Lorenzo's Oil - Revisited

An article at the BBC site talks about this in detail this week. This information is probably interesting to those with an interest in pediatric neuroradiology.

Lorenzo's Oil was released in 1993. Susan Sarandon's performance was absolutely terrific, though I wasn't sure about the claims made by the movie about the oil itself, basically an oleic acid derivative, used to treat children with adrenoleukodystrophy.

The article traces the history of treatment with this oil - glyceryl trioleate-trierucate. It apparently is now known not to work in patients already having ALD, but has had excellent results in those who are at risk for developing ALD, but are not as yet symptomatic.

The influence of movies such as these has also been documented in the Journal of Clinical Pharmacology.

MRI for mandibular involvement in squamous cell carcinoma

Buccal carcinoma in our country is ubiquitous due to the widespread habit of tobacco chewing. One determinant of the surgical method is the presence of underlying bone involvment. If the bone is not involved, it may be left alone or a rim resection may be done to achieve the necessary tumor-free margins. If the cortex is involved, a segmental or marginal mandibulectomy is required.

We have been using CT for this purpose for a long time. Adding dental CT with thinner sections and paraxial and panoramic reconstructions helps.

However MRI, especially in the Western countries is now routinely used for all head and neck tumors including buccal carcinomas. The ability of MRI to depict bone involvement has been a bit of a question mark however. There is a new study from Italy published in this month's issue of the Archives of Otolaryngology Head Neck Surgery by Bolzoni A et al that shows that MRI in fact does very well in picking up bone involvement. In the forty-three patients who underwent surgery, MRI missed one patient with bone involvement and overdiagnosed two patients in the retromolar trigone region.

The advantage of MRI is in its ability to pick up marrow involvement, though CT is probably superior in picking up subtle buccal involvement. With the advent of isotropic imaging, CT may still be good enough, though the comforting thought is even we do perform MRI in these patients, it is unlikely that we will be missing bone involvement.

Unfortunately, a contrast enhanced MRI costs at least twice as much as a contrast-enhanced CT, so its routine use is unlikely.

Coronary plaque imaging with MSCT

A series of articles in different journals in the past few months have added fuel to the possible role of multi-slice CT in the diagnosis and follow-up of coronary artery plaques.

The first is an article by Leber AW et al in the Journal of the American College of Cardiology (JACC), where the authors compared 16-slice CT with intravascular ultrasound. Their conclusion was: "this study demonstrates that, in the case of diagnostic image quality, contrast-enhanced MDCT permits an accurate identification of coronary plaques and that computed tomography density values measured within plaques reflect echogenity and plaque composition."

This week there is an article in Circulation by Jensen LO et al that shows that simvastatin over 12 months is associated with significant reduction in the plaque plus media volumes as well as the external elastic membrane volumes in coronary arteries. They studied 40 males with hypercholesterolemia with state-of-the-art intravascular ultrasound of the coronary arteries, at baseline, 3 months after a lipid-lowering diet and 12 months after simvastatin. Similar studies have already shown reduction in plaque in the aorta and carotid arteries with various types of statins.

Another article this week in JAMA by Wiegman A et al shows that in patients with familial hypercholesterolemia, the use of pravastatin shows definite regression of the carotid intima-media thickness as measured by ultrasound.

IVUS is an invasive technique that cannot be used routinely in clinical practice to diagnose plaque and to monitor it. Coronary artery CT can be used for this purpose since it is relatively non-invasive and simple to perform. If coronary CT is equivalent to IVUS, then CT will also be able to do both; diagnose plaques as well as show regression on treatment. This may become more and more important as statins become over-the-counter (OTC) drugs, as has just happened in the UK.

Not only that, the associated use of calcium scoring also helps. Calcium scoring has already has become a routine affair and Achenbach et al have even shown reduction of the total calcium burden with the use of statins.

In addition to showing stenoses, if coronary CT can help in the diagnosis and management of non-stenosing atherosclerotic disease and show eventually reduced cardiac events and mortality in the general population, it will become a tremendously important modality in cardiac practice.

