Diffusion-weighted MRI of ischemic stroke at 3T: Value of synthetic b-values

2021 ◽  
Vol 94 (1121) ◽  
pp. 20200869
Author(s):  
Thomas Sartoretti ◽  
Elisabeth Sartoretti ◽  
Michael Wyss ◽  
Manoj Mannil ◽  
Luuk van Smoorenburg ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Image Quality ◽  
Detection Rate ◽  
Contrast Ratio ◽  
B Value ◽  
Lesion Detection ◽  
B Values ◽  
Diffusion Weighted ◽  
Synthetic Images ◽  
Lesion Conspicuity

Objectives: Diffusion-weighted imaging (DWI) plays a crucial role in the diagnosis of ischemic stroke. We assessed the value of computed and acquired high b-value DWI in comparison with conventional b = 1000 s mm−2 DWI for ischemic stroke at 3T. Methods: We included 36 patients with acute ischemic stroke who presented with diffusion abnormalities on DWI performed within 24 h of symptom onset. B-values of 0, 500, 1000 and 2000 s mm−2 were acquired. Synthetic images with b-values of 1000, 1500, 2000 and 2500 s mm−2 were computed. Two readers compared synthetic (syn) and acquired (acq) b = 2000 s mm−2 images with acquired b = 1000 s mm−2 images in terms of lesion detection rate, image quality, presence of uncertain hyperintensities and lesion conspicuity. Readers also selected their preferred b-value. Contrast ratio (CR) measurements were performed. Non-parametrical statistical tests and weighted Cohens’ κ tests were computed. Results: Syn1000 and syn1500 matched acq1000 images in terms of lesion detection rate, image quality and presence of uncertain hyperintensities but presented with significantly improved lesion conspicuity (p < 0.01) and were frequently selected as preferred b-values. Acq2000 images exhibited a similar lesion detection rate and improved lesion conspicuity (p < 0.01) but worse image quality (p < 0.01) than acq1000 images. Syn2000 and syn2500 images performed significantly worse (p < 0.01) than acq1000 images in most or all categories. CR significantly increased with increasing b-values. Conclusion: Synthetic images at b = 1000 and 1500 s mm−2 and acquired DWI images at b = 2000 s mm−2 may be of clinical value due to improved lesion conspicuity. Advances in knowledge: Synthetic b-values enable improved lesion conspicuity for DWI of ischemic stroke.

scholarly journals Image quality and diagnostic value of diffusion-weighted breast magnetic resonance imaging: Comparison of acquired and computed images

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247379
Author(s):  
Hye Shin Ahn ◽  
Sung Hun Kim ◽  
Ji Youn Kim ◽  
Chang Suk Park ◽  
Robert Grimm ◽  
...  
Keyword(s):  
Image Quality ◽  
Predictive Value ◽  
B Value ◽  
Diagnostic Value ◽  
Quality Parameters ◽  
Lesion Detection ◽  
Breast Cancers ◽  
Lesion Detectability ◽  
High B Value ◽  
Diffusion Weighted

Purpose To compare the image quality of acquired diffusion-weighted imaging (DWI) and computed DWI and evaluate the lesion detectability and likelihood of malignancy in these datasets. Materials and methods This prospective study was approved by our institutional review board. A total of 29 women (mean age, 43.5 years) underwent DWI between August 2018 and April 2019 for 32 breast cancers and 16 benign breast lesions. Three radiologists independently reviewed the acquired DWI with b-values of 1000 and 2000 s/mm2 (A-b1000 and A-b2000) and the computed DWI with a b-value of 2000 s/mm2 (C-b2000). Image quality was scored and compared between the three DWI datasets. Lesion detectability was recorded, and the lesion’s likelihood for malignancy was scored using a five-point scale. Results The A-b1000 images were superior to the A-b2000 and C-b2000 images in chest distinction, fat suppression, and overall image quality. The A-b2000 and C-b2000 images showed comparable scores for all image quality parameters. C-b2000 showed the highest values for lesion detection among all readers, although there was no statistical difference in sensitivity, specificity, positive predictive value, negative predictive value, and accuracy between the DWI datasets. The malignancy scores of the DWI images were not significantly different among the three readers. Conclusions A-b1000 DWI is suitable for breast lesion evaluations, considering its better image quality and comparable diagnostic values compared to that of A-b2000 and C-b2000 images. The additional use of computed high b-value DWI may have the potential to increase the detectability of breast masses.

