Monday, October 31, 2005

Fetal MRI-How to obtain True orthogonal planes

Optimization of acquisition time for MRI of fetal head: the eyes have it.
Hosseinzadeh K, Owens E
Diagnostic Imaging, University of Maryland School of Medicine, University of Maryland Medical Center, Baltimore, MD 21201.
OBJECTIVE: This article describes a technique to minimize MRI time and obtain true orthogonal T2-weighted projections of the fetal head. The technique takes advantage of the symmetry of fetal orbits to establish a line of reference through the orbits to obtain true sagittal, coronal, and axial projections of the intracranial anatomy.
CONCLUSION: This technique results in a 50% reduction in imaging time and thus decreases fetal exposure to the electromagnetic field.


Full Article At-
AJR Am J Roentgenol. 2005 Oct;185(4):1060-2.

Sunday, October 30, 2005

Low Voltage CT.

Abdominal CT with Low Tube Voltage: Preliminary Observations about Radiation Dose, Contrast Enhancement, Image Quality, and Noise.
Nakayama Y, Awai K, Funama Y, Hatemura M, Imuta M, Nakaura T, Ryu D, Morishita S, Sultana S, Sato N, Yamashita Y.
PURPOSE: To prospectively investigate the effect of low tube voltage on radiation dose, contrast enhancement, image quality, and image noise at abdominal dynamic computed tomography (CT).
MATERIALS AND METHODS: The institutional review board approved this study. Prior informed consent was obtained from all patients. Forty patients (24 women, 16 men; mean age, 62 years) underwent initial abdominal CT at 120 kV with 100 mL of contrast material (protocol A). Then all patients were randomly assigned to one of two protocols (protocol B, CT at 90 kV with 100 mL contrast material; protocol C, CT at 90 kV with 80 mL contrast material). The CT numbers of their abdominal organs were assessed quantitatively and qualitatively. Statistical analysis was performed by using the two-tailed paired t test, Kruskal-Wallis test, and kappa test of interobserver agreement. The radiation dose was measured with a phantom that consisted of glass-rod dosimeters.
RESULTS: Quantitative analysis revealed that protocols B and C yielded significantly better enhancement of the aorta, liver, pancreas, spleen, and kidney than did protocol A (P < .05). With qualitative analysis, the difference among the three protocols in regard to image quality was not significant. At 90 kV versus 120 kV, the radiation dose reduction in the center of the phantom was 56.8% (6.3 vs 14.6 mGy); in the periphery, it was 46.2% (13.6 vs 25.3 mGy).
CONCLUSION: By decreasing the tube voltage, the amount of contrast material can be reduced without image quality degradation. In scans obtained with a low tube voltage, the radiation dose can be reduced as much as 56.8%, and higher contrast material enhancement can be achieved.
Full Article at-

MRI in carotid artery disease-New horizons

Low-grade carotid stenosis: looking beyond the lumen with MRI.

Wasserman BA, Wityk RJ, Trout HH 3rd, Virmani R.
The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Hospital, Baltimore, MD 21287, USA. bwasser@jhmi.edu

BACKGROUND AND PURPOSE: The management of carotid atherosclerosis is well-established for symptomatic stenosis above 69%, but the optimal approach for managing lower degrees of narrowing remains uncertain. Because the risk of stroke increases with higher grades of stenosis, we are inclined to consider low-grade disease to be low risk. This approach, however, does not take into account other factors such as plaque size or composition. Plaque may progress to a substantial size before it demonstrates significant stenosis by angiography. We know that low-grade disease can result in cerebrovascular ischemic events, but predicting vulnerable lesions has not been possible by relying on stenosis alone.
SUMMARY OF REVIEW: An understanding of the clinical behavior of plaque causing little to no narrowing is now possible with the advent of high-resolution black blood MRI, a modality that does not rely on luminal narrowing for detection.
CONCLUSIONS: Authors present the current understanding of the clinical implications of low-grade carotid stenosis with an example of the MRI assessment of high-risk carotid plaque causing minimal narrowing that highlights the importance of looking beyond the lumen.
Full Article at-

Friday, October 28, 2005

Image Quiz-Chest Imaging


A five year old male child presented with respiratory distress, a chest CT was done as a part of evaluation. Representative Lung window scan is given here.

