How to Shorten MRI Sequences

2010 ◽  
pp. 19-32
Author(s):  
Matthew Clemence
Keyword(s):  
2021 ◽  
Vol 20 ◽  
pp. 153303382110330
Author(s):  
Lulu Yin ◽  
Yan Liu ◽  
Xi Zhang ◽  
Hongbing Lu ◽  
Yang Liu

Intratumor heterogeneity is partly responsible for the poor prognosis of glioblastoma (GBM) patients. In this study, we aimed to assess the effect of different heterogeneous subregions of GBM on overall survival (OS) stratification. A total of 105 GBM patients were retrospectively enrolled and divided into long-term and short-term OS groups. Four MRI sequences, including contrast-enhanced T1-weighted imaging (T1C), T1, T2, and FLAIR, were collected for each patient. Then, 4 heterogeneous subregions, i.e. the region of entire abnormality (rEA), the regions of contrast-enhanced tumor (rCET), necrosis (rNec) and edema/non-contrast-enhanced tumor (rE/nCET), were manually drawn from the 4 MRI sequences. For each subregion, 50 radiomics features were extracted. The stratification performance of 4 heterogeneous subregions, as well as the performances of 4 MRI sequences, was evaluated both alone and in combination. Our results showed that rEA was superior in stratifying long-and short-term OS. For the 4 MRI sequences used in this study, the FLAIR sequence demonstrated the best performance of survival stratification based on the manual delineation of heterogeneous subregions. Our results suggest that heterogeneous subregions of GBMs contain different prognostic information, which should be considered when investigating survival stratification in patients with GBM.


2008 ◽  
Vol 113 (2) ◽  
pp. 214-224 ◽  
Author(s):  
M. B. Damasio ◽  
A. Tagliafico ◽  
E. Capaccio ◽  
C. Cancelli ◽  
N. Perrone ◽  
...  

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Endre Grøvik ◽  
Darvin Yi ◽  
Michael Iv ◽  
Elizabeth Tong ◽  
Line Brennhaug Nilsen ◽  
...  

AbstractThe purpose of this study was to assess the clinical value of a deep learning (DL) model for automatic detection and segmentation of brain metastases, in which a neural network is trained on four distinct MRI sequences using an input-level dropout layer, thus simulating the scenario of missing MRI sequences by training on the full set and all possible subsets of the input data. This retrospective, multicenter study, evaluated 165 patients with brain metastases. The proposed input-level dropout (ILD) model was trained on multisequence MRI from 100 patients and validated/tested on 10/55 patients, in which the test set was missing one of the four MRI sequences used for training. The segmentation results were compared with the performance of a state-of-the-art DeepLab V3 model. The MR sequences in the training set included pre-gadolinium and post-gadolinium (Gd) T1-weighted 3D fast spin echo, post-Gd T1-weighted inversion recovery (IR) prepped fast spoiled gradient echo, and 3D fluid attenuated inversion recovery (FLAIR), whereas the test set did not include the IR prepped image-series. The ground truth segmentations were established by experienced neuroradiologists. The results were evaluated using precision, recall, Intersection over union (IoU)-score and Dice score, and receiver operating characteristics (ROC) curve statistics, while the Wilcoxon rank sum test was used to compare the performance of the two neural networks. The area under the ROC curve (AUC), averaged across all test cases, was 0.989 ± 0.029 for the ILD-model and 0.989 ± 0.023 for the DeepLab V3 model (p = 0.62). The ILD-model showed a significantly higher Dice score (0.795 ± 0.104 vs. 0.774 ± 0.104, p = 0.017), and IoU-score (0.561 ± 0.225 vs. 0.492 ± 0.186, p < 0.001) compared to the DeepLab V3 model, and a significantly lower average false positive rate of 3.6/patient vs. 7.0/patient (p < 0.001) using a 10 mm3 lesion-size limit. The ILD-model, trained on all possible combinations of four MRI sequences, may facilitate accurate detection and segmentation of brain metastases on a multicenter basis, even when the test cohort is missing input MRI sequences.