scholarly journals Conspicuity of Peripheral Zone Prostate Cancer on Computed Diffusion-Weighted Imaging: Comparison of cDWI1500, cDWI2000, and cDWI3000

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Metin Vural ◽  
Gökhan Ertaş ◽  
Aslıhan Onay ◽  
Ömer Acar ◽  
Tarık Esen ◽  
...  
Keyword(s):  
Diffusion Weighted Imaging ◽  
Contrast Ratio ◽  
Peripheral Zone ◽  
Lesion Detection ◽  
Prostate Tissue ◽  
Detection Rates ◽  
Diffusion Weighted ◽  
Image Set ◽  
Average Contrast ◽  
Lesion Conspicuity

Introduction and Objective. Disadvantages associated with direct highb-value measurements may be avoided with use of computed diffusion-weighted imaging (cDWI). The purpose of this study is to assess the diagnostic performance of cDWI image sets calculated for highb-values of 1500, 2000, and 3000 s/mm2.Materials and Methods. Twenty-eight patients who underwent multiparametric MRI of the prostate and radical prostatectomy consecutively were enrolled in this retrospective study. Using a software developed at our institute, cDWI1500, cDWI2000, and cDWI3000image sets were generated by fitting a monoexponential model. Index lesions on cDWI image sets were scored by two radiologists in consensus considering lesion conspicuity, suppression of background prostate tissue, distortion, image set preferability, and contrast ratio measurements were performed.Results. Lesion detection rates are the same for computedb-values of 2000 and 3000 s/mm2and are better thanb-values of 1500 s/mm2. Best lesion conspicuity and best background prostate tissue suppression are provided by cDWI3000image set. cDWI2000image set provides the best zonal anatomical delineation and less distortion and was chosen as the most preferred image set. Average contrast ratio measured on these image sets shows almost a linear relation with theb-values. Conclusion. cDWI2000image set with similar conspicuity and the same lesion detection rate, but better zonal anatomical delineation, and less distortion, was chosen as the preferable image set.

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 evaluation of computed and voxelwise computed diffusion-weighted imaging in breast cancer

2019 ◽  
Vol 92 (1100) ◽  
pp. 20180978
Author(s):  
Qingyuan Cheng ◽  
Shuxin Ye ◽  
Chuqi Fu ◽  
Jiejie Zhou ◽  
Xiaxia He ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Diffusion Weighted Imaging ◽  
Signal To Noise Ratio ◽  
Contrast Ratio ◽  
B Value ◽  
B Values ◽  
Diffusion Weighted ◽  
Malignant Lesions ◽  
The Mean ◽  
Age Range

Objectives: To assess the value of computed diffusion-weighted imaging (cDWI) and voxelwise computed diffusion-weighted imaging (vcDWI) in breast cancer. Methods: This retrospective study involved 130 patients (age range, 25–70 years; mean age ± standard deviation, 48.6 ± 10.5 years) with 130 malignant lesions, who underwent MRI examinations, including a DWI sequence, prior to needle biopsy or surgery. cDWIs with higher b-values of 1500, 2000, 2500, 3000, 3500, and 4000 s/mm2, and vcDWI were generated from measured (m) DWI with two lower b-values of 0/600, 0/800, or 0/1000 s/mm2. The signal-to-noise ratio (SNR) and contrast ratio (CR) of all image sets were computed and compared among different DWIs by two experienced radiologists independently. To better compare the CR with the SNR, the CR value was multiplied by 100 (CR100). Results: The CR of vcDWI, and cDWIs, except for cDWI1000, differed significantly from that of measured diffusion-weighted imaging (mDWI) (cDWI1000: CR = 0.4904, p = 0.394; cDWI1500: CR = 0.5503, p = 0.006; cDWI2000: CR = 0.5889, p < 0.001; cDWI2500: CR = 0.6109, p < 0.001; cDWI3000: mean = 0.6214, p < 0.001; cDWI3500: CR = 0.6245, p < 0.001; cDWI4000: CR = 0.6228, p < 0.001). The vcDWI provided the highest CR, while the CRs of all cDWI image sets improved with increased b-values. The SNR of neither cDWI1000 nor vcDWI differed significantly from that of mDWI, but the mean SNRs of the remaining cDWIs were significantly lower than that of mDWI. The SNRs of cDWIs declined with increasing b-values, and the initial decrease at low b-values was steeper than the gradual attenuation at higher b-values; the CR100 rose gradually, and the two converged on the b-value interval of 1500–2000 s/mm2 . Conclusions: The highest CR was achieved with vcDWI; this could be a promising approach easier detection of breast cancer. Advances in knowledge: This study comprehensively compared and evaluated the value of the emerging post-processing DWI techniques (including a set of cDWIs and vcDWI) in breast cancer.

