Apparent diffusion coefficient-based histogram analysis differentiates histological subtypes of periampullary adenocarcinoma.

BACKGROUND: For periampullary adenocarcinoma, the histological subtype is a better prognostic predictor than the site of tumor origin. Intestinal-type periampullary adenocarcinoma (IPAC) is reported to have a better prognosis than the pan-creatobiliary-type periampullary adenocarcinoma (PPAC). However, the classification of histological subtypes is difficult to determine before surgery. Apparent diffusion coefficient (ADC) histogram analysis is a noninvasive, non-enhanced method with high reproducibility that could help differentiate the two subtypes. AIM: To investigate whether volumetric ADC histogram analysis is helpful for distinguishing IPAC from PPAC. METHODS: Between January 2015 and October 2018, 476 consecutive patients who were suspected of having a periampullary tumor and underwent magnetic resonance imaging (MRI) were reviewed in this retrospective study. Only patients who underwent MRI at 3.0 T with different diffusion-weighted images (b-values = 800 and 1000 s/mm2) and who were confirmed with a periampullary adenocarcinoma were further analyzed. Then, the mean, 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles of ADC values and ADCmin, ADCmax, kurtosis, skewness, and entropy were obtained from the volumetric histogram analysis. Comparisons were made by an independent Student's t-test or Mann-Whitney U test. Multiple-class receiver operating characteristic curve analysis was performed to determine and compare the diagnostic value of each significant parameter. RESULTS: In total, 40 patients with histopathologically confirmed IPAC (n = 17) or PPAC (n = 23) were enrolled. The mean, 5th, 25th, 50th, 75th, 90th, and 95th percentiles and ADCmax derived from ADC1000 were significantly lower in the PPAC group than in the IPAC group (P < 0.05). However, values derived from ADC800 showed no significant difference between the two groups. The 75th percentile of ADC1000 values achieved the highest area under the curve (AUC) for differentiating IPAC from PPAC (AUC = 0.781; sensitivity, 91%; specificity, 59%; cut-off value, 1.50 × 10-3 mm2/s). CONCLUSION: Volumetric ADC histogram analysis at a b-value of 1000 s/mm2 might be helpful for differentiating the histological subtypes of periampullary adenocarcinoma before surgery.

Quantitative diffusion-weighted magnetic resonance enterography in ileal Crohn's disease: A systematic analysis of intra and interobserver reproducibility.

BACKGROUND: Magnetic resonance enterography (MRE) is increasingly attractive as a noninvasive and radiation-free tool for assessing Crohn's disease (CD). Diffusion-weighted imaging (DWI) is recommended as an optional MRE sequence for CD by the European Society of Gastrointestinal and Abdominal Radiology, and has shown a superb potential as a quantitative modality for bowel inflammation evaluation. However, the measurement reproducibility of quantitative DWI analysis in MRE has not been ascertained so far. To facilitate the application of quantitative diffusion-weighted MRE in the clinical routine, systematic investigations of the intra and interobserver reproducibility of DWI quantitative parameters should be performed. AIM: To evaluate the intra and interobserver reproducibility of quantitative analysis for diffusion-weighted MRE (DW-MRE) in ileal CD. METHODS: Forty-four subjects (21 with CD and 23 control subjects) who underwent ileocolonoscopy and DW-MRE (b = 800 s/mm2) within one week were included. Two radiologists independently measured apparent diffusion coefficients (ADC) of the terminal ileum and signal intensity ratio (SR) of the terminal ileum to ipsilateral psoas muscle on DWI images (b = 800 s/mm2). Between- and within-reader agreements were assessed using intraclass correlation coefficients (ICC), coefficients of variation (CoV), and 95% limits of agreement of Bland-Altman plots (BA-LA LoA). Diagnostic performances of ADC and SR for identifying inflamed terminal ileum from the normal were evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: There were no significant differences in ADC or SR values between the two sessions or between the two radiologists either in the CD or control group (paired t-test, P > 0.05). The intra and interobserver reproducibility of ADC (ICC: 0.952-0.984; CoV: 3.73-6.28%; BA-LA LoA: ±11.27% to ±15.88%) and SR (ICC: 0.969-0.989; CoV: 3.51%-4.64%; BA-LA LoA: ±10.62% to ±15.45%) was excellent for CD. Agreement of ADC measurements was slightly less in control subjects (ICC: 0.641-0.736; CoV: 10.47%-11.43%; BA-LA LoA: ± 26.59% to ± 30.83%). SR of normal terminal ileum demonstrated high intra and interobserver reproducibility (ICC: 0.944-0.974; CoV: 3.73%-6.28%; BA-LA LoA: ± 18.58% to ± 24.43%). ADC and SR of two readers had outstanding diagnostic efficiencies (area under the ROC curve: 0.923-0.988). CONCLUSION: Quantitative parameters derived from DW-MRE have good to excellent intra and interobserver agreements with high diagnostic accuracy, and can serve as robust and efficient quantitative biomarkers for CD evaluation.