What is the diagnosis?

Correct Answer- Foreign body bronchus with right lower lobe collapse

Winners-Massoud Pezeshki Rad,Mash

Leave your answers in the comments section. Correct answer and the winner will be published next week.
COPYRIGHT (SUMER)

Diffusion tensor-based imaging in adrenomyeloneuropathy.

Diffusion tensor-based imaging reveals occult abnormalities in adrenomyeloneuropathy.
Dubey P, Fatemi A, Huang H, Nagae-Poetscher L, Wakana S, Barker PB, van Zijl P, Moser HW, Mori S, Raymond GV
Department of Neurogenetics and Functional Magnetic Resonance Imaging Kirby Center, Kennedy Krieger Institute, Baltimore, MD, 21205.
"Pure" adrenomyeloneuropathy (AMN) is the noninflammatory myeloneuropathic variant of X-linked adrenoleukodystrophy, where the disease process appears to be restricted to spinal cord tracts and peripheral nerves. The absence of obvious brain involvement makes it distinct from the inflammatory cerebral phenotypes of X-linked adrenoleukodystrophy. However, some pure AMN patients later experience development of cerebral demyelination, but little is known about the extent of brain involvement in pure AMN patients who have normal brain magnetic resonance imaging. We used diffusion tensor imaging to investigate possible occult cerebral abnormalities in such pure AMN patients. Fractional anisotropy and trace were studied in three-dimensional reconstructions of white matter tracts commonly involved in cerebral phenotypes of X-linked adrenoleukodystrophy. Results demonstrated reduced fractional anisotropy and increased trace in bilateral corticospinal tracts and genu of corpus callosum. Diffusion tensor imaging-based three-dimensional fiber tracking showed occult tract-specific cerebral microstructural abnormalities in pure AMN patients who had a normal conventional brain magnetic resonance image. Corticospinal tract abnormalities could reflect a centripetal extension of spinal cord long-tract distal axonopathy. Accompanying abnormalities in genu of corpus callosum indicate that the disease pathology in pure AMN may not be limited to spinal cord long tracts alone, although the involvement of the latter is most prominent and severe.
Full Article at-

Tuesday, October 25, 2005

CT of the Heart- Review article in CardioVascular and Interventional Radiology

Multislice Spiral Computed Tomography of the Heart: Technique, Current Applications, and Perspective
Multislice spiral computed tomography (MSCT) is a rapidly evolving, noninvasive technique for cardiac imaging. Knowledge of the principle of electrocardiogram–gated MSCT and its limitations in clinical routine are needed to optimize image quality. Therefore, the basic technical principle including essentials of image postprocessing is described. Cardiac MSCT imaging was initially focused on coronary calcium scoring, MSCT coronary angiography, and analysis of left ventricular function. Recent studies also evaluated the ability of cardiac MSCT to visualize myocardial infarction and assess valvular morphology. In combination with experimental approaches toward the assessment of aortic valve function and myocardial viability, cardiac MSCT holds the potential for a comprehensive examination of the heart using one single examination technique.

