Indeterminate Orbital Masses: Restricted Diffusion at MR Imaging with Echo-planar Diffusion-weighted Imaging Predicts Malignancy

Abstract Aim To determine the role of diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) values in differentiating benign and malignant orbital masses. Materials and Methods After obtaining institutional ethical board approval and informed consent from all patients, an observational study was done for a period of 24 months in the radiology department of a tertiary care hospital in South India. Conventional magnetic resonance imaging and DWI using a 3T scanner was done for all patients with suspected orbital mass lesion. ADC value and clinicohistopathological correlation were studied for every patient. Chi-square test was used to compare the signal characteristics of DWI and ADC maps between benign and malignant lesions. A comparison of mean ADC values for benign and malignant masses was performed using Student’s t-test for independent samples. The cut-off value for ADC was obtained using the receiver operating characteristic (ROC) curve. Results Of 44 patients with orbital lesions, 70% were benign and 30% were malignant. There was a significant difference in the mean ADC values of benign and malignant orbital masses. Using ROC curve analysis, an optimal ADC threshold of 1.26 × 10−3 mm2/s was calculated for the prediction of malignancy with 100% sensitivity, 80.65% specificity, and 86.36% accuracy (95% confidence interval: 0.872, 1.00, p < 0.0001). Two ADC thresholds were used to characterize the orbital masses with more than 90% confidence. Conclusion Quantitative assessment of ADC is a useful noninvasive diagnostic tool for differentiating benign and malignant orbital masses. Malignant orbital lesions demonstrate significantly lower ADC values as compared with benign lesions.

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Comparison between turbo spin-echo and echo planar diffusion-weighted imaging of the female pelvis with 3T MRI

Acta Radiologica Open ◽

10.1177/2058460121994737 ◽

2021 ◽

Vol 10 (2) ◽

pp. 205846012199473

Author(s):

Takeshi Yoshizako ◽

Rika Yoshida ◽

Hiroya Asou ◽

Megumi Nakamura ◽

Hajime Kitagaki

Keyword(s):

Image Quality ◽

Diffusion Weighted Imaging ◽

Spin Echo ◽

Turbo Spin Echo ◽

Female Pelvis ◽

3T Mri ◽

Turbo Spin ◽

Diffusion Weighted ◽

Adc Values ◽

Echo Planar

Background Echo-planar imaging (EPI)-diffusion-weighted imaging (DWI) may take unclear image affected by susceptibility, geometric distortions and chemical shift artifacts. Purpose To compare the image quality and usefulness of EPI-DWI and turbo spin echo (TSE)-DWI in female patients who required imaging of the pelvis. Material and Methods All 57 patients were examined with a 3.0-T MR scanner. Both TSE- and EPI-DWI were performed with b values of 0 and 1000 s/mm2. We compared geometric distortion, the contrast ratio (CR) of the myometrium to the muscle and the apparent diffusion coefficient (ADC) values for the myometrium and lesion. Two radiologists scored the TSE- and EPI-DWI of each patient for qualitative evaluation. Results The mean percent distortion was significantly smaller with TSE- than EPI-DWI ( p = 0.00). The CR was significantly higher with TSE- than EPI-DWI ( p = 0.003). There was a significant difference in the ADC value for the uterus and lesions between the EPI- and TSE-DWI ( p < 0.05). Finally, the ADC values of cancer were significantly different from those for the uterus and benign with both the two sequences ( p < 0.05). The scores for ghosting artifacts were higher with TSE- than EPI-DWI ( p = 0.019). But there were no significant differences between TSE- and EPI-DWI with regard to image contrast and overall image quality. Conclusion TSE-DWI on the female pelvis by 3T MRI produces less distortion and higher CR than EPI-DWI, but there is no difference in contrast and image quality.

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Detection of recurrent hepatocellular carcinoma after surgical resection: Non-contrast liver MR imaging with diffusion-weighted imaging versus gadoxetic acid-enhanced MR imaging

British Journal of Radiology ◽

10.1259/bjr.20180177 ◽

2018 ◽

Vol 91 (1090) ◽

pp. 20180177 ◽

Cited By ~ 3

Author(s):

Ji Hye Min ◽

Young Kon Kim ◽

Seo-Youn Choi ◽

Tae Wook Kang ◽

Woo Kyoung Jeong ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Mr Imaging ◽

Surgical Resection ◽

Diffusion Weighted Imaging ◽

Gadoxetic Acid ◽

Recurrent Hepatocellular Carcinoma ◽

Diffusion Weighted

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Embolic Complications of Endovascular Surgery for Cerebrovascular Diseases Evaluation with Diffusion-Weighted MR Imaging

Interventional Neuroradiology ◽

10.1177/15910199000060s137 ◽

2000 ◽

Vol 6 (1_suppl) ◽

pp. 223-226 ◽

Cited By ~ 5

Author(s):

H. Sakai ◽

N. Sakai ◽

I. Nakahara ◽

T. Shimozuru ◽

T. Higashi ◽

...

Keyword(s):

Mr Imaging ◽

B Value ◽

Cerebrovascular Diseases ◽

Endovascular Surgery ◽

Single Shot ◽

Planar Imaging ◽

Diffusion Weighted ◽

Screening Study ◽

Cerebral Ischemic ◽

Echo Planar

The purpose of this study was to evaluate asymptomatic embolisms during cerebral endovascular surgery for cerebrovascular diseases with diffusion-weighted magnetic resonance imaging (DWI) which allowed sensitive and early detection of cerebral ischemic lesions. 71 patients who underwent a total of 74 cerebral endovascular procedures were subjected to DWI screening study. MR imaging was performed on a 1.5T system by using single-shot SE echo-planar imaging (EPI) with b value of 1100 seconds per mm2 in pre- and post-treatment periods (between day 2 and 5 after procedures). In 38 (51.3%) of 74 procedures, new high intensity lesions, as recent infarctions related to procedures, were detected on post-procedural DWI. In 18 Of the patients (47.4%), symptomatic infarctions occurred and resulted in TIAs (n = 4), RINDs (n = 8), minor strokes (n = 6) and no major strokes and no death. 20 (52.6%) of the recent infarctions detected by DWI were asymptomatic lesions. Most of the asymptomatic ischemic lesions were likely to be distributed in watershed border areas. On the other hand, symptomatic lesions tended to be distributed in cortical and/or perforator regions and to be multiple. Thus, DWI is a useful method that can detect neurologically silent and asymptomatic ischemic lesions. It can be used to help to evaluate the safety and efficacy of neurovascular intervention.

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