Keywords:
Obstruction / Occlusion, Imaging sequences, MR-Diffusion/Perfusion, MR, Kidney, Abdomen
Authors:
O. T. Kalayci1, M. Apaydin2, F. Sonmezgoz3, S. Calık4, M. Koruyucu1; 1İzmir/TR, 2IZMIR/TR, 3Malatya/TR, 4Elazıg/TR
DOI:
10.1594/ecr2013/C-1990
Methods and Materials
Forty-one patients with hydronephrotic kidneys,
26 patients (20 male and 6 female; mean age,
58; age range,
24-90 years old) with benign etiology and 15 patient (10 male and 5 female; mean age,
62; age range 21-80 years old) with malign etiology and 26 healthy volunteers (8 male and 21 female; mean age 49; age range,
27–65 years old) who had no history of renal disease and had normal creatine level (0.7±0.12) were included in this study.
Seven of 26 patients with benign etiology and seven of 15 patients with malignancy,
had bilateral hydronephrosis.
Therefore fifty-five kidneys of 41 patients and fifty-two kidneys of 26 healthy volunteers underwent MRI.
Thirty-three kidneys of obstructive uropathy with benign etiology were consist of benign prostatic hyperplasia (n=10); ureter stone (n=5); narrowness of ureter (n=8); nephrolithiasis (n=8); retroperitoneal fibrosis (n=2).
The twenty-two kidneys of obstructive uropathy with malignant etiology were consist of bladder cancers (n=9); colon cancers (n=2); cervical cancers (n=3); uterine cancers (n=1); prostate cancers (n=1); retroperitoneal tumors (n=2) and pelvic tumors (n=4).
All volunteers were consist of hepatic hemangioma patients with upper abdominal MRI study.
Serum creatinine values were obtained from all patients on the day of the MR examination.
The local ethics committee approved the study protocol,
and informed consent was obtained from all volunteers and patients.
MR imaging was performed using with a 1.5T whole–body superconducting MR scanner (General Electric signa hi–speed scanner,
Milwaukee,
WI,
USA) equipment with hi–speed gradients.
Body coil was used for all images.
Axial T2–weighted fat saturation spin–echo images (TE:90,
TR:5700,
slice thickness 8 mm,
intersection gap 1.5,
number of excitation 4,
matrix size,
512 x 512) were obtained in all patients for demonstration of pelvicalyceal system.
DWIs (TE:72,
TR:8000,
FOV:30x30,
slice thickness:5 mm,
intersection gap:0,
number of excitation:1,
matrix size:128 x 128) were obtained using single–shot spin–echo,
echo–planar imaging (EPI) sequences with the following diffusion gradient b values: 100,
600,
1000 s/mm2.
Obtained maximum slice 26–40,
examination time 30 s,
direction of diffusion all.
All images were obtained without breath–holding.
The DWI data were transferred to workstation (Advantege Windows,
software version 2.0,
GE Medical systems).
A large circular region of interests (ROI) were placed in the corticomedullar junction for the measurement of ADC values normal and obstructed kidneys (Fig.
1).
For each kidney,
three ROIs were placed middle portion of the kidneys and mean ADC values with standard deviations were calculated.
ADC maps were calculated automatically with the MR system.
Statistical analysis was performed with the SPSS 12.0 software packages program.
The ADC values of the volunteers and patients with obstructed uropathy are reported as the mean ±standard deviation.
Independent samples t test was used for the comparison of paranchymal ADC values of the normal kidneys and the obstructed kidneys which had benign and malign ethiology .
A p value of less than .05 was considered to indicate a statistically significant difference.