Preoperative prediction of perineural invasion of rectal cancer based on a magnetic resonance imaging radiomics model: A dual-center study.

BACKGROUND: Perineural invasion (PNI) has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer (RC). Preoperative prediction of PNI status is helpful for individualized treatment of RC. Recently, several radiomics studies have been used to predict the PNI status in RC, demonstrating a good predictive effect, but the results lacked generalizability. The preoperative prediction of PNI status is still challenging and needs further study. AIM: To establish and validate an optimal radiomics model for predicting PNI status preoperatively in RC patients. METHODS: This retrospective study enrolled 244 postoperative patients with pathologically confirmed RC from two independent centers. The patients underwent pre-operative high-resolution magnetic resonance imaging (MRI) between May 2019 and August 2022. Quantitative radiomics features were extracted and selected from oblique axial T2-weighted imaging (T2WI) and contrast-enhanced T1WI (T1CE) sequences. The radiomics signatures were constructed using logistic regression analysis and the predictive potential of various sequences was compared (T2WI, T1CE and T2WI + T1CE fusion sequences). A clinical-radiomics (CR) model was established by combining the radiomics features and clinical risk factors. The internal and external validation groups were used to validate the proposed models. The area under the receiver operating characteristic curve (AUC), DeLong test, net reclassification improvement (NRI), integrated discrimination improvement (IDI), calibration curve, and decision curve analysis (DCA) were used to evaluate the model performance. RESULTS: Among the radiomics models, the T2WI + T1CE fusion sequences model showed the best predictive performance, in the training and internal validation groups, the AUCs of the fusion sequence model were 0.839 [95% confidence interval (CI): 0.757-0.921] and 0.787 (95%CI: 0.650-0.923), which were higher than those of the T2WI and T1CE sequence models. The CR model constructed by combining clinical risk factors had the best predictive performance. In the training and internal and external validation groups, the AUCs of the CR model were 0.889 (95%CI: 0.824-0.954), 0.889 (95%CI: 0.803-0.976) and 0.894 (95%CI: 0.814-0.974). Delong test, NRI, and IDI showed that the CR model had significant differences from other models (P < 0.05). Calibration curves demonstrated good agreement, and DCA revealed significant benefits of the CR model. CONCLUSION: The CR model based on preoperative MRI radiomics features and clinical risk factors can preoperatively predict the PNI status of RC noninvasively, which facilitates individualized treatment of RC patients.

The CT-guided percutaneous drainage of pancreatic pseudocyst accompanied by pseudoaneurysm: A case report.

RATIONALE: This case report discusses the CT-guided percutaneous drainage of a pancreatic pseudocyst accompanied by a pseudoaneurysm. Pancreatic pseudocysts can erode the peripancreatic artery and produce pseudoaneurysms. This is rare, but it can be life-threatening. PATIENT CONCERNS: The case presented involves a 58-year-old female who was diagnosed with pancreatic cancer and underwent surgical treatment. She presented with hematochezia, dizziness, and hypodynamic findings with no obvious cause. Imaging revealed a pancreatic pseudocyst and small arterial aneurysms. To reduce the risk of aneurysm rupture, the patient underwent transcatheter arterial coil embolization. Three days later, CT-guided catheter drainage was performed to reduce the erosion of the arterial wall caused by pancreatic fluid. DIAGNOSES: The contrast-enhanced-CT imaging showed a round, slightly high-density lesion in the cyst, suggesting the presence of a pseudoaneurysm. INTERVENTIONS: The patient was sent for another transcatheter arterial embolization with coils and n-butyl-2-cyanoacrylate. OUTCOMES: After receiving the transcatheter arterial embolization, the patient had no serious bleeding or other complications. LESSONS: Early detection and accurate assessment of pseudoaneurysms are essential for appropriate management. This case shows that contrast-enhanced CT is necessary before CT-guided percutaneous drainage of pancreatic pseudocysts. It also shows that, due to the many complications that pancreatic pseudocysts may cause, appropriate treatment of pseudocysts complicated with pseudoaneurysm has important clinical significance.

MR Imaging of Migrated Nucleus Pulposus after Collagenase Injection of Lumbar Disc Herniation: A Case Report.

Magnetic resonance images (MRI) of migrated nucleus pulposus after collagenase treatment of lumbar disc herniation are rarely published. Here, we describe a 65-year-old woman with L5-S1 intervertebral disc herniation on the rear left. The patient was treated with a lumbar disc collagenase injection, and the pain was relieved. Two weeks later, the patient suddenly developed pain again after engaging in weight-bearing activity. Lumbar MRI showed a nodule in the spinal canal at the L5-S1 level. The patient underwent surgical treatment two days later. Pathology showed that the nodule was nucleus pulposus tissue. Teaching point: It is important to understanding the MR manifestations of migrated nucleus pulposus after collagenase treatment to prevent such misdiagnosis.