Donald H. Hulnick

Computed tomography of the abnormal appendix

This report describes the CT features of 29 abnormal appendices visualized during abdominal CT examinations. There were 22 cases of acute appendicitis, five mucoceles, and two mucinous adenocarcinomas of the appendix. The inflammed appendix appeared either as a fluid-filled slightly distended structure or as a collapsed small tubular structure. It was visualized on either cross or longitudinal sections and showed slight circumferential wall thickening. Periappendiceal inflammation was detected in 19 cases and intraluminal appendicoliths in six cases. Mucocele appeared as a larger fluid-filled round, oval, or tubular structure having a thin, sharp wall, low density contents, and no periappendiceal inflammation. Mucinous carcinoma appeared either as a single or as multiloculated, irregular shaped cystic lesion with solid elements. Infiltration of cecum and terminal ileum was seen in one case. In five cases the abnormal appendix was not recognized initially and was identified only after repeat 5 X 5 mm sections were obtained. During CT examination, demonstration of an abnormal appendix establishes the source of the abdominal pathology and helps greatly in the differential diagnosis.

Computed tomography of intramural intestinal hemorrhage and bowel ischemia.

The CT findings of eight patients with intramural intestinal hemorrhage are described and illustrated. Two patients had ischemic bowel disease: in the other six cases pertinent clinical histories led to an accurate diagnosis. Computed tomography demonstrated similar findings consisting of circumferential and symmetrical wall thickening homogeneous in density, a slightly narrowed intestinal lumen, and sharp outer contour. The disease had a segmental distribution affecting different parts of the intestinal tract. In six patients edematous and congestive mesenteric changes were seen and in two patients intraperitoneal blood was detected. An adequate history and careful clinical evaluation are crucial in differentiating the more benign forms of intramural hemorrhage from bowel ischemia.

Air insufflation of the colon as an adjunct to computed tomography of the pelvis

Air insufflation of the colon as an adjunct to pelvic CT examinations was performed in 49 patients for evaluation of a known or suspected pelvic mass or in follow-up of treated pelvic tumors. This safe, simple method of colonic visualization clearly outlines the rectosigmoid colon and permits a reliable assessment of the mucosa, wall thickness, and extrinsic abnormalities, thereby improving diagnostic accuracy in staging pelvic malignancy and evaluating pelvic pathology.

Computed tomography of lobar collapse: 1. Endobronchial obstruction.

The computed tomographic (CT) appearance of lobar collapse has yet to be defined. In an attempt to determine the characteristic appearance of collapse 95 cases were reviewed retrospectively in a wide variety of clinical settings over a 3 year period ending January 1983. In this report 38 cases of lobar collapse secondary to endobronchial occlusion are analyzed; the appearance of collapse without endobronchial obstruction forms the basis of a subsequent report. Computed tomography was accurate in determining the site of bronchial occlusion in all cases. In 36 of 38 cases collapse was caused by endobronchial tumors, including bronchogenic carcinoma, bronchial carcinoids, endobronchial metastases, and lymphoma. Differentiation between these tumors was not feasible with CT. Most cases of collapse were caused by central tumor. In those cases in which a bolus of contrast material was used differentiation between tumor mass and collapsed pulmonary parenchyma was possible. Two of 38 cases were found to have benign bronchial occlusion. In one case a mucous plug obstructing the left lower lobe bronchus was accurately defined. In another case a bronchial stricture occluded the right lower lobe bronchus. This represented the only false positive case in this series. It is concluded that CT is an accurate means for establishing the diagnosis of endobronchial obstruction. In most cases the diagnosis of neoplasia was possible, provided a bolus of contrast material was used to define tumor mass. The potential role of CT in evaluating patients with lobar collapse is discussed.

Computed Tomography of Midline Cysts of the Prostate

Midline cysts in the male pelvis are a confusing entity due to their relatively infrequent presentation and the uncertainty as to their origin and classification. We report on CT appearance of four cases of midline prostatic cysts. Ultrasound correlation was available in one case. Two patients presented with lower urinary tract symptoms (hematospermia and/or hematuria), and two were asymptomatic, with one case detected on physical examination and one found incidentally on CT. Computed tomography demonstrated a characteristic sharply marginated, low density, homogeneous midline cyst within the prostate. On ultrasound a well defined midline anechoic cystic mass was seen. These cases are illustrated and a discussion of cystic masses in the male pelvis is included.

Lumbar Artery Pseudoaneurysm: CT Demonstration

A psoas mass in a patient with a history of penetrating trauma to the area was demonstrated by computed tomography (CT) to represent a lumbar artery pseudoaneurysm surrounded by hematoma. This report emphasizes the importance of recognizing the anatomic position of the lumbar arteries on CT images and considering the possibility of pseudoaneurysm in the differential diagnosis of post-traumatic psoas masses.

Gastric duplication cyst: GI series and CT correlation.

The radiographic and computed tomographic findings of a communicating gastric duplication first diagnosed in a 55-year-old man are presented and the pertinent literature is reviewed.

Computed tomography of lobar collapse: 2. Collapse in the absence of endobronchial obstruction

The computed tomographic appearance of collapse without endobronchial obstruction is reviewed. These 57 cases were classified by the etiology of collapse. The largest group consisted of 29 patients with passive atelectasis, i.e., collapse secondary to fluid, air, or both in the pleural space. Twenty-three of 29 proved secondary to malignant pleural disease. Computed tomography accurately predicted a malignant etiology in 22 of 23 cases. The second largest group of patients had lobar collapse secondary to cicatrization from chronic inflammation. In all cases the underlying etiology was tuberculosis. Radiation caused adhesive atelectasis in six patients secondary to a lack of production of surfactant. In each case a sharp line of demarcation could be defined between normal and abnormal collapsed pulmonary parenchyma. Three cases of unchecked tumor growth caused a peripheral form of collapse (replacement atelectasis). This form of collapse was characterized by an absence of endobronchial obstruction and extensive tumor not delineated by the normal boundaries of the pulmonary lobes.

Computed tomography of the diaphragm: Peridiaphragmatic fluid localization

Fifty-eight consecutive cases of peridiaphragmatic fluid collections were correctly localized by computed tomography. The key to accurate localization of peridiaphragmatic fluid is identification of the hemidiaphragms. Pulmonary consolidation and pleural fluid collections lie adjacent and peripheral to the convexity of the hemidiaphragms. Free pleural fluid distends the posterior pleural recesses, important anatomic landmarks beneath the bases of the lungs. Intra-abdominal fluid collections lie adjacent and central to the convexity of the hemidiaphragms. On the right side intraperitoneal fluid is restricted from contact with the bare area of the liver by the coronary ligaments. It is concluded that peridiaphragmatic fluid collections can generally be readily identified if one is familiar with normal cross-sectional anatomy.

Retroperitoneal fibrosis presenting as colonic dysfunction: CT diagnosis.

In a patient who presented with pelvic pain and changed bowel habits, barium enema and sigmoidoscopic examinations demonstrated a nonspecific asymmetric narrowing of the colon at the rectosigmoid junction with normal mucosal appearance. Computed tomography revealed the etiology to be retroperitoneal fibrosis with pelvic extension and entrapment of the colon at this level. The importance of CT in diagnosis of this unusual manifestation of retroperitoneal fibrosis is discussed.