound-attribute relationships: frequency, waveform shapes, standing wave amplification, reflective-structure sound-wave focusing, and tissue/air/liquid boundary concentration or cavitation effects. 

 

Energy, when applied to cells and tissues has many proven transformative bad (and some gentle and good) effects on life in the form of cells, tissues, biofilms, and organic and cellular systems. Forms of energy include: Electro-Magnetic radiation [intensity, frequency (audio-radio), waveforms]; Heat/cold (IR); Ultraviolet; Lasers; Diathermy.  Forms of physical motion energy include: Exercise; Massage; Chiropractic manipulation; Sound/ultrasound [frequency, amplitudes, waveforms], etc.  Ultrasound has been used to provide visibility and in other studies calcification disruption/break-up and blood-brain membrane cell-disrupting destruction.

 

Persistent effects with little healing

In a nano scale, ultrasound destroys/modifies parts of the body’s cells and organelles in a persistent way. Regeneration/replacement of damaged tissue and nerve cells is needed and may be defective as occurs for trauma and burn recovery. Too little attention is given to vitamin nutrition in promoting recovery from ultrasound treatment injuries, which are subtle and remain unnoticed and denied by practitioners.

Destructive Ultrasound therapy

Recent PMID Ultrasound research is targeted to traumatic disrupting of the blood brain barrier in order to enable passage of otherwise blocked medical agents. One study shows marked tissue damage. Proof of microscopic tissue and cellular harm in rabbit experiments. Rapid recovery is postulated as a hypothetical goal but complete recovery from trauma is not proved. Degree of damage is hard to quantify without biopsy. Many other studies have shown traces of permanent neural-system developmental retardation and regressive functional impairment along with disruptive damage.

 

NLM recent papers indicate they are using the disruption creatively with disregard for the long term permanent and delayed effects. Evidence of ultrasound caused tissue damage was found in one paper.  No follow-up on long term harms that show up later. Disruption of BBB allows drugs into the brain and also makes brain more vulnerable to infection, perhaps permanently more susceptible to meningitis.

 

Systemic ideological Blindness or “science based” fraud?

It is unlikely that the systemic ideological blindnesses of the medical consensus over the last 200 years are likely to change in the next 50 years. This is clear in the case of systematic ignorance of vitamin C’s therapeutic dosage and its pharmacodynamic actions. See Ely “Unprofitable Modalities” and “Denial of Infectious Theory of Diseases”. Ely Dr John Ely’s well-reasoned papers are too gentle on those who claim to be scientists, but ignore science and who profit while doing harm to the public.

 

Ultrasound can be harmful; the money is in promoting its widespread profitable use; not in increasing its safe use. Improvement in safety depends on funding. The funding-gatekeepers depend on the medical support industry. Documenting a complex and “unproven” safety issue is always a low priority. Creating disabilities harms the patients, increases medical insurance costs, but is good for the practitioner business.  The medical consensus has a profit-based conflict-of-interest that promotes oblivious denial of the reality of harmful practices. Add overcharging and multiple-counting of costs hidden in the billing or overhead costs and you have some of the bases of our medical system corruption’s runaway costs.

 

After doing all the bottom-up research I found that a game is being played with the public.  A Google top-down search [Ultrasound Dangers] brought up a first entry from a site http://www.sciencebasedmedicine.org/  that was at variance with all the material I found citing the underlying real science of the dangers.

 

This website is obviously a propaganda site used to display articles specially written to pretend that Science is supporting safety and other practices, where dangers can be written about and minimized. They selectively categorize medical studies showing harmful results of ultrasound as not credible. This is not truthful.

 

So it is not just a bunch of confused ignorant scientists that should know better. Here is an organization that publishes propaganda supplied by their supporters, which have socially harmful ideological, financial and business interests. This would be fine if the public was not being harmed by their practices. But this is not the case. Some of their profits are dirty.

 

One can conclude that “science based medicine” is a fraud.  Just like the pseudo-science of global warming that was shown to lead to taxes flowing to undeserving profiteers. I have found other evidences of stacking-the-deck with articles that are pushed to the top of the search results. This is just one of the most obvious.

 

“Science Based Medicine” articles need to be examined critically for validity.  All of them may be planted to produce a plausible justification for practices that either rip off the medical consumer or are actually harmful.

 

Caveat Emptor! Beware meta-study selection bias and “Science-based” propaganda. They are well financed by the medical profit making providers.

 

Examine the contrasting studies of researchers that are not cited to get the full picture.  WWW.Whale.to is a good place to start.

 

Conclusions: First, do no harm.

Our medical system’s politicians need to be replaced by midwives who will approve research justifying comprehensive ultrasound safety testing. When proven dangerous, ultrasound machines need to be made safe or made illegal for human medical use. Legal recourse to compensation in cases of harm needs to be enabled. Where ultrasound was used and it did harm, the government, the propagandists and the manufacturers jointly should be liable. It may be easy to prove Rico Act Conspiracy.

 

But first, stop doing all the unnecessary ultrasounds, as the AMA has requested.

 

Ultrasound Dangers Web References:

1.        http://www.midwiferytoday.com/articles/ultrasound.asp Ultrasound: Weighing the Propaganda Against the Facts, By Beverly L. Beech, 1999, Midwifery Today

2.        http://www.whale.to/a/questions9.html Questions about Prenatal Ultrasound and the Alarming Increase in Autism, By Caroline Rodgers  2006 Midwifery Today

3.        http://www.sonicrelief.com/learn/whitepaper.pdf  Dr John Srbely, Bio-physical Effects

4.        http://www.whale.to/a/ultrasound_unsound.html    Included below with updates.