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.

Image quality and diagnostic accuracy of complex-averaged high b value images in diffusion-weighted MRI of prostate cancer

2019 ◽  
Vol 44 (6) ◽  
pp. 2244-2253 ◽  
Author(s):  
Hamed Kordbacheh ◽  
Ravi Teja Seethamraju ◽  
Elisabeth Weiland ◽  
Berthold Kiefer ◽  
Marcel Dominik Nickel ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Image Quality ◽  
Diagnostic Accuracy ◽  
B Value ◽  
Diffusion Weighted Mri ◽  
High B Value ◽  
Diffusion Weighted

scholarly journals Diagnostic value of diffusion-weighted imaging with synthetic b-values in breast tumors: comparison with dynamic contrast-enhanced and multiparametric MRI

2020 ◽  
Vol 31 (1) ◽  
pp. 356-367
Author(s):  
Isaac Daimiel Naranjo ◽  
Roberto Lo Gullo ◽  
Carolina Saccarelli ◽  
Sunitha B. Thakur ◽  
Almir Bitencourt ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Image Quality ◽  
Cancer Detection ◽  
Multiparametric Mri ◽  
Breast Cancer Detection ◽  
Dense Breast ◽  
B Values ◽  
Dce Mri ◽  
Adc Values ◽  
Lesion Conspicuity

Abstract Objectives To assess DWI for tumor visibility and breast cancer detection by the addition of different synthetic b-values. Methods Eighty-four consecutive women who underwent a breast-multiparametric-MRI (mpMRI) with enhancing lesions on DCE-MRI (BI-RADS 2–5) were included in this IRB-approved retrospective study from September 2018 to March 2019. Three readers evaluated DW acquired b-800 and synthetic b-1000, b-1200, b-1500, and b-1800 s/mm2 images for lesion visibility and preferred b-value based on lesion conspicuity. Image quality (1–3 scores) and breast composition (BI-RADS) were also recorded. Diagnostic parameters for DWI were determined using a 1–5 malignancy score based on qualitative imaging parameters (acquired + preferred synthetic b-values) and ADC values. BI-RADS classification was used for DCE-MRI and quantitative ADC values + BI-RADS were used for mpMRI. Results Sixty-four malignant (average = 23 mm) and 39 benign (average = 8 mm) lesions were found in 80 women. Although b-800 achieved the best image quality score, synthetic b-values 1200–1500 s/mm2 were preferred for lesion conspicuity, especially in dense breast. b-800 and synthetic b-1000/b-1200 s/mm2 values allowed the visualization of 84–90% of cancers visible with DCE-MRI performing better than b-1500/b-1800 s/mm2. DWI was more specific (86.3% vs 65.7%, p < 0.001) but less sensitive (62.8% vs 90%, p < 0.001) and accurate (71% vs 80.7%, p = 0.003) than DCE-MRI for breast cancer detection, where mpMRI was the most accurate modality accounting for less false positive cases. Conclusion The addition of synthetic b-values enhances tumor conspicuity and could potentially improve tumor visualization particularly in dense breast. However, its supportive role for DWI breast cancer detection is still not definite. Key Points • The addition of synthetic b-values (1200–1500 s/mm2) to acquired DWI afforded a better lesion conspicuity without increasing acquisition time and was particularly useful in dense breasts. • Despite the use of synthetic b-values, DWI was less sensitive and accurate than DCE-MRI for breast cancer detection. • A multiparametric MRI modality still remains the best approach having the highest accuracy for breast cancer detection and thus reducing the number of unnecessary biopsies.