Full Article-

CardioVascular and Interventional Radiology
Publisher: Springer-Verlag New York
ISSN: 0174-1551 (Paper) 1432-086X (Online)
DOI: 10.1007/s00270-003-9218-6
Issue: Volume 28, Number 4
Date: August 2005
Pages: 388 - 399



RADIOLOGY UPCOMING EVENTS

RADIOLOGY WORLD EVENT CALENDER

Diagnostic Imaging 2005 OCT 30 - 2005, 4 NOV location Maui, Hawaii, USA http://postgrad.radiology.ucsf.edu

AAWR, Annual Meeting of the American Association for Women Radiologists 2005 NOV 11 - 2005 NOV 18, Orlando, Florida, USA http://www.aawr.org

RSNA, 91st Scientific Assembly andAnnual Meeting of the Radiological Society of North America2005 NOV 27 - 2005 DEC 02, Chicago, USA http://www.rsna.org

SCVIR, Society of Cardiovascular & Interventional Radiology 44th Annual Scientific Meeting 2006 MAR 27 - 2006 APR 04, Toronto, Ontario, Canada http://www.scvir.org

ASNR, American Society of Neuroradiology 44th Annual Meeting 2006 APR 29 - 2006 MAY 05, San Diego, California, USA http://www.asnr.org

Thursday, October 20, 2005

Teleradiology

The wicked queen, staring at her glass, is presented with a picture of Snow White, a maiden more beautiful than she in a faraway place. A familiar fairy tale, but now moving closer to reality. There are many definitions of teleradiology, but a reasonable working one defines it as the use of telecommunications to deliver radiology services to patients who are located in a different place from the radiologist. Some physicians are familiar with limited transfer of computed tomograms from one centre to another, often by means of slow and fairly cumbersome systems. Anyone visiting this year's annual clinical meeting of the Radiological Society of North America would have seen clearly that teleradiology in the United States is now part of every day practice and not the interesting novelty of a few years ago. The experience in the United States is worth reflecting on as Americans lead the world in this subject. ...

READ ON
Full artilce at
http://bmj.bmjjournals.com/archive/6991ed4.htm

Very interesting article from The Internet Journal of Radiology

Unfortunately, well over 10 years of a “just say yes” philosophy applied, not just in a clinical realm, but in academic realms, is now paying off with grave and dire consequences. While “just say yes” is an effective means of expediting and efficiently obtaining imaging studies for patients, this works when the referring physician is an adequately and competently trained clinician, referring cases for which they have already performed some pre-screening evaluation. In particular, these patients have already undergone a physical exam and historical evaluation by their referring physician that allows them to have a reasonable differential diagnosis of limited scope constructed and then referred for appropriate tailored imaging studies. By removing the radiologist in a primary non-teaching academic center, this allows efficient imaging studies that have been reasonably and appropriately ordered to be performed and to be readily and rapidly interpreted. Though this may allow some unnecessary imaging, particularly as technology evolves, and the referring clinical services are not adequately educated, generally the indication for studies is valid and the efficacy and consequent predictive value positive is high.
In addition, “just say yes” has, in the academic center, trained a generation of clinical physicians to view radiology as strictly a diagnostic tool without need for any expert intervention and as such the radiologist is viewed, in more and more academic centers, as a superfluous intermediary. Many clinical physicians have since expressed that interpretation is viewed as a technical skill rather than as a consultation. If we wish to see a new generation of imaging where radiologists are not viewed in a consultation fashion, but merely as technicians, and their income, livelihood and resources are regulated by actuaries in an insurance system then we should continue “just say yes” for another 10 years. We can hope that the current generation of retiring radiologists can be benevolent enough to understand when they cannot access the imaging that they or their family needs in the next decade.
Full Article at-
Also Read another revealing article by me-

