Assessment of PI-RADS v2 categories ≥ 3 for diagnosis of clinically significant prostate cancer.

PURPOSE: To assess the diagnostic accuracy of PI-RADS v2 categories ≥ 3 to detect clinically significant prostate cancer (csPCa) against histopathology of Transperineal Mapping Biopsy (TPMB). MATERIALS AND METHODS: IRB-approved retrospective cohort study included 47 men who had 3.0 T multi-parametric MRI (mpMRI) and TPMB of prostate. Two radiologists independently evaluated T2, DWI, ADC map, and DCE images using PI-RADS v2 categories. A third radiologist served as tie-breaker. PI-RADS v2 score (PS) ≥ 3 lesions were correlated with 3D model of TPMB (3DTPMB) results based on prostate sectors. Two groups of csPCa status were separately analyzed for accuracy measures at lesion and person levels: Group 1 with GS (Gleason Score) ≥ 7 and group 2 with tumor volume ≥ 0.5 cc. Inter-rater reliability for PS and MR lexicon was calculated. RESULTS: Forty-seven patients with 3DTPMB had at least one lesion with PS ≥ 3 on mpMRI. PS of 5 had high PPV and high specificity of 100% at the lesion and person levels. Sensitivity of a PS ≥ 3 was 68.27% for group 1 and was 48.39% for group 2. Specificity was 93.56% for group 1 and was 95.53% for group 2. At the person level, sensitivity of PS ≥ 3 was 81.25% for group 1 and was 82.35% for group 2. Specificity was 32.26% for group 1 and was 53.85% for group 2. CONCLUSION: PI-RADS v2 category of 5 had high PPV and specificity; however, combined PS ≥ 3 had mixed performance in detection of csPCa.

Magnetic resonance imaging in prostate brachytherapy: Evidence, clinical end points to data, and direction forward.

The integration of multiparametric MRI into prostate brachytherapy has become a subject of interest over the past 2 decades. MRI directed high-dose-rate and low-dose-rate prostate brachytherapy offers the potential to improve treatment accuracy and standardize postprocedure quality. This article reviews the evidence to date on MRI utilization in prostate brachytherapy and postulates future pathways for MRI integration.

Normal main portal vein diameter measured on CT is larger than the widely referenced upper limit of 13 mm.

OBJECTIVE: We determined mean main portal vein diameter in healthy patients evaluated with CT, compared this value to the "upper limit of normal" reported previously, and evaluated effects of age, sex, height, and BMI on portal vein diameter. MATERIALS AND METHODS: Our cohort of healthy patients underwent abdominal CT as potential renal donors. We excluded patients with evidence of liver or severe cardiac disease. We recorded patients' age, sex, height, weight, and BMI. Patients' main portal vein diameters were measured by fellowship-trained abdominal imagers on non-contrast and post-contrast images in axial and coronal projections at a defined location. A general linear mixed model was used for analysis. RESULTS: 191 patients with 679 main portal vein measurements were included in the analysis. Mean main portal vein diameter was 15.5 ± 1.9 mm; this value was significantly different from the upper limit of normal of 13 mm commonly referenced in the literature (95% CI: 2.22-2.69 mm higher, p < 0.0001). Portal vein diameter does not vary significantly when measured on axial vs. coronal images. On average, post-contrast main portal veins were 0.56 mm larger compared to non-contrast, (95% CI: 0.40-0.71 mm, p < 0.0071). Patient height and BMI are positively correlated with MPV diameter. CONCLUSIONS: Normal mean portal vein diameter measured on CT was significantly larger (mean 15.5 mm) than the accepted upper limit of 13 mm. Contrast-enhanced main portal veins are significantly larger (0.56 mm) than unenhanced. Sex, height, and BMI significantly affect main portal vein diameter.

Unusual presentation of a pancreatic cyst resulting from osteosarcoma metastasis.

Pancreatic metastases are uncommon. They have been reported in lung cancer, gastrointestinal malignancies, breast cancer, renal cell carcinoma, melanoma, lymphoma and sarcoma, and usually have solid morphology. Cystic metastasis to the pancreas is even more rare with few case reports in the literature. However, with the increasing use of computed tomography and magnetic resonance imaging as well as endoscopic ultrasound, more such lesions may be detected. Metastasis to the pancreas from osteosarcoma is highly unusual, but can be seen with the increasing survival of patients with osteosarcoma. We present an extremely rare case of a predominantly cystic lesion of the pancreas, which was diagnosed as metastasis from osteosarcoma. The pathophysiology of the cystic component of the metastasis of osteosarcoma is unknown. Cystic necrotic degeneration of the solid metastasis or pancreatitis secondary to the metastasis with development of associated fluid collection can be considered. Metastasis should remain a differential consideration even for primarily cystic lesions of the pancreas.

