Accuracy of CT in estimating extent of pancreatic necrosis

The objective of this study was to determine whether nonenhancing pancreatic lesions are accurate in estimating pancreatic necrosis. Twenty-six consecutive abdominal computed tomography (CT) examinations performed over a 3-year period that met the CT criteria for pancreatic necrosis were reviewed. Follow-up CTs in three of 26 patients demonstrated pancreatic enhancement, indicating viable parenchyma, within the previously nonenhancing regions. All three patients had undergone surgical debridement in that area. Twenty-three cases demonstrated either no change or enlargement of the nonenhancing pancreatic lesions. Follow-up ranged from 1 week to 26 months. While CT is accurate in diagnosing pancreatic necrosis, lack of enhancement in CT may occasionally overestimate the extent of necrosis. Nonenhancing, viable but at-risk tissue may be present adjacent to frankly necrotic tissue. Surgical debridement may facilitate recovery of this viable tissue, which may enhance normally on follow-up CT.     

Acute myocardial ischemia: MR imaging with Mn-TP

Cardiac-gated magnetic resonance (MR) imaging was performed in rats to determine the effects of manganese ethylenediaminetetraphosphonate (TP). Ten normal rats received Mn-TP in a dose of 50 mumol/kg through a tail-vein injection. Spin-echo MR images were obtained before and every 10 minutes after Mn-TP injection for 1 hour. Cardiac signal intensity (SI) increased more than 70% after Mn-TP injection and remained nearly unchanged 1 hour after injection. Myocardial T1 was 517 +/- 49 msec in eight control rats and 282 +/- 61 msec (P less than .001) in six rats 81 +/- 0 minutes after injection. Nine rats underwent occlusion of the left anterior descending coronary artery prior to MR imaging. Images were obtained before and 15, 30, and 60 minutes after Mn-TP injection. In normal myocardium, SI increased up to 82% and remained elevated for 1 hour. In ischemic myocardium, SI rose 11%, leading to a marked contrast between the two tissue zones. T1 was also different in the two regions: In normal tissue, it was 206 msec +/- 54; in ischemic tissue, 338 +/- 82 (P less than .001). With T1-weighted MR imaging, Mn-TP showed a potential for delineating the jeopardized area after acute myocardial ischemia.     

Septic thrombosis of the portal vein: CT and clinical observations

The CT and clinical findings were reviewed in seven patients with septic thrombosis of the portal vein (STPV). Of the seven patients, five had associated pyogenic liver abscesses. Five of seven patients presented de novo with STPV without a clinically obvious extrahepatic source of intraabdominal infection. All seven patients were successfully managed nonsurgically with intravenous antibiotics and in two patients percutaneous drainage of hepatic abscesses. Serial follow-up examinations in five patients demonstrated complete resolution of portal venous thrombus in three patients and progression to cavernous transformation in two. When diagnosed early by CT or sonography, STVP may have a more benign clinical course following appropriate antibiotic therapy.     

Gallbladder wall thickening: patients without intrinsic gallbladder disease

Retrospective analysis of 22 patients with increased gallbladder wall thickness (4--10 mm) in the absence of gallbladder disease revealed that 19 were hypoalbuminemic (albumin less than 3.6 g/dl). To test the hypothesis that hypoalbuminemia was a causal factor, gallbladder wall thickness was measured in 40 patients selected prospectively solely on the basis of hypoalbuminemia. This group was compared to 25 normal volunteers. Hypoalbuminemic patients had significantly thickened gallbladder walls compared to volunteers (p less than 10(-9)). This thickening was associated not only with hypoalbuminemia, but also with increased main portal vein diameter, which reflects portal venous blood pressure. Gallbladder wall thickening unrelated to intrinsic gallbladder disease seems to be influenced by the same parameters as ascites formation--plasma colloid oncotic pressure and portal venous pressure.     

Prospective evaluation of the sonographic murphy sign in suspected acute cholecystitis

The sonographic Murphy sign, the presence of maximal tenderness elicited over a sonographically localized gallbladder, has been considered useful in the evaluation of patients with suspected acute cholecystitis. We prospectively evaluated this sign in 427 consecutive patients referred for evaluation of acute cholecystitis. The overall accuracy of the sonographic Murphy sign in the 219 patients with sufficient confirmation to be included in the statistical analysis was 87.2%. Sensitivity was 63% and specificity was 93.6%. The predictive value of a positive sign was 72.5%, while the predictive value of a negative sign was 90.5%. The sonographic Murphy sign is a useful, albeit imperfect, adjunct in the assessment of patients with suspected acute cholecystitis.     

Tumoral calcinosis: sonographic sedimentation sign

We present the sonographic findings of tumoral calcinosis in two patients compared with conventional radiography, CT, and MRI. Sonography in both patients demonstrated fluid-sedimentation levels, with more echogenic debris layering dependently. This appearance has been referred to as the "sedimentation sign" on conventional radiography and results from dependent layering of hydroxyapatite crystals within cystic spaces of the lesion. There are only three reported cases in the world literature of sonographic findings in patients with tumoral calcinosis. We describe the first two cases of sonography demonstrating the "sedimentation sign," which may aid in the diagnosis of tumoral calcinosis.