5.        http://www.greenmedinfo.com/anti-therapeutic-action/obstetric-ultrasonography  

6.        http://web.archive.org/web/20020205080758/http://gentle-birth.com/ultrasound.htm

7.        http://www.whale.to/w/autism.html     Good Overview Page.

8.        http://www.whale.to/a/when1.html  

9.        http://www.whale.to/a/ultrasound1.html

10.   http://web.archive.org/web/20040211043958

 

 

Mercola ultrasound articles:

1.        http://articles.mercola.com/sites/articles/archive/2008/01/02/ultrasound-may-harm-unborn.aspx

2.        http://articles.mercola.com/sites/articles/archive/2006/08/22/for-the-health-of-your-baby-stay-away-from-unnecessary-ultrasounds.aspx

  1. http://articles.mercola.com/sites/articles/archive/2001/12/19/ultrasound.aspx

 

Copyright KF and KM Poehlmann, January 2013, all rights reserved.

Our Experience and Qualifications

(Katherine Poehlmann, PhD and Karl Poehlmann)

Inflammation, chronic infections, nutrition and immunity are topics we have researched broadly in our studies of worldwide medical knowledge, documented on the Internet and in the historical archives of medicine.  We have spent over ten calendar years reading about these inter-related subjects, attending postgraduate medical conferences. We have read countless medical texts, abstracts, and papers, online in the National Library of Medicine and contained at various authoritative medical, nutritional and biological websites. The mass of the available information worldwide is tremendous. Search engines can reach much of it, so it can be correlated productively.

 

Disclaimer

Nothing herein or referenced herein should be considered prescriptive for any medical condition.  This information is for study and education purposes only.  The readers are advised to find and consult well-educated, trained and licensed medical and nutritional practitioners who shall evaluate the many circumstances and conditions of each of their patients and will devise appropriate treatments and nutritional plans for them.  It is recognized that each person has the right and duty to be well informed about the best foods, nutrition and medical practices available that will promote their own good health.  The opinions expressed herein are those of the author(s) and the sources cited and there are many divergences of opinions on many topics. The readers must resolve the conflicts, in their own minds, after careful consideration of all the details and after any further necessary research and study.

 

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Google [Ultrasound Dangers]  > 2 million hits

    

 

 

Science-Based Medicine Are Prenatal Ultrasounds Dangerous?

www.sciencebasedmedicine.org/.../are-prenatal-ultrasounds-da...

Aug 30, 2011 – Several questionable sources are spreading alarms about the possible dangers of prenatal ultrasound exams (sonograms). An example is ...

    

 

 

 

Ultrasound - just looking can hurt! - Green Health Watch Magazine

www.greenhealthwatch.com/newsstories/.../ultrasound-hurt.ht...

Ultrasound, ultrasound pictures, dangers 3d ultrasound fetus, 3d ultrasound dangers to fetal, fetal ultrasound dangers - Ultrasound - just looking can hurt!- Green ...

          If ultrasound destroys sperm, why is it safe for a fetus?

www.naturalnews.com/028853_ultrasound_fetus.htmlShare

 

    

 

 

The Dangers of Ultrasound Machines

www.everyday-wisdom.com/dangers-of-ultrasound.html

Knowing the threats and potential dangers of ultrasound may help you stay well and healthy. The potential threats are....

    

 

 

 

Prenatal Portraits: Darling or Dangerous?

www.webmd.com/baby/.../prenatal-portraits-darling-dangerou...

Prenatal Portraits: Darling or Dangerous? Many businesses offer ultrasound pictures and videos of unborn babies for entertainment purposes, but some experts ...

    

 

 

 

Questions about Prenatal Ultrasound and the Alarming Increase in ...

www.midwiferytoday.com/articles/ultrasoundrodgers.asp

by C Rodgers - Related articles
A far simpler possibility worthy of investigation is the pervasive use of prenatal ultrasound, which can cause potentially dangerous thermal effects.

    

 

 

 

The Dangers of Prenatal Ultrasound

www.unhinderedliving.com/pultra.html

NO STUDIES have been done which prove the safety of these devices, and the American Medical Association recommends AGAINST unnecessary exposure.

    

 

 

 

So really, how dangerous are ultrasounds? - pregnancy resolved ...

ask.metafilter.com/.../So-really-how-dangerous-are-ultrasound...

19 answers - Sep 9, 2009

http://www.ncbi.nlm.nih.gov/pubmed/19291813. This study is a meta-analysis which means that it summarizes the different epidemiological studies ...

    

 

 

 

The Dangers of Ultrasounds - Yahoo! Voices - voices.yahoo.com

voices.yahoo.com/the-dangers-ultrasounds-178087.html

Jan 30, 2007 – The american Medical Association has warned of the possible dangers of prenatal ultrasounds and has advised that medical professionals ...

 

 

Notes:  Whale.TO:  Ultrasound  Link To Other Articles

Ultrasound Unsound? (Collection of info) 

The following pages contain notes on ultrasound safety factors documented on the web.  The information is both compelling and disturbing.  Changes have been made to recover broken link articles cited by reference to the web.archive website aka Web Wayback Machine.   http://www.whale.to/a/ultrasound_unsound.html

 Original website text

[Updated here to fix broken links to dead websites using web.archive.org = Web “Wayback Machine”]

Here is a link to an interesting article entitled Ultrasound - Weighing the propaganda against the facts.  It was written by the
author of Ultrasound Unsound?
http://web.archive.org/web/20040211043958/http://www.aims.org.uk/ultrasound.htm

I have seen other studies identifying negative side effects of ultrasounds.  One in particular found that as little as 1 ultrasound could delay a child's speech by as much as 9 months.  This study was done in Canada, not the US.  Other findings have suggested that the increase in left-handedness among children who were scanned before birth is linked to the ultrasound, which would show that the scan does alter the brain in some way. 

