Cardiac CT & MRI Literature

Anomalous Coronary Arteries in Adults: Depiction at Multi-Detector Row CT Angiography -- Datta et al. 235 (3): 812 -- Radiology

This article is a multi-centre article that describes coronary anomalies seen in 18 patients, using a 4 or 16-slice CT scanner. They have divided the anomalies into a) ectopic origin from a coronary sinus, b)absent coronary artery and c) ectopic origin from a pulmonary artery

Again, keeping in mind the scanner and workstation used, the images are nice.

Link: Anomalous Coronary Arteries in Adults: Depiction at Multi-Detector Row CT Angiography -- Datta et al. 235 (3): 812 -- Radiology.

A Pictorial Review of Coronary Artery Bypass Grafts at Multidetector Row CT -- Marano et al. 127 (4): 1371 -- Chest

This article by Marano et al is a pictorial essay describing the various types of grafts and their appearance on cardiac CT. Since the scanners used are 4-slice and 16-slice, the quality is not as good as those now seen on 64-slice scanners.

Link: A Pictorial Review of Coronary Artery Bypass Grafts at Multidetector Row CT -- Marano et al. 127 (4): 1371 -- Chest.

NEJM -- Long-Term Outcomes of Coronary-Artery Bypass Grafting versus Stent Implantation

This article looks at patients from the New York registry and shows that in patients with two-vessel disease or more, CABG is better than PCI (stent implantation) as far as long-term, overall survival is concerned. The accompanying editorial helps explain this better as well.

Link: NEJM -- Long-Term Outcomes of Coronary-Artery Bypass Grafting versus Stent Implantation.

MDCT Evaluation of the Coronary Arteries, 2004: How We Do It--Data Acquisition, Postprocessing, Display, and Interpretation -- Lawler et al. 184 (5): 1402 -- American Journal of Roentgenology

This article is for 16-slice CT scanners and though most of it can be extrapolated to the newer 64-slice scanners, not all of the material is relevant. This again illustrates the problem with the frustratingly slow pace of publication in radiology - the article was submitted in Feb 2004 and has been published in June 2005.

Among the issues not relevant to 64-slice CT scanners, are those of dose-modulation, contrast injection and timing and phase reconstruction. These will be discussed in detail in the "Images" blog this month.

Link: MDCT Evaluation of the Coronary Arteries, 2004: How We Do It--Data Acquisition, Postprocessing, Display, and Interpretation -- Lawler et al. 184 (5): 1402 -- American Journal of Roentgenology.

JAMA -- Abstract: Noninvasive Coronary Angiography With Multislice Computed Tomography, May 25, 2005, Hoffmann et al. 293 (20): 2471

This is finally the "big" one. Following in the vein of all the previous articles by authors from Germany and Netherlands, this one by Hoffman et al shows how well CT angiography on a 16-slice CT does, as compared to conventional catheter angiography. The negative and positive predictive values are above 90%. As with previous articles, almost all false positive cases are related to the presence of extensive calcification.

Link: JAMA -- Abstract: Noninvasive Coronary Angiography With Multislice Computed Tomography, May 25, 2005, Hoffmann et al. 293 (20): 2471.

Accuracy of MSCT coronary angiography with 64-slice technology: first experience -- Leschka et al., 10.1093/eurheartj/ehi261 -- European Heart Journal

This is the first proper article on the use of 64-slice CT for coronary angiography. Their results are as expected spectacular, with a negative predictive value of 99% - this means that when the test is reported to be normal, it will be normal 99% of the times for ruling out coronary artery disease. The sensitivity was also very good - 94%, which means thatn 94% of all lesions were picked up as well.

All their studies were done using 370ms, rather than 330ms. As more and more experience and expertise is gained, the accuracy levels are bound to go up more. The cases shown in our Images blog, reflect our levels of accuracy as well.

Link: Accuracy of MSCT coronary angiography with 64-slice technology: first experience -- Leschka et al., 10.1093/eurheartj/ehi261 -- European Heart Journal.

Surgery is the best intervention for severe coronary artery disease -- Taggart 330 (7494): 785 -- BMJ

This opinion piece by Dr. Taggart, though controversial (as seen by the number of comments) helps put things in perspective. This is the path by and large followed in India. Severe multi-vessel disease is best treated with a CABG, whereas single or two vessel disease with single stenotic lesions, are best treated by PCI (percutaneous coronary intervention) using stents, most usually drug-elutin.

Link: Surgery is the best intervention for severe coronary artery disease -- Taggart 330 (7494): 785 -- BMJ.

Late gadolinium-enhanced magnetic resonance imaging in acute and chronic myocardial infarction: improved prediction of regional myocardial contraction in the chronic state by measuring thickness of nonenhanced myocardium.

This article in the Mar 2005 issue of JACC compares many parameters in patients with acute infarcts imaged during the acute episode and later in the chronic phase, using CMR/MRI with delayed hyperenhancement. They form the following conclusions
1. Acute infarcts as defined by the areas of enhancement reduce in size in the chronic phase, probably due to contracture of scar tissue.
2. The non-enhancing myocardium increases as well probably due to compensatory hypertrophy.
3. The thickness of the non-enhancing myocardium (>5.1mm) in the chronic phase and >3.9mm in the acute phase predicts functional recovery with good sensitivity and specificity.
4. Percentage transmural involvement of the myocardium by infarction correlates with functional recovery with the same specificity and sensitivity as with other studies done previously.

Automatic Detection and Size Quantification of Infarcts by Myocardial Perfusion SPECT: Clinical Validation by Delayed-Enhancement MRI -- Slomka et al. 46 (5): 728 -- The Journal of Nuclear Medicine

The best part of this article is not that SPECT an reliably pick up infarcts, but the acceptance of the fact that DE-MRI is the gold-standard for infarct evaluation. Despite this fact having been conclusively proven in multiple publications in the last 3-4 years, at least in our part of the world, it is not easy getting this message across to cardiologists and physicians.

It stands to reason that if contrast-enhanced MRI is a gold standard for infarct imaging, it is a gold standard for viability imaging as well.

Link: Automatic Detection and Size Quantification of Infarcts by Myocardial Perfusion SPECT: Clinical Validation by Delayed-Enhancement MRI -- Slomka et al. 46 (5): 728 -- The Journal of Nuclear Medicine.

The role of magnetic resonance imaging in the assessment of suspected extrinsic tracheobronchial compression due to vascular anomalies -- Malik et al., 10.1136/adc.2004.070250 -- Archives of Disease in ChildhoodT

This article talks about an obvious issue - that CMR/MRI picks up vascular anomalies with ease. Having said that, contrast-enhanced CT does the same too, and with better resolution and the ability to perform exquisite 3D reconstructions, etc.

The role of magnetic resonance imaging in the assessment of suspected extrinsic tracheobronchial compression due to vascular anomalies -- Malik et al., 10.1136/adc.2004.070250 -- Archives of Disease in Childhood.