Sunday, October 16, 2005

A Radiologist's Brain- An amazing article

What is different about a radiologist's brain?
Haller S, Radue EW.
Department of Diagnostic Radiology, Division of Neuroradiology, University Hospital Basel, CH-4031 Basel, Switzerland. shaller@uhbs.ch
PURPOSE: To investigate neuronal activations during processing of radiologic and nonradiologic images by experienced radiologists and nonradiologist subjects by using event-related functional magnetic resonance (MR) imaging.
MATERIALS AND METHODS: Study was approved by local ethics committee, and informed consent was obtained. Radiologic and control images were presented to 12 experienced radiologists (mean age, 35.8 years +/- 3.6 [standard deviation]) and 12 nonradiologist subjects (mean age, 33.0 years +/- 6.9). Half of the images were artificially manipulated-that is, for example, a local shadow was introduced. Subjects had to indicate whether a visually presented image was original or manipulated, while neuronal activity was assessed by using event-related functional MR imaging. Analysis was performed on the basis of fixed-effects general linear models with correction for multiple comparisons (false discovery rate).
RESULTS: Radiologic images, when compared with control images, evoked stronger activations exclusively in the group of radiologists, notably in the bilateral middle and inferior temporal gyrus, bilateral medial and middle frontal gyrus, and left superior and inferior frontal gyrus (P < .001, corrected). Additionally, visual processing of control images (ie, nonradiologic images) differed significantly between experienced radiologists and nonradiologist subjects (P < .001, corrected).
Radiologists showed strongest activation in the left-dominant more posterior superior and inferior parietal lobule, while nonradiologist subjects showed strongest activation in the right-dominant more anterior superior and inferior parietal lobule and postcentral gyrus.
CONCLUSION: With radiologic experience, there is selective enhancement of brain activation with radiologic images, and the visual system is modified in general.
From-

Wednesday, October 12, 2005

Antenatal US diagnosis of Horseshoe kidney

Prenatal diagnosis of horseshoe kidney by measurement of the renal pelvic angle.
Cho JY, Lee Y, Toi A, Macdonald B.
Department of Radiology, Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea. radjycho@skku.edu
METHODS: We retrospectively measured the renal pelvic angle in 19 fetuses with horseshoe and 20 fetuses with normal kidneys in the second and third trimesters. Renal pelvic angle was defined as the angle between the long axis of the renal pelves on the axial view of the abdomen. We compared the renal pelvic angles of horseshoe and normal kidneys with unpaired t-test. Taking 140 degrees as a cut-off value, we calculated the sensitivity, specificity and accuracy of pelvic angle measurement for the prenatal diagnosis of horseshoe kidney.
RESULTS: The mean pelvic angles in the fetuses with horseshoe kidney were 116 degrees and 110 degrees in the second and third trimester, respectively. In the normal fetuses, the equivalent angles were 172 degrees and 161 degrees. The difference between the two groups was statistically significant.
CONCLUSION: Observation and measurement of the renal pelvic angle is a simple and useful method in the prenatal diagnosis of the horseshoe kidney.

Tuesday, October 11, 2005

Interesting Vascular Case on Indian Radiology.


Presentation- A 28 year Indian female presented with hypertension, MR Angiogram was done.


Diagnosis- Aorto-arteritis
Extended Reading-
Hypertension in the young in eastern India.
Panja M, Kumar S, Sarkar CN, Sinha DP, Ray S, Chatterjee A, Panja S, Mitra D, Kar AK, Pahari DK.
Department of Cardiology, Institute of Post-graduate Medical Education & Research, Calcutta.
Three hundred and forty-one young hypertensives in the age group of 18-30 years were evaluated over a 7-year period. Essential hypertension constituted the single largest group (35.8%). Renal pathology was the most common cause of secondary hypertension (26.4%). Congenital coarctation of the aorta and endocrine causes accounted for 14.1 percent and 3.2 percent cases of secondary hypertension, respectively. A strikingly high incidence of nonspecific aortoarteritis (20.1%) was a distinguishing feature amongst secondary causes. Aortoarteritis was the commonest cause of renal artery stenosis.

