Computed tomography radiogenomics: A potential tool for prediction of molecular subtypes in gastric stromal tumor.

BACKGROUND: Preoperative knowledge of mutational status of gastrointestinal stromal tumors (GISTs) is essential to guide the individualized precision therapy. AIM: To develop a combined model that integrates clinical and contrast-enhanced computed tomography (CE-CT) features to predict gastric GISTs with specific genetic mutations, namely KIT exon 11 mutations or KIT exon 11 codons 557-558 deletions. METHODS: A total of 231 GIST patients with definitive genetic phenotypes were divided into a training dataset and a validation dataset in a 7:3 ratio. The models were constructed using selected clinical features, conventional CT features, and radiomics features extracted from abdominal CE-CT images. Three models were developed: ModelCT sign, modelCT sign + rad, and model CTsign + rad + clinic. The diagnostic performance of these models was evaluated using receiver operating characteristic (ROC) curve analysis and the Delong test. RESULTS: The ROC analyses revealed that in the training cohort, the area under the curve (AUC) values for modelCT sign, modelCT sign + rad, and modelCT sign + rad + clinic for predicting KIT exon 11 mutation were 0.743, 0.818, and 0.915, respectively. In the validation cohort, the AUC values for the same models were 0.670, 0.781, and 0.811, respectively. For predicting KIT exon 11 codons 557-558 deletions, the AUC values in the training cohort were 0.667, 0.842, and 0.720 for modelCT sign, modelCT sign + rad, and modelCT sign + rad + clinic, respectively. In the validation cohort, the AUC values for the same models were 0.610, 0.782, and 0.795, respectively. Based on the decision curve analysis, it was determined that the modelCT sign + rad + clinic had clinical significance and utility. CONCLUSION: Our findings demonstrate that the combined modelCT sign + rad + clinic effectively distinguishes GISTs with KIT exon 11 mutation and KIT exon 11 codons 557-558 deletions. This combined model has the potential to be valuable in assessing the genotype of GISTs.

Preoperative prediction of gastrointestinal stromal tumors with high Ki-67 proliferation index based on CT features.

BACKGROUND: To determine whether preoperative computed tomography (CT) features can be used for the prediction of gastrointestinal stromal tumors (GISTs) with a high Ki-67 proliferation index (Ki-67 PI). METHODS: A total of 198 patients with surgically and pathologically proven GISTs were retrospectively included. All GISTs were divided into a low Ki-67 PI group (<10%) and a high Ki-67 PI group (≥10%). All imaging features were blindly interpreted by two radiologists. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the predictive performance of the imaging features. RESULTS: Imaging features were found to be significantly different between the low and the high Ki-67 PI groups (P<0.05). Wall thickness of necrosis showed the highest predictive ability, with an area under the curve (AUC) of 0.838 [95% confidence interval (CI): 0.627-0.957], followed by necrosis, necrosis degree, hyperenhancement of the overlying mucosa (HYOM), and long diameter (LD) (AUC >0.7, P<0.05). HYOM was the strongest predictive feature for the high Ki-67 PI GISTs group, with an odds ratio (OR) value of 30.037 (95% CI: 5.707-158.106). CONCLUSIONS: Imaging features, including the presence of necrosis, high necrosis degree, thick wall of necrosis, and HYOM were significant predictive indicators for the high Ki-67 PI GISTs group.

Insight into gastrointestinal heterotopic pancreas: imaging evaluation and differential diagnosis.

Heterotopic pancreas (HP) is an uncommon congenital abnormality in the developmental process of the pancreas, with gastrointestinal heterotopic pancreas (GHP) being the most common HP. The clinical manifestations of GHP may have variable patterns of presentation, dictated by both the anatomic location and the functional ability of the lesion. The most common imaging modality in detecting GHP is computed tomography (CT), while gastrointestinal barium fluoroscopy, endoscopic ultrasonography, and magnetic resonance imaging (MRI) are also applied. The density and enhancement patterns of GHP are consistent with histological classifications. GHP with a predominantly acinar tissue component manifests homogeneous and marked enhancement on CT images, whereas a predominantly ductal GHP presents heterogeneous and mild enhancement. On MRI, the appearance and signal intensity of GHP were paralleled to the normal pancreas on all sequences and were characterized by T1-weighted high signal and early marked enhancement. This article provides a comprehensive review of the histopathology, clinical manifestations, imaging features of various modalities, and differential diagnosis of GHP. It is hoped that this review will improve clinicians' knowledge of GHP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate.

