scholarly journals Integrated slice-specific dynamic shimming diffusion weighted imaging (DWI) for rectal Cancer detection and characterization

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jianxing Qiu ◽  
Jing Liu ◽  
Zhongxu Bi ◽  
Xiaowei Sun ◽  
Xin Wang ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Image Quality ◽  
Diffusion Weighted Imaging ◽  
Rectal Tumor ◽  
B Values ◽  
Primary Rectal Cancer ◽  
Diffusion Weighted ◽  
Adc Values ◽  
Group 2 ◽  
Group 1

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.

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

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.

High-Resolution Diffusion-Weighted Imaging for Evaluation of Extramural Tumor Invasion in Primary Rectal Cancer

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Eun Joo Park ◽  
Seung Ho Kim ◽  
Sung Jae Jo ◽  
Kyung Han Nam ◽  
Yun-jung Lim ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
High Resolution ◽  
Tumor Invasion ◽  
Diffusion Weighted Imaging ◽  
Primary Rectal Cancer ◽  
Diffusion Weighted

scholarly journals The role of MRI with diffusion-weighted imaging in restaging rectal cancers after neoadjuvant chemoradiotherapy

2016 ◽  
Vol 20 (1) ◽  
Author(s):  
Irem Bayram ◽  
Baris Bakir ◽  
Merve G.D. Kartal ◽  
Enver Kunduz ◽  
Onur Bayram ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Predictive Value ◽  
Diffusion Weighted Imaging ◽  
Locally Advanced ◽  
Neoadjuvant Chemoradiotherapy ◽  
Staging System ◽  
Tnm Staging ◽  
Kappa Statistics ◽  
Diffusion Weighted ◽  
Adc Values

Background: It is challenging to restage rectal cancer at MRI, in patients who have had neoadjuvant chemoradiotherapy.Objective: To investigate the accuracy of MRI with diffusion-weighted imaging (DWI) in the restaging of rectal cancer.Materials and methods: Pre- and post-neoadjuvant chemoradiotherapy MRI examinations of 35 patients diagnosed with locally advanced rectal cancer were evaluated and subsequently compared with post-operative pathology results.Results: The accuracy of MRI with DWI to determine the T-stage status was calculated as 54.28%. Kappa statistics revealed poor concordance with pathology results, with a κ value of 0.212 ± 0.114 (p = 0.028). The apparent diffusion coefficient (ADC) values measured after the neoadjuvant chemotherapy revealed a significant increase when compared with pre-treatment ADC values (p < 0.000001). MRI accuracy rate for lymph node involvement was calculated as 57.14% with a κ value of 0.001 (p = 0.989). MRI had 80% sensitivity and 100% specificity in determining mesorectal fascia involvement, with a calculated positive predictive value of 100% and a calculated negative predictive value of 96%. The accuracy of MRI in overall staging according to the TNM staging system was 28%.Conclusion: The accuracy of MRI in restaging rectal cancer is not yet sufficient and is not on par with the accuracy of MRI in the primary staging of the disease. This is attributed to post-treatment changes. Adding DWI to the protocol is promising, but more expanded data are required.

scholarly journals Clinical Usefulness of Diffusion-weighted Imaging Using Low and High b-values to Detect Rectal Cancer

2006 ◽  
Vol 5 (4) ◽  
pp. 173-177 ◽  
Author(s):  
Tomonori HOSONUMA ◽  
Mitsuhiro TOZAKI ◽  
Noriatsu ICHIBA ◽  
Tohru SAKUMA ◽  
Daichi HAYASHI ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Diffusion Weighted Imaging ◽  
Clinical Usefulness ◽  
B Values ◽  
Diffusion Weighted

scholarly journals Diagnostic Benefit of High b-Value Computed Diffusion-Weighted Imaging in Patients with Hepatic Metastasis

2021 ◽  
Vol 10 (22) ◽  
pp. 5289
Author(s):  
Maxime Ablefoni ◽  
Hans Surup ◽  
Constantin Ehrengut ◽  
Aaron Schindler ◽  
Daniel Seehofer ◽  
...  
Keyword(s):  
Image Quality ◽  
Hepatic Metastasis ◽  
Diffusion Weighted Imaging ◽  
Hepatic Metastases ◽  
B Value ◽  
Primary Tumors ◽  
B Values ◽  
Lesion Detectability ◽  
High B Value ◽  
Diffusion Weighted