What is required to be an ultrasound technologist

There is a pretty neat answer in sci.med.radiology to a query raised by someone who wants to pursue a career as an ultrasound technologist.

We hardly have ultrasound technologist positions in our country, partly because we as radiologists do our own ultrasound and rarely use technologists for this purpose. Having said that, in larger groups and practices as well as in hospitals, there are a few technologist jobs available.

Some of the advice may not be applicable in our environment, but the general gist is valid.

Fibrous dyplasia - pictorial essay

Fibrous dysplasia is not an uncommon condition and monostotic disease especially in the facial bones and in the pelvis and extremities is often seen in practice.

This article published last year is a nice pictorial essay on the imaging findings in fibrous dysplasia with all modalities. Monostotic vs polyostic disease, the various associated syndromes (McCune-Albright & Mazabraud) as well as the correlation of the histopathology with the x-ray appearances are touched upon.

Though a reading of the disease in Don Resnick's book is probably more comprehensive, this essay has good illustrations while being brief and is worth a read.

Developmental lung anomalies: rad-path correlation

There is a very nice review article on developmental lung anomalies by Zylak CJ et al from Henry Ford in Detroit. It was published a couple of years ago, but it makes very interesting reading.

The anomalies are broadly classified into lung bud anomalies (agenesis, CCAM, atresias, etc), vascular anomalies (absent artery, anomalous origins, etc) and mixed (sequestration, hypogenetic lung syndrome).

Each condition is dealt with succintly with good examples. More images are available online as well.

Election news 2004 - 05

Dr. Bharat Parekh is also standing for the post of Chairman of the ICRI. We have just received his letter.

"Just Say Yes"

Richard Tello in the Internet Journal of Radiology talks about the consequences of "Just Say Yes". This journal does however now seem to be defunct, but nevertheless this article is prescient.

It talks about the consequences of radiologists not acting as gate-keepers, deciding on the relevance of studies ordered by various categories of physicians. If studies are not ordered following a thorough clinical evaluation and if the pre-test probabalities of finding abnormalites are low, it is likely that radiology studies are being misused.

Moreover he argues that this also leads to a situation where referring doctors keep thinking of radiologists as technicians rather than consultants who can add value.

Heart remodelling surgery in ischemic cardiomyopathy

This article in the NY Times uses the story of a patient in Columbus, Ohio to highlight a new study being performed in patients with ischemic cardiomyopathy, with low ejection fractions, who are treated either with drugs or with heart remodelling surgery.

The idea of talking about this article is to highlight at the quality of lay medical reporting in a newspaper like the NY Times. After reading the trashy medical reporting (complete with grammatical errors, spelling mistakes, misquotes, etc) that our leading newspapers like the Times of India indulge in, these articles come as a relief, reinforcing our belief in medical journalism at least to some extent.

Not that things are likely to improve in the near future in our part of the world.

MSCT pulmonary venography prior to atrial fibrillation

Auntminnie.com has an excellent review article on the use of MSCT angiography to evaluate the left atrium prior to electrical ablation in patients with atrial fibrillation. The electrophysiologists need to know the anatomy of the pulmonary veins and their confluence into the left atrium in great detail and MSCT provides this information with exquisite detail.

The only unfortunate part is that in our part of the world AF ablation is hardly being done at all.

Quiz answer - Pelvis - Fetal USG - Block 15 Quiz 2

The fetus had enlarged lungs with increased echogenecity and flattened diaphragms, findings suggestive of high airway obstruction. The answer is also available here.

The following radiologists got the correct answer:
Dharmashi Bhate, Godwin Jeeva, K G Srinivasan, Kelkar CM, Rajapandian Ilangovan, Reshma Dalvi, Ritesh Kamat, Shirish Hardikar, Sudipta Das

Incidentally the new quiz this week is a Neuroradiology case showing intracranial MRI angio images.

