Department of Radiology, Sisli Etfal Training and Research Hospital, 34360 Sisli, Istanbul, Turkey.
Clin Imaging. 2013 Nov-Dec;37(6):1077-83. doi: 10.1016/j.clinimag.2013.04.012. Epub 2013 Jul 30.
The purposes of our study were to investigate the feasibility of diffusion-weighted imaging in the detection of malignant bladder tumors, with comparison to the high-resolution thin-section fast spin-echo (FSE) T2-weighted MRI, and also to compare the apparent diffusion coefficient (ADC) values of the bladder tumors with the surrounding structures.
Fifty-three consecutive patients consisting of 44 males and 9 females who presented with a bladder mass were prospectively enrolled in this study. Mean age was 62.53 ± 12.03 (age range, 33-86 years). These patients were evaluated by high-resolution thin-section FSE T2-weighted and diffusion-weighted MRI for the detection of bladder masses. Following MRI, within 2 weeks, all patients were subjected to either surgery or cystoscopic biopsy, and the obtained histopathological proofs were used as the reference standard. Furthermore, ADC values of the bladder tumors, urine, the normal bladder wall, the central and peripheral zones of the prostate, the seminal vesicule, and the uterus outer myometrium were also calculated. ADC values of the bladder carcinomas and the related surrounding structures were compared as to whether a statistically significant difference was present or not.
In a total of 47 patients, consisting of 39 males and 8 females, bladder carcinomas were clearly shown as having conspicuous high and intermediate signal intensity masses, relative to the surrounding structures on diffusion-weighted and T2-weighted images, respectively. An 89% sensitivity and a 100% positive predictive value were obtained for both FSE T2-weighted and diffusion-weighted MRI in the diagnosis of bladder carcinoma. Mean ADC values and standard deviations of the bladder tumors and the surrounding structures were as follows: bladder carcinomas (n=47): 1.28 ± 0.31, normal bladder wall (n=47): 1.98 ± 0.41, urine (n=47): 3.12 ± 0.24, seminal vesicle (n=39): 1.82 ± 0.33, peripheral zone of prostate (n=39): 1.80 ± 0.29, central zone of prostate (n=39): 1.55 ± 0.33, and uterus outer myometrium (n=8): 1.53 ± 0.19. It can be clearly seen that the mean ADC values of the bladder carcinomas were significantly lower than the surrounding structures (P<.05).
High-resolution thin-section FSE T2 and diffusion-weighted MRI show high diagnostic performance and are comparable in the detection of bladder tumors. Diffusion-weighted MRI provides high quality images of the malignant bladder tumors against a suppressed background signal. Diffusion-weighted MRI using ADC measurements may be useful in the evaluation of tumor invasion to the adjacent organs.
本研究旨在探讨扩散加权成像在检测恶性膀胱肿瘤中的可行性，并与高分辨率薄层快速自旋回波（FSE）T2 加权 MRI 进行比较，同时比较膀胱肿瘤与周围结构的表观扩散系数（ADC）值。
连续纳入 53 例男性 44 例，女性 9 例，均表现为膀胱肿块。平均年龄 62.53±12.03（年龄范围 33-86 岁）。这些患者均接受高分辨率薄层 FSE T2 加权和扩散加权 MRI 检查以检测膀胱肿块。MRI 后 2 周内，所有患者均行手术或膀胱镜活检，以获得的组织病理学结果作为参考标准。此外，还计算了膀胱肿瘤、尿液、正常膀胱壁、前列腺中央区和外周区、精囊和子宫外肌层的 ADC 值。比较了膀胱癌及其相关周围结构的 ADC 值，以确定是否存在统计学差异。
在总共 47 例患者中，男性 39 例，女性 8 例，在扩散加权和 T2 加权图像上，膀胱癌均清晰显示为具有明显高信号和中等信号的肿块，相对于周围结构。FSE T2 加权和扩散加权 MRI 对膀胱癌的诊断敏感性分别为 89%和 100%，阳性预测值均为 100%。膀胱肿瘤及其周围结构的平均 ADC 值和标准差如下：膀胱癌（n=47）：1.28±0.31，正常膀胱壁（n=47）：1.98±0.41，尿液（n=47）：3.12±0.24，精囊（n=39）：1.82±0.33，前列腺外周区（n=39）：1.80±0.29，前列腺中央区（n=39）：1.55±0.33，子宫外肌层（n=8）：1.53±0.19。可以清楚地看到，膀胱癌的平均 ADC 值明显低于周围结构（P<.05）。
高分辨率薄层 FSE T2 和扩散加权 MRI 显示出较高的诊断性能，在检测膀胱肿瘤方面具有可比性。扩散加权 MRI 可提供高质量的恶性膀胱肿瘤图像，背景信号抑制良好。使用 ADC 测量值的扩散加权 MRI 可能有助于评估肿瘤对邻近器官的侵犯。
