Computed tomography of normal and calcified coronary arteries.

The association between coronary artery calcification (CAC) and coronary artery disease is well established. The objectives of this article are to define the cross-sectional anatomy of the coronary arteries and to demonstrate the prevalence of CAC as seen on routine computed tomography (CT) of the thorax. A CT scan of a cadaver heart was performed in normal anatomic position. Additionally, a retrospective analysis of 103 consecutive thoracic scans was done by three experienced radiologists. The cross-sectional anatomy of the coronary arteries is described based on both these studies, and the prevalence of coronary calcification from the retrospective review was determined. The left anterior descending was the most commonly calcified artery (43% of all patients) followed in order by the left coronary (37%), circumflex (33%), and right coronary (20%). Seventy-nine percent of patients older than age 65 demonstrated coronary calcification on CT. This prevalence approaches that of reported autopsy series. Knowledge and understanding of the cross-sectional anatomy of coronary arteries is essential for detection of coronary artery calcification. We recommend that the presence of CAC should be reported on all thoracic CT scans because coronary calcification may signal unsuspected coronary artery disease.

Linear echoes in the fetal cisterna magna.

Linear echoes are seen in the fetal cisterna magna, (CM) on obstetrical sonography. These echoes often are paired, joining as they descend toward the base of the posterior fossa. Histologic correlation suggests that these echoes are most consistent with dural folds, which likely represent the inferior attachment of the falx cerebelli. A prospective series of 322 prenatal studies was performed in which the sonographer was asked to look for the linear echoes in the cisterna magna and image them. Linear echoes were identified in 84% of all fetuses studied. Identification of these echoes was dependent on CM size, in that they were seen less commonly when the CM was less than 3 mm in diameter. However, their identification was not dependent on gestational age. In addition, 18 fetuses with Dandy Walker cyst or Dandy Walker variant were evaluated and in 16 linear echoes were not seen. We conclude that recognition of normal anatomy within the fetal brain, specifically the fetal CM, is helpful for identifying abnormalities in the size of the CM, whether large or small.

Internal carotid artery dissections: duplex ultrasound imaging.

Duplex ultrasound findings in seven patients (eight vessels) demonstrating extracranial internal carotid artery (ICA) dissections are presented. The two-dimensional (2D) sonographic findings of ICA dissection consisted of three categories: (1) normal, (2) luminal flap with or without thrombus formation, and (3) hypoechoic thrombus with or without lumen narrowing. The Doppler ultrasound waveforms were variable. In the common carotid artery (CCA) these included (1) normal, (2) resistive, damped, or biphasic CCA waveforms, and (3) positive temporal artery tap in the mid-CCA. In the ICA, the appearances included (1) normal, (2) damped, resistive, or biphasic waveforms, (3) absent flow, and (4) high velocity flow. Although these appearances are nonspecific, the finding of some of these duplex ultrasound waveforms in the appropriate clinical setting suggests a diagnosis of extracranial internal carotid artery dissection.

Carotid duplex sonography: bisferious pulse contour in patients with aortic valvular disease.

Characteristic systolic and diastolic pulse contours occur in the carotid Doppler waveforms of patients with aortic valvular disease that have not previously been described in publications concerning carotid duplex sonography. The purpose of this study was to evaluate the presence and characterize the nature of these carotid duplex waveform abnormalities in patients with known aortic valve disease and to correlate these changes with the severity of valve dysfunction. The study group consisted of 26 patients with aortic regurgitation or combined aortic regurgitation and aortic stenosis. Duplex studies were retrospectively reviewed by two radiologists for the presence of two systolic peaks, and for the presence of diastolic reversal of flow direction. This pattern of two systolic peaks, characteristic of aortic regurgitation, is called bisferious from the Latin "twice beating." Aortic regurgitation was graded by echocardiography as mild, moderate, or severe by the cardiologists reviewing the examination. A group of 20 age-matched patients without aortic valvular disease were similarly assessed. The bisferious pattern was demonstrated in 13 (50%) of 26 patients. Five (19%) of 26 patients had significant reversal of diastolic flow. Four patients were studied both before and after aortic valve replacement. Three had bisferious wave contours preoperatively; two of these also had diastolic reversal of flow. The fourth patient had retrograde flow in diastole without systolic contour abnormality. Postoperatively, all carotid waveforms were normal. None of the duplex waveforms in the control group demonstrated characteristic systolic or diastolic abnormalities. The bisferious waveform and retrograde diastolic flow are Doppler patterns associated with aortic valvular disease. These patterns are reversible after aortic valve replacement. While echocardiography remains the study of choice in the evaluation of suspected valvular dysfunction, up to one third of patients with aortic regurgitation may not have a detectable murmur. Therefore, identifying these patterns on carotid duplex examinations may provide clinically useful information and serve as a clue to previously unsuspected cardiovascular disease.

Limited correlation of left ventricular end-diastolic pressure with radiographic assessment of pulmonary hemodynamics.

Left ventricular end-diastolic pressure (LVEDP) is a reliable indicator of the diastolic function of the left ventricle. The purpose of this study was to correlate the radiographic assessment of pulmonary hemodynamics with LVEDP. The study population consisted of 104 consecutive patients with four categories of LVEDP: less than 13 mm Hg (n = 26), 13-19 mm Hg (n = 30), 20-24 mm Hg (n = 24), and more than 24 mm Hg (n = 24). Chest radiographs obtained within 24 hours of cardiac catheterization were assessed for evidence of congestive heart failure (CHF) by three experienced radiologists. Findings were graded from 0 to 3 (normal to abnormal) on the basis of the following signs of CHF: redistribution, perihilar and perivascular haze, peribronchial cuffing, pulmonary artery-bronchus ratio, septal lines, subpleural edema, air-space edema, pleural effusion, cardiomegaly, and overall radiographic assessment of CHF. A consensus report was then generated. In patients with LVEDP over 20 mm Hg, 38% did not show CHF in the overall assessment. Correlation between radiographic signs of CHF and LVEDP was limited.