Understanding and Interpreting MRI of the Genitourinary Tract

Differentiating solid, non-macroscopic fat containing, enhancing renal masses using fast Fourier transform analysis of multiphase CT

OBJECTIVE

To test the feasibility of two-dimensional fast Fourier transforms (FFT)-based imaging metrics in differentiating solid, non-macroscopic fat containing, enhancing renal masses using contrast-enhanced CT images. We quantify image-based intratumoral textural variations (indicator of tumor heterogeneity) using frequency-based (FFT) imaging metrics.

METHODS

In this Institutional Review Board approved, Health Insurance Portability and Accountability Act -compliant, retrospective case-control study, we evaluated 156 patients with predominantly solid, non-macroscopic fat containing, enhancing renal masses identified between June 2009 and June 2016. 110 cases (70%) were malignant RCC, including clear cell, papillary and chromophobe subtypes and, 46 cases (30%) were benign renal masses: oncocytoma and lipid-poor angiomyolipoma. Whole lesions were manually segmented using Synapse 3D (Fujifilm, CT) and co-registered from the multiphase CT acquisitions for each tumor. Pathological diagnosis of all tumors was obtained following surgical resection. Matlab function, FFT2 was used to perform the image to frequency transformation.

RESULTS

A Wilcoxon rank sum test showed that FFT-based metrics were significantly (p < 0.005) different between 1. benign vs malignant renal masses, 2. oncocytoma vs clear cell renal cell carcinoma and 3. oncocytoma vs lipid-poor angiomyolipoma. Receiver operator characteristics analysis revealed reasonable discrimination (area under the curve >0.7, p < 0.05) within these three groups of comparisons.

CONCLUSION

In combination with other metrics, FFT-metrics may improve patient management and potentially help differentiate other renal tumors. Advances in knowledge: We report for the first time that FFT-based metrics can differentiate between some solid, non-macroscopic fat containing, enhancing renal masses using their contrast-enhanced CT data.

Rare cause of adult female incontinence: complete duplication of the collecting system and ectopic ureter of the kidney draining into the vagina treated by laparoscopic upper pole heminephrectomy and ureterectomy

A 38-year-old woman presented with a lifelong history of involuntary urinary leakage. The patient reported that she had been operated for her urinary leakage with the diagnosis of stress incontinence with transobturator tape two times at two different institutions. Preoperative computed tomography scan showed complete duplication of the left kidney with poorly functioning upper pole and a tortuous left dilated ureter running down and opening into the vagina. Laparoscopic left upper pole heminephrectomy and ureterectomy were performed uneventfully. Her incontinence improved immediately after surgery.

Renal dysplasia with single system ectopic ureter: Diagnosis using magnetic resonance urography and management with laparoscopic nephroureterectomy in pediatric age

Single system ureteral ectopia and associated congenital dysplastic kidney is surgically curable etiology of incontinence with other wise normal pattern of voiding in female child. We share our experience of eight cases in last one year and its management with laparoscopic nephroureterectomy at a tertiary care hospital in India which is one of the largest series in such a short duration of this rare anomaly.

Role of magnetic resonance urography in the diagnosis of single-system ureteral ectopia with congenital renal dysplasia: a tertiary care center experience in India

OBJECTIVE

The purpose of this article is to study the role of magnetic resonance urography (MRU) in single-system ureteral ectopia with congenital renal dysplasia in children.

MATERIALS AND METHODS

Patients of incontinence with an otherwise normal voiding pattern were investigated by MRU and conventional radiology. All the patients underwent laparoscopic nephroureterectomy after MRU.

RESULTS

Magnetic resonance urography picked up the dysplastic moieties and their location as well as functional status and also depicted the course of the ectopic ureter in all the 7 patients.

CONCLUSION

Magnetic resonance urography is the better method of investigation for the diagnosis of this condition than conventional radiologic investigations and renal scan.