Tuberous sclerosis complex: Imaging characteristics in 11 cases and review of the literature.

Tuberous sclerosis complex (TSC) is an uncommon multiorgan disorder that may present many and different manifestations on imaging. Radiology plays an important role in diagnosis and management, and can substantially improve the clinical outcome of TSC. Therefore, a comprehensive understanding of this disease is essential for the radiologist. The manifestations of TSC on computer tomography (CT) and magnetic resonance (MR) images were analyzed. Eleven patients with a clinical diagnosis of TSC were retrospectively reviewed. Central nervous system lesions included subependymal nodules (SENs) (11/11), subependymal giant cell astrocytomas (SEGAs) (2/11), cortical and subcortical tuber lesions (5/11), and white matter lesions (4/11). Of the 6 patients with abdominal scans, there were 6 cases of renal angiomyolipomas (AMLs), and one case of hepatic AMLs. Of the 4 patients undergoing chest CT, lung lymhangioleiomyomatosis (LAM) (2/4), and multiple small sclerotic bone lesions (2/4) were observed. Different modalities show different sensitivity to the lesion. Analysis of images should be integrated with patients' history in order to diagnose TSC.

Assessing the Early Response of Advanced Cervical Cancer to Neoadjuvant Chemotherapy Using Intravoxel Incoherent Motion Diffusion-weighted Magnetic Resonance Imaging: A Pilot Study.

BACKGROUND: Diffusion-weighted imaging (DWI) with the intravoxel incoherent motion (IVIM) model has shown promising results for providing both diffusion and perfusion information in cervical cancer; however, its use to predict and monitor the efficacy of neoadjuvant chemotherapy (NACT) in cervical cancer is relatively rare. The study aimed to evaluate the use of DWI with IVIM and monoexponential models to predict and monitor the efficacy of NACT in cervical cancer. METHODS: Forty-two patients with primary cervical cancer underwent magnetic resonance exams at 3 time points (pre-NACT, 3 weeks after the first NACT cycle, and 3 weeks after the second NACT cycle). The response to treatment was determined according to the response evaluation criteria in solid tumors 3 weeks after the second NACT treatment, and the subjects were classified as two groups: responders and nonresponders groups. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion-related pseudo-diffusion coefficient (DFNx01), and perfusion fraction (f) values were determined. The differences in IVIM-derived variables and ADC between the different groups at the different time points were calculated using an independent samples t-test. RESULTS: The D and ADC values were all significantly higher for the responders than for the nonresponders at all 3 time points, but no significant differences were observed in the DFNx01 and f values. An analysis of the receiver operating characteristic (ROC) curves indicated that a D value threshold <0.93 × 10-3 mm 2 /s and an ADC threshold <1.11 × 10-3 mm 2 /s could differentiate responders from nonresponders at pre-NACT time point, yielding area under the curve (AUC) of which were 0.771 and 0.806, respectively. The ROC indicated that the AUCs of D and ADC at the 3 weeks after the first NACT cycle and 3 weeks after the second NACT cycle were 0.823, 0.763, and 0.787, 0.794, respectively. The AUC values of D and ADC at these 3 time points were not significantly different (P = 0.641, 0.512, and 0.547, respectively). CONCLUSIONS: D and ADC values may be useful for predicting and monitoring the efficacy of NACT in cervical cancer. An IVIM model may be equal to monoexponential model in predicting and monitoring the efficacy of NACT in cervical cancer.

[A comparative study of CT virtual endoscopy imaging and pathologies of lower alimentary tract mesenchymal tumors].