Diffusion-weighted imaging (DWI) has rapidly become an essential tool for the detection of malignant liver lesions. The aim of this study was to investigate the usefulness of high b-value computed DWI (c-DWI) in comparison to standard DWI in patients with hepatic metastases. In total, 92 patients with histopathologic confirmed primary tumors with hepatic metastasis were retrospectively analyzed by two readers. DWI was obtained with b-values of 50, 400 and 800 or 1000 s/mm2 on a 1.5 T magnetic resonance imaging (MRI) scanner. C-DWI was calculated with a monoexponential model with high b-values of 1000, 2000, 3000, 4000 and 5000 s/mm2. All c-DWI images with high b-values were compared to the acquired DWI sequence at a b-value of 800 or 1000 s/mm2 in terms of volume, lesion detectability and image quality. In the group of a b-value of 800 from a b-value of 2000 s/mm2, hepatic lesion sizes were significantly smaller than on acquired DWI (metastases lesion sizes b = 800 vs. b 2000 s/mm2: mean 25 cm3 (range 10–60 cm3) vs. mean 17.5 cm3 (range 5–35 cm3), p < 0.01). In the second group at a high b-value of 1500 s/mm2, liver metastases were larger than on c-DWI at higher b-values (b = 1500 vs. b 2000 s/mm2, mean 10 cm3 (range 4–24 cm3) vs. mean 9 cm3 (range 5–19 cm3), p < 0.01). In both groups, there was a clear reduction in lesion detectability at b = 2000 s/mm2, with hepatic metastases being less visible compared to c-DWI images at b = 1500 s/mm2 in at least 80% of all patients. Image quality dropped significantly starting from c-DWI at b = 3000 s/mm2. In both groups, almost all high b-values images at b = 4000 s/mm2 and 5000 s/mm2 were not diagnostic due to poor image quality. High c-DWI b-values up to b = 1500 s/mm2 offer comparable detectability for hepatic metastases compared to standard DWI. Higher b-value images over 2000 s/mm2 lead to a noticeable reduction in imaging quality, which could hamper diagnosis.

scholarly journals Quantitative T2*-Weighted Imaging and Reduced Field-of-View Diffusion-Weighted Imaging of Rectal Cancer: Correlation of R2* and Apparent Diffusion Coefficient With Histopathological Prognostic Factors

2021 ◽  
Vol 11 ◽  
Author(s):  
Yang Peng ◽  
Yan Luo ◽  
Xuemei Hu ◽  
Yaqi Shen ◽  
Daoyu Hu ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Diffusion Coefficient ◽  
Prognostic Factors ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Imaging ◽  
Field Of View ◽  
T Stage ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Adc Values

PurposeTo assess T2*-weighted imaging (T2*WI) and reduced field-of-view diffusion-weighted Imaging (rDWI) derived parameters and their relationships with histopathological factors in patients with rectal cancer.MethodsFifty-four patients with pathologically-proven rectal cancer underwent preoperative T2*-weighted imaging and rDWI in this retrospective study. R2* values from T2*-weighted imaging and apparent diffusion coefficient (ADC) values from rDWI were compared in terms of different histopathological prognostic factors using student’s t-test or Mann-Whitney U-test. The correlations of R2* and ADC with prognostic factors were assessed by Spearman correlation analysis. The diagnostic performances of R2* and ADC were analyzed by receiver operating characteristic curves (ROC) separately and jointly.ResultsSignificant positive correlation was found between R2* values and T stage, lymph node involvement, histological grades, CEA level, the presence of EMVI and tumor deposit (r = 0.374 ~ 0.673, p = 0.000–0.006), with the exception of CA19-9 level, CRM status and tumor involvement in the circumference lumen (TIL). Meanwhile, ADC values negatively correlated with almost all the prognostic factors (r = −0.588 to −0.299, p = 0.000–0.030), except CA19-9 level. The AUC range was 0.724–0.907 for R2* and 0.674–0.887 for ADC in discrimination of different prognostic factors. While showing the highest AUC of 0.913 (0.803–1.000) in differentiation of T stage, combination of R2* and ADC with reference to different prognostic factors did not significantly improve the diagnostic performance in comparison with individual R2*/ADC parameter.ConclusionsR2* and ADC were associated with important histopathological prognostic factors of rectal cancer. R2* might act as additional quantitative imaging marker for tumor characterization of rectal cancer.

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

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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