Renal cell carcinoma (RCC) is the most common malignant tumor involving the kidney. Determining the subtypes of renal cell carcinoma is among the major goals of preoperative radiological work-up. Among all modalities, magnetic resonance imaging (MRI) has several advantages, such as inherent soft tissue contrast, detection of lipid and blood products, and excellent sensitivity to detect small amounts of intravenous contrast, which facilitate the discrimination of subtypes of RCC. In this article, we review MRI and pathological features used for determining the main histologic subtypes of RCC, including clear cell, papillary, collecting duct, chromophobe, multilocular cystic, and unclassified RCC. Renal cell carcinoma (RCC) is the most common malignant epithelial tumor of the kidney, accounting for 85%-90% of all solid renal tumors in adults and comprising 1%-3% of all malignant visceral neoplasms (1). Approximately 40% of patients with RCC eventually die from progression of this disease, making it the most lethal urologic malignancy (2). Today, most RCC instances are incidental masses identified on imaging studies performed for nonurological reasons.Percutaneous biopsy is a minimally invasive method, and its accuracy for identifying renal tumors ranges from 70% to 90% (3, 4). However, widespread use of percutaneous biopsy remains controversial due to the potential complications of biopsy, the possibility of sampling errors, the dependence on an adequate biopsy sample for analysis, and concerns about how the biopsy information might alter the treatment plan (5). Therefore, histopathological characterization of renal masses with magnetic resonance imaging (MRI) compared with percutaneous biopsy becomes more advantageous.Determining subtypes of RCC has significant prognostic and theraupeutic implications for patients who are poor surgical candidates, for patients who have a metastatic disease, for surgical planning in patients who are surgical candidates, and for immunotherapy and use of the tyrosine kinase inhibitors "sunitinib" and "sorafenib" for clear cell RCC and "temsirolimus" for papillary RCC (6-9).The need for a different approach to the management of RCC among classical surgical procedures has arisen. Nephron-preserving surgical methods, cryoablation, radiofrequency ablation, targeted molecular therapy or follow-up, and MRI are believed to surpass other modalities both in the diagnosis of RCC and determination of its subtypes (10,11).In this article, we review MRI findings and pathological features used for determining the main histologic subtypes of RCC, including clear cell carcinoma, papillary, collecting duct, chromophobe, multilocular cystic, and unclassified RCC. The role of MRI in renal imagingThere are three indispensable components of renal MRI: breathhold imaging, three-dimensional (3D) gradient echo pulse sequence, and fat detection techniques.Breathhold imaging is one of the essential techniques in renal mass MRI protocols. Suspended expiration eliminates respiratory motion artifacts an...

To achieve consistent contrast enhancement during pulmonary CT angiography, the amount of contrast medium can be adjusted to the patient's body weight.

Objective. Lipoma arborescens (diffuse articular lipomatosis) is a rare intra-articular lesion consisting of subsynovial villous proliferation of mature fat cells. The usual clinical presentation is painless swelling. The aim of this series was to emphasize the importance of gray scale and color Doppler sonography through the investigation of chronic joint swelling. Methods. Lipoma arborescens of the knee and extensor digitorum longus tendon sheath at the ankle region are described. The latter is extremely rare. We examined 2 patients with sonography before using cross-sectional modalities. Results. Gray scale sonography revealed hyperechoic irregular villous and frondlike projections within prominent joint effusion. A wavelike motion of the projections was shown by dynamic compression and manipulation of the effusion. We observed moderate vascularity on color Doppler sonography. Spectral analysis revealed a low-resistance arterial waveform. Conclusions. Gray scale sonography is a useful diagnostic modality that can be performed to evaluate chronic joint swelling before the use of cross-sectional and more expensive modalities.

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The aim of this retrospective study was to evaluate the diagnostic value of mean platelet volume (MPV) and D-dimer for acute deep venous thromboembolism (DVT). Two hundred and fifty six patients who presented to the emergency or cardiovascular surgery department with suspected lower limb DVT were retrospectively recruited. Plasma levels of MPV, platelet count, and D-dimer were obtained and duplex sonography examination was performed for all patients. Eighty four patients had acute DVT which was diagnosed by duplex ultrasonography. MPV was significantly higher in patients with DVT than in those without DVT (p < 0.01). The mean MPV was 7.97 ± 17.8 and 7.58 ± 0.87 fL in patients with DVT and without DVT, respectively (p < 0.01). D-dimer was significantly higher in patients with DVT (p < 0.01). For all the patients, a positive MPV when the cut-off value was 7.3 fL, had 69.7 % sensitivity and 43.9 % specificity. D-dimer (with a cut-off value of 0.5 μg/mL) had 82.9 % sensitivity and 32.7 % specificity. In case of combination of MPV and D-dimer, the specificity exceeded (65.9 %) despite the reduction in sensitivity (59.2 %). Elevated MPV was found to be associated with acute DVT and high levels of MPV might increase the specificity of D-dimer for exclusion of DVT.

The RI is insensitive for detection of obstruction in patients with acute renal colic, and its value in routine practice seems quite controversial.

Late-phase PIHI is a useful technique for characterizing hepatic lesions and demonstrating both a greater number of and smaller metastases. It may help to differentiate benign from malignant liver masses and may obviate unnecessary and expensive further imaging.

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