Clinical and radiological outcomes of dynamic cervical implant arthroplasty: A 5-year follow-up.

BACKGROUND: Dynamic cervical implant (DCI) stabilization has been reported to have satisfactory clinical and radiological results with short- and mid-term follow-up in the treatment of cervical degenerative disc disease. However, few reports about the clinical and radiological outcome with more than 5-year follow-up exist. AIM: To investigate the long-term clinical and radiological results of DCI arthroplasty. METHODS: A total of 40 patients who received DCI arthroplasty were consecutively reviewed from May 2010 to August 2015. Visual analogue scale (VAS), neck disability index (NDI) score, Japanese Orthopaedic Association (JOA) score, and SF-36 items were used to assess neural function rehabilitation. Static and dynamic radiographs and 3-dimentional computed tomography were used to evaluate the radiological outcomes. RESULTS: The scores of neck/arm VAS, NDI, JOA, and 8-dimensions of SF-36 were significantly improved at the 1-mo follow-up (P < 0.05) and maintained until the last follow-up (P < 0.05). The range of motion (ROM) of C2-C7, functional spinal unit (FSU), upper/lower adjacent level, C2-C7 lateral bending, and FSU lateral bending decreased at the 1-mo follow-up (P < 0.05), whereas they increased to the preoperative level at the later follow-up intervals (P > 0.05), except the ROM of FSU lateral bending (P < 0.05). The C2-C7 alignment and FSU angle kept more lordotic at the last follow-up (P < 0.05). The intervertebral height increased significantly at the 1-mo follow-up (P < 0.05) and decreased at later follow-ups (P > 0.05). At the last follow-up, 12 (26.1%) segments developed heterotopic ossification. CONCLUSION: DCI arthroplasty is a safe and effective non-fusion technique to treat cervical degenerative disc disease in long-term follow-up.

Massive Calcified Epithelioid Hemangioendothelioma With Multifocal Involvement: An Imaging Diagnosis Dilemma and a Rare Case Report.

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor that develops from vascular endothelial or pre-endothelial cells. More than 60% patients have single-organ involvement, and involvement of multiple organs including the liver, lungs, and bones is extremely rare. The typical radiographic features of EHE include multiple small nodules in both lungs, which are usually located near small- and medium-sized blood vessels and the bronchi, and solitary, multiple, or diffuse lesions located at the hepatic periphery, spreading within the branches of the portal and hepatic veins. Radiologic calcification has been rarely reported in the literature. Here, we firstly described a case of a 53-year-old woman with EHE who presented with lungs, liver, bone, and right hilar lymph node involvement, manifesting as massive calcification on computed tomography. This case reminds physicians that EHE may present with unusual imaging manifestations, like massive calcification, and should be considered during the diagnostic process.

Use of computed tomography for distinguishing heterotopic pancreas from gastrointestinal stromal tumor and leiomyoma.

PURPOSE: To determine whether morphologic features and semiquantitative parameters of computed tomography (CT) could be used to distinguish heterotopic pancreas from gastrointestinal stromal tumor (GIST) and leiomyoma. METHODS: This retrospective study evaluated CT images of heterotopic pancreases (n = 28), GISTs (n = 57), and leiomyomas (n = 26) located in the upper gastrointestinal tract. Morphologic imaging features of lesions were analyzed, including location, contour, margin, attenuation, growth pattern, enhancement type, enhancement degree, enlarged vessels feeding or draining the mass, hyperenhancement of the overlying mucosa, low intralesional attenuation, calcification, and a duct-like structure. Semiquantitative parameters included long diameter (LD), short diameter (SD), LD/SD ratio, and lesion and aorta CT values during plain CT (Lp and Ap), arterial phase (La and Aa), and venous phase (Lv and Av). Diagnostic performance of these findings and parameters were evaluated by receiver operating characteristic (ROC) analysis. RESULTS: Morphologic CT findings (including lesion contour, margin, attenuation, growth pattern, enhancement type, and enhancement degree) and semiquantitative parameters except for LD/SD were demonstrated to be significant for differentiating heterotopic pancreas from GIST and leiomyoma (all P < 0.01). Of these, location, low intralesional attenuation, duct-like structure and LD, SD, Lv, and Sv values showed good diagnostic performance with the areas under curve (AUC) higher than 0.70. The presence of a duct-like structure demonstrated the best diagnostic ability with AUC of 0.929 [95% confidence interval (CI) 0.864-0.969], sensitivity of 5.7% (95% CI 67.3-96.0), and specificity of 100% (95% CI 95.7-100), respectively. When the three morphologic features (location, low intralesional attenuation, duct-like structure) were used in combination, the AUC was improved to 0.980 (95% CI 0.952-1). CONCLUSION: CT features, especially the morphologic features, could be used to differentiate heterotopic pancreas from GIST and leiomyoma in the upper gastrointestinal tract and, thus, provide a more accurate method for non-invasive preoperative diagnosis. Additionally, the presence of a duct-like structure demonstrated to be a reliable indicator for heterotopic pancreas among the morphologic and semiquantitative CT features.

