Journal of X-Ray Science and Technology - Volume 29, issue 1

Authors: He, Junlin | Zhang, Heng | Wang, Xian | Sun, Zongqiong | Ge, Yuxi | Wang, Kang | Yu, Chunjing | Deng, Zhaohong | Feng, Jianxin | Xu, Xin | Hu, Shudong

Article Type: Research Article

Abstract: OBJECTIVE: To investigate efficiency of radiomics signature to preoperatively predict histological features of aggressive extrathyroidal extension (ETE) in papillary thyroid carcinoma (PTC) with biparametric magnetic resonance imaging findings. MATERIALS AND METHODS: Sixty PTC patients with preoperative MR including T2WI and T2WI-fat-suppression (T2WI-FS) were retrospectively analyzed. Among them, 35 had ETE and 25 did not. Pre-contrast T2WI and T2WI-FS images depicting the largest section of tumor were selected. Tumor regions were manually segmented using ITK-SNAP software and 107 radiomics features were computed from the segmented regions using the open Pyradiomics package. Then, a random forest model was built to …do classification in which the datasets were partitioned randomly 10 times to do training and testing with ratio of 1:1. Furthermore, forward greedy feature selection based on feature importance was adopted to reduce model overfitting. Classification accuracy was estimated on the test set using area under ROC curve (AUC). RESULTS: The model using T2WI-FS image features yields much higher performance than the model using T2WI features (AUC = 0.906 vs. 0.760 using 107 features). Among the top 10 important features of T2WI and T2WI-FS, there are 5 common features. After feature selection, the models trained using top 2 features of T2WI and the top 6 features of T2WI-FS achieve AUC 0.845 and 0.928, respectively. Combining features computed from T2WI and T2WI-FS, model performance decreases slightly (AUC = 0.882 based on all features and AUC = 0.913 based on top features after feature selection). Adjusting hyper parameters of the random forest model have negligible influence on the model performance with mean AUC = 0.907 for T2WI-FS images. CONCLUSIONS: Radiomics features based on pre-contrast T2WI and T2WI-FS is helpful to predict aggressive ETE in PTC. Particularly, the model trained using the optimally selected T2WI-FS image features yields the best classification performance. The most important features relate to lesion size and the texture heterogeneity of the tumor region. Show more

Keywords: Thyroid cancer, neoplasm staging, radiomics, diagnosis, magnetic resonance imaging

DOI: 10.3233/XST-200760

Citation: Journal of X-Ray Science and Technology, vol. 29, no. 1, pp. 171-183, 2021

Authors: Zhang, Zejian | Chen, Dong | Deng, Ling | Li, Wei | Wang, Xisheng | Zhang, Yixiang | Liekui, Fang | Feloney, Michael P. | Zhang, Yuanyuan

Article Type: Research Article

Abstract: PURPOSE: To avoid Iatrogenic ureteral injury during retroperitoneal laparoscopy for large renal cyst (diameter > 70 mm), we present two cases of iatrogenic ureteral injury and discuss their clinical courses and final outcomes. PATIENTS AND METHODS: Two male patients (47 years old and 74 years old) with large left simple renal cysts underwent a retroperitoneal laparoscopic operation to treat the cysts. In the first patient, the left proximal ureter was partially transected (Grade 3) during the operation. The injury was identified intraoperatively. The transection was managed with a primary ureteroureterostomy (end to end) along with a double J ureteral stent. In …the second patient, the left proximalureter was partially transected (Grade 4). However, the injury was unrecognized postoperatively for two days. After recognition of the complication, the injury was managed with an early primary ureteroureterostomy, which followed a failed attempt to place ureteral stent endoscopically. RESULTS: In the first patient, a postoperative urinary leakage developed and lasted for 13 days. During long term follow-up of the first patient after the urine leak resolved, there were no reports of pain in the lumbar region or other discomfort. No recurrence of the renal cyst occurred, which was confirmed with an ultrasound at one year postoperatively. In the second patient a ureteral fistula and severe perirenal infection occurred and lasted for 86 days. The patient ultimately underwent a left nephrectomy after conservative management for this surgical complication failed. This patient developed a chronic wound infection that lasted for 3.14 months following the nephrectomy. During follow-up post nephrectomy, the patient developed stage 3B moderate chronic kidney disease (CKD) (GFR = 30 –44 ml/min). CONCLUSIONS: For single large (diameter > 70 mm) renal cysts located at the lower pole of the kidney, it is recommended to not completely dissect out and mobilize the entire renal cyst for cyst decortication in order to avoid injuring the ureter. Iatrogenic ureteral injury increases the risk of readmission and serious life-threatening complications. The immediate diagnosis and proper management ureteric injury can reduce complications and long term sequalae. Show more

Keywords: Renal cyst, iatrogenic ureteral injury, laparoscopic renal cyst decortication

DOI: 10.3233/XST-200804

Citation: Journal of X-Ray Science and Technology, vol. 29, no. 1, pp. 185-196, 2021