Attention deficit disorder

This article in the NY Times talks about this condition in great detail from a lay perspective. Reading the article, I couldn't stop thinking of the many people (doctors, administrative staff, etc.) who fit the bill and probably have the attention deficit disorder.

If a good number of people at the workplace have this condition, it makes sense for us to know about it and then hopefully help these colleagues/employees deal with the problem.

The biggest problem is their inability to multi-task; among other things, people with this order are badly organized, often late, cannot finish routine work on time and may be badly dressed as well.

Treatment is with drugs and behavior therapy.

A 42-years old woman with pleuritic chest pain - weekly case

This is a case at the Korean Society of Thoracic Radiology site that I would have never guessed off-hand in a million years, simply because of the rarity of this condition in our part of the world, though it is probably pretty common in Korea.

A 30-years old woman with pericardial effusion

This is a CPC from NEJM about a 30-years old woman who developed pericardial effusion and tamponade.

The chest x-ray and CT scan seem reasonably diagnostic for the disease process. See what you can make of it.

The full-text is free if accessed from India.

Mitral valve area analysis using CMR

Along with the previously described article on CMR in aortic valve planimetry is another article in a recent issue of the Journal of the American College of Cardiology that compares CMR velocity encoded measurements to Doppler measurements for assessing mitral valve area, by measuring the flow and using the pressure half-time method.

The authors have found excellent correlation between these two techniques and suggest the use of CMR in situations where echo / Doppler is not possible, feasible or shows discrepancies.

CMR planimetry of the aortic valve

Adding one more indication to the growing list of CMR indications is an article by Kupfahl et al in the recent issue of Heart on the use of CMR in planimetry of the aortic valve area. This article is available as free full-text if accessed from India.

Their conclusion: "CMR planimetry is highly reliable and reproducible. Further, CMR planimetry had the best sensitivity and specificity of all non-invasive methods for detecting severe aortic stenosis in comparison with cardiac catheterisation. Therefore, CMR planimetry of AVA with steady state free precession is a new powerful diagnostic tool, particularly for patients with uncertain or discrepant findings by other modalities."

There was another similar article in the Journal of the Americal College of Cardiology in 2003 on the same subject, with almost similar results. This is not surprising. Using TrueFISP imaging, the resolution that can be obtained for assessing the anatomy of various structures in the heart is amazing. CMR easily allow visualization of the valve in various planes and direct measurement of the area. Though flow measurements through the valve may have artifacts and need a little more expertise and fine tuning of the machine, anatomic area measurements are pretty straightforward.

Filarial dance sign

Dr. Suresh was one of the first in the country to show the filarial dance sign on ultrasound, in the scrotum. NK Shyamkumar et al from CMC Vellore, in a recent issue of the Internet Journal of Urology have published an article on the filarial dance sign. The video files are available for review as well.

Their contention is that this sign is actually due to the thousands of microfilaria within the lymphatic spaces of the scrotum rather than the adult worms themselves. This probably does not change management but helps in the understanding of the pathology and the sign itself.

Post-op expansion of intramedullary signal after cervical laminoplasty

In post-operative cases of cervical spine laminoplasty, sometimes there is an increase in the cord signal or expansion of the previously compressed cord with abnormali signal. Having seen these on a couple of occassions, we've never been sure of the significance of these findings.

Seichi et al have addressed this problem in the current issue of Spine. They studied 114 patients with post-operative MRI within 3 weeks after laminoplasty. "Seven patients (6.1%) showed postoperative abnormal expansion of the T2 high-signal intensity area; 3 of the 7 were asymptomatic".

They concluded that "Spinal cord enlargement with abnormal expansion of the T2 high-signal intensity area, although not common, is an unpreventable complication after laminoplasty. This was strongly related with distal and diffuse type of postoperative paresis of the upper extremity without deterioration of lower motor function, but was little associated with a proximal type of paresis, so-called C5 and C6 palsies."

The full-text of this article is available for those interested.