Current and Potential Applications of Artificial Intelligence in Gastrointestinal Stromal Tumor Imaging.

The most common mesenchymal tumors are gastrointestinal stromal tumors (GISTs), which have malignant potential and can occur anywhere along the gastrointestinal system. Imaging methods are important and indispensable of GISTs in diagnosis, risk staging, therapy, and follow-up. The recommended imaging method for staging and follow-up is computed tomography (CT) according to current guidelines. Artificial intelligence (AI) applies and elaborates theses, procedures, modes, and utilization systems for simulating, enlarging, and stretching the intellectual capacity of humans. Recently, researchers have done a few studies to explore AI applications in GIST imaging. This article reviews the present AI studies in GISTs imaging, including preoperative diagnosis, risk stratification and prediction of prognosis, gene mutation, and targeted therapy response.

Liver fibrosis is a major risk factor for liver regeneration: A comparison between healthy and fibrotic liver.

BACKGROUND: Blood flow factors, such as congestion or ischemia after hepatectomy, have a significant impact on liver regeneration, but with the popularization of precise hepatectomy technology, segmental hepatectomy without congestion or ischemia has become the preferred treatment. Our aim is to investigate the factors affecting liver regeneration after hepatectomy without blood flow changes, and to provide clinical evidence for surgeons on the timing of second hepatectomy for cirrhosis patients with hepatocellular carcinoma (HCC). METHODS: This study retrospectively analyzed data from patients who underwent right hepatectomy without middle hepatic vein (MHV) in West China Hospital between January 2016 and January 2018. Eighteen living-donors without MHV as normal group and 45 HCC patients, further classified into 3 subgroups based on the severity of fibrosis using the Scheure system. Demographic data, pre- and postoperative liver function indexes, and remnant liver volume (RLV) were retrospectively compared. We also analyzed the remnant liver regeneration rate (RLRR) post-operatively in each group. The significant indexes in univariate analysis were further analyzed using both receiver operating characteristic (ROC) analysis and multivariate regression analysis. RESULTS: Liver regeneration occurred in both living-donor and HCC groups after hepatectomy; the RLRRs at 1 month were 59.46 ±â€Š10.39% and 57.27 ±â€Š4.77% (P = .509), respectively. Regeneration in the cirrhosis group occurred more slowly and less completely compared with that in other groups. The regeneration rate in the first 6 months showed rapid increase and the RLRR reached above 70% in cirrhosis group. Multivariate and ROC analyses revealed that Alb and the hepatic fibrosis grade in the early postoperative period were significant predictors of remnant liver regeneration. CONCLUSION: The liver regenerated in all HCC patients; however, regeneration was significantly slower and less complete compared with the normal liver, especially in the patients with cirrhosis. Therefore, it can be concluded that the degree of liver fibrosis is a major predictor of liver regeneration. Furthermore, the optimal time for second resection in recurrent HCC patients with cirrhosis was 6 months after the first operation.

Multi-modal radiomics model to predict treatment response to neoadjuvant chemotherapy for locally advanced rectal cancer.

