Computed tomographic evaluation of paraesophageal hernia

Paraesophageal hernias are relatively rare compared to the more commonly diagnosed sliding hiatus hernia. They tend to be asymptomatic initially, but may gradually enlarge and present with life-threatening complications. The treatment is surgical reduction, preferably as an elective procedure. Computed tomography (CT) clearly demonstrates a paraesophageal hernia through a widened esophageal hiatus, often as an incidental finding, and accurately documents the size, contents, and orientation of the herniated stomach within the lower thoracic cavity. In this report, the CT appearance of 4 patients with paraesophageal hernias is described along with a discussion of this uncommon but important surgical condition.     

Computed tomographic scan evaluation of pulmonary blastomycosis

BACKGROUND:

Blastomycosis is an uncommon granulomatous pulmonary and extrapulmonary infectious disease caused by the thermally dimorphic fungus Blastomyces dermatitidis. Diagnosis may be delayed or difficult because of varied presentation. The characteristics of blastomycosis on computed tomographic (CT) scan of the chest are not well characterized.

METHODS:

The images from 34 chest CT scans from patients with confirmed pulmonary blastomycosis were retrospectively reviewed.

RESULTS:

The most common CT findings were air bronchograms in 22 patients (65%), consolidation in 21 patients (62%), nodules (smaller than 3 cm) in 21 patients (62%) and lymph node enlargement (mediastinal and hilar nodes combined) in 12 patients (35%). Only four patients (12%) had a miliary pattern.

CONCLUSIONS:

A specific abnormality characteristic of pulmonary blastomycosis was not identified on CT scanning. The diagnosis can only be made in the context of a high index of clinical suspicion with histological or culture confirmation.     

Computed tomography in staging of oesophageal carcinoma

The computed tomographic (CT) findings in 45 patients with histologically proved oesophageal carcinoma are reviewed. In 20 of these patients the CT findings were correlated with findings at surgery (19 patients) or autopsy (1 patient). Correlation analysis showed that the accuracy of CT in assessing both invasion of adjacent organs and mediastinal and abdominal lymph node involvement is limited. Twenty-five patients were considered inoperable; in 15 of these the conclusion was based on CT findings of distant metastases (14 patients) or definite local invasion (1 patient). Ten patients were inoperable for other reasons (general health condition). We found the value of CT to be in detecting distant metastases, thus avoiding unnecessary radical surgery; it is not a reliable way of defining the primary tumour.     

Computed tomographic colonography

Computed tomographic colonography is a modern technique to evaluate the colon, which may be more appealing to patients than invasive methods. The potential of this test, including current and future developments are presented in this review. The essential steps required to perform a diagnostic quality computed tomographic colonography are discussed as well as different methods of study interpretation. The current status and promising areas of future investigation are also discussed.     

Computed tomographic colonography

Computed tomographic colonography, also called virtual colonoscopy, is an evolving technology under evaluation as a new method of screening for colorectal cancer. However, its performance as a test has varied widely across studies, and the reasons for these discrepancies are poorly defined. We provide an overview of some potential causes and discuss the available, often indirect, evidence. In addition, several other obstacles that may influence implementation are discussed. Future investigations should demonstrate the influence of these potential factors on sensitivity of computed tomographic colonography. Despite a growing body of evidence, it remains uncertain to what extent patient acceptance, radiation issues, flat lesions, and extracolonic findings will be a stumbling block to using computed tomographic colonography for colorectal cancer screening.     

Computed tomographic features of colorectal carcinoma liver metastases predict posthepatectomy patient survival

PURPOSE: The gross appearance of colorectal carcinoma liver metastases reflects the biologic behavior of the tumor, yielding prognostic information. The aims of this retrospective study were to determine whether preoperative computed tomographic features of colorectal carcinoma liver metastases reflect the gross appearance of resected specimens and whether these computed tomographic hepatic features predict survival after hepatectomy. METHODS: Eighty-five patients underwent curative partial hepatectomy for colorectal carcinoma liver metastases. Preoperative computed tomographic features of the largest hepatic deposit were classified by the contour of advancing margin of the tumor into two types: lobular tumors with indentations with an acute angle and nonlobular tumors without such indentations. The correlation between computed tomographic features and 18 other clinicopathologic factors was examined. RESULTS: The overall five-year survival rate was 34.1 percent. Of 85 hepatic tumors examined, 49 were lobular and 36 were nonlobular. Computed tomographic features correlated significantly with gross appearance (P = 0.007). Univariate analysis revealed that computed tomographic features (P < 0.0001), gross appearance (P = 0.0063), size of the largest hepatic deposit (P = 0.0075), age (P = 0.0140), and satellite lesions (P = 0.0443) were significant prognosticators. The five-year survival rates in patients with lobular and nonlobular tumors were 10.4 and 66.1 percent, respectively. By multivariate analysis, computed tomographic features (P < 0.0001) and size of the largest hepatic deposit (P = 0.0419) were independently significant. CONCLUSIONS: Computed tomographic features of colorectal carcinoma liver metastases correlate with their gross appearance. The computed tomographic characterization of liver metastases is the most important independent prognostic factor in patients undergoing curative hepatectomy.     

Computed tomographic findings of trichuriasis

In this report, we present computed tomographic findings of colonic trichuriasis. The patient was a 75-year-old man who complained of abdominal pain, and weight loss. Diagnosis was achieved by colonoscopic biopsy. Abdominal computed tomography showed irregular and nodular thickening of the wall of the cecum and ascending colon. Although these findings are nonspecific, they may be one of the findings of trichuriasis. These findings, confirmed by pathologic analysis of the biopsied tissue and Kato-Katz parasitological stool flotation technique, revealed adult Trichuris. To our knowledge, this is the first report of colonic trichuriasis indicated by computed tomography.     

