Predictive value of multi-detector computed tomography for accurate diagnosis of serous cystadenoma:Radiologic-pathologic correlation

AIM： To identify multi-detector computed tomography （MDCT） features most predictive of serous cystadenomas （SCAs）, correlating with histopathology, and to study the impact of cyst size and MDCT technique on reader performance. METHODS： The MDCT scans of 164 patients with surgically verified pancreatic cystic lesions were reviewed by two readers to study the predictive value of various morphological features for establishing a diagnosis of SCAs. Accuracy in lesion characterization and reader confidence were correlated with lesion size （≤3 cm or 〉≥3 cm） and scanning protocols （dedicated vs routine）. RESULTS： 28/164 cysts （mean size, 39 mm; range, 8-92 mm） were diagnosed as SCA on pathology. The MDCT features predictive of diagnosis of SCA were microcystic appearance （22/28, 78.6%）, surface Iobulations （25/28, 89.3%） and central scar （9/28, 32.4%）. Stepwise logistic regression analysis showed that only microcystic appearance was significant for CT diagnosis of SCA （P = 0.0001）. The sensitivity, specificity and PPV of central scar and of combined microcystic appearance and Iobulations were 32.4%/100%/100% and 68%/100%/100%, respectively. The reader confidence was higher for lesions 〉 3 cm （P = 0.02） and for MDCT scans performed using thin collimation （1.25-2.5 mm） compared to routine 5 mm collimation exams （P 〉 0.05）. CONCLUSION： Central scar on MDCT is diagnostic of SCA but is seen in only one third of SCAs. Microcystic morphology is the most significant CT feature in diagnosis of SCA. A combination of microcystic appearance and surface Iobulations offers accuracy comparable to central scar with higher sensitivity.

Quantitative study of prostate cancer using three dimensional fiber tractography

AIM:To investigate feasibility of a quantitative study of prostate cancer using three dimensional(3D)fiber tractography.METHODS:In this institutional review board approved retrospective study,24 men with biopsy proven prostate cancer underwent prostate magnetic resonance imaging(MRI)with an endorectal coil on a 1.5 T MRI scanner.Single shot echo-planar diffusion weighted images were acquired with b = 0.600 s/mm^2,six gradient directions.Open-source available software Track Vis and its Diffusion Toolkit were used to generate diffusion tensor imaging(DTI)map and 3D fiber tracts.Multiple 3D spherical regions of interest were drawn over the areas of tumor and healthy prostatic parenchyma to measure tract density,apparent diffusion coefficient(ADC)and fractional anisotropy(FA),which were statistically analyzed.RESULTS:DTI tractography showed rich fiber tract anatomy with tract heterogeneity.Mean tumor region and normal parenchymal tract densities were 2.53 and 3.37 respectively(P < 0.001).In the tumor,mean ADC was 0.0011 × 10^(-3 )mm^2/s vs 0.0014 × 10^(-3) mm^2/s in the normal parenchyma(P < 0.001).The FA values for tumor and normal parenchyma were 0.2047 and 0.2259 respectively(P = 0.3819).CONCLUSION:DTI tractography of the prostate is feasible and depicts congregate fibers within the gland.Tract density may offer new biomarker to distinguish tumor from normal tissue.