BACKGROUND: Neoadjuvant chemotherapy is currently recommended as preoperative treatment for locally advanced rectal cancer (LARC); however, evaluation of treatment response to neoadjuvant chemotherapy is still challenging. AIM: To create a multi-modal radiomics model to assess therapeutic response after neoadjuvant chemotherapy for LARC. METHODS: This retrospective study consecutively included 118 patients with LARC who underwent both computed tomography (CT) and magnetic resonance imaging (MRI) before neoadjuvant chemotherapy between October 2016 and June 2019. Histopathological findings were used as the reference standard for pathological response. Patients were randomly divided into a training set (n = 70) and a validation set (n = 48). The performance of different models based on CT and MRI, including apparent diffusion coefficient (ADC), dynamic contrast enhanced T1 images (DCE-T1), high resolution T2-weighted imaging (HR-T2WI), and imaging features, was assessed by using the receiver operating characteristic curve analysis. This was demonstrated as area under the curve (AUC) and accuracy (ACC). Calibration plots with Hosmer-Lemeshow tests were used to investigate the agreement and performance characteristics of the nomogram. RESULTS: Eighty out of 118 patients (68%) achieved a pathological response. For an individual radiomics model, HR-T2WI performed better (AUC = 0.859, ACC = 0.896) than CT (AUC = 0.766, ACC = 0.792), DCE-T1 (AUC = 0.812, ACC = 0.854), and ADC (AUC = 0.828, ACC = 0.833) in the validation set. The imaging performance for extramural venous invasion detection was relatively low in both the training (AUC = 0.73, ACC = 0.714) and validation (AUC = 0.578, ACC = 0.583) sets. The multi-modal radiomics model reached an AUC of 0.925 and ACC of 0.886 in the training set, and an AUC of 0.93 and ACC of 0.875 in the validation set. For the clinical radiomics nomogram, good agreement was found between the nomogram prediction and actual observation. CONCLUSION: A multi-modal nomogram using traditional imaging features and radiomics of preoperative CT and MRI adds accuracy to the prediction of treatment outcome, and thus contributes to the personalized selection of neoadjuvant chemotherapy for LARC.

Hepatocellular carcinoma: Can LI-RADS v2017 with gadoxetic-acid enhancement magnetic resonance and diffusion-weighted imaging improve diagnostic accuracy?

BACKGROUND: The Liver Imaging Reporting and Data System (LI-RADS), supported by the American College of Radiology (ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma (HCC). Diffusion-weighted imaging (DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging (MRI) for HCC. AIM: To determine whether the use of DWI can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC. METHODS: In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity (SE), specificity (SP), accuracy (AC), positive predictive value (PPV), and negative predictive value (NPV) of LI-RADS were calculated. Youden index values were used to compare the diagnostic performance of LI-RADS with or without DWI. RESULTS: Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS (kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and 71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and 75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR- 4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%, 75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647. CONCLUSION: LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC.

Mediastinal myelolipoma/extramedullary hematopoiesis presenting as a mass: rare differential diagnosis among mediastinal tumors.

OBJECTIVES: Mediastinal myelolipoma/extramedullary hematopoiesis presenting as a mass is infrequent and can lead to misdiagnosis. Here we describe a large series aiming to illustrate the clinicopathologic features. METHODS: We retrospectively searched mediastinal tumors and myelolipoma diagnosed at the Department of Pathology, West China Hospital from 2010 to 2015 and collected 14 mediastinal myelolipoma/extramedullary hematopoiesis cases presenting as an encapsulated mass among 1324 mediastinal mass diseases and 252 myelolipomas. RESULTS: There were 8 females and 6 males aged from 35 to 67 years old, most of whom were diagnosed incidentally. Cross-sectional imaging revealed encapsulated masses located in the posterior mediastinum with fat and soft tissue density showing heterogeneous enhancement. Radiologic diagnosis was neurogenic tumor for most cases. All but one patient underwent surgery and postoperative pathologic findings showed fat and hematologic elements. Considering the accompanying hematologic disorders, 5 patients were diagnosed as extramedullary hematopoiesis and the remaining 9 as myelolipoma. The average hematopoietic tissue percentage in extramedullary hematopoiesis was 70%, significantly higher than it was in myelolipoma. Patients showed no sign of recurrence or metastasis apart from the patient with hepatocellular carcinoma. CONCLUSIONS: Mediastinal myelolipoma/extramedullary hematopoiesis is a rare entity of solid tumors in the posterior mediastinum, affecting patients from their third decades, with no sex predilection and lacking unique clinical symptoms, and may be misdiagnosed as a malignant tumor on cross-sectional imaging. The final diagnosis relies on pathologic findings, and the precise classification of myelolipoma or extramedullary hematopoiesis relies on percentage of hematopoietic tissue and accompanying clinical symptoms. Surgery is the recommended treatment.

Diagnostic Utility of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Small Solid Renal Tumors (≤ 4 cm) at 3.0T Magnetic Resonance Imaging.

