Two-dimensional shear wave elastography utilized in patients with ascites: a more reliable method than transient elastography for noninvasively detecting the liver stiffness-an original study with 170 patients.

Background: Two dimensional shear wave elastography (2D-SWE) is an ultrasound elastography technique based on shear waves implemented on a diagnostic ultrasound system. Transient elastography (TE) uses an ultrasound displacement M-mode and A-mode image produced by the system. So, TE mechanically induced impulse at tissue surface and difficultly across water. This paper compared the reliability and reproducibility of 2D-SWE with that of TE in patients with chronic hepatic disease. Comparisons were made in terms of the success rate, reliability, reproducibility, operation time, and influence of operator experience. Methods: A total of 170 patients were included in this study. Participants underwent 2D-SWE and TE performed by 2 different operators (a novice and veteran) on the same day. Nonparametric statistical tests were used to compare the technical success rate and reliable measurement rate, and inter-operator reproducibility was evaluated using intra-class correlation coefficients (ICCs). Results: The 2D-SWE technique showed a higher technical success rate than TE. Either 2D-SWE or TE can be utilized in patients with ascites lamella of less than 10 mm or ascites lamella plus skin-capsular distance of less than 25 mm. However, although the reliability rate of liver stiffness measurement with 2D-SWE did not significantly differ between the novice and veteran operators, for TE, there was a significant difference when body mass index (BMI) ≤25 kg/m2. When performed by the novice and veteran operators, 2D-SWE and TE both showed excellent inter-operator agreement, with ICCs of 0.968 and 0.973, respectively. Both 2D-SWE and TE displayed reliable measurement and excellent reproducibility in patients with chronic liver disease, were minimally influenced by operator experience. Conclusions: 2D-SWE may be a more reliable method for clinical application in noninvasive detecting the liver stiffness.

Shear wave elastography for liver fibrosis in chronic hepatitis B: Adapting the cut-offs to alanine aminotransferase levels improves accuracy.

OBJECTIVES: To determine and validate alanine aminotransferase (ALT)-adapted dual cut-offs of liver stiffness measurements (LSMs) for assessing liver fibrosis with two-dimensional shear wave elastography (2D-SWE) in patients with chronic hepatitis B (CHB) infection. METHODS: Patients with CHB infection who underwent liver biopsy to assess liver fibrosis were consecutively included. 2D-SWE confirmation thresholds with a positive likelihood ratio ≥10 and 2D-SWE exclusion thresholds with a negative likelihood ratio ≤0.1 were identified to rule in or rule out significant fibrosis and cirrhosis, respectively. RESULTS: The first 515 patients (index cohort) and the next 421 patients (validation cohort) were included in the final analysis. The low and high cut-offs to rule out and rule in patients with significant fibrosis (≥ F2) were 5.4 kPa and 9.0 kPa, respectively, in patients with ALT levels ≤ 2 × the upper limit of normal (ULN) and 7.1 kPa and 11.2 kPa in patients with ALT levels > 2 × ULN. For cirrhosis (F4), the corresponding values were 8.1 kPa and 12.3 kPa in patients with ALT levels ≤ 2 × ULN and 11.9 kPa and 24.7 kPa in patients with ALT levels > 2 × ULN. The dual cut-off values showed an overall accuracy of more than 90% for diagnosis of the presence or absence of significant fibrosis and cirrhosis in the index and validation cohorts. There were no significant differences in the accuracy values between the cohorts (all p>0.05). CONCLUSION: The ALT-adapted dual cut-offs of LSMs showed high accuracy for diagnosis of the presence or absence of significant fibrosis and cirrhosis in patients with CHB infection. KEY POINTS: • The ALT-adapted dual cut-off values of LSMs showed high accuracy for diagnosis of the presence or absence of significant fibrosis and cirrhosis. • ALT levels did not influence the overall diagnostic accuracy for predicting significant fibrosis and cirrhosis. • The ALT-adapted dual cut-offs in patients with ALT levels > 2 × ULN were markedly higher than those in patients with ALT levels ≤ 2 × ULN.

Intracavitary Contrast-Enhanced Ultrasound in the Management of Post-Surgical Gastrointestinal Fistulas.

The goal of this study was to investigate intracavitary contrast-enhanced ultrasound (IC-CEUS) measures in the management of post-surgical gastrointestinal (GI) fistula throughout detection, treatment and follow-up. From June 2010 to August 2016, patients who were administered ultrasound contrast agent (UCA) via a drainage tube for IC-CEUS were enrolled and retrospectively analyzed. They were suspected of having GI anastomotic fistulas or had been found to have fluid collections with ultrasound that were accompanied by abdominal pain or fever after surgical procedures. Forty-two patients met the inclusion criteria and were enrolled into this study. Twenty-two were confirmed to have GI fistulas confirmed by standard references. None were detected by conventional ultrasound. Although IC-CEUS successfully detected GI fistulas in 16 patients, it missed GI fistulas in 6 patients. One patient was misdiagnosed with a GI fistula. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the diagnosis of GI fistulas by IC-CEUS were 72.7% (16/22), 95.0% (19/20), 94.1% (16/17), 76.0% (19/25) and 83.3% (35/42), respectively. Twenty peritoneal fluid collections in 14 patients were related to fistulas by IC-CEUS based on the distribution of ultrasound contrast agents. Additional drainage was performed in 14 fistula-related fluid collections. Eight GI fistulas were judged to be cured after IC-CEUS re-evaluation, and the drainage tubes