Texture and shape analysis of diffusion‐weighted imaging for thyroid nodules classification using machine learning

2021 ◽  
Author(s):  
Ahmed Sharafeldeen ◽  
Mohamed Elsharkawy ◽  
Reem Khaled ◽  
Ahmed Shaffie ◽  
Fahmi Khalifa ◽  
...  
Stroke ◽  
2021 ◽  
Author(s):  
Arsany Hakim ◽  
Søren Christensen ◽  
Stefan Winzeck ◽  
Maarten G. Lansberg ◽  
Mark W. Parsons ◽  
...  

Background and Purpose: The ISLES challenge (Ischemic Stroke Lesion Segmentation) enables globally diverse teams to compete to develop advanced tools for stroke lesion analysis with machine learning. Detection of irreversibly damaged tissue on computed tomography perfusion (CTP) is often necessary to determine eligibility for late-time-window thrombectomy. Therefore, the aim of ISLES-2018 was to segment infarcted tissue on CTP based on diffusion-weighted imaging as a reference standard. Methods: The data, from 4 centers, consisted of 103 cases of acute anterior circulation large artery occlusion stroke who underwent diffusion-weighted imaging rapidly after CTP. Diffusion-weighted imaging lesion segmentation was performed manually and acted as a reference standard. The data were separated into 63 cases for training and 40 for testing, upon which quality metrics (dice score coefficient, Hausdorff distance, absolute lesion volume difference, etc) were computed to rank methods based on their overall performance. Results: Twenty-four different teams participated in the challenge. Median time to CTP was 185 minutes (interquartile range, 180–238), the time between CTP and magnetic resonance imaging was 36 minutes (interquartile range, 25–79), and the median infarct lesion size was 15.2 mL (interquartile range, 5.7–45). The best performance for Dice score coefficient and absolute volume difference were 0.51 and 10.1 mL, respectively, from different teams. Based on the ranking criteria, the top team’s algorithm demonstrated for average Dice score coefficient and average absolute volume difference 0.51 and 10.2 mL, respectively, outperforming the conventional threshold-based method (dice score coefficient, 0.3; volume difference, 15.3). Diverse algorithms were used, almost all based on deep learning, with top-ranked approaches making use of the raw perfusion data as well as methods to synthetically generate complementary information to boost prediction performance. Conclusions: Machine learning methods may predict infarcted tissue from CTP with improved accuracy compared with threshold-based methods used in clinical routine. This dataset will remain public and can be used to test improvement in algorithms over time.


2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Georgios Kaissis ◽  
Sebastian Ziegelmayer ◽  
Fabian Lohöfer ◽  
Hana Algül ◽  
Matthias Eiber ◽  
...  

Abstract Background To develop a supervised machine learning (ML) algorithm predicting above- versus below-median overall survival (OS) from diffusion-weighted imaging-derived radiomic features in patients with pancreatic ductal adenocarcinoma (PDAC). Methods One hundred two patients with histopathologically proven PDAC were retrospectively assessed as training cohort, and 30 prospectively accrued and retrospectively enrolled patients served as independent validation cohort (IVC). Tumors were segmented on preoperative apparent diffusion coefficient (ADC) maps, and radiomic features were extracted. A random forest ML algorithm was fit to the training cohort and tested in the IVC. Histopathological subtype of tumor samples was assessed by immunohistochemistry in 21 IVC patients. Individual radiomic feature importance was evaluated by assessment of tree node Gini impurity decrease and recursive feature elimination. Fisher’s exact test, 95% confidence intervals (CI), and receiver operating characteristic area under the curve (ROC-AUC) were used. Results The ML algorithm achieved 87% sensitivity (95% IC 67.3–92.7), 80% specificity (95% CI 74.0–86.7), and ROC-AUC 90% for the prediction of above- versus below-median OS in the IVC. Heterogeneity-related features were highly ranked by the model. Of the 21 patients with determined histopathological subtype, 8/9 patients predicted to experience below-median OS exhibited the quasi-mesenchymal subtype, whilst 11/12 patients predicted to experience above-median OS exhibited a non-quasi-mesenchymal subtype (p < 0.001). Conclusion ML application to ADC radiomics allowed OS prediction with a high diagnostic accuracy in an IVC. The high overlap of clinically relevant histopathological subtypes with model predictions underlines the potential of quantitative imaging in PDAC pre-operative subtyping and prognosis.


2018 ◽  
Vol 28 (4) ◽  
pp. 460 ◽  
Author(s):  
Soheil Kooraki ◽  
Leila Aghaghazvini ◽  
Hashem Sharifian ◽  
Nasrin Yazdani ◽  
Melina Hosseiny ◽  
...  

