Diffusion weighted imaging in the detection of upper urinary tract urothelial tumors

Abstract

Purpose: Diffusion-weighted (DW) magnetic resonance imaging (MRI) provides information about the biophysical properties of tissues such as cell organization and density. DW imaging (DWI) is becoming important in the assessment of malignant tumors. The purpose of our study was to evaluate the capability and reliability of DWI in the evaluation of upper urinary tract urothelial tumors. Materials and Methods: DWI was performed in seventeen patients with upper urinary tract urothelial tumor, previously diagnosed by either CT or retrograde pyelography. An histological evaluation was performed after surgical resection. Each MRI was carried out using a 1.5T superconductive magnet MRI system. DWI images were obtained with b value of 1000 s/mm 2 under normal breathing. The apparent diffusion coefficient (ADC) values were measured. Results: In nine patients with renal pelvis tumors and seven patients with ureteral tumors, the lesions were shown as high-signal intensity in the corresponding region on DWI. In one patient with carcinoma in situ (CIS) of the ureter, the lesion was not depicted with DWI. The mean ADC value of the tumor was 1.125 ± 0.217 x 10 -3 mm 2 /s and was significantly lower than those of the renal parenchyma (1.984 ± 0.238 x 10 -3 mm 2 /s, p < 0.01) and the urine (2.941 ± 0.315 x 10 -3 mm 2 /s, p < 0.01). Conclusions: In our study, the renal pelvic and ureteral tumors except CIS were shown clearly with DWI. Although further studies are required, DWI may take the place of invasive retrograde urography for detecting tumors of the upper urinary tract.

Multidetector CT imaging features of invasive renal parenchyma urothelial carcinoma

“…6 Although upper tract infiltrating urothelial carcinomas have been relatively well described in pathology and imaging studies, IRPUC is scanty. 7,8 Some imaging features have been reported, such as infiltrative growth 9 and cystic component. However, some imaging features remain uncertain or contradictory, such as tumour location, capsule sign, calcification and enhancement pattern.…”

The usefulness of diffusion-weighted magnetic resonance imaging in bladder cancer staging and functional analysis

“…[11] DW-MRI is used in several urological malignancies, such as prostate cancer, upper urinary tract cancer, and kidney cancer. [12,13] In bladder cancer, several studies have shown that the accuracy of T staging with DW-MRI exceeds that of conventional methods. [2,[4][5][6] We also showed that DW-MRI provides significant additional information for the T staging of bladder cancer.…”

Role of diffusion‐weighted magnetic resonance imaging as an imaging biomarker of urothelial carcinoma

“…Since that report, several studies have reported on the application of DW‐MRI in the management of UTUC, consistently showing excellent diagnostic performance (Table ) . In retrospective studies including patients with known UTUC cancers, the sensitivity of DW‐MRI in detecting UTUC was reported to be 88.9–100% .…”