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Coronary artery disease (CAD) is a major cause of disease and death in the United States. Presently, coronary angiography is the diagnostic imaging technique of choice for evaluating CAD. Because it requires insertion of a catheter into the coronary vessels, this technique is very invasive and can be painful and risky, as well as expensive. A noninvasive technique is very desirable. Magnetic resonance (MR) imaging, an imaging technique that uses magnetic properties of tissues to produce images of them, is presently used to evaluate arterial disease in the kidney and brain. This study examined using MR imaging to evaluate CAD. Previous studies have found MR evaluation of coronary arteries to be complicated by respiratory movements. In this study, MR images were taken with an ultrafast technique while subjects held their breath. The technique was performed on 22 healthy adults. While the subjects held a single breath, a number of MR images were taken of sections of the coronary arteries. The sections were 4 millimeters in thickness. Within 10 to 20 minutes time, a sufficient number of sections covering a large portion of the arteries was obtained. When images of the sections were overlapped, the coronary arteries could be depicted. These results indicated that MR imaging has the potential to be very useful in noninvasive evaluation of CAD. (Consumer Summary produced by Reliance Medical Information, Inc.)

A patient with cyanosis in an uncomplicated ostium secundum atrial septal defect Without pulmonary hypertension is described. There were no anatomic abnormalities in right-sided cardiac valves or venous return and no evidence of right ventricular hypoplasia or hypertrophy; however, the diastolic pressure curve suggested a decreased compliance. We suggest that this unusual finding may be a result of intrinsically abnormal right ventricular compliance.

Thallium-201 imaging has been utilized to estimate myocardial salvage after thrombolytic therapy for acute myocardial infarction. However, results from recent animal studies have suggested that as a result of reactive hyperemia and delayed necrosis, thallium-201 imaging may overestimate myocardial salvage. To determine whether early overestimation of salvage occurs in humans, intracoronary thallium-201 scans 1 hour after thrombolytic therapy were compared with intravenous thallium-201 scans obtained approximately 10 and 100 days after myocardial infarction in 29 patients.

The feasibility of in vivo coronary angioscopy was tested utilizing a 1.8 mm angioscope in vessels where blood had been replaced by optically clear liquids, including a new perfluorocarbon emulsion. After trials in postmortem canine and human coronary arteries, in vivo intraluminal visualization was accomplished in the dog with a catheterization technique and in patients during open heart surgery. The results demonstrate the feasibility and potential clinical usefulness of direct visualization of intravascular anatomy and disease, analogous to endoscopy of other organ systems.

The technique of impedance phlebography for the detection of deep vein thrombi was evaluated. A total of 410 examinations were performed on 111 patients. Approximately 20% of these patients were not suitable candidates for this technique. Twenty-one patients underwent radiographic venography by a method that routinely visualizes all of the named deep veins. Of these 21 patients having venograms, eight had false negative impedance studies. The frequent occurrence of false negative impedance studies casts doubt on the value of impedance phlebography for the diagnosis of suspected deep vein thrombosis or for the screening of high-risk patient groups.

In technique for lower extremity phlebography the patient is in a semi-upright position, supporting his weight on the contralateral foot. The dye injection is made into a dorsal pedal vein and no tourniquet is used. Fluoroscopy is used to maximize efficiency of the filming. More than 300 phlebograms have been made with this method. The four cardinal signs of phlebothrombosis are constant filling defects, abrupt termination of the dye column, nonfilling of the entire deep venous system or portions thereof, and diversion of flow. Pitfalls in interpretation occur when artifacts are created by bearing weight on the leg under study, by tourniquets, by an improper injection site, or by incomplete mixing of the contrast material as it flows through the veins.