scholarly journals MRI-detected extramural venous invasion of rectal cancer: Multimodality performance and implications at baseline imaging and after neoadjuvant therapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Akitoshi Inoue ◽  
Shannon P. Sheedy ◽  
Jay P. Heiken ◽  
Payam Mohammadinejad ◽  
Rondell P. Graham ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Rectal Wall ◽  
Venous Invasion ◽  
Cancer Staging ◽  
Observer Agreement ◽  
High Signal ◽  
Post Contrast ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Clinical Scenarios

AbstractMRI is routinely used for rectal cancer staging to evaluate tumor extent and to inform decision-making regarding surgical planning and the need for neoadjuvant and adjuvant therapy. Extramural venous invasion (EMVI), which is intravenous tumor extension beyond the rectal wall on histopathology, is a predictor for worse prognosis. T2-weighted images (T2WI) demonstrate EMVI as a nodular-, bead-, or worm-shaped structure of intermediate T2 signal with irregular margins that arises from the primary tumor. Correlative diffusion-weighted images demonstrate intermediate to high signal corresponding to EMVI, and contrast enhanced T1-weighted images demonstrate tumor signal intensity in or around vessels. Diffusion-weighted and post contrast images may increase diagnostic performance but decrease inter-observer agreement. CT may also demonstrate obvious EMVI and is potentially useful in patients with a contraindication for MRI. This article aims to review the spectrum of imaging findings of EMVI of rectal cancer on MRI and CT, to summarize the diagnostic accuracy and inter-observer agreement of imaging modalities for its presence, to review other rectal neoplasms that may cause EMVI, and to discuss the clinical significance and role of MRI-detected EMVI in staging and restaging clinical scenarios.

DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING OF THE ULNAR NERVE IN CUBITAL TUNNEL SYNDROME

Hand Surgery ◽  
2010 ◽  
Vol 15 (01) ◽  
pp. 11-15 ◽  
Author(s):  
K. Iba ◽  
T. Wada ◽  
M. Tamakawa ◽  
M. Aoki ◽  
T. Yamashita
Keyword(s):  
Magnetic Resonance ◽  
Ulnar Nerve ◽  
Signal Intensity ◽  
Cubital Tunnel Syndrome ◽  
Cubital Tunnel ◽  
High Signal ◽  
Diffusion Weighted Mri ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Tunnel Syndrome

Diffusion-weighted images based on magnetic resonance reveal the microstructure of tissues by monitoring the random movement of water molecules. In this study, we investigated whether this new technique could visualize pathologic lesions on ulnar nerve in cubital tunnel. Six elbows in six healthy males without any symptoms and eleven elbows in ten patients with cubital tunnel syndrome underwent on diffusion-weighted MRI. No signal from the ulnar nerve was detected in normal subjects. Diffusion-weighted MRI revealed positive signals from the ulnar nerve in all of the eleven elbows with cubital tunnel syndrome. In contrast, conventional T2W-MRI revealed high signal intensity in eight elbows and low signal intensity in three elbows. Three elbows with low signal MRI showed normal nerve conduction velocity of the ulnar nerve. Diffusion-weighted MRI appears to be an attractive technique for diagnosis of cubital tunnel syndrome in its early stages which show normal electrophysiological and conventional MRI studies.

scholarly journals Radiological evaluation of deep soft tissue fibromatosis, the characteristic MR criteria on conventional and corresponding diffusion-weighted images

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Rania Zeitoun ◽  
Sarah Maged Khafagy ◽  
Ikram Hamed Mahmoud ◽  
Nagui Mohamed Abd El-Wahab
Keyword(s):  
Mr Images ◽  
Post Contrast ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Local Staging ◽  
Diffusion Pattern ◽  
Adc Values ◽  
Characteristic Features ◽  
And Diffusion ◽  
Deep Fibromatosis

Abstract Background To analyze the characteristic features of deep fibromatosis on conventional and diffusion-weighted MR images. Result The lesions were growing along the musculoaponeurotic fascia, mostly invaded the muscles, and showed ill-defined margins, low T2 signal bands and areas, and facial tail sign. Diffusion images showed mostly high or high mixed with low signal; only 2 lesions showed a persistent low signal. The average mean and minimum ADC values were 1.41 ± 0.26 × 10−3 mm2/s and 0.79 ± 0.43 × 10−3 mm2/s respectively. Post-contrast and DWI detected synchronous lesions and extensions missed on T1 and T2 images. Conclusion The most frequent MR features of deep fibromatosis are low T2 signal bands and areas, fascial tail sign, ill or partially defined margins, and predominant restricted diffusion pattern in addition to areas of “T2-blackout effect.” Post-contrast and DWI are more valuable in local staging of the tumor.

