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Pseudoenhancement of renal cysts may occur if helical CT is performed during peak renal enhancement. CT algorithm modification may be necessary to correct for this effect, which is likely related to an inadequate algorithmic correction for beam hardening.

Jill E.Jacobs1 BernardA. Birnbaum1 MichaelA. Shapiro1'2 CurtisR Langlotz1 FrancoisSlosman1'3 StephenE.Rubesin1 StevenC.Horii1OBJECTIVE. The purposeof thestudywasto developquantitativeandqualitativecriteria for diagnosing fatty liver on contrast-enhancedhelical CT.SUBJECTS AND METHODS. Differential liverâ€"spleen attenuationwas evaluatedbe tween 80 and I 20 sec after injection in 76 patients who underwent contrast-enhancedhelical CT. UnenhancedCT images had earlier establishedfatty liver when the liver minus spleen at tenuation difference was less than or equal to â€"¿ 10 H (n = 18). Four observers who had not seen the unenhanced images used contrast-enhanced CT images to assess the presence of fatty liver on a five-point Likert scale, the presenceof geographic areassparedfrom fatty infi tration, and the relative liverâ€"spleen attenuation. The diagnostic accuraciesof various imaging criteria were compared using McNemar's chi-square test (for sensitivity and specificity) and analysis of receiver operating characteristic curves.RESULTS. Sensitivity,specificity, andreceiveroperatingcharacteristic curveareasfor ob servers' qualitative judgments were 54%, 95%, and .91, respectively; for quantitative differ ential liverâ€"spleen attenuation (80â€"100sec; â€"¿ 20.5 H discriminatory value), the values were

No correlations exist between injection rate and extravasation rate or overall reaction rate.

Diagnostic accuracy of helical CT for acute appendicitis improved significantly with use of intravenous contrast material.

Cardiac diverticula most commonly occur in the left ventricle but have been reported to occur in all chambers of the heart. Despite reports of their rare occurrence, cardiac ventricular diverticula are fairly common findings in patients undergoing cardiac MDCT angiography.

The CT finding of pneumatosis does not always indicate transmural infarction of the bowel in intestinal ischemia. Patients with associated portomesenteric venous gas are more likely to have transmural infarction than those with pneumatosis alone.

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