In the US, keep in mind that medical equipment does not undergo the type of testing that a drug must go through to get on the market.  The scans used today are more invasive than the earlier ones, so it will take a few more decades to really know the outcome.  The recent generations of children who have been scanned are in fact the guinea pigs that will decide the safety of ultrasounds -- which have done nothing to lower childbirth death rates, but have sent the C-section rate dangerously high in the US.  

The article above points out that the doppler, used to detect heart tones on every prenatal visit unless you have a midwife who uses a fetalscope), may cause even more damage than the ultrasound.

-Susan

*******

This is straight from the journal "Epidemiology" (Dec 2001), and suggests that ultrasound is associated with mild brain damage.
http://web.archive.org/web/20020803214823/http://www.mercola.com/2001/dec/19/ultrasound.htm

My boss, Dr. Mark Ellisman, is a world-renowned research scientist at UCSD who specializes in imaging technologies for the study of brain structure at the cellular level; he has personally found evidence of something called "cavitation", which is the "rapid formation and collapse of vapor pockets" in fluid within tissue. When my wife and I became pregnant he warned me to keep the ultrasound as short as possible. He knows what he's talking about.

Here's a relevant quote:

   "Free radical production in amniotic fluid and blood plasma by medical ultrasound, probably following gaseous cavitation, has been detected by Crum et al (1987). This provides a likely mechanism for the origin of the DNA damage. Because of these confirmations and a report by Ellisman et al (1987) that diagnostic levels of ultrasound may disrupt  myelination in neonatal rats, the need for regulation, guidance, and properly controlled clinical studies is clear."  http://www.aimsusa.org/ultrasnd.htm

   
Here's another useful link:  http://www.alternamoms.com/ultrasound.html


So please don't consider this a benign procedure or an opportunity  to get some pretty pictures. and *please* don't get an extra 3D ultrasound, which is a very long scan, to get the 3D picture of your baby. There is a real risk, and it's just not worth it. Do a Google search on "+ultrasound +cavitation" or "+ultrasound +Ellisman"  and convince yourself.

Just my .02  Dave
*******
http://web.archive.org/web/20020804150336/http://www.mothering.com/11-0-0/html/11-2-0/ultrasound-risk.shtml

 
Weighing the Risks: What You Should Know about Ultrasound
By Sarah Buckley
Issue 102, September/October 2000

Ultrasonography was originally developed during World War II to detect enemy submarines. Its use in medicine was pioneered in Glasgow, Scotland,  by Dr. Ian Donald, who first used ultrasound to look at abdominal tumors, and later babies in utero in the mid-1950s.1 The use of ultrasound in  pregnancy spread quickly.

In westernized healthcare systems, ultrasound, which may be offered to a pregnant woman either to investigate a possible problem at any stage of  pregnancy or as a routine scan at around 18 weeks, has become almost universal in pregnancy. In Australia, where I live, 99 percent of pregnant  women have at least one scan, paid for in part by our federal government,  through Medicare. In fact, from 1997 to 1998 Medicare paid out AU$39 million for obstetric scans, compared to AU$54 million for all other obstetric Medicare costs. In the US, the American College of Obstetrics and Gynecology (ACOG) estimates that 60 to 70 percent of pregnant women are
scanned, despite an official statement from ACOG that recommends against routine ultrasound.2 At a cost of roughly $300 per procedure, this represents a cost of approximately $70 to $80 million each year in the US.

Besides routine scans, ultrasound can be prescribed to investigate problems such as bleeding in early pregnancy. Later in pregnancy, ultrasound can be used when a baby is not growing, or when breech or twin births are suspected. In such cases, the information gained from ultrasound can be very useful in decision-making, and generally most professionals support the use of ultrasound in this context.

It is such use of routine prenatal ultrasound (RPU) that is more controversial, as this practice involves scanning all pregnant women in the hope of improving the outcome for some mothers and babies. RPU seeks to gain four main types of information:

Estimated due date.

Dating a pregnancy is most accurate at early stages, when babies vary the least in size. By contrast, at 18 to 20 weeks the expected date of delivery is only accurate to within a week either way.  Some studies have suggested, however, that an early examination or a woman's own estimation of her due date can be as accurate as RPU.3,4 Unsuspected physical abnormalities. While many women are reassured by a normal scan, in fact RPU detects only between 17 percent and 85 percent of the one in 50 babies that have major abnormalities at birth.5,6 A recent study from Brisbane, Australia, showed that ultrasound at a major women's hospital missed about 40 percent of abnormalities, many of which are difficult or impossible to detect.7 The major causes of intellectual disability, such as cerebral palsy and Down syndrome, or heart and kidney abnormalities, are unlikely to be picked up on a routine scan.

There is also a small chance that the diagnosis of an abnormality is false positive. In some instances, normal babies have been aborted because of false-positive diagnoses.8 A United Kingdom survey found that one in 200 babies aborted for major abnormalities were wrongly diagnosed.9

In addition to false positives, there are also uncertain cases in which the ultrasound image cannot be easily interpreted, and the outcome for the baby is not known. In one study involving babies at higher risk of abnormalities, almost 10 percent of scans were uncertain.10 This can create immense anxiety for the woman and her family that may not be allayed by the birth of a normal baby: in the same study, mothers with questionable diagnoses still had associated anxiety three months after the child's birth. Uncertain findings also lead to repeated and/or prolonged scans, increasing the expense, inconvenience, and dosage of ultrasound.

In some cases of uncertainty, further tests such as amniocentesis are recommended. In such situations, there may be up to two weeks wait for results, during which time a mother must consider whether or not she will terminate the pregnancy if an abnormality is found. Even mothers who receive reassuring news have felt that this process has interfered with their relationship with their babies.11

Location of the placenta.