scholarly journals The Image Information Of Mri Brain In Axial Diffusion Weighted Image (Dwi) With Variation B Value In Ischemic Stroke

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Siti Masrochah ◽  
Yeti Kartikasari ◽  
Ayu Mahanani
Keyword(s):  
Ischemic Stroke ◽  
Quantitative Research ◽  
B Value ◽  
Axial Plane ◽  
Diffusion Weighted Image ◽  
Image Information ◽  
Weighted Image ◽  
Mri Brain ◽  
Diffusion Weighted ◽  
Brain Examination

The purpose of the research is to identify the differences between image information of MRI Brain in axial plane Diffusion Weighted Image (DWI) sequence and variation b value in case ischemic stroke, and to determine optimal b value in examination MRI Brain in case Ischemic Stroke. This research was a quantitative research with experimental approach. This research was done in Panti Rapih Hospital, Yogyakarta and used 8 ischemic stroke patients with 3 variasion b value (500s/mm2, 1000 s/mm2, 1500 s/mm2) and 3 radiologists as respondents. The data were analyzed using Friedman test. Result showed that there was difference between image information of MRI Brain in axial plane Diffusion Weighted Image (DWI) sequence and variation b value in case ischemic stroke with p0.05 which means there is a difference between Basal Ganglia, Cerebellum, and the border of the infarction. Meanwhile, Cortex Cerebri, Thalamus and Pons obtained no difference in image information and the optimal b value for MRI Brain examination of ischemic stroke 1500 s/mm2. Based on the result there was a difference  between image information of MRI Brain in axial plane Diffusion Weighted Image (DWI) sequence and variation b value in case ischemic stroke. Optimal value of variation b value for MRI Brain examination of ischemic stroke was 1500 s/mm2.

scholarly journals Factors Affecting Image Quality and Lesion Evaluability in Breast Diffusion-Weighted MRI: Observations from the ECOG-ACRIN Cancer Research Group Multisite Trial (A6702)

2020 ◽  
Author(s):  
Jennifer G Whisenant ◽  
Justin Romanoff ◽  
Habib Rahbar ◽  
Averi E Kitsch ◽  
Sara M Harvey ◽  
...  
Keyword(s):  
Image Quality ◽  
Secondary Analysis ◽  
Breast Mri ◽  
B Value ◽  
Quality Factors ◽  
Planar Imaging ◽  
Factors Affecting ◽  
Diffusion Weighted ◽  
Imaging Sequence ◽  
Apparent Diffusion

Abstract Objective The A6702 multisite trial confirmed that apparent diffusion coefficient (ADC) measures can improve breast MRI accuracy and reduce unnecessary biopsies, but also found that technical issues rendered many lesions non-evaluable on diffusion-weighted imaging (DWI). This secondary analysis investigated factors affecting lesion evaluability and impact on diagnostic performance. Methods The A6702 protocol was IRB-approved at 10 institutions; participants provided informed consent. In total, 103 women with 142 MRI-detected breast lesions (BI-RADS assessment category 3, 4, or 5) completed the study. DWI was acquired at 1.5T and 3T using a four b-value, echo-planar imaging sequence. Scans were reviewed for multiple quality factors (artifacts, signal-to-noise, misregistration, and fat suppression); lesions were considered non-evaluable if there was low confidence in ADC measurement. Associations of lesion evaluability with imaging and lesion characteristics were determined. Areas under the receiver operating characteristic curves (AUCs) were compared using bootstrapping. Results Thirty percent (42/142) of lesions were non-evaluable on DWI; 23% (32/142) with image quality issues, 7% (10/142) with conspicuity and/or localization issues. Misregistration was the only factor associated with non-evaluability (P = 0.001). Smaller (≤10 mm) lesions were more commonly non-evaluable than larger lesions (p &lt;0.03), though not significant after multiplicity correction. The AUC for differentiating benign and malignant lesions increased after excluding non-evaluable lesions, from 0.61 (95% CI: 0.50–0.71) to 0.75 (95% CI: 0.65–0.84). Conclusion Image quality remains a technical challenge in breast DWI, particularly for smaller lesions. Protocol optimization and advanced acquisition and post-processing techniques would help to improve clinical utility.

Sign in / Sign up

Export Citation Format

Share Document