Computed tomographic and ultrasonic appearances of primary carcinoma of the common bile duct.

Two patients with obstructive jaundice due to surgically proved primary carcinoma of the common bile duct were examined by CT and ultrasound. The combination of the two modalities showed dilatation of the extrahepatic biliary system and the main pancreatic duct. The diagnosis of primary bile duct carcinoma is suggested by these findings in the presence of a normal pancreatic head, although similar findings may occur with a small pancreatic or ampullary carcinoma.     

Computed tomographic scanning in sarcoidosis

Sarcoidosis is a granulomatous disease of unknown etiology that involves the lungs or intrathoracic lymph nodes in more than 90% of patients. The clinical spectrum of sarcoidosis is protean, but pulmonary manifestations often dominate. Chest radiographs are abnormal in 90 to 95% of patients with sarcoidosis; the most characteristic feature is bilateral hilar lymphadenopathy (BHL), present in 50 to 80% of patients. Pulmonary parenchymal infiltrates are present in 25 to 50% of patients. In this article, we review the radiographic features of sarcoidosis (both typical and atypical), and the impact of chest radiographic stage on long-term prognosis. Computed tomographic (CT) scans are more sensitive than chest radiographs in delineating parenchymal, mediastinal, and hilar structures, and distinctive CT patterns may be virtually pathognomonic for sarcoidosis in some patients. Routine CT scan is not appropriate to diagnose or manage sarcoidosis, but CT may be invaluable in patients with atypical clinical or chest radiographic findings or specific complications of sarcoidosis (pulmonary or extrapulmonary), or to assess prognosis. High-resolution thin-section CT scans (HRCT) may be helpful in selected patients with stage II or III sarcoidosis to discriminate active inflammation from irreversible fibrosis. This article discusses the salient HRCT features of sarcoidosis, accuracy of CT in the differential diagnosis, and correlations of HRCT with disease extent and activity, pulmonary function, and lesion reversibility.     

Computed tomographic appearances of cardiac amyloidosis

Computed tomography was used to identify the characteristic appearances of histologically confirmed cardiac amyloidosis in two patients. Mean myocardial density and 95% confidence limits in one of these patients (30.6 +/- 3.4 Hounsfield units (HU) ) were significantly lower than in patients with diffuse hypertrophic cardiomyopathy (range from 38.8 +/- 5.7 HU to 45.9 +/- 4.4 HU) and normal myocardium (range from 41.9 +/- 4.3 HU to 44.8 +/- 4.4 HU) on pre-contrast computed tomograms. Although only an approximate myocardial density was obtained in the second patient with amyloidosis, a similar result (30 HU) was noted on pre-contrast tomograms. Diffuse thickening of the interventricular septum and left ventricular free wall was found in both patients. Myocardial density on post-contrast computed tomograms was 102.8 +/- 5.2 HU in one patient and approximately 100 HU in the other. A pericardial effusion was noted in the first patient. A low myocardial density on pre-contrast tomograms and diffuse myocardial thickening on post-contrast tomograms are considered to be important features of cardiac amyloidosis.     

Computed tomographic diagnosis of radiation ileitis

Two patients were studied by CT after resection of colon carcinoma followed by abdominal radiation therapy. Based upon the findings of a localized, mass-like confluence of shortened loops of bowel with thickening of bowel wall, adherence of adjoining loops, thickening of the adjacent mesentery, and increased density of mesenteric fat the patients were considered to have radiation ileitis. Recurrent tumor was excluded by autopsy and confirmed by a 1-year asymptomatic follow-up period.     

Computed tomographic findings in bowel ischemia

Computed tomography (CT) has been used in the evaluation of 11 patients with ischemic bowel lesions before confirmation of the disease with surgery or autopsy. The CT abnormalities were thickened bowel wall (10 patients) with post-contrast enhancement (9 patients), dilated fluid-filled bowel (9 patients), intramural low attenuation zones (5 patients), intramural gas (8 patients), and focal or diffuse free intraperitoneal fluid (5 patients). The diagnosis of bowel ischemia should be considered when performing CT in patients with abdominal pain of unknown etiology.     

Computed tomography in the preoperative evaluation of gastric carcinoma

Computed tomography (CT) of the abdomen was done in 49 patients with gastric carcinoma. These cases were retrospectively staged and evaluated as to operability. Various staging parameters were also evaluated separately. The results were correlated to findings on surgery, liver scan, and cytology. Overall accuracy of CT staging and operability assessment was 72 and 82%, respectively. Among the various CT parameters, perigastric fat invasion had a positive predictive value of 91%. The demonstration of local node involvement and invasion of adjacent organs was unreliable. Since surgery is currently the only treatment for gastric carcinoma, CT staging has limited clinical value. The principal role of CT is in the assessment of operability in patients with carcinoma of the stomach.     

Computed tomographic angiography in tetralogy of Fallot

Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, -2; range, -11.1-0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range, -2.53-3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.     

Computed tomographic assessment of left ventricular aneurysms

Twenty patients with left ventricular aneurysms were studied by left ventricular angiography and computed tomography. Measurements of left ventricular short axis, percentage of non-aneurysmal myocardium, and size of aneurysm were determined by both techniques. Qualitative assessments of left ventricular size together with the anatomical relation of the aneurysm to the ventricle were also made. The aneurysm was assessed for resectability by both techniques using these criteria. In all cases there was a distinct and diagnostic change in the contour of the ventricle on computed tomography. Computed tomography indicated eight aneurysms to be unresectable, and this agreed with the angiographic assessment. Of the remaining 12 aneurysms, seven were considered to be resectable on angiography. Computed tomography appears to be a reliable non-invasive technique for identifying left ventricular aneurysms and a useful screening method for identifying unresectable aneurysms.