Multiphase convolutional dense network for the classification of focal liver lesions on dynamic contrast-enhanced computed tomography.

BACKGROUND: The accurate classification of focal liver lesions (FLLs) is essential to properly guide treatment options and predict prognosis. Dynamic contrast-enhanced computed tomography (DCE-CT) is still the cornerstone in the exact classification of FLLs due to its noninvasive nature, high scanning speed, and high-density resolution. Since their recent development, convolutional neural network-based deep learning techniques has been recognized to have high potential for image recognition tasks. AIM: To develop and evaluate an automated multiphase convolutional dense network (MP-CDN) to classify FLLs on multiphase CT. METHODS: A total of 517 FLLs scanned on a 320-detector CT scanner using a four-phase DCE-CT imaging protocol (including precontrast phase, arterial phase, portal venous phase, and delayed phase) from 2012 to 2017 were retrospectively enrolled. FLLs were classified into four categories: Category A, hepatocellular carcinoma (HCC); category B, liver metastases; category C, benign non-inflammatory FLLs including hemangiomas, focal nodular hyperplasias and adenomas; and category D, hepatic abscesses. Each category was split into a training set and test set in an approximate 8:2 ratio. An MP-CDN classifier with a sequential input of the four-phase CT images was developed to automatically classify FLLs. The classification performance of the model was evaluated on the test set; the accuracy and specificity were calculated from the confusion matrix, and the area under the receiver operating characteristic curve (AUC) was calculated from the SoftMax probability outputted from the last layer of the MP-CDN. RESULTS: A total of 410 FLLs were used for training and 107 FLLs were used for testing. The mean classification accuracy of the test set was 81.3% (87/107). The accuracy/specificity of distinguishing each category from the others were 0.916/0.964, 0.925/0.905, 0.860/0.918, and 0.925/0.963 for HCC, metastases, benign non-inflammatory FLLs, and abscesses on the test set, respectively. The AUC (95% confidence interval) for differentiating each category from the others was 0.92 (0.837-0.992), 0.99 (0.967-1.00), 0.88 (0.795-0.955) and 0.96 (0.914-0.996) for HCC, metastases, benign non-inflammatory FLLs, and abscesses on the test set, respectively. CONCLUSION: MP-CDN accurately classified FLLs detected on four-phase CT as HCC, metastases, benign non-inflammatory FLLs and hepatic abscesses and may assist radiologists in identifying the different types of FLLs.

Primary duodenal NK/T-cell lymphoma with massive bleeding: A case report.

Primary natural killer/T-cell (NK/T-cell) lymphoma of the gastrointestinal tract is a very rare disease with a poor prognosis, and the duodenum is quite extraordinary as a primary lesion site. Here, we describe a unique case of a primary duodenal NK/T-cell lymphoma in a 26-year-old man who presented with abdominal pain and weight loss. Abdominal computed tomography scan demonstrated a hypodense tumor in the duodenum. Because of massive upper gastrointestinal tract bleeding during hospitalization, the patient was examined by emergency upper gastrointestinal endoscopy. Under endoscopy, an irregular ulcer with mucosal edema, destruction, necrosis, a hyperplastic nodule and active bleeding was observed on the duodenal posterior wall. Following endoscopic hemostasis, a biopsy was obtained for pathological evaluation. The lesion was subsequently confirmed to be a duodenal NK/T-cell lymphoma. The presenting symptoms of primary duodenal NK-/T-cell lymphoma in this patient were abdominal pain and gastrointestinal bleeding, and endoscopy was important for diagnosis. Despite aggressive treatments, the prognosis was very poor.

[The clinical application of 320-slice Computed Tomography (CT) hepatic artery images in patients with liver transplantation].

OBJECTIVE: To evaluate the clinical significance of 320-slice CT hepatic artery images in patients with liver transplantation. METHODS: A total of 58 patients underwent CT scanning by 320-slice scanner after liver transplantation. They were divided into 2 groups according to the concentration of contrast media as follows: Group A (27 cases, 350 mgI/ml iopromide), Group B (31 cases, 370 mgI/ml iopromide). Contrast medium was infused at 6 ml/s, with a total dose of 50 ml. Images were generated by dynamic volume scanning and were processed by 4D digital subtraction angiography (DSA) imaging software. The time-density curve (TDC) of the hepatic artery was delineated. The time to peak, peak contrast enhancement were recorded. The physiological parameters such as body weight and height were analyzed. RESULTS: (1) There were no differences in clinical parameters such as age, sex, height, weight, or BMI between groups. The time to peak of hepatic artery of group A and B was (19.71+/-3.11) s and (20.06+/-3.67) s, and had no significant difference. The maximum peak enhancement of hepatic artery in groups B was higher than that group A (P < 0.05). (2) 4D DSA revealed hepatic artery pseudo-aneurysm (n = 2), and hepatic artery mild stenosis (n = 13), moderate stenosis (n = 5), severe stenosis (n = 9) and occlusion (n = 1), segmental moderate and severe stenosis (n = 4), and compensatory circulation with hepatic artery severe stenosis and occlusion (n = 6). hepatoportal arteriovenous fistulas (HPAVF, n = 12), donor-recipient hepatic artery mismatch (n = 3). Hepatic arterial branch are decreased and opened in 15 cases and 8 cases. CONCLUSION: 320-slice CT hepatic artery images is safe, noninvasive, and accurate technique to evaluate hepatic arterial complications after liver transplantation.

