Evaluation of locally recurrent pelvic malignancy: Performance of T2‐ and diffusion‐weighted MRI with image fusion

Abstract

Purpose:To evaluate the performance of T2-and diffusionweighted magnetic resonance imaging (MRI) with image fusion for detection of locally recurrent pelvic malignancy. Materials and Methods:The study group consisted of 28 patients (27 female, 1 male) who underwent pelvic MRI at 1.5 T after treatment of pelvic malignancy. MR images were reviewed independently by three blinded readers. The performance of the four sequences for detecting local recurrence was evaluated using receiver operating characteristic analysis: T2-weighted fast spin-echo (FSE), diffusionweighted echo-planar imaging (DWI), dynamic contrast-enhanced (DCE) fat-suppressed T1-weighted spoiled gradient echo (SPGR), and T2-DWI with image fusion, the latter created using OsiriX Medical Imaging Software.Results: Local recurrence was confirmed at biopsy in 16 patients. Twelve patients showed no evidence of recurrence on two consecutive MRI studies. The Az value for T2-DWI with image fusion (0.949) was statistically greater than that for T2-weighted FSE (0.849) (P Ͻ 0.05). The sensitivity and specificity was 87.5% and 47.2%, respectively, for T2-weighted FSE, 100.0% and 50.0% for DWI, 95.8% and 58.3% for DCE fat-suppressed T1-weighted SPGR, and 93.8% and 72.2% for T2-DWI with image fusion. Conclusion:For depicting locally recurrent pelvic malignancy, T2-DWI with image fusion outperforms standard T2-weighted FSE and DWI and is comparable to DCE fatsuppressed T1-weighted SPGR.

Usefulness of diffusion-weighted MR imaging in the evaluation of pulmonary lesions

“…However, such an approach limits the acquisition time and, consequently, both the signal-to-noise ratio (SNR) and the spatial resolution are compromised. Therefore, in this study, a single-shot echo-planar imaging sequence with a relatively high b value and free breathing was used for DWI, as free breathing DWI offers thinner slices, increased anatomical coverage, and higher SNR compared with breath-hold DWI [13]. Additionally, a phase array coil and ASSET were used, which offered improvements in image quality and speed.…”

Prostate cancer: Utility of fusion of T2‐weighted and high b‐value diffusion‐weighted images for peripheral zone tumor detection and localization

“…One possible technique to improve the anatomic localization of findings identified on high bvalue DWI is to perform fusion of these images with T2WI. Indeed, higher accuracy has been shown for the detection of locally recurrent pelvic malignancy (13) and of abdominal malignancy (14) when using fusion of T2WI and DWI compared with the use of these two image sets in a separate manner. However, to our knowledge, no previous study has evaluated fusion of T2WI and high b-value DWI for prostate cancer detection.…”

MR/CT image fusion of the spine after spondylodesis: a feasibility study

“…Although anterolisthesis is present between L5 and S1, the intervertebral nerve root is neither compressed nor irritated by metal or osseous structures, as shown by the MR (b) and fused images (c). Important information from both modalities is combined on one image (c) algorithm of the fusion software that works better with fewer registration points [12][13][14][15]22]. Although diagnostic information of CT and MR were combined on one image, we assume that fused images are not superior to MR and CT alone when considering diagnostic accuracy.…”