 A very low-lying placenta (placenta previa) puts mother and baby at risk of severe bleeding, and usually necessitates a cesarean section. However, 19 out of 20 women who have placenta previa detected on RPU will be needlessly worried, as the placenta will effectively move upwards as the pregnancy progresses.12 Furthermore,
detection of placenta previa by RPU has not been found to be safer than detection in labor.13

Multiple fetuses. Ultrasound can detect the presence of more than one baby at an early stage of pregnancy, but this knowledge affords no documented health advantages for mother or babies, and, without RPU, almost all multiple pregnancies are discovered before birth.14

Why Are RPUs So Popular?
Supporters of RPU argue that availability of ultrasonic information leads to better outcomes for mother and baby. While this seems logical, researchers have not found evidence of significant benefit from RPU, and the issue of the safety of ultrasound has not yet been resolved.

From a research perspective, the most significant benefit of RPU is a small reduction in perinatal mortality, that is the number of babies dying around the time of birth. This is, however, merely a statistical reduction since perinatal mortality rates do not include deaths that occur before five to six months' gestation. Often when a baby is found to have a fatal
abnormality on RPU, the pregnancy is terminated before this time, excluding the baby from perinatal statistics.

RPU proponents presume that early diagnosis and termination is beneficial to women and their families. However, the discovery of a major abnormality on RPU can lead to very difficult decision-making. Some women who agree to
have an ultrasound are unaware that they may get information about their baby that they do not want, as they would not contemplate a termination. Other women can feel pressured to have a termination, or at least feel some emotional distancing from their "abnormal" baby.15

Furthermore, there is no evidence that women who have chosen termination are, in the long term, psychologically better off than women whose babies have died at birth. In fact, there are suggestions that the reverse may be true in some cases.16 In choosing a possible stillbirth over a termination, women at least get social acknowledgment and support, and are able to
grieve openly. Where termination has been chosen, women are unlikely to share their story with others and can experience considerable guilt and pain from the knowledge that they themselves chose the loss.17

Another purported benefit of RPU is a reduced risk of being induced for being "overdue," because RPU dating gives a more certain estimated due date. However, there is no clear evidence that this is true, as the possibility of induction is more determined by hospital or doctor policy than by the availability of RPU.19

Many supporters of RPU claim that it's a pleasurable experience, and contributes to bonding between mother (and father, if he is present) and baby. While it is true that it can be exciting to get a first glimpse of one's baby in utero, there is no evidence that it helps attachment or encourages healthier behavior toward the baby.20 For most women, bonding occurs naturally when they begin to feel fetal movements at 16 to 20 weeks.

Reasons for Concern
Ultrasound waves are known to affect living tissues in at least two ways. First, the sonar beam heats the highlighted area by about 1C (2F). This is presumed to be insignificant, based on whole-body heating in pregnancy, which seems to be safe up to 2.5C (5F).21 The second effect is cavitation, where the small pockets of gas that exist within mammalian tissue vibrate and then collapse. In this situation "...temperatures of many thousands of degrees Celsius in the gas create a wide range of chemical products, some of which are potentially toxic."22 The significance of cavitation in human tissue is unknown.

A number of studies have suggested that these effects are of real concern in living tissues. The first study indicating problems analyzed cells grown in the lab. Cell abnormalities caused by exposure to ultrasound were seen to persist for several generations.23 Another study showed that, in newborn rats (who are at a similar stage of brain development as humans at four to five months in utero), ultrasound can damage the myelin that covers nerves,24 indicating that the nervous system may be particularly susceptible to damage from this technology. In 1999, an animal study by Brennan and colleagues, reported in New Scientist,25 showed that exposing mice to dosages typical of obstetric ultrasound caused a 22 percent reduction in the rate of cell division, and a doubling of the rate of cell death in the cells of the small intestine.

Studies on humans exposed to ultrasound have shown possible adverse effects, including premature ovulation,26 preterm labor or miscarriage,27, 28 low birthweight,29 poorer condition at birth,30, 31 dyslexia,32 delayed speech development,33 and less right-handedness,34, 35 a factor which in some circumstances can be a marker of damage to the developing brain. In addition, one Australian study showed that babies exposed to five or more ultrasounds were 30 percent more likely to develop intrauterine growth retardation (IUGR)--a condition that ultrasound is often used to detect.36

Two long-term randomized controlled trials, comparing exposed and unexposed children's development at eight to nine years of age, found no measurable effect from ultrasound.37, 38 However, as the authors note, intensities used today are many times higher than in 1979 to 1981. A later report of one of these trials39 indicated that scanning time was only three minutes. More studies are obviously needed in this area, particularly in Doppler ultrasound, where exposure levels are much higher, and in vaginal ultrasound, where there is less tissue shielding the baby from the transducer.

A further problem with studying ultrasound's effect is the huge range of output, or dose, possible from a single machine. Modern machines can give comparable ultrasound pictures using either a lower or a 5,000 times higher dose,40 and there are no standards to ensure that the lowest dose is used. Because of the complexity of machines, it is difficult to even quantify the dose given in each examination.41 In the US, as in Australia, training is voluntary (even for obstetricians), and the skill and experience of operators varies widely.

In all the research done on ultrasound, there has been very little interest in women's opinions of RPU, and the consequences of universal scanning for women's experience of pregnancy. In her thoughtful book on prenatal diagnosis, The Tentative Pregnancy,42 Barbara Katz Rothman suggests that the large numbers of screening tests currently being offered to check for abnormalities makes every pregnancy tentative until reassuring results come back.

Ultrasound is not compulsory, and I suggest that each woman consider the risks, benefits, and implications of scanning for her own particular situation. If you decide to have a scan, be clear about the information that you do and do not want to be told. Have your scan done by an operator with a high level of skill and experience (usually this means performing at least 750 scans per year) and say that you want the shortest scan possible. If an abnormality is found, ask for counseling and a second opinion as soon as practical. And remember, it's your baby and your choice.