2019 ◽  
Author(s):  
Weidan Kong ◽  
Xiuhui Yue ◽  
Jiliang Ren ◽  
xiaofeng tao

Abstract Background: Diffusion-weighted imaging (DWI) and ultrasound are commonly used methods to examine thyroid nodules, but their comparative value is rarely studied. We evaluated the utility of DWI and ultrasound in differentiating benign and malignant thyroid nodules. Methods: A total of 100 patients with 137 nodules who underwent both DWI and ultrasound before operation were enrolled. The T1 and T2 signal intensity ratio (SIR) of each thyroid nodule was calculated by measuring the mean signal intensity divided by that of paraspinal muscle. The apparent diffusion coefficient (ADC) value and the SIR of benign and malignant thyroid nodules were analyzed by two-sample independent t tests. The sensitivity, specificity, and accuracy of DWI and ultrasound were compared with chi-square tests. Results: There was no significant difference in the SIR between benign and malignant thyroid nodules. The ADC value was significantly different. At the threshold value was 1.12 × 10 -3 mm 2 /s, the maximum area under the curve was 0.944. The sensitivity, specificity, and accuracy were 84.9%, 92.2%, and 87.6% respectively. The corresponding values of ultrasound diagnosis were 90.1%, 80.4%, and 86.9%. Conclusions: Ultrasound has high sensitivity in differentiating benign and malignant thyroid nodules, and the ADC value has high specificity, but there is no statistical difference in sensitivity or specificity between the two modalities. DWI and ultrasound each have their own advantages in differentiating benign and malignant thyroid nodules. Keywords Thyroid nodules, Ultrasound, Diffusion-weighted imaging


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1406
Author(s):  
Lan-Yan Yang ◽  
Tiing Yee Siow ◽  
Yu-Chun Lin ◽  
Ren-Chin Wu ◽  
Hsin-Ying Lu ◽  
...  

Precise risk stratification in lymphadenectomy is important for patients with endometrial cancer (EC), to balance the therapeutic benefit against the operation-related morbidity and mortality. We aimed to investigate added values of computer-aided segmentation and machine learning based on clinical parameters and diffusion-weighted imaging radiomics for predicting lymph node (LN) metastasis in EC. This prospective observational study included 236 women with EC (mean age ± standard deviation, 51.2 ± 11.6 years) who underwent magnetic resonance (MR) imaging before surgery during July 2010–July 2018, randomly split into training (n = 165) and test sets (n = 71). A decision-tree model was constructed based on mean apparent diffusion coefficient (ADC) value of the tumor (cutoff, 1.1 × 10−3 mm2/s), skewness of the relative ADC value (cutoff, 1.2), short-axis diameter of LN (cutoff, 1.7 mm) and skewness ADC value of the LN (cutoff, 7.2 × 10−2), as well as tumor grade (1 vs. 2 and 3), and clinical tumor size (cutoff, 20 mm). The sensitivity and specificity of the model were 94% and 80% for the training set and 86%, 78% for the independent testing set, respectively. The areas under the receiver operating characteristics curve (AUCs) of the decision-tree was 0.85—significantly higher than the mean ADC model (AUC = 0.54) and LN short-axis diameter criteria (AUC = 0.62) (both p < 0.0001). We concluded that a combination of clinical and MR radiomics generates a prediction model for LN metastasis in EC, with diagnostic performance surpassing the conventional ADC and size criteria.


2019 ◽  
Author(s):  
Wei dan Kong ◽  
Xiu hui Yue ◽  
Ji liang Ren ◽  
Xiao feng Tao

Abstract Background Diffusion weighted imaging and ultrasound are commonly used methods to examine thyroid nodules, but their comparative value is rarely studied. To evaluate the value of diffusion weighted imaging and ultrasound in differentiing benign and malignant thyroid nodules Methods A total of 100 patients with 137 nodules were enrolled. who underwent both diffusion weighted imaging and ultrasound before operation. T1 and T2 signal intensity ratio (SIR) of each thyroid nodule was calculated by measuring the mean signal intensity divided by that of paraspinal muscle. The value of ADC,signal intensity ratio (SIR) of benign and malignant thyroid nodules were analyzed by two independent sample t test. The sensitivity, specificity and accuracy of DWI and ultrasound were compared and analyzed by chi-square test. Results There was no significant difference in signal intensity ratio between benign and malignant thyroid nodules. The ADC value had significant difference. When the threshold value was 1.12 ×10-3 mm2/s, the maximum area under the curve was 0.944,The sensitivity, specificity and accuracy were 84.9%, 92.2% and 87.6% respectively. The sensitivity and specificity of ultrasound diagnosis were 90.1%, 80.4% and 86.9% respectively. Conclusion Ultrasound has high sensitivity in differentiating benign and malignant thyroid nodules, and ADC value has high specificity in differentiating thyroid nodules, but there is no statistical difference in sensitivity and specificity between the two. DWI and Ultrasound have their own advantages in differentiating benign and malignant thyroid nodules.


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