Multi-parametric MRI findings of transitional zone prostate cancers: correlation with 3-dimensional transperineal mapping biopsy.

PURPOSE: A preliminary project to correlate MR findings with mapping prostate biopsy to help differentiate malignant transitional zone lesions form benign prostatic hyperplasia (BPH) nodules. MATERIALS AND METHODS: Institutional IRB approved retrospective study with 14 patients suspected of having prostate cancer who underwent both prostate 3T MRI using endorectal coil and 3D transperineal mapping prostate biopsy. MR exams were independently reviewed by two abdominal radiologists blinded to pathology with disagreement resolved by consensus. An MRI lesion was defined as having hypointense T2 signal subjectively without corresponding T1 high signal intensity and low signal on ADC maps in the central gland. Mapping biopsy consisted of systematic transperineal US guided biopsy with 55-108 cores per patient. RESULTS: Twenty-nine lesions were detected on MRI. Of these, 13 correlated with Gleason 6 or higher biopsy samples. 16 were biopsy negative. Among the various MRI characteristics assessed, lack of T2 hypointense rim demonstrated the highest specificity (93%) and positive predictive value (89%). Highest sensitivity (85%) and negative predictive value (78%) were seen with ill-defined nodules. When suspicious MR characteristics were combined, the specificity and PPV rose to 100% while sensitivity decreased to 45% and NPV decreased to 73%. CONCLUSIONS: Preliminary study indicates MR findings which can help differentiate a BPH nodule from transitional zone prostate cancers which could help direct biopsy in the large and growing number of people suspected of having prostate cancer. Further work will be needed for validation.

Current MR imaging lipid detection techniques for diagnosis of lesions in the abdomen and pelvis.

One application of the unique capability of magnetic resonance (MR) imaging for characterizing soft tissues is in the specific detection of lipid. Adipose tissue may be abundant in the body, but its presence in a lesion can greatly limit differential diagnostic considerations. This article reviews MR imaging fat detection techniques and discusses lesions in the abdomen and pelvis that can be readily diagnosed by using these techniques. Traditional fat detection methods include inversion-recovery and chemically selective fat-suppression pulse sequences, with the former being less sensitive to field heterogeneity and less tissue specific than the latter. Chemical shift-based sequences, which exploit the inherent resonance frequency difference between lipid and water to depict intracytoplasmic fat, have great utility for evaluating hepatic steatosis and lesions such as adrenal and hepatic adenomas, hepatocellular carcinoma, focal lipomatosis of the pancreas, and adrenal cortical carcinoma. The signal from large amounts of fat can be suppressed by using a narrow radiofrequency pulse for selective excitation of fat protons (ie, fat saturation imaging), a technique that increases image contrast resolution and highlights lesions such as contrast-enhancing tissue, edema, and blood products. This technique is especially useful for evaluating renal angiomyolipomas, adrenal myelolipomas, ovarian teratomas, and liposarcomas. MR spectroscopy is a promising method for quantifying absolute liver fat concentration and changes in hepatic triglyceride content during treatment. New and evolving techniques include magnetization transfer and modified Dixon sequences. A solid understanding of these techniques will help improve the interpretation of abdominal and pelvic imaging studies.

Incidentally detected cystic lesions of the pancreas on CT: review of literature and management suggestions.

PURPOSE: To facilitate a better understanding of incidentally noted cystic pancreatic lesions, since these lesions often pose a challenge regarding appropriate management. METHODS: This article reviews pathophysiology, prevalence, significance, and recommendations for management of the various pancreatic cystic lesions. Illustrative cases are demonstrated. RESULTS: Diagnostic benign lesions can be left alone. Cross-sectional imaging can be used to follow-up benign appearing lesions and to stage more aggressive ones. Endoscopic ultrasound with fine needle aspiration and cyst fluid analysis can be performed on certain indeterminate lesions. Lesions with high malignant potential should undergo resection. CONCLUSIONS: A better understanding of the variety of incidentally detected pancreatic cystic lesions can help direct appropriate management.

Endovascular embolization of large hepatic arteriovenous fistulas.

Treatment of hepatic artery to portal vein fistulas (HAPFs) has shifted in the past two decades from surgical resection of the involved liver to embolization. A uniform technique for percutaneous intervention has not been established because the approach is influenced by the size, location, and number of feeding arteries. We report two cases of HAPFs treated with embolization at our institution. Different outcomes in these two patients illustrate several fundamental principles in the treatment of HAPFs.

Emissions reductions as a result of automobile improvement.

Remote sensing of light duty vehicle on-road tailpipe exhaust has been used to measure on-road mass emissions of automobile fleets in Denver for 13 years and in two other U.S. cities for 5 years. Analysis of these fleets shows that newer automobiles, during a period of fairly constant new car standards, have become continually less polluting independent of measurement location. Improving emissions control technology spurred by federal regulations is thought to have brought about these trends.