Notes
1. Ann Oakley, "The History of Ultrasonography in Obstetrics," Birth 13, no. 1 (1986): 8-13.

2. American College of Obstetricians and Gynecologists, "Routine Ultrasound in Low-Risk Pregnancy, ACOG Practice Patterns:  Evidence-Based Guidelines for Clinical Issues," Obstetrics and Gynecology 5 (August 1997).

3. O. Olsen et al., "Routine Ultrasound Dating Has Not Been Shown to Be More Accurate Than the Calendar Method," Br J Obstet Gynaecol 104, no. 11 (1997): 1221-1222.

4. H. Kieler, O. Axelsson, S. Nilsson, and U. Waldenstrom, "Comparison of Ultrasonic Measurement of Biparietal Diameter and Last Menstrual Period as a Predictor of Day of Delivery in Women with Regular 28-Day Cycles," Acta-Obstet-Gynecol-Scand 75, no. 5 (1993): 347-349.

5. B. G. Ewigman, J. P. Crane, F. D. Frigoletto et al., "Effect of Prenatal Ultrasound Screening on Perinatal Outcome," N Engl J Med 329, no. 12 (1993): 821-827.

6. C. A. Luck, "Value of Routine Ultrasound Scanning at 19 Weeks: A Four Year Study of 8849 Deliveries," British Medical Journal 34, no. 6840 (1992): 1474-1478.

7. F. Y. Chan, "Limitations of Ultrasound," paper presented at Perinatal Society of Australia and New Zealand 1st Annual Congress, Freemantle, 1997.

8. AIMS UK, "Ultrasound Unsound?," AIMS UK Journal 5, no. 1 (Spring 1993).

9. I. R. Brand, P. Kaminopetros, M. Cave et al., "Specificity of Antenatal Ultrasound in the Yorkshire Region: A Prospective Study of 2261 Ultrasound Detected Anomalies," Br J Obstet Gynaecal 101, no. 5 (1994): 392-397.

10. J. W. Sparling, J. W. Seeds, and D. C. Farran, "The Relationship of Obstetric Ultrasound to Parent and Infant Behavior," Obstet Gynecol 72, no. 6 (1988): 902-907.

11. A. Brookes, "Women's Experience of Routine Prenatal Ultrasound," Healthsharing Women: The Newsletter of Healthsharing Women's Health Resource Service (Melbourne, Australia) 5, no.s 3, 4 (December 1994-March 1995).

12. MIDIRS, Informed Choice for Professionals, Ultrasound Screening in the First Half of Pregnancy: Is It Useful for Everyone? (UK: MIDIRS and the NHS Centre for Reviews and Dissemination, 1996).

13. A. Saari-Kemppainen, O. Karjalainen, P. Ylostalo et al., "Ultrasound Screening and Perinatal Mortality: Controlled Trial of Systematic One-stage Screening in Pregnancy," The Lancet 336, no. 8712 (1990): 387-391.

14. See Note 12.

15. See Note 11.

16. D. Watkins, "An Alternative to Termination of Pregnancy," The Practitioner 233, no. 1472 (1989): 990, 992.

17. See Note 12.

18. Ibid.

19. Ibid.

20. Ibid.

21. "American Institute of Ultrasound Medicine Bioeffects Report 1988," J Ultrasound Med 7 (September 1988): S1-S38.

22. Ibid.

23. D. Liebeskind, R. Bases, F. Elequin et al., "Diagnostic Ultrasound: Effects on the DNA and Growth Patterns of Animal Cells," Radiology 131, no. 1 (1979): 177-184.

24. M. H. Ellisman, D. E. Palmer, and M. P. Andre, "Diagnostic Levels of Ultrasound May Disrupt Myelination," Experimental Neurology 98, no. 1 (1987): 78-92.

25. Brennan et al., "Shadow of Doubt," New Scientist 12 (June 1999): 23.

26. J. Testart, A. Thebalt, E. Souderis, and R. Frydman, "Premature Ovulation after Ovarian Ultrasonography," Br J Obstet Gynaecol 89, no. 9 (1982): 694-700.

27. See Note 13.

28. R. P. Lorenz, C. H. Comstock, S. F. Bottoms, and S. R. Marx, "Randomised Prospective Trial Comparing Ultrasonography and Pelvic Examination for Preterm Labor Surveillance," Am J Obstet Gynecol 162, no. 6 (1990): 1603-1610.

29. J. Newnham, S. F. Evans, C. A. Michael et al., "Effects of Frequent Ultrasound During Pregnancy: A Randomised Controlled Trial," The Lancet 342, no. 8876 (1993): 887-891.

30. S. B. Thacker, "The Case of Imaging Ultrasound in Obstetrics: A Review," Br J Obstet Gynaecol 92, no. 5 (1985): 437-444.

31. J. P. Newnham et al., "Doppler Flow Velocity Wave Form Analysis in High Risk Pregnancies: A Randomised Controlled Trial," Br J Obstet Gynaecol 98, no. 10 (1991): 956-963.

32. C. R. Stark, M. Orleans, A. D. Havercamp et al., "Short and Long Term Risks after Exposure to Diagnostic Ultrasound in Utero," Obstet Gynecol 63 (1984): 194-200.

33. J. D. Campbell et al., "Case-control Study of Prenatal Ultrasonography
in Children with Delayed Speech," Can Med Ass J 149, no. 10 (1993): 1435-1440.

34. K. A. Salvesen, L. J. Vatten, S. H. Eik-nes et al., "Routine Ultrasonography in Utero and Subsequent Handedness and Neurological Development," British Medical Journal 307, no. 6897 (1993) 159-164.

