Diffusion-Weighted MR Imaging of Benign and Malignant Breast Lesions Before and After Contrast Enhancement

Abstract

Mamma 130Janka R et al. 50, 400 und 800) wurde vor und nach KM-Gabe gemessen und die entsprechenden ADC-Werte der Läsionen verglichen. Vor der Berechnung der ADC-Werte wurden die Läsionen bezüglich ihrer konstanten Lokalisation in den diffusionsgewichteten Sequenzen analysiert. Ergebnisse: Die mittlere Größe der Läsionen war 1,5 ± 0,8 cm. Auf der Basis der b50-und b400-Messung betrug der durchschnittliche ADC-Wert der benignen Läsionen 1,89 ± 0,30 × 10 -3 mm 2 /s vor und 1,85 ± 0,28 × 10 -3 mm 2 /s nach KM-Gabe. Die entsprechenden Werte für zwei muzinöse Karzinome betrugen 1,88 × 10 -3 mm 2 /s und 1,81 × 10 3 mm 2 /s und für die übrigen malignen Läsionen 1,00 ± 0,18 × 10 -3 mm 2 /s und 0,88 ± 0,21 × 10 -3 mm 2 . Auf der Basis der b50-, b400-und b800-Messung betrug der durchschnittliche ADC-Wert der benignen Läsionen 1,99 ± 0,37 × 10 -3 mm 2 /s vor und 1,97 ± 0,30 × 10 -3 mm 2 /s nach KM-Gabe. Der mittlere ADC-Wert der malignen Läsionen betrug 0,90 ± 0,14 × 10 -3 mm 2 /s vor und 0,80 ± 0,14 × 10 -3 mm 2 /s nach KM-Gabe. Während der ADC-Wert der gutartigen Läsionen durch das Kontrastmittel nicht signifikant beinflusst wurde, war er bei den malignen Läsionen nach Kontrastmittelgabe signifikant niedriger. Abstract !Purpose: Many publications describe the use of diffusion-weighted imaging (DWI) in breast MRI. This article addresses the question of when to apply the DWI sequence in the course of the scan protocol. The effect of T1-shortening contrast media (CM) on the ADC values of breast lesions is investigated. Materials and Methods: Data were acquired on a 1.5 T scanner. 60 patients with 79 lesions (20 benign, 59 malignant) were included. The DWI sequence (4 mm slice thickness, b-values: 50, 400, 800) was applied before and after CM administration. Before calculating the ADC map, the b50, b400 and b800 series were analyzed concerning lesion displacement. ADC values before and after CM application were compared.

Effect of gadolinium injection on diffusion-weighted imaging with background body signal suppression (DWIBS) imaging of breast lesions

“…The twenty false positive cases among lesions with an ADC value of less than 1.44 × 10 -3 mm 2 /s occurred in our series could be explained by the presence of benign nodules with a predominant fibrous component or other benign conditions characterized by inflammatory changes, such as complicated cysts showing low ADC values, probably due to high cellularity, fibrosis, leukocytes, chronic inflammatory elements, as already reported in other series [17,20,25]. On the other side, the two false negative cases among lesions with ADC values of more than 1.44 × 10 -3 mm 2 /s occurred in our series are probably due to the presence of low cellularity breast tumors, such as mucinous forms [22,30].…”

“…Also in the case of breast lesions, the mean ADC values decreased after CMI in benign and malignant lesions probably due to the decrease of micro-perfusion induced by contrast material, especially in hyper-vascular lesions such as malignant tumors [22]. In fact, ADC values depend not only on Brownian motion of molecules but also on capillary blood circulation.…”

“…By using DW SE-EPI fs pulse sequences before and after the injection of gadobutrol, they found no significant difference for benign lesions and a highly significant ADC value decrease in post-contrast malignant lesions. However, with the exception of mucinous tumors, no overlap between ADC values of benign and malignant lesions in pre-or post-CMI DWI sequences occurred [22,[32][33][34][35][36]. Moreover, the difference between the highest ADC value of malignant lesions and the lowest ADC value of the benign lesions increased by using b 50, b 400 and b 800 for calculating the ADC map and allowed a more accurate differential diagnosis between benign and malignant lesions [22].…”

“…However, the question of when to apply the DWI sequence in the course of the scan protocol has been recently addressed and the effect of gadolinium injection on diffusion-weighted spin-echo EPI with fat saturation (DW SE-EPI fs) has been investigated concluding that DWI after contrast material injection (CMI) is possible and even leads to slightly better breast lesion discrimination between benign and malignant [22].…”

Fast and Noninvasive Characterization of Suspicious Lesions Detected at Breast Cancer X-Ray Screening: Capability of Diffusion-weighted MR Imaging with MIPs

“…In patients with known breast cancer and clinically suspicious findings, DW imaging has been shown to be of high value in discriminating malignant from benign lesions (8,(16)(17)(18)(19)(20)(21). It has been suggested that DWIBS displays breast lesions even better than DW imaging (9,10), because the background suppression makes breast lesions more conspicuous.…”