Diffusion weighted magnetic resonance imaging in renal masses.

INTRODUCTION : Renal cell carcinoma is a common urological cancer. Patients usually presents with loin pain and haematuria. CT and MRI are the two important investigations that are available to diagnose and stage renal masses. The density of a renal mass and its intensity on unenhanced imaging and the presence of enhancement after contrast administration has been used to determine the nature of renal masses. In case of a cystic renal mass, the Bosniak classification uses the CT or MR imaging appearances and it stratifies the risk of malignancy associated with the renal cyst. In the recent times ,contrast CT has been used to differentiate clear cell renal cancer from papillary renal cell cancer in which the later usually has a homogenous appearance whereas the former has a heterodense appearance . Inspite of these investigations there are no imaging techniques that easily differentiate the benign renal mass from the malignant which is shown by the fact that about 20% of nephrectomies are done on benign lesions .Therefore, preoperative imaging studies would play an important diagnostic role if they could be used to precisely differentiate between the two categories of renal masses. Diffusion weighted MRI is being used in neuroradiology for the diagnosis of differentiation between the benign and malignant tissue. The diffusion of molecules within the cell follows Brownian movement. The highly cellular malignant tissue has restricted diffusion and the benign lesions have a high diffusion coefficient. The restricted diffusion images have a low ADC value and the benign lesions have high ADC value. AIM OF THE STUDY : To predict the histopathological nature of renal masses by using Diffusion weighted Magnetic Resonance Imaging (DW MRI). To study the correlation of DW MRI findings with clinical, radiological and pathological findings. MATERIALS AND METHODS : Informed consent obtained from all the patients after explaining details of the study. All details were recorded in a proforma as an inpatient procedure. Analysis was done with the collected details prospectively. All cases of renal masses will be evaluated by clinical examination, renal function tests, S.calcium , E.S.R , Complete haemogram ,LFT, CXR, imaging studies in the form of USG with Doppler / CECT KUB. Inclusion Criteria: All newly diagnosed cases of renal masses. Exclusion Criteria: 1. Patients with Renal masses less than 2 cm. 2. Previously received chemotherapy or radiotherapy for renal masses. 3. Prior diagnosis of TCC pelvis. CONCLUSION : In conclusion, our study states that Diffusion weighted MR imaging can be used in the management of renal masses, more so to differentiate between benign mass lesions from renal cell cancer. The histologic subtype of RCC can be diagnosed pre op from the ADC values and can guide targeted therapy. It also establishes the grade of the tumor in clear cell RCC thereby prognosis of the disease is known. When the use of contrast is contraindicated, such as gadolinium, there is a role for DWI in the diagnosis of malignant renal masses