BACKGROUND: The aim of this study was to assess the performance of apparent diffusion coefficient (ADC) measurement obtained with diffusion-weighted magnetic resonance imaging (DW-MRI) to distinguish renal cell carcinomas (RCCs) from small benign solid renal tumors (≤ 4 cm). METHODS: In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/mm 2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. RESULTS: The tumors consisted of 33 cases of clear-cell RCCs (ccRCCs) and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases of oncocytomas. The ADCs showed significant differences among benign tumors ([0.90 ± 0.52] × 10-3 mm 2 /s), ccRCCs ([1.53 ± 0.31] × 10-3 mm 2 /s) and the normal renal parenchyma ([2.22 ± 0.12] × 10-3 mm 2 /s) (P < 0.001). Moreover, there was statistically significant difference between high and low-grade ccRCCs (P = 0.004). Using a cut-off ADC of 1.36 × 10-3 mm 2 /s, DW-MRI resulted in an area under the curve (AUC), sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor (inside the contour of the kidney) and appearance of stiff blood vessel were significantly helpful for diagnosing ccRCCs. CONCLUSIONS: DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors (≤ 4 cm), and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.

Magnetic resonance tumor targeting imaging using gadolinium labeled human telomerase reverse transcriptase antisense probes.

To develop a molecular probe for MRI detection of human tumor telomerase reverse transcriptase (hTERT) mRNA expression. Uniformly phosphorothioate-modified hTERT antisense oligonucleotide (ASON) homing hTERT mRNA was labeled with gadolinium (Gd) through the bifunctional chelator 1,4,7, 10-tetraazacyclododecane-N, N', N'', N'''-tetraacetic acid (DOTA) stirred within 45 minutes at 60 °C. The Gd labeled probes were characterized in vitro. The cellular uptake rate and biodistribution of (99m) Tc-DOTA-ASON was measured instead of that of Gd-DOTA-ASON. A549 lung adenocarcinoma model was established in BALB/c nude mice and Gd-DOTA-ASON was injected intraperitoneally and MR images were acquired using 7.0T Micro-MRI (Bruker Biospec, Ettlingen, Germany) at different time points. Immunohistochemical analysis of telomerase activity of each xenograft was operated two days after in vivo imaging. The binding efficiency of Gd-DOTA-ASON reached as high as 71.7 ± 4.5% (n = 6). Gd-DOTA-ASON displayed perfect stability in fresh human serum at 37 °C for 24 h. Compared with normal lung cells, A549 cells showed an obviously higher uptake of (99m) Tc-DOTA-ASON than that of lung cells (10.5 ± 2.7% vs. 4.8 ± 2.6%, P < 0.05). The signal intensity of A549 xenografts can be enhanced by Gd-DOTA-ASON and the signal to noise ratio (SNR) of tumor to muscle reached 2.37 and maintained a relatively high level within 6 h after injection. The activity of hTERT in A549 tumors can be suppressed by Gd-DOTA-ASON in pathological slices. The results of this study show that Gd-DOTA-ASON can be a promising intracellular MR contrast probe for targeting telomerase-positive carcinomas.

[Correlation analysis of computed tomography imaging scoring to the presence of acute kidney injury in severe acute pancreatitis].

OBJECTIVE: To investigate the multi-detector-row spiral CT (MDCT) imaging findings of severe acute pancreatitis (SAP) complicated with acute kidney injury (AKI), and to evaluate the correlation of MDCT imaging scoring to the presence of AKI in SAP. METHODS: One hundred and nineteen patients with confirmed diagnosis of SAP during March 2008-December 2010 in our hospital were retrospectively included into the study. The imaging features including pancreatic size, areas and degrees of pancreatic necrosis, peripancreatic retroperitoneal and intraperitoneal inflammation and other organs involvement (liver, kidney, spleen, gastrointestinal tract, etc.) were observed, as well as related CT severity indexes such as Balthazar CT score, CT severity index (CTSI) and extra-pancreatic inflammation on CT (EPIC) score were calculated. At the mean time, the clinical data including serum creatinine, urine output and the eventual prognosis were collected and compared with CT indexes, which was used for statistical analysis. RESULTS: SAP with AKI patients were often associated with the high incidence of multiple organ dysfunction (MODS) (88.1%) and high mortality (47.6%). In SAP with AKI patients, the CT indexes were significantly higher than those of SAP without AKI patients. Among the CT indexes, EPIC score showed the larger area under the ROC curve (AUC = 0.903) than CTSI score (AUC = 0.721) and Balthazar CT score (AUC = 0.571). CONCLUSION: Among the CT indexes, EPIC score has a better prediction of AKI in SAP patients than CTSI and Balthazar CT scores.