Non-invasive quantification of tumour heterogeneity in water diffusivity to differentiate malignant from benign tissues of urinary bladder: a phase I study

Abstract

Objectives To quantify the heterogeneity of the tumour apparent diffusion coefficient (ADC) using voxel-based analysis to differentiate malignancy from benign wall thickening of the urinary bladder. Methods Nineteen patients with histopathological findings of their cystectomy specimen were included. A data set of voxel-based ADC values was acquired for each patient’s lesion. Histogram analysis was performed on each data set to calculate uniformity (U) and entropy (E). The k-means clustering of the voxel-wised ADC data set was implemented to measure mean intra-cluster distance (MICD) and largest inter-cluster distance (LICD). Subsequently, U, E, MICD, and LICD for malignant tumours were compared with those for benign lesions using a two-sample t-test. Results Eleven patients had pathological confirmation of malignancy and eight with benign wall thickening. Histogram analysis showed that malignant tumours had a significantly higher degree of ADC heterogeneity with lower U (P = 0.016) and higher E (P = 0.005) than benign lesions. In agreement with these findings, k-means clustering of voxel-wise ADC indicated that bladder malignancy presented with significantly higher MICD (P < 0.001) and higher LICD (P = 0.002) than benign wall thickening. Conclusions The quantitative assessment of tumour diffusion heterogeneity using voxel-based ADC analysis has the potential to become a non-invasive tool to distinguish malignant from benign tissues of urinary bladder cancer.

Histogram analysis of dynamic contrast-enhanced magnetic resonance imaging for differentiating malignant from benign orbital lymphproliferative disorders

“…Heterogeneity is an intrinsic characteristic of tumors; accurate assessment of tumor heterogeneity was of high clinical importance for tumor diagnosis, prognosis prediction, and treatment monitor (9–11). In our study, compared with mean k ep , 90th k ep showed better diagnostic efficiency and might be the independent differentiating variable for malignant OLPDs.…”

“…However, only the mean value of the pharmacokinetic parameters was used as the differentiating metric, which would underestimate the heterogeneity of the tumors. Heterogeneity is an intrinsic characteristic of tumors, which makes tumor tissue different from normal tissue (9). Previous studies have indicated that assessment of tumor heterogeneity was very crucial for tumor diagnosis, prognosis prediction, and treatment monitor (9)(10)(11).…”

Rectal Cancer Invasiveness: Whole-Lesion Diffusion-Weighted Imaging (DWI) Histogram Analysis by Comparison of Reduced Field-of-View and Conventional DWI Techniques

“…While many studies reported mean ADC values from single slice-based ROIs, whole-lesion histogram analysis of ADC maps has been increasingly recognized for quantitative evaluation of intratumoral heterogeneity and tissue characteristics. One intrinsic feature of tumors is characterized by heterogeneity, which makes tumor tissue distinguished from normal tissue 26 . The whole-lesion method may better capture heterogeneous tumor areas with various diffusion characteristics demonstrated in the histogram and potential selective sampling bias could be decreased by measurement of whole tumor volumes 27 .…”

Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Staging of Bladder Cancer

“…Во многих исследованиях доказано, что данные методики визуализации следует относить к функциональным, то есть отражающим метаболизм и структуру опухоли [16,17]. Их объединяет возможность оценить опухоль и подлежащие структуры не только с помощью качественных критериев, но и количественных.…”

“…В частности, с помощью ДКУ можно оценить микроциркуляцию (васкуляризацию и проницаемость), а с помощью ДВИ -диффузию протонов водорода. Оценка диффузии подразумевает уточнение степени свободы межклеточной жидкости и соответственно -плотности расположения клеток (клеточность, целлюлярность) [17]. Ограничение диффузии свойственно для опухолевой ткани, характеризующейся высокой клеточностью.…”