Role of MR imaging in diagnosis and staging of renal cell carcinoma

Twenty sex patients with renal masses diagnosed by ultrasonography and/or CT and highly suspected to be renal cell carcinomas, underwent pre-operative MR imaging to assess the value of MR in diagnosis and staging of renal cell carcinoma. Renal lesions in all the studied patients were examined histopathologically and proved to be renal cell carcinomas. Renal ceil carcinoma had a varied MR signal, the most common appearance being a mass with an intensity intermediate between renal cortex and medulla on Tl-weighted images in 15 patients and heterogeneous intensity on T2-weighted images in 16 patients, The renal masses showed enhancement in 23 patients [homogeneous in 4 patients and heterogeneous in 19 patients] and in 3 patients no enhancement was detected on post-contrast Tl -weighted images. MR staging revealed stage I in 12 patients, stage II in 6 patients, stage III in 6 patients [stage IIIa in 3 patients, stage IIIb in 2 patients and stage IIlc in one patient] and stage IV in 2 patients [stage I Va in one patient and stage IVb in one patient]. Accurate MR staging detected in 23 patients [88% accuracy], in the other 3 patients, the MR stage changed by surgical and pathological findings from stage I into stage II in 2 patients [due to presence of microscopic perinephric fat involvement] and from stage IIlb into stage II in one patient [because of the enlargement of the para-aortic lymph node was found to be reactive, no malignant infiltration detected in the lymph node], MRI showed venous invasion clearly without need for intravenous contrast medium with 100% sensitivity. MRI is an excellent modality in preoperative evaluation of renal cell carcinoma

Value of MRI in grading of supratentorial diffuse astrocytomas

The present study included 15 patients [8 males and 7 females] with their age ranged from 25 years to 68 years. The MR images in the studied patients with biopsy-proven diffuse ostrocytomas were analyzed in order to demonstrate which MRI features of gliomas that correlate with the histopathologically determined tumor grade. According to the histopathological diagnosis, 3 patients had grade II astrocytomas, 5 patients had grade III astrocytomas and 7 patients had glioblastoma multiformes [GBMs]. The MRI features studied included tumor heterogeneity, edema, mass effect, border sharpness, contrast enhancement, hemorrhage and the presence of flow voids. Contrast enhancement was found to be the best predictor of histological grade followed by necrosis, signal heterogeneity and border sharpness. Hemorrhage, flow void and necrosis were common in the GBM group and were absent in grade II astrocytoma group. In particular, flow void was found only in GBM [n=3 patients], hemorrhage was present in GBM [n= 3 patients] and in grade III astrocytoma [one patient]. Necrosis was found in all 7 GBM cases and in 5 patients with histological diagnosis of anaplastic astrocytoma [grade III astrocytoma]. No areas of necrosis detected in grade II astrocytoma [3 patients]. All GBM cases [n = 7] showed grade 3 edema [larger than the tumor volume], marked and heterogeneous enhancement, midline shift and heterogeneous signal intensity on both Tl-W and T2-W images. In grade III astrocytomas [n = 5 patients], there is edema of grade 2 [less than the tumor volume], moderate contrast enhancement, midline shift and heterogeneous signal intensity on T2-W images. In grade II astrocytomas [n = 3 patients], there is edema of grade 1 [none-to mild], subarachnoid space effacement, none- to mild contrast enhancement and homogeneous signal intensity. The frontal lobe was the most commonly affected lobe, frontal gliomas were present in 9 patients, fronto-parietal gliomas in 4 patients and fronto-temporal gliomas in 2 patients. In conclusion, all MRI features can help to distinguish the pathological grade of diffuse astrocytic tumours and help in planning treatment strategies

CT angiography versus intra - arteiral digital subtraction angiography in eyaluation of potential living kidney donors

The present study included 50 living kidney donors [22 males and 28 females] with their age ranged from 21 years to 55 years. The objective of this work is to study the renovascular anatomy of the potential living kidney donors by CT angiography and to compare CT angiography and IA-DSA in evaluation of the number and location of the donor's renal arteries and in identification of major renal vascular abnormalities that may preclude safe renal donation. Single renal arteries were detected by CT angiography in 34 donors and double renal arteries were diagnosed in 11 donors. Single renal arteries were diagnosed in 35 donors and double renal arteries in 10 donors by IA-DS aortography. Single renal arteries were detected in 33 donors and double renal arteries in 12 donors by IA-selective renal angiography, At nephrectomy, 32 donors had single renal arteries, 12 donors had double renal arteries and one donor had triple renal arteries. 5 donors were excluded from donation, 3 donors had viral hepatitis and 2 donors had diabetes mellitus. CT angiography had similar sensitivity [100%] and better specificity [81.2%] than IA-DS aortography [76.4%]. However, in equivocal and indeterminate cases selective renal angiography is recommended for better assessment, accuracy 95.5% versus 93.3%-for CT angiography