scholarly journals Analysis of 7-tesla diffusion-weighted imaging in the prediction of pituitary macroadenoma consistency

2020 ◽  
pp. 1-9
Author(s):  
John W. Rutland ◽  
Joshua Loewenstern ◽  
Daniel Ranti ◽  
Nadejda M. Tsankova ◽  
Christopher P. Bellaire ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Diffusion Weighted Imaging ◽  
Extent Of Resection ◽  
7 Tesla ◽  
Tumor Vascularity ◽  
Diffusion Weighted ◽  
Adc Values ◽  
Tumor Consistency ◽  
Consistency Rating ◽  
Pituitary Macroadenomas

OBJECTIVEEndoscopic surgery is an effective treatment strategy for pituitary adenomas; however, intrinsic tumor properties such as tumor consistency can challenge or preclude gross-total resection. Preoperative characterization of tumor consistency may help to guide the surgical approach and to predict the extent of resection that is possible. Advanced radiological modalities such as 7T diffusion-weighted imaging (DWI) may be useful in probing biological tissue properties of pituitary adenomas. The objective of the present study was to examine 7T DWI as a novel method of measuring the consistency of pituitary adenomas.METHODSThirteen patients with pituitary macroadenomas underwent 7T MRI, including a DWI image acquisition. Tumor apparent diffusion coefficient (ADC) was normalized to the adjacent temporal gray matter ADC. All patients underwent resection, and a single neurosurgeon blinded to ADC values rated tumor firmness from 1 (least firm) to 5 (most firm) using objective criteria. The tumor specimens were evaluated histopathologically for cellularity, collagen content, and vascularity by a neuropathologist who was also blinded to ADC values. The tumor ADC was correlated with intraoperative consistency rating, histopathology, and extent of resection. Receiver operating characteristic (ROC) curve analyses were performed to identify thresholds to predict tumor consistency.RESULTSCorrected ADC values were significantly correlated with both tumor firmness (r = −0.60, p = 0.029) and the extent of trichrome staining (r = −0.72, p = 0.009) such that greater ADC values were associated with both decreased tumor firmness and decreased collagen staining. Correlations between ADC values and tumor vascularity were not significant (r = −0.09, p = 0.78). Corrected ADC values in totally resected tumors (1.54) were greater than those in subtotally resected tumors (0.85) (p = 0.02), and ADC values were greater with moderate tumor cellularity (1.51) than with high tumor cellularity (0.8) (p = 0.035). There was a trend-level association for partial resections to exhibit greater tumor firmness rating (3 vs 1.7; p = 0.051). Finally, the degree of trichrome staining positively correlated with tumor firmness (r = 0.60, p = 0.04). The optimal threshold for predicting intraoperative consistency rating was an ADC ratio of 0.87 (sensitivity 80%, specificity 100%, area under the curve [AUC] 0.90; p = 0.043). The optimal cutoff for distinguishing the extent of resection was 1.19 (sensitivity 85.7%, specificity 83.3% AUC 0.833; p = 0.046).CONCLUSIONSThe authors’ results suggest that a high-resolution ADC of pituitary adenomas is a sensitive measure of tumor consistency. 7T DWI may hold clinical value in the preoperative workup and surgical management of patients with pituitary macroadenomas.

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 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.

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.

scholarly journals Diffusion-Weighted Imaging of Different Breast Cancer Molecular Subtypes: A Systematic Review and Meta-Analysis

Breast Care ◽  
2021 ◽  
pp. 1-8
Author(s):  
Hans-Jonas Meyer ◽  
Andreas Wienke ◽  
Alexey Surov
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Diffusion Weighted Imaging ◽  
Triple Negative ◽  
Molecular Subtypes ◽  
Luminal A ◽  
Diagnose Breast Cancer ◽  
Luminal B ◽  
Diffusion Weighted ◽  
Adc Values

Background: Magnetic resonance imaging can be used to diagnose breast cancer (BC).Diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) can be used to reflect tumor microstructure. Objectives: This analysis aimed to compare ADC values between molecular subtypes of BC based on a large sample of patients. Method: The MEDLINE library and Scopus database were screened for the associations between ADC and molecular subtypes of BC up to April 2020. The primary end point of the systematic review was the ADC value in different BC subtypes. Overall, 28 studies were included. Results: The included studies comprised a total of 2,990 tumors. Luminal A type was diagnosed in 865 cases (28.9%), luminal B in 899 (30.1%), human epidermal growth factor receptor (Her2)-enriched in 597 (20.0%), and triple-negative in 629 (21.0%). The mean ADC values of the subtypes were as follows: luminal A: 0.99 × 10–3 mm2/s (95% CI 0.94–1.04), luminal B: 0.97 × 10–3 mm2/s (95% CI 0.89–1.05), Her2-enriched: 1.02 × 10–3 mm2/s (95% CI 0.95–1.08), and triple-negative: 0.99 × 10–3 mm2/s (95% CI 0.91–1.07). Conclusions: ADC values cannot be used to discriminate between molecular subtypes of BC.