OBJECTIVE: To study the pathological and immunohistochemical features of alimentary tract mesenchymal tumors and compare with computed tomographic virtue endoscopy (CTVE) imaging technology to evaluate the diagnostic value of CTVE in alimentary tract mesenchymal tumors. METHODS: Seventy-four pathological specimens of alimentary tract mesenchymal tumors were collected. The pathological features and the expression of CD(117), CD(34), SMA and S-100 were observed by immunohistochemical method with light microscope. The pathological types and characteristics were determined by pathologists and compared with CTVE imaging technology. RESULTS: In the 74 cases of alimentary tract mesenchymal tumors, 40 cases were diagnosed as stromal tumor with pathological and immunohistochemical methods(54.1%). Sixteen of them were malignant, accounting for 40% of the stromal tumor while 33 cases were diagnosed as leiomyoma (44.6%) and 1 case as schwannoma (1.4%). In the 74 GIMTs cases, 33 were jejunum GIMTs, 21 were ileum GIMTs and 20 were large intestine GIMTs. Immunohistochemistry assay in the 74 GIMTs cases showed that 51.4% GIMTs were positive for CD(117), approximately 36.5% were positive for CD(34), 62.2% were positive for smooth-muscle actin (SMA) and 1.4% were positive for S-100 protein. In the 74 GIMTs cases, 69 cases were diagnosed right in the accuracy for location with CTVE (93.2%) with 51 cases in small intestinal (94.4%) and 18 cases in large intestinal (90.0%). The sensitivity and the specificity of CTVE to distinguish benign from malignant stromal tumors by CTVE characteristics were 84.2% and 85.7% respectively. CONCLUSIONS: GIST is common in GIMTs and is often originated from the small intestinal. The immunohistochemistry has great value in diagnosing alimentary tract mesenchymal tumors. The CTVE imaging technology also has great value in diagnosing alimentary tract mesenchymal tumors which can show the localization, shape size and artery of the tumor clearly. The diagnostic sensitivity and specificity of CTVE are high to distinguish benign from malignant alimentary tract GISTs. CTVE plays an important role in guiding the clinical management of GISTs.

[Evaluation of whole body MRI and diffusion-weighted MRI in detecting intranodal lesions in patients with lymphoma].

OBJECTIVE: To evaluate the whole body MRI and diffusion-weighted MRI in detecting intranodal lesions in patients with lymphoma. METHODS: Whole body MRI and diffusion-weighted MRI (DWI) were performed in 23 patients with histologically proven lymphoma. A conventional coronal MRI scan from head to inguinal groove was done for whole body scanning. In the DWI, axial MRI scans were performed after segmentation based on SENSE technique, and all images were merged into whole body image reconstruction by software. RESULTS: 417 lymph nodes were detected by MRI in the 23 patients. The overall positive rate of whole body MRI and DWI was 79.1% and 89.7%, respectively. It was 70.9% versus 85.2% and 79.4% versus 90.1% for the lymph nodes of < 2 cm and 2-3 cm in diameter, with a significant difference between the two methods (P < 0.01). However, it was 94.7% versus 97.9% for the lymph nodes of > 3 cm in diameter, not significantly different between the two methods (P > 0.05). Both methods had similar sensitivity in detecting the lymph nodes in the neck, supraclavicular and infraclavicular fossae, mediastinum and axillary fossa. However, the positive rate of whole body MRI was 51.2%, 43.8% and 52.2%, significantly less sensitive than 83.7%, 71.9% and 87.0%, respectively, by DWI in detecting the lymph nodes in the retroperitoneal space, pelvic cavity and inguinal groove (all P < 0.01). CONCLUSION: Both whole body MRI and diffusion-weighted MRI have a relative high sensitivity in detecting intranodal lesions for patients with lymphoma, showing a certain value in clinical application.

Role of mesohepatectomy with or without transcatheter arterial chemoembolization for large centrally located hepatocellular carcinoma.

BACKGROUND: The role of preoperative transcatheter arterial chemoembolization (TACE) for resectable hepatocellular carcinoma (HCC) was controversial. METHODS: 246 patients with large centrally located HCC underwent mesohepatectomy (MH) and were divided into two groups: group A, 89 patients with preoperative TACE; group B, 157 patients without preoperative TACE. The aim was to evaluate the influence of preoperative TACE on postoperative complications and long-term results of patients with large centrally located HCC. RESULTS: In the 89 patients of the TACE-MH group, a total of 123 (mean 1.4 per patient) preoperative TACEs were performed. The differences in postoperative complications (34.8 vs. 24.2%; p=0.075) and overall hospital mortality (3.4 vs. 0.6%; p=0.103) between the two groups were not significant. The postoperative recurrence rate in the remnant liver was higher in the MH group than in the TACE-MH group (79.6 vs. 73.0%), while the extrahepatic metastasis rate in the TACE-MH group was higher than that in the MH group (11.1 vs. 7.0%). Overall 1-, 3-, and 5-year survival rates were 87.1, 62.9, and 46.2%, respectively, for the TACE-MH group, and 82.2, 54.4, and 31.7%, respectively, for the MH group (p=0.001); 1-, 3-, and 5-year disease-free survival rates were 75.0, 46.2, and 31.8%, respectively, for the TACE-MH group, and 69.6, 38.0, and 16.5%, respectively, for the MH group (p=0.002). CONCLUSIONS: Long-term outcomes of patients with preoperative TACE were improved and the pattern of the recurrences after surgery was altered. The patients with large centrally located HCC could benefit more from this neoadjuvant treatment, although there was some influence of preoperative TACE on postoperative complications.

