Differentiation of noncancerous tissue and cancer lesions by apparent diffusion coefficient values in transition and peripheral zones of the prostate

Abstract

Purpose:To compare the apparent diffusion coefficient (ADC) values of prostate cancer in both the peripheral zone (PZ) and the transition zone (TZ) with those of benign tissue in the same zone using echo-planar diffusion weighted imaging with a parallel imaging technique. Materials and Methods:A total of 29 consecutive male patients (mean age 61.3 years, age range 53-88 years) with suspected prostate cancer were referred for MR imaging. All patients underwent transrectal ultrasound (TRUS)-guided biopsy of the prostate after MR imaging at 1.5 T, including ADC. For each patient, seven to 10 specimens were obtained from the prostate, and regions of interest (ROIs) were drawn on the ADC map by referring to the urologist's illustration of TRUSguided biopsy sites. ADC values of cancerous tissue in both the PZ and TZ were compared to those of noncancerous tissue in the same zone. Results:Out of 29 patients, 23 had cancer tissue. In the 23 patients with cancer, the mean ADC value of all cancer ROIs and that of all noncancer ROIs, respectively, were 1.11 Ϯ 0.41 ϫ 10 -3 and 1.68 Ϯ 0.40 ϫ 10 -3 mm 2 /second (values are mean Ϯ SD) (P Ͻ 0.01). The mean ADC value of TZ cancer ROIs and that of TZ noncancer ROIs, respectively, were 1.13 Ϯ 0.42 ϫ 10 -3 and 1.58 Ϯ 0.37 ϫ 10 -3 mm 2 /second (P Ͻ 0.01).Conclusions: ADC measurement with a parallel imaging technique showed that ADC values of prostate cancer in both the PZ and TZ were significantly lower than those of benign tissue in the PZ and TZ, respectively.

Apparent diffusion coefficient: Prostate cancer versus noncancerous tissue according to anatomical region

“…Most studies have conducted a simple comparison of ADC between prostate cancer and adjacent noncancerous tissue (16 -19). Studies that compared the ADC in the nonprostatic tissues divided the prostate into peripheral and central glands or into peripheral and transitional zones but did not consider the ADC in the prostatic base (12)(13)(14)(15)20,21). However, our results suggest that the prostatic base may be the most confusing region in which to differentiate prostate cancer from noncancerous tissue.…”

“…However, investigators have also suggested the wide variability of ADC in noncancerous tissue, which causes a considerable overlap of ADC between cancer and noncancerous tissue (12)(13)(14)(15). As the microscopic structure of the prostate varies according to the anatomical compartment, we suggest that structural variability by anatomical region may cause a wide range of ADC in the prostate.…”

Apparent diffusion coefficient values in peripheral and transition zones of the prostate: Comparison between normal and malignant prostatic tissues and correlation with histologic grade

“…DWI is used clinically for the evaluation of strokes, brain infections, and tumors, and now also has clinical applications in body imaging due to recent improvements in MRI technology, such as high-performance gradient coils, parallel imaging techniques, and phased-array receiver coils (16,25).…”

“…In recent years, the utility of diffusion-weighted imaging (DWI) in the diagnosis of prostate cancer has been reported in a number of preliminary studies, leading to high expectations for clinical applications as an additional method to T2-weighted imaging, dynamic MR studies, and MR spectroscopic imaging (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). However, all of these studies have focused on comparisons between cancer and normal regions in prostate cancer patients and limited cases of healthy individuals.…”

Diffusion‐weighted images differentiate benign from malignant thyroid nodules

“…Prostate cancer is one of the most investigated tumors by DWI. A recent study showed that there was a significant difference in the ADC values between cancerous and noncancerous tissues of the prostate (24).…”