35. H. Kieler, O. Axelsson, B. Haguland et al., "Routine Ultrasound Screening in Pregnancy and the Children's Subsequent Handedness," Early Human Development 50, no. 2 (1998): 233-245.

36. See Note 31.

37. K. A. Salvesen, L. S. Bakketeig, S. H. Eik-nes et al., "Routine Ultrasonography in Utero and School Performance at Age 8-9 Years," The Lancet 339, no. 8785 (1992):85-89.

38. H. Kieler, G. Ahlsten, B. Haguland et al., "Routine Ultrasound Screening in Pregnancy and the Children's Subsequent Neurological Development," Obstet Gynecol 91, no. 5 (1998): 750-756.

39. See Note 37.

40. H. B. Meire, "The Safety of Diagnostic Ultrasound," Br J Obstet Gynaecol 94 (1987): 1121-1122.

41. K. J. W. Taylor, "A Prudent Approach to Ultrasound Imaging of the Fetus and Newborn," Birth 17, no. 4 (1990): 218-223.

42. Barbara Katz Rothman, The Tentative Pregnancy: How Amniocentesis Changes the Experience of Motherhood (New York: W. W. Norton, 1993).

For more information on ultrasound, see the following articles in past issues of Mothering: "Ultrasound: More Harm Than Good?" no. 77; "The Trouble with Ultrasound," no. 57; "How Sound Is Ultrasound?" no. 34; "Ultrasound," no. 24; and "Diagnostic Ultrasound," no. 19.

Sarah Buckley (40) is a New Zealand-trained GP (family MD), and still in training as partner to Nicholas. Mother of Emma (9), Zoe (6), and Jacob (4), she is currently expecting her fourth baby and lives in Brisbane, Australia, where she writes about pregnancy, birth, and parenting.
 

********
Shadow of a doubt

by Rob Edwards

ULTRASOUND SCANS can stop cells from dividing and make them commit suicide.
A research team in Ireland say this is the first evidence that routine scans, which have let doctors peek at fetuses and internal organs for the past 40 years, affect the normal cell cycle.

A team led by Patrick Brennan of University College Dublin gave 12 mice an 8-megahertz scan lasting for 15 minutes. Hospital scans, which reflect inaudible sound waves off soft tissue to produce images on a monitor, use frequencies of between 3 and 10 megahertz and can last for up to an hour

The researchers detected two significant changes in the cells of the small intestine in scanned mice compared to the mice that hadn't been scanned. Four and a half hours after exposure, there was a 22 per cent reduction in the rate of cell division, while the rate of programmed cell death or "apoptosis" had approximately doubled.

Brennan believes there will be similar effects in humans. "It has been assumed for a long time that ultrasound has no effect on cells," he says. "We now have grounds to question that assumption."

Brennan stresses, however, that the implications for human health are uncertain. "There are changes happening, but we couldn't say whether they are harmful or harmless," he explains. The intestine is a very adaptable organ that can compensate for alterations in the cell cycle, says Brennan.

It is possible that the sound waves damage the DNA in cells, delaying cell division and repair. Brennan suggests that ultrasound might be switching on the p53 gene which controls cell deaths. This gene, dubbed "the guardian of the genome", produces a protein that helps cells recognise DNA damage and then either self-destruct or stop dividing.

Studies in the early 1990s by researchers at the University of Rochester in New York and the Batelle Pacific Northwest Laboratories in Richland, Washington, showed that tissue heating due to ultrasound can cause bleeding in mouse intestines. Ultrasonographers now tune the power of scans to reduce such heating.

But Brennan's work is the first evidence that scans create changes in cells. "Our results are preliminary and need further investigation," he says. The team presented their results at the Radiology 1999 conference in Birmingham last month and are now preparing them for submission to a peer-reviewed journal.

Alex Elliott, a researcher in clinical physics at the University of Glasgow, thinks that Brennan's results are important and should be followed with further studies. "If the conditions of his experiments really compare to the clinical use of ultrasound," he says, "we may have to review the current safety limits."


>From New Scientist, 12 June 1999
*******

Here are some excerpts about ultrasound from "What Doctors Don't Tell You"
by Lynne McTaggart.    "No well controlled study has yet proved that routine scanning of prenatal patients will improve the outcome of pregnancy" - official statement from American College of Obstetrics & Gynecology in 1984

Some studies show that, with ultrasound, you are more likely to lose your baby.  A study from Queen Charlotte's and Chelsea Hospital in London found that women having doppler ultrasound were more likely to lose their babies than those who received only standard neonatal care (17 deaths to 7).

A Norwegian study of 2,000 babies found that those subjected to routine ultrasound scanning were 30% more likely to be left-handed than those who weren't scanned.  An Australian study demonstrates that frequent scans increased the proportion of growth-restricted babies by a third, resulting in a higher number of small babies.  Exposure to ultrasound also caused
delayed speech, according to Canadian researcher Professor James Campbell.

The International Childbirth Education Association has maintained that ultrasound is most likely to affect development (behavioral & neurological), blood cells, the immune system, & a child's genetic makeup.

Besides the safety issue, there are considerable questions about accuracy. There is a significant chance that your scan will indicate a problem when there isn't one, or fail to pick up a problem actually there.  One study found a "high rate" of false positives, 17% of the pregnant women scanned were shown to have small-for-dates babies, when only 6% actually did - an
error rate of nearly one out of three.  Another study from Harvard showed that among 3,100 scans, 18 babies were  erroneously labeled abnormal, and 17 fetuses with problems were missed.

Linda

********
this is from another list...

<<<According to Anne Frye, midwife and author of "Understanding Lab Work in  the Childbearing Year" (4th Ed.)p. 405
Doppler Devices: Many women do not realize that Doppler fetoscopes are ultrasound devices. (apparently, neither do many care providers. Time after time, women are assured by doctors and even some nurse midwives that a Doppler is not an ultrasound device.) . . . .