2015 ◽  
Vol 59 (2) ◽  
pp. 317-319
Author(s):  
Zbigniew Adamiak ◽  
Yauheni Zhalniarovich ◽  
Paulina Przyborowska ◽  
Joanna Głodek ◽  
Adam Przeworski

AbstractThe aim of the study was to identify magnetic resonance imaging (MRI) sequences that contribute to a quick and reliable diagnosis of brachial plexus tumours in dogs. The tumours were successfully diagnosed in 6 dogs by the MRI with the use of SE, FSE, STIR, Turbo 3 D, 3D HYCE, and GE sequences and the gadolinium contrast agent


1995 ◽  
Vol 13 (3) ◽  
pp. 481-488 ◽  
Author(s):  
B. Stöver ◽  
J. Laubenberger ◽  
J. Hennig ◽  
C. Niemeyer ◽  
K. Rückauer ◽  
...  
Keyword(s):  

2016 ◽  
Vol 12 ◽  
pp. P518-P518
Author(s):  
Xiaowei Song ◽  
Hui Guo ◽  
Ryan C.N. D'Arcy ◽  
William Siu ◽  
John Diggle ◽  
...  

2022 ◽  
Vol 22 (1) ◽  
pp. 1-30
Author(s):  
Rahul Kumar ◽  
Ankur Gupta ◽  
Harkirat Singh Arora ◽  
Balasubramanian Raman

Brain tumors are one of the critical malignant neurological cancers with the highest number of deaths and injuries worldwide. They are categorized into two major classes, high-grade glioma (HGG) and low-grade glioma (LGG), with HGG being more aggressive and malignant, whereas LGG tumors are less aggressive, but if left untreated, they get converted to HGG. Thus, the classification of brain tumors into the corresponding grade is a crucial task, especially for making decisions related to treatment. Motivated by the importance of such critical threats to humans, we propose a novel framework for brain tumor classification using discrete wavelet transform-based fusion of MRI sequences and Radiomics feature extraction. We utilized the Brain Tumor Segmentation 2018 challenge training dataset for the performance evaluation of our approach, and we extract features from three regions of interest derived using a combination of several tumor regions. We used wrapper method-based feature selection techniques for selecting a significant set of features and utilize various machine learning classifiers, Random Forest, Decision Tree, and Extra Randomized Tree for training the model. For proper validation of our approach, we adopt the five-fold cross-validation technique. We achieved state-of-the-art performance considering several performance metrics, 〈 Acc , Sens , Spec , F1-score , MCC , AUC 〉 ≡ 〈 98.60%, 99.05%, 97.33%, 99.05%, 96.42%, 98.19% 〉, where Acc , Sens , Spec , F1-score , MCC , and AUC represents the accuracy, sensitivity, specificity, F1-score, Matthews correlation coefficient, and area-under-the-curve, respectively. We believe our proposed approach will play a crucial role in the planning of clinical treatment and guidelines before surgery.


Author(s):  
Brett A. Shannon ◽  
Shivani Ahlawat ◽  
Carol D. Morris ◽  
Adam S. Levin ◽  
Laura M. Fayad

2021 ◽  
pp. 028418512110472
Author(s):  
Veysel Ayyildiz ◽  
Ali Koksal ◽  
Onur Taydas ◽  
Hayri Ogul

Background Giant tumefactive perivascular spaces (PVSs) are uncommon benign cystic lesions. They can imitate cystic neoplasms. Purpose To evaluate the contribution of advanced neuro magnetic resonance imaging (MRI) techniques in the diagnosis of giant tumefactive PVSs and to further characterize these unusual cerebral lesions. Material and Methods The MRI scans of patients with tumefactive PVS diagnosed between 2010 and 2019 were retrospectively reviewed. All imaging studies included three plane conventional cerebral MRI sequences as well as precontrast 3D T1 MPRAGE, post-gadolinium 3D T1 acquisitions, sagittal plane 3D T2 SPACE, diffusion-weighted imaging, and time-of-flight (TOF) angiography. Some patients received perfusion MR, MR spectroscopy, diffusion tensor imaging (DTI), and contrast-enhanced TOF MR angiography. Results A perforating vessel was demonstrated in 16 patients (66.7%) by TOF imaging. In four patients, there were intracystic vascular collaterals on contrast-enhanced TOF MR angiography. Septal blooming was observed in four patients in susceptibility-weighted imaging. On perfusion MR, central hyperperfusion was observed in four patients, and peripheral hyperperfusion was observed in one patient. On MR spectroscopy, choline increase was observed in two patients, and there was a lactate peak in three patients, and both a choline increase and lactate peak in one patient. On DTI, there was fiber distortion in five patients and fiber deformation in one patient. Conclusion Advanced MRI techniques and 3D volumetric high-resolution MRI sequences can provide a valuable contribution to the diagnosis and can be successfully used in the management of these lesions.


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