[The effects of lipiodol-hydroxyapatite nanoparticle on apoptosis, proliferation, and angiogenesis in hepatic tumor: experiment with rabbits].

OBJECTIVE: To investigate the effects of lipiodol-hydroxyapatite nanoparticle (lipi-nHAP) on the growth, necrosis, apoptosis, proliferation, and angiogenesis of hepatic tumor. METHODS: Ultrasound-emulsification was used to make lipi-nHAP Eighty New Zealand white rabbits underwent implantation of carcinoma cells of the line VX2 into the left lobe of liver. Two weeks later the rabbits underwent catheterization into the gastroduodenal artery so that, and then the rabbits were randomly divided into four equal groups to receive infusion via the hepatic artery of different drugs: physiological saline (Group A), lipiodol (Group B), adriamycin + lipiodol (Group C), and lipi-nHAP (Group D). Seven and 14 days after the treatment the size of tumor was observed by spiral CT scan, and the volume and growth rate of tumor were calculated. Two weeks after the treatment 8 rabbits from each group were killed and their liver tumors were taken out and the survival rates of remaining rabbits were observed. The necrosis rate of the liver tumor was assessed by measuring the area of the tumor and the necrosis. The apoptotic rate was examined by TUNEL method. Mcrovessel density (MVD) was examined by immunohistochemistry anti-CD31 antibody. Anti-proliferating cell nuclear antigen (PCNA) monoclonal antibody was used to detect the expression of PCNA so as to calculate the proliferation index of the cells. RESULTS: The tumor volume and growth rate of Group D 7 and 14 days after treatment were both significantly lower than those of other groups (all P < 0.05) and the necrosis rate and apoptotic index of Group D were both significantly higher than those of other groups (all P < 0.05). The values of MVD were higher in Groups C and D compared with those of Group A. Compared with those in other groups, the values of MVD and expression level of PCNA were significantly lower in group D (all P < 0.05). The survival time of Group D was longer than those of other groups (all P < 0.05). CONCLUSION: lipi-nHAP can suppress the growth of tumor, increase the tumor's necrosis rate and apoptotic index, inhibit the development of neovascularization, decrease the expression level of PCNA of residual tumor, and prolong the surviving time of the animals with hepatic tumor. It may become an effective embolization material to treat liver cancer.

Cell apoptosis and regeneration of hepatocellular carcinoma after transarterial chemoembolization.

AIM: To evaluate whether cell apoptosis and regeneration were existed in normal liver cells adjacent to carcinoma after transarterial chemoembolization (TACE). METHODS: Fifty rabbits with hepatic carcinoma were divided into 5 groups at random: group A (control group), groups B and C (TACE treatment groups), groups D and E (partial hepatectomy groups). There were 10 rabbits in each group. Rabbits in groups B-E were treated by transarterial chemoembolization (TACE) and partial hepatectomy (PH) respectively. The changes of S-phase cell fraction (SPF), proliferation index (PI) and cell apoptosis in the normal liver tissue were determined with flow cytometry (FCM) after operations on the first and third days. We determined the mitosis index (MI) with histo-pathological method and the apoptosis index (AI) with TUNEL method at the same time. RESULTS: Twenty-four hours after operations, compared with control group, the rabbits in TACE group had much higher index of SPF, PI and MI (MI: t=4.89, P<0.001; SPF:t=5.27, P<0.001; PI: t=4.87, P<0.001). Moreover, the proliferation of liver cells in TACE group was much weaker than that of the cells treated by partial hepatectomy, and the differences were significant (MI: t=7.02, P<0.001; SPF: t=4.06, P<0.001; PI: t=2.70, P<0.05). Seventy-two h after operations, FCM showed a small sub-G1 peak in TACE group and PH group, compared with the control group, but there was no difference between them (t=0.41, P>0.05). TACE showed that AI in the treated rabbits was higher than that in control group (t=3.07, P<0.05), and there were no differences between TACE group and PH group, either (t=0.93, P>0.05). CONCLUSION: Cell apoptosis and regeneration exist in rabbit liver tissues after TACE in some degree, which may be associated with the selective embolization of iodised oil, chemotherapeutic drug and free radical damage.