Vertebral bone marrow diffusivity in normal adults with varying bone densities at 3T diffusion-weighted imaging

2017 ◽  
Vol 59 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Jie He ◽  
Hao Fang ◽  
Xiao na Li
Keyword(s):  
Bone Marrow ◽  
Bone Density ◽  
Diffusion Weighted Imaging ◽  
Mineral Density ◽  
Vertebral Bone ◽  
Normal Bone ◽  
Diffusion Weighted ◽  
Adc Values ◽  
Vertebral Bone Marrow ◽  
Normal Adults

Background There has been controversy surrounding the relationship between diffusivity and bone mineral density (BMD) in vertebral bone marrow. Moreover, sex-related differences of vertebral bone marrow diffusivity in relation to varying bone densities have not yet been evaluated. Purpose To prospectively investigate the role of diffusion-weighted imaging (DWI) in assessing vertebral marrow changes in normal adults with varying bone densities. Material and Methods A total of 124 normal adult volunteers were enrolled in this study. Sagittal magnetic resonance (MR) DWI of the lumbar spine was performed. The ADC values of vertebral bone marrow were measured. Volumetric BMD measurement was performed by quantitative computed tomography (QCT) using Mindways QCT analysis software. All participants were divided into three groups according to BMD (normal, osteopenia, osteoporosis). The differences of the apparent diffusion coefficient (ADC) values of the three groups was compared, and partial correlation analysis was used to evaluate the correlation between ADC values and BMD. Results ADC values decreased as BMD decreased in female participants. When compared with the normal bone density group, ADC values were significantly decreased in the osteoporotic group and in the osteopenic group of female participants. ADC values of female participants were significantly higher than of male participants in the normal bone density group ( P < 0.001). ADC values correlated positively with BMD values (r = 0.307, P = 0.016) for female participants. Conclusion The diffusivity in vertebral bone marrow with varying bone densities differed by sex. ADC values correlated positively with BMD in women. DWI can quantitively evaluate osteoporosis in women.

scholarly journals Prediction of secondary ischemic lesions with diffusion-weighted imaging after transient middle cerebral artery occlusion in rats

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 352-352
Author(s):  
Fuhai Li ◽  
Matthew D Silva ◽  
Xiangjun Meng ◽  
Christopher H Sotak ◽  
Marc Fisher
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Diffusion Weighted Imaging ◽  
Artery Occlusion ◽  
Lesion Volume ◽  
Diffusion Weighted ◽  
Adc Values ◽  
Cerebral Artery Occlusion ◽  
Initial Lesions

P75 Background and Purpose: Previous studies demonstrated that secondary ischemic lesions documented by diffusion-weighted imaging might be smaller than, larger than or similar to initial lesions that occur during ischemia. The purpose of this study was to investigate if the size of secondary lesions can be predicted. Methods: Twelve rats underwent 30 minutes of transient middle cerebral artery occlusion with the intraluminal suture method. Diffusion- and perfusion-weighted images were performed just before reperfusion, 90 minutes and 24 hours after reperfusion. The ischemic lesion size was calculated by tracing visual abnormalities on the apparent diffusion coefficient (ADC) maps. Cerebral blood flow index (CBF i ) ratio was calculated by dividing the ipsilateral CBF i by the contralateral CBF i . Based on difference between initial and secondary lesion volume, rats were assigned to reperfusion-benefit group (n=6) where secondary lesions were smaller than initial lesions (less than 85% of initial lesions) and reperfusion-nonbenefit group (n=6) where secondary lesions were similar to or larger than initial lesions (more than 85% of initial lesions). Results: At 90 minutes after reperfusion, the initial ischemic lesions almost disappeared in both groups. At 24 hours, secondary lesions were 54±11% (mean±SD) of the initial lesions in the reperfusion-benefit group and 100±14% of the initial lesions in the reperfusion-nonbenefit group (p<0.001). There was no difference in ADC values (47±2×10 -5 mm 2 /s vs 46±5×10 -5 mm 2 /s, p=0.7) and CBF i ratio (0.62±0.06 vs 0.67±0.04, p=0.2) between the two groups before reperfusion. However, the initial lesion volume was significantly smaller in the reperfusion-benefit group than in the reperfusion-nonbenefit group (125±54 mm 3 vs 195±36 mm 3 , p=0.037). Conclusions: Changes of ADC values and CBF before reperfusion are unable to predict if initial ischemic lesions will eventually shrink or not after reperfusion. Smaller size of initial lesions may suggest that secondary lesions will be smaller than initial lesions.

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