Not well publicized for obvious reasons, Doppler devices expose the fetus to more powerful ultrasound than real time (imaging) ultrasound exams. One minute of Doppler exposure is equal to 35 minutes of real time ultrasound. This is an important point for women to consider when deciding between an ultrasound exam and listening with a Doppler to determine viability in early pregnancy. . . . .

If you have a Doppler, put it aside and make a concerted effort to learn to listen yourself! Save your Doppler for those rare occasions when you cannot hear the heart rate late into pushing or to further investigate suspected fetal death. " copyright l990, Anne Frye, B.H. Holistic Midwifery.

Personally, after 23 years of attending births, I would not permit a Doppler in my house if I were pregnant. You always know that something is ultrasound because there will be "jelly" involved. If you want a cheap listening device for the baby's heart just save the core from a roll of toilet paper. Put one end on the lower belly and the other on hubby's ear. If you want to know your baby is doing well, count the fetal movements in a day. Starting at 9 a.m. count each time the baby kicks. There should be l0 distinct movements by 3 p.m.

I think it's sad that some people will do anything to make a buck of the huge pregnant market in North America. Please feel free to forward this post on to any other lists.

Gloria Lemay, Vancouver BC  Wise Woman Way of Birth Courses
http://web.archive.org/web/20000902050959/http://www.birthlove.com/pages/wise_woman.html

>>>

********
http://web.archive.org/web/20070306212725/http://news.bbc.co.uk/1/hi/health/1751177.stm



This made me wonder what ultrasound does to developing babies if it  can have such a drastic effect on a testicle.

******

http://web.archive.org/web/20040831020747/http://www.mothering.com/11-0-0/html/11-2-0/prenatal-testing.shtml


Prenatal Testing and Informed Consent: Base Your Choices on the Evidence

By Peggy O'Mara Issue 120, September/October 2003

“Is Ultrasound Safe? The National Institutes of Health cautions against routine use of ultrasound, noting that "the data on clinical efficacy and safety do not allow recommendation for routine screening at this time; there is a need for multidisciplinary randomized controlled clinical trials for an adequate assessment."7

“Similarly, the World Health Organization (WHO) urges prudence: "Ultrasound screening during pregnancy is now in widespread use without sufficient evaluation. Research has demonstrated its efficacy for certain complications of pregnancy but the published material does not justify the routine use of ultrasound in pregnant women."8

“According to perinatal epidemiologist Marsden Wagner, the safety of ultrasound has never been clinically proven. The editors of the Cochrane Database, a review of over 9,000 controlled trials from 85 different countries, note that "there has been surprisingly little well-organized research to evaluate possible adverse effects of ultrasound exposure on human fetuses."9

“In a 1999 study, six scientists at University College Dublin found that ultrasound creates changes in cells. Patrick Brennan, the lead researcher, said, "It has been assumed for a long time that ultrasound had no effect on cells. We now have grounds to question that assumption."10 Further evidence that ultrasound has an effect on cells is indicated in recent research that shows a higher-than-average rate of left-handedness in boys exposed to ultrasound in utero.11

 

End  Ultrasound_Unsound from Whale.TO  Comment:

Ultrasound disrupts Blood Brain Barrier (BBB) and causes tissue damage in presence of contrast agent in rabbits.

Some NLM recent  papers indicate they are using the disruption creatively with some disregard for the long term permanent and delayed effects. Evidence of tissue damage in one paper.  No follow-up on long term harms that show up later. Disruption of BBB allows drugs into the brain and also makes brain more vulnerable to infection, perhaps permanently more susceptible to meningitis.

 

Ultrasound for drug and gene delivery to the brain.

Hynynen K

Source

Department of Medical Biophysics, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, ON, Canada. khynynen@sri.utoronto.ca

Abstract

Noninvasive, transient, and local image-guided blood-brain barrier disruption (BBBD) has been demonstrated with focused ultrasound exposure in animal models. Most studies have combined low pressure amplitude and low time average acoustic power burst sonications with intravascular injection of pre-formed micro-bubbles to produce BBBD without damage to the neurons. The BBB has been shown to be healed within a few hours after the exposure. The combination of focused ultrasound beams with MR image guidance allows precise anatomical targeting as demonstrated by the delivery of several marker molecules in different animal models. This method may in the future have a significant impact on the diagnosis and treatment of central nervous system (CNS) disorders. Most notably, the delivery of the chemotherapy agents (liposomal Doxorubicin and Herceptin) has been shown in a rat model.

PMID: 18486271 [PubMed - indexed for MEDLINE]  http://www.ncbi.nlm.nih.gov/pubmed/18486271 

 

 

focused ultrasound for blood-brain disruption and delivery of therapeutic molecules into the brain.

Hynynen K

Source

Department of Medical Biophysics, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada. khynynen@sri.utoronto.ca

Abstract

Noninvasive, transient and local image-guided blood-brain barrier disruption can be accomplished using focused ultrasound exposure with intravascular injection of preformed microbubbles. MRI-guided blood-brain barrier disruption has been demonstrated and has been shown to heal in within a few hours after exposure. The delivery of several marker molecules has been demonstrated in different animal models with minimal or no damage to the brain tissue. Most notably, the delivery of antibodies and liposomal doxorubicin has been shown. The method may potentially open a new era in CNS drug delivery and perhaps also aid in molecular imaging and targeting. However, effective clinical devices and methods need to be developed further and the clinical feasibility demonstrated.

PMID: 17184160  [PubMed - indexed for MEDLINE] http://www.ncbi.nlm.nih.gov/pubmed/17184160

 

The threshold for brain damage in rabbits induced by bursts of ultrasound in the presence of an ultrasound contrast agent (Optison).

