Inflammatory aneurysm of aorta: development documented by computed tomography.

Aortic aneurysmal disease appears to be the central focus of the inflammatory process resulting in inflammatory aneurysm formation. Some authors believe that inflammatory aortic aneurysm disease is a distinct clinicopathologic entity; however, others have included it with retroperitoneal fibrosis. The histologic features of inflammatory aneurysm suggest an immunologic basis for the lesion, with the atherosclerotic aorta as a possible source of the allergen.

CT demonstration of dissecting hematoma originating in abdominal aorta.

This report presents two cases of abdominal aortic dissecting hematoma without involvement of the thoracic aorta. Computed tomography can reliably diagnose or exclude aortic dissection by demonstrating the specific findings of an intimal flap and displacement of intimal calcification into the aortic lumen.

Pseudoaneurysm with rupture in pancreatic pseudocyst wall as demonstrated by computed tomography.

In chronic pancreatitis, inflammation originating in the pancreas may produce walled-off collections of fluid referred to as pseudocysts. This same histolytic process can also erode into adjacent arteries producing pseudoaneurysms that may hemorrhage secondary to rupture. The most common angiographic finding in patients bleeding secondary to pancreatitis is rupture of a pseudoaneurysm. We present a case of this condition that was first discovered incidentally by computed tomography during evaluation of a right renal carcinoma.

Computed tomographic evaluation of the thoracic prevertebral and paravertebral spaces.

The thoracic prevertebral and paravertebral spaces are defined by the vertebrae and fascial planes. Many important structures lie within these spaces, for example, the intercostal arteries, descending aorta, the azygos and hemiazygos veins, sympathetic nerve trunk, thoracic duct, and lymph nodes. Computed tomography has been notably successful in evaluating the mediastinum and specifically the prevertebral and paravertebral spaces. Computed tomography of the normal anatomy and some examples of pathology involving these specific areas are presented. Computed tomography is strongly indicated to evaluate pathology in this area.

Computed tomography in the renal transplant patient: problems in interpretation.

Fluid collections associated with a transplanted kidney can be easily imaged and classified by Hounsfield Unit (HU) into definite categories (2). However, in some entities HU measurements overlap, with differentiation on the basis of clinical course being difficult as well (1,3). This article is addressed to these problems. Although routine radiologic techniques may provide useful knowledge, the usually can add nothing to the definitive solution.

The right posterolateral tracheal band.

Changes in the right posterolateral tracheal band and the right retrotracheal recess are reliable parameters for evaluating pathology in the right superior mediastinum. We have measured the posterolateral tracheal band at the sternal notch and 2 cm below the sternal notch in computed tomograms. At the sternal notch, the average thickness was 8.4 +/- 3.8 mm. At the level 2 cm below the sternal notch, the posterolateral band was 6.4 +/- 1.8 mm. This represents measurements from 100 normal patients. Pathology in the lungs, pleura, esophagus, soft tissues, and other mediastinal structures can clearly affect the posterolateral tracheal band, causing abnormal contours and widening of the band.

Systemic venous blood return via the portal vein.

The patterns of collateral circulation which develop following obstruction of the inferior vena cava have been classically divided into three groups depending upon the level of obstruction, i.e., infrarenal, middle caval, and upper caval. The portal vein can play an active role at all three levels. Multiple potential routes to the portal vein are described and 6 cases are presented.

Computed tomography in renal transplant problems.

Nineteen patients were studied with computed tomography immediately after kidney transplantation and subsequently if declining renal function was noted. Abscess formation, hematoma and lymphocele were satisfactorily demonstrated. Of 8 diagnosed abnormal densities, 5 were proved correct (abscess 2; serous collection and old blood 1; lymphocele 1; and hematoma (fresh) 1). Two were not proved but abnormalities resolved on medical therapy. There was one incorrect diagnosis: what was thought to be an abnormal fluid collection was really a markedly enlarged edematous rejected kidney. Computed tomography represents an excellent method of following the course of therapy, whether surgical or conservative.

Left internal mammary artery--coronary artery bypass anatomy.

Bypass coronary surgery has made good use of the anatomic proximity of the internal mammary artery and the left anterior descending coronary artery. In preparing the internal mammary artery for bypass surgery, several of its proximal branches remain intact and are visualized during selective studies of the bypass graft. A brief description of these vessels is presented with specific attention to the branching and position of the pericardial vessels and their relationship to the grafted left anterior descending artery.

Radiographic visualization of left ventricular aneurysms on lateral chest film.

The diagnosis of left ventricular aneurysm on routine chest examination can be elusive. Six cases are presented which illustrate a radiographic sign not previously emphasized: a soft tissue border seen retrosternally or superiorly on lateral chest film produced by the wall of the aneurysm silhouetting against the midline cardiac shadow. This sign is not always present since it is dependent on the direction of projection of the aneurysm. However, when observed, it should suggest the proper diagnosis.

Percutaneous transhepatic cholangiography. Problems in interpretation.

The patient who presents with jaundice, regardless of the etiology, cannot be adequately examined by a gallbladder series and intravenous cholangiography. Clinical evaluation aided by laboratory analysis will not always differentiate between primary liver parenchymal disease and biliary tract obstruction. Percutaneous transhepatic cholangiography, when successfully performed, answers the question of whether the jaundice is due to primary liver parenchymal disease or due to biliary tract obstruction. The point to emphasize is that under no circumstances is it appropriate to presume any information if the biliary system is not entered and visualized successfully. The proper interpretation of the level of block can fall prey to the mistake of incomplete aspiration of the thick, inspissated bile in the obstructed biliary tree before injection of contrast material. The problem will be worsened by a peripheral entrance into the biliary system rather than a more central one. Gastrointestinal series should always be available to aid in identifying pathology at the entrace of the common bile duct into the duodenum. Lastly, identifying the etiology at the site of the block will require additional procedures. Selective visceral angiography has contributed greatly in this area. During the 20 years of clinical usage of percutaneous transhepatic cholangiography, we feel it has become the single examination capable of preventing unnecessary exploration of the jaundiced patient with primary liver parenchymal disease and the most useful potential source of practical information if laparotomy is necessary to correct biliary tract obstruction.