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

2020 ◽  
Vol 125 (6) ◽  
pp. 522-530
Author(s):  
Roberto Fornell-Perez ◽  
Valentina Vivas-Escalona ◽  
Joel Aranda-Sanchez ◽  
M. Carmen Gonzalez-Dominguez ◽  
Jano Rubio-Garcia ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Diffusion Weighted Imaging ◽  
Venous Invasion ◽  
Diffusion Weighted

scholarly journals MSBC-Net: Automatic Rectal Cancer Segmentation from MR Scans

2021 ◽  
Author(s):  
Ping Meng ◽  
Chao Sun ◽  
Yi Li ◽  
Long Zhou ◽  
Xinyu Zhao ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Rectal Wall ◽  
Region Of Interest ◽  
Cancer Staging ◽  
Medical Image Segmentation ◽  
Research Progress ◽  
Dice Similarity Coefficient ◽  
Boundary Constraints ◽  
Segmentation Strategy ◽  
Magnetic Resonance Imaging Mri

<div>Accurate segmentation of rectal cancer and rectal wall based on high-resolution T2-weighted magnetic resonance imaging (MRI-HRT2) is the basis of rectal cancer staging. However, complex imaging background, highly characteristics variation and poor contrast hindered the research progress of the automatic rectal cancer segmentation. In this study, a multi-task learning network, namely mask segmentation with boundary constraints (MSBC-Net), is proposed to overcome these limitations and to obtain accurate segmentation results by locating and segmenting rectal cancer and rectal wall automatically. Specifically, at first, a region of interest (RoI)-based segmentation strategy is designed to enable end-to-end multi-task training, where a sparse object detection module is used to automatically localize and classify rectal cancer and rectal wall to mitigate the problem of background interference, and a mask and boundary segmentation block is used to finely segment the RoIs; second, a modulated deformable backbone is introduced to handle the variable features of rectal cancer, which effectively improves the detection performance of small objects and adaptability of the proposed model. Moreover, the boundary head is fused into the mask head to segment the ambiguous boundary of the target and constrain the mask head to obtain more refined segmentation results. In total, 592 annotated rectal cancer patients in MRI-HRT2 are enrolled, and the comprehensive results show that the proposed MSBC-Net outperforms state-of-the-art methods with a dice similarity coefficient (DSC) of 0.801 (95\% CI, 0.791-0.811), which can be well extended to other medical image segmentation tasks with high potential clinical applicability.</div>

scholarly journals MSBC-Net: Automatic Rectal Cancer Segmentation from MR Scans

2021 ◽  
Author(s):  
Ping Meng ◽  
Chao Sun ◽  
Yi Li ◽  
Long Zhou ◽  
Xinyu Zhao ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Rectal Wall ◽  
Region Of Interest ◽  
Cancer Staging ◽  
Medical Image Segmentation ◽  
Research Progress ◽  
Dice Similarity Coefficient ◽  
Boundary Constraints ◽  
Segmentation Strategy ◽  
Magnetic Resonance Imaging Mri

<div>Accurate segmentation of rectal cancer and rectal wall based on high-resolution T2-weighted magnetic resonance imaging (MRI-HRT2) is the basis of rectal cancer staging. However, complex imaging background, highly characteristics variation and poor contrast hindered the research progress of the automatic rectal cancer segmentation. In this study, a multi-task learning network, namely mask segmentation with boundary constraints (MSBC-Net), is proposed to overcome these limitations and to obtain accurate segmentation results by locating and segmenting rectal cancer and rectal wall automatically. Specifically, at first, a region of interest (RoI)-based segmentation strategy is designed to enable end-to-end multi-task training, where a sparse object detection module is used to automatically localize and classify rectal cancer and rectal wall to mitigate the problem of background interference, and a mask and boundary segmentation block is used to finely segment the RoIs; second, a modulated deformable backbone is introduced to handle the variable features of rectal cancer, which effectively improves the detection performance of small objects and adaptability of the proposed model. Moreover, the boundary head is fused into the mask head to segment the ambiguous boundary of the target and constrain the mask head to obtain more refined segmentation results. In total, 592 annotated rectal cancer patients in MRI-HRT2 are enrolled, and the comprehensive results show that the proposed MSBC-Net outperforms state-of-the-art methods with a dice similarity coefficient (DSC) of 0.801 (95\% CI, 0.791-0.811), which can be well extended to other medical image segmentation tasks with high potential clinical applicability.</div>

scholarly journals High Signal Intensity on Diffusion-Weighted Images Reflects Acute Phase of Deep Vein Thrombus