Hynynen K

Source

Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA. kullervo@bwh.harvard.edu

Abstract

The purpose of this study was to test the hypothesis that burst ultrasound (US) in the presence of a US contrast agent using parameters similar to those used in brain blood flow measurements causes tissue damage. The brains of 10 rabbits were sonicated in 3-8 locations with 1.5-MHz, 10- micro s bursts repeated at a frequency of 1 kHz at temporal peak acoustic pressure amplitudes ranging from 2 to 12.7 MPa. The total sonication time for each location was 20 s. Before each sonication, a bolus of US contrast agent was injected IV. Contrast-enhanced magnetic resonance (MR) images were obtained after the sonications to detect local enhancement in the brain. Whole brain histological evaluation was performed, and the sections were stained with hematoxylin and eosin (H and E), TUNEL, and vanadium acid fuchsin (VAF) staining to evaluate tissue effects, including apoptosis and ischemia. Both the magnetic resonance imaging (MRI) contrast enhancement and histology findings indicated that brain tissue damage was induced at a pressure amplitude level of 6.3 MPa. The damage included vascular wall damage, hemorrhage and, eventually, necrosis. Mild vascular damage was observed localized in a few microscopic tissue volumes in about half of the sonicated locations at all pressure values tested (down to 2 MPa). However, these sonications did not induce any detectable tissue effects, including ischemia or apoptosis. As a conclusion, the study showed that the US exposure levels currently used for blood flow measurements in brain are below the threshold of blood-brain barrier opening or brain tissue damage. However, one should be aware that brain damage can be induced if the exposure level is increased.

PMID: 12706199  [PubMed - indexed for MEDLINE] http://www.ncbi.nlm.nih.gov/pubmed/12706199

 

local and reversible blood-brain barrier disruption by noninvasive focused ultrasound at frequencies suitable for trans-skull sonications.

Hynynen K

Source

Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. kullervo@bwh.harvard.edu

Abstract

The purpose of this study was to test the hypothesis that burst ultrasound in the presence of an ultrasound contrast agent can disrupt the blood-brain barrier (BBB) with acoustic parameters suitable for completely noninvasive exposure through the skull. The 10-ms exposures were targeted in the brains of 22 rabbits with a frequency of 690 kHz, a repetition frequency of 1 Hz, and peak rarefactional pressure amplitudes up to 3.1 MPa. The total exposure (sonication) time was 20 s. Prior to each sonication, a bolus of ultrasound contrast agent was injected intravenously. Contrast-enhanced MR images were obtained after the sonications to detect localized BBB disruption via local enhancement in the brain. Brain sections were stained with H&E, TUNEL, and vanadium acid fuchsin (VAF)-toluidine blue staining. In addition, horseradish peroxidase (HRP) was injected into four rabbits prior to sonications and transmission electron microscopy was performed. The MRI contrast enhancement demonstrated BBB disruption at pressure amplitudes starting at 0.4 MPa with approximately 50%; at 0.8 MPa, 90%; and at 1.4 MPa, 100% of the sonicated locations showed enhancement. The histology findings following 4 h survival indicated that brain tissue necrosis was induced in approximately 70-80% of the sonicated locations at a pressure amplitude level of 2.3 MPa or higher. At lower pressure amplitudes, however, small areas of erythrocyte extravasation were seen. The electron microscopy findings demonstrated HRP passage through vessel walls via both transendothelial and paraendothelial routes. These results demonstrate that completely noninvasive focal disruption of the BBB is possible.

PMID: 15588592  http://www.ncbi.nlm.nih.gov/pubmed/15588592

 Grant Support

CA089017/CA/NCI NIH HHS/United States

CA76550/CA/NCI NIH HHS/United States

Focal disruption of the blood-brain barrier due to 260-kHz ultrasound bursts: a method for molecular imaging and targeted drug delivery.

Hynynen K

Source

Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. khynynen@sri.utoronto.ca

Abstract

OBJECT:

The goal of this study was to explore the feasibility of using low-frequency magnetic resonance (MR) image-guided focused ultrasound as a noninvasive method for the temporary disruption of the blood-brain barrier (BBB) at targeted locations.

METHODS:

Rabbits were placed inside a clinical 1.5-tesla MR imaging unit, and sites in their brains were targeted for 20-second burst sonications (frequency 260 kHz). The peak pressure amplitude during the burst varied between 0.1 and 0.9 MPa. Each sonication was performed after an intravenous injection of an ultrasound contrast agent (Optison). The disruption of the BBB was evaluated with the aid of an injection of an MR imaging contrast agent (MAG-NEVIST). Additional tests involving the use of MION-47, a 20-nm magnetic nanoparticle contrast agent, were also performed. The animals were killed at different time points between 3 minutes and 5 weeks postsonication, after which light or electron microscopic evaluation was performed. The threshold for BBB disruption was approximately 0.2 MPa. More than 80% of the brain sites sonicated showed BBB disruption when the pressure amplitude was 0.3 MPa; at 0.4 MPa, this percentage was greater than 90%. Tissue necrosis, ischemia, and apoptosis were not found in tissue in which the pressure amplitude was less than 0.4 MPa; however, in a few areas of brain tissue erythrocytes were identified outside blood vessels following exposures of 0.4 MPa or higher. Survival experiments did not show any long-term adverse events.

CONCLUSIONS:

These results demonstrate that low-frequency ultrasound bursts can induce local, reversible disruption of the BBB without undesired long-term effects. This technique offers a potential noninvasive method for targeted drug delivery in the brain aided by a relatively simple low-frequency device.

PMEDID =16961141 http://www.ncbi.nlm.nih.gov/pubmed/16961141