Primary and post-chemoradiotherapy MRI detection of extramural venous invasion in rectal cancer: the role of diffusion-weighted imaging

Abstract Purpose To compare integrated slice-specific dynamic shimming (iShim) diffusion weighted imaging (DWI) and single-shot echo-planar imaging (SS-EPI) DWI in image quality and pathological characterization of rectal cancer. Materials and methods A total of 193 consecutive rectal tumor patients were enrolled for retrospective analysis. Among them, 101 patients underwent iShim-DWI (b = 0, 800, and 1600 s/mm2) and 92 patients underwent SS-EPI-DWI (b = 0, and 1000 s/mm2). Qualitative analyses of both DWI techniques was performed by two independent readers; including adequate fat suppression, the presence of artifacts and image quality. Quantitative analysis was performed by calculating standard deviation (SD) of the gluteus maximus, signal intensity (SI) of lesion and residual normal rectal wall, apparent diffusion coefficient (ADC) values (generated by b values of 0, 800 and 1600 s/mm2 for iShim-DWI, and by b values of 0 and 1000 s/mm2 for SS-EPI-DWI) and image quality parameters, such as signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of primary rectal tumor. For the primary rectal cancer, two pathological groups were divided according to pathological results: Group 1 (well-differentiated) and Group 2 (poorly differentiated). Statistical analyses were performed with p < 0.05 as significant difference. Results Compared with SS-EPI-DWI, significantly higher scores of image quality were obtained in iShim-DWI cases (P < 0.001). The SDbackground was significantly reduced on b = 1600 s/mm2 images and ADC maps of iShim-DWI. Both SNR and CNR of b = 800 s/mm2 and b = 1600 s/mm2 images in iShim-DWI were higher than those of b = 1000 s/mm2 images in SS-EPI-DWI. In primary rectal cancer of iShim-DWI cohort, SIlesion was significantly higher than SIrectum in both b = 800 and 1600 s/mm2 images. ADC values were significantly lower in Group 2 (0.732 ± 0.08) × 10− 3 mm2/s) than those in Group 1 ((0.912 ± 0.21) × 10− 3 mm2/s). ROC analyses showed significance of ADC values and SIlesion between the two groups. Conclusion iShim-DWI with b values of 0, 800 and 1600 s/mm2 is a promising technique of high image quality in rectal tumor imaging, and has potential ability to differentiate rectal cancer from normal wall and predicting pathological characterization.

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Role of Quantitative Diffusion-Weighted Imaging in Differentiating Benign and Malignant Orbital Masses

Indian Journal of Radiology and Imaging ◽

10.1055/s-0041-1730120 ◽

2021 ◽

Author(s):

Preeti Mundhada ◽

Sudarshan Rawat ◽

Ullas Acharya ◽

Dhananjay Raje

Keyword(s):

Roc Curve ◽

Diffusion Weighted Imaging ◽

Care Hospital ◽

Adc Value ◽

Diffusion Weighted ◽

Significant Difference ◽

Orbital Masses ◽

Adc Values ◽

Orbital Lesions

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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Role of quantitative diffusion weighted imaging in characterization of breast masses

The Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1016/j.ejrnm.2015.05.006 ◽

2015 ◽

Vol 46 (3) ◽

pp. 805-810 ◽

Cited By ~ 5

Author(s):

Yosra Abdelzaher Ibrahim ◽

Lobna Habib ◽

Ahmed Deif

Keyword(s):

Diffusion Weighted Imaging ◽

Breast Masses ◽

Diffusion Weighted

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Primary and secondary cholesteatomas, cholesterol granuloma, and mucocele of the temporal bone: Role of computed tomography and magnetic resonance imaging with emphasis on diffusion-weighted imaging

Operative Techniques in Otolaryngology-Head and Neck Surgery ◽

10.1016/j.otot.2013.11.006 ◽

2014 ◽

Vol 25 (1) ◽

pp. 36-48

Author(s):

Mahmood F. Mafee ◽

Asae Nozawa

Keyword(s):

Magnetic Resonance Imaging ◽

Computed Tomography ◽

Magnetic Resonance ◽

Temporal Bone ◽

Diffusion Weighted Imaging ◽

Cholesterol Granuloma ◽

Resonance Imaging ◽

Diffusion Weighted

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Role of Diffusion Weighted Imaging in Differentiating Benign from Pathological Vertebral Compression

QJM ◽

10.1093/qjmed/hcab106.010 ◽

2021 ◽

Vol 114 (Supplement_1) ◽

Author(s):

Faten Mohammed Mahmoud Kamel ◽

Hazem Ibrahim Abdel Rahman ◽

Amany Sayed Khaleel Ahmed Elkhayat

Keyword(s):

Vertebral Fractures ◽

Diffusion Weighted Imaging ◽

Laboratory Evaluation ◽

Vertebral Collapse ◽

Adc Value ◽

Conventional Mri ◽

Diffusion Weighted ◽

Significant Difference

Abstract Background Vertebral collapse is a common problem due to benign conditions (trauma, infection, osteoporosis) or malignant process. And although the spine is the most common site of bone metastases (39% of bony metastases in patients with primary neoplasms) benign vertebral fractures due to osteopenia occur in one third of cancer patients, making it essential to determine whether the cause of vertebral collapse is benign or malignant. Aim of the Work To establish the role of DWI in differentiating benign from pathologic vertebral fractures using ADC values in comparison with histopathology report /laboratory evaluation and clinical follow-up. Patients and Methods A cross sectional study is approved by the ethics review board of Ain Shams University Hospital (Al Demerdash). All patients provided informed consent for the MR imaging examinations and for inclusion of their data in this analysis. From April 2020 to october 2020, 25 cases with previous imaging with vertebral compression underwent conventional MRI study on the affected region. Diffusion weighted imaging and ADC was added. Results We performed DWI using maximum b-values 600, and quantitative analysis, named apparent diffusion coefficient (ADC). We correlated the ADC number to histopathology, laboratory finding and clinical follow up. In our study there was significant difference (p < 0.04) between DWI of the benign and malignant groups. Also the ADC value showed significant difference <0.001. The mean ADCs of benign VCFs were higher significantly than those of pathological fractures. Conclusion DWI with ADC value was helpful when added to conventional MRI to differentiate benign from pathological (malignant) vertebral compression. It should be a routine sequence in patients with vertebral compression fractures for accurate diagnosis and successful management also can decrease no of biopsies.

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