Saturday, October 08, 2005

Cervical Spine Injury-Evaluation

Exclusion of unstable cervical spine injury in obtunded patients with blunt trauma: is MR imaging needed when multi-detector row CT findings are normal?
Hogan GJ, Mirvis SE, Shanmuganathan K, Scalea TM
Department of Diagnostic Radiology, University of Maryland School of Medicine, 22 S Greene St, Baltimore, MD 21201, USA. ghogan@umm.edu
PURPOSE: To retrospectively determine what information, if any, magnetic resonance (MR) imaging of the cervical spine in obtunded and/or "unreliable" patients with blunt trauma adds to multi-detector row computed tomography (CT) of the entire cervical spine (including routine multiplanar sagittal and coronal reformations) when the CT findings are normal.
RESULTS: MR images were negative for acute injury in 354 of the 366 patients and negative for cervical spine ligamentous injury in 362. Seven of the 366 patients had cervical cord contusions, four patients had ligamentous injuries, three patients had intervertebral disk edema, and one patient had a cord contusion, a ligamentous injury, and an intervertebral disk injury. Four patients had ligamentous injuries; however, all of these patients had ligament injuries limited to only one of the three columns of cervical spine ligament support. Multi-detector row CT had negative predictive values of 98.9% (362 of 366 patients) for ligament injury and 100% (366 of 366 patients) for unstable cervical spine injury.
CONCLUSION: A normal multi-detector row CT scan of the total cervical spine in obtunded and/or "unreliable" patients with blunt trauma enabled the authors to exclude unstable injuries on the basis of findings at follow-up cervical spine MR imaging.

Full Article at-
Radiology. 2005 Oct;237(1):106-13

Thursday, October 06, 2005

Carotid Ultrasound-an article by Dr Sumer Kumar Sethi In Indian Journal Of Radiology and Imaging

The introduction of Doppler imaging has dramatically changed the diagnostic evaluation of suspected carotid disease. Doppler sonography provides a rapid, non-invasive, relatively inexpensive and accurate means of diagnosing carotid stenosis. Physicians have long sought methods for identifying stroke-prone patients, with the hope that timely intervention might avert stroke and its accompanying disability.
Full article with technique and images on Carotid Doppler Ultrasound in-
SK SETHI, RS SOLANKI, H GUPTA

Tuesday, October 04, 2005

MRCP-The current status

Is magnetic resonance cholangiopancreatography the new gold standard in biliary imaging?
Shanmugam V, Beattie GC, Yule SR, Reid W, Loudon MA
Departments of Surgery and Radiology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZN.
The timing and technique of perioperative biliary imaging in relation to laparoscopic surgery remains controversial. This study assessed the predictive value of magnetic resonance cholangiopancreatography (MRCP) in the diagnosis of biliary pathology. Clinical, laboratory and investigational data were evaluated from 374 patients undergoing MRCP at two hospital sites over a 5-year period. MRCP findings were compared with endoscopic retrograde cholangiopancreatography (ERCP) or operative findings and appropriate clinical endpoints. Complete data were available for 351 of the 374 patients (94%), of whom 232 (66%) were female. Median age was 64 years. The predominant presentation was abdominal pain (n=190). Features of pancreatitis were present in 59, cholangitis in 26 and jaundice in 109 patients. Ultrasound was the initial investigation in 312 (89%) (176-gallstone positive). Common duct dilatation was evident in 114 patients and ductal calculi in 31. ERCP was successful in 212/283 (75%) patients. Significant ERCP induced pancreatitis occurred in 12 (5.6%). Comparison between MRCP and ERCP was not possible in 85 due to failure of either technique. Nine patients underwent other investigations including intraoperative cholangiogram (IOC), percutaneous transhepatic cholangiogram (PTC) and were included. Of the 221 patients with full comparative data available the MRCP showed a sensitivity of 97.98% and specificity of 84.4%. MRCP is highly sensitive and specific for choledocholithiasis and avoids the need for invasive imaging in most patients with suspected choledocholithiasis.
Full article at-

Saturday, October 01, 2005

Sumer's Radiology Site is in compliance with HON code

HON code certificate confirms that the site respects and pledges to honor the 8 principles of the HON (Health On the Net Foundation) Code of Conduct (HONcode).

Blogging for a Radiologist features in Radiographics

Blogging for a Radiologist: An Easy Method for Web Site Building and Information Exchange
An eLetter from Dr Sumer Kumar Sethi features in Radiographics Online.
Check out the link-

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