2020 ◽  
Vol 120 (10) ◽  
pp. 1463-1473
Author(s):  
Toshihiro Gi ◽  
Yasuyoshi Kuroiwa ◽  
Atsushi Yamashita ◽  
Yuko Mizutani ◽  
Taketoshi Asanuma ◽  
...  
Keyword(s):  
Acute Phase ◽  
Human Blood ◽  
Signal Intensity ◽  
High Signal ◽  
Dependent Manner ◽  
Venous Thrombus ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted ◽  
Deep Vein

AbstractThe effects of antithrombotic therapy on deep vein thrombosis (DVT) can be affected by thrombus age, which cannot be reliably determined by noninvasive imaging modalities. We investigated whether magnetic resonance (MR) diffusion-weighted imaging (DWI) can localize and determine the age of venous thrombus in patients with DVT, animal models, and human blood in vitro. Signal intensity (SI) on DWI and the apparent diffusion coefficient (ADC) of thrombi were assessed in eight patients with DVT using a 1.5-T MR imaging (MRI) system. We assessed the organizing processes as venous thrombus developed in the rabbit jugular vein using a 3.0-T MRI system over time. We also assessed MRI signals of human blood in vitro using the 1.5-T MRI system. Venous thrombi were detected by DWI as areas of high or mixed high and iso SI in all patients. The ADCs were lower in the proximal, than in the distal portion of the thrombi. The thrombi of rabbit jugular veins histologically organized in a time-dependent manner, with high SI on DWI at 4 hours, mixed high and iso SI at 1 and 2 weeks, and iso SI at 3 weeks. The ADC correlated negatively with erythrocyte content, and positively with smooth muscle cells, macrophages, hemosiderin, and collagen content. MRI signals of human blood in vitro showed that ADCs were affected by erythrocyte content, but not by blood clotting. MR-DWI can detect venous thrombus, and high SI on DWI accompanied by a low ADC might reflect erythrocyte-rich, acute-phase thrombi.

scholarly journals The Role of 3-D Endorectal Ultrasound in Rectal Cancer: Our Experience

2014 ◽  
Vol 99 (2) ◽  
pp. 106-111 ◽  
Author(s):  
Nikola Y. Kolev ◽  
Anton Y. Tonev ◽  
Valentin L. Ignatov ◽  
Aleksander K. Zlatarov ◽  
Vasil M. Bojkov ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Rectal Wall ◽  
Preoperative Staging ◽  
Three Dimensional ◽  
Cancer Staging ◽  
Endorectal Ultrasound ◽  
Diagnostic Methods ◽  
Diagnostic Modality ◽  
Locoregional Staging

Abstract In the last 20 years, endorectal ultrasound (ERUS) has been one of the main diagnostic methods for locoregional staging of rectal cancer. ERUS is accurate modality for evaluating local invasion of rectal carcinoma into the rectal wall layers (T category). Adding the three-dimensional modality (3-D) increases the capabilities of this diagnostic tool in rectal cancer patients. We review the literature and report our experience in preoperative 3-D ERUS in rectal cancer staging. In the group of 71 patients, the staging of preoperative 3-D endorectal ultrasonography was compared with the postoperative morphologic examination. Three-dimensional ERUS preoperative staging was confirmed with morphologic evaluation in 66 out of 71 cases (92.9%). The detection sensitivities of rectal cancer with 3-D ERUS were as follows: T1, 92.8%; T2, 93.1%; T3, 91.6%; and T4, 100.0%; with specificity values of T1, 98.2%; T2, 95.4%; T3, 97.8%; and T4, 98.5%. Three-dimensional ERUS correctly categorized patients with T1, 97.1%; T2, 94.3%; T3, 95.7%; and T4, 98.5%. The percentage of total overstaged cases was 2.75% and that of understaged cases was 6.87%. The metastatic status of the lymph nodes was determined with a sensitivity of 79.1% (19 of 24), specificity of 91.4% (43 of 47), and diagnostic accuracy of 87.3% (62 of 71). In our experience, 3-D ERUS has the potential to become the diagnostic modality of choice for the preoperative staging of rectal cancer.

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