[Low dose contrast-enhanced 4D DSA with the 320-detector row computed tomography scanner for post-operative evaluation of the hepatic artery complications after liver transplantation].

OBJECTIVE: To evaluate the value of low-dose contrast-enhanced 4D DSA acquired from 320-detector row CT on the diagnosis of the hepatic artery complications after liver transplantation. METHODS: 320-detector row CT were performed in fifth patients with liver dynamic enhanced using volume CT body-perfusion protocol, hepatic artery phase images obtained after intravenous injection of 50 ml of contrast at a rate of 6 ml/s were acquired based on 4D DSA. The time-density curve (TDC) of the hepatic artery was delineated. The time to peak, peak contrast enhancement were recorded. The data of artery phase were sent to workstation to reconstruct the hepatic artery with VR, MIP and MPR. RESULTS: The delay mean time and the peak CT value of hepatic artery was 20 (10.0 - 24.2) s and 373 (310 - 440) HU; 4D DSA revealed hepatic artery pseudo-aneurysm (n = 2), and hepatic artery mild stenosis (n = 3), moderate stenosis (n = 4), severe stenosis (n = 1) and occlusion (n = 1). Compensatory circulation was seen in 2 cases. 4 patients were appeared segmental stenosis and hepatoportal arteriovenous fistulas (HPAVF). Hepatic arterial branch are decreased and opened in 9 cases and 4 cases. 4D DSA also displayed other signs including hepatic hemangioma and the splenic artery aneurysms (SAA) and ectasi (n = 1), donor-recipient hepatic artery mismatch (n = 3). CONCLUSION: 4D DSA provided a safe, noninvasive and accurate method for guiding the diagnosis of hepatic artery complication and play an effective role after liver transplantation.

[Diagnostic value of multislice spiral CT and MRI in detection of tumor recurrence after liver transplantation for hepatocellular carcinoma].

OBJECTIVE: To investigate the manifestation and diagnostic value of multislice spiral CT (MSCT) and MRI imaging in detection of tumor recurrence after liver transplantation for hepatocellular carcinoma (HCC). METHODS: The clinical data of 161 consecutive HCC patients who underwent orthotopic liver transplantation were retrospectively reviewed. Twenty-nine HCC patients were classified by pTNM according to the "Pittsburgh criteria". MSCT and MRI findings of tumor recurrence after liver transplantation were evaluated retrospectively in 29 stage II-IVb HCC patients. The recurrence site and relapse interval between liver transplantation and recurrence were analyzed. RESULTS: Lung tumor recurrence were found in 21 cases, presented as cotton-like lesions in a diameter of 2 - 3 cm, with a clear margin and homogeneous density. Pleural tumor recurrence was detected in 4 cases. Liver tumor recurrence were found in 9 cases, which can be divided into four subtypes: multinodular in 4 cases, diffuse lesion in 2 cases, huge mass in 2 cases, and uninodular in 1 case. Two cases showed tumor thrombus in the inferior vena cava and portal vein. Lymph node tumor recurrence was found in 9 cases, presented as multiple nodules at hepatic hilum, lesser peritoneal sac, posterior mediastinum, retroperitoneum, or around pancreatic head, and accompanied with merging and necrosis in one case. Bone tumor recurrence were found as osteolytic destruction in 4 cases, and accompanied with adjacent soft-tissue mass in 2 cases. The recurrence sites of the 29 cases were as following: lung (21 cases, 72.4%), liver (9 cases, 31.0%), lymph nodes (9 cases, 31.0%), bone (4 cases, 13.8%) and other sites (3 cases, 10.3%). Lung tumor recurrence was found in all the 10 stage IVb patients with tumor recurrence after liver transplantation, significantly more frequent than that in stage IVa patients (P = 0.023). After liver transplantation, all 25 patients with stage III approximately IVb HCC developed recurrence within one year, but in the 4 cases with stage II HCC at one year later (P = 0.009). CONCLUSION: The results of our study show that in hepatocellular carcinoma patients after liver transplantation, the lung and pleura are the most frequent site of recurrence, followed by liver, lymph node and bone as the second and third sites. The Stage IVb hepatocellular carcinoma should be regarded as a contradiction for liver transplantation due to rapid recurrence. Tumor recurrence occurs later in stage II HCC than in stage III approximately IVb patients. MSCT and MRI are of significant importance in diagnosis and formulating operation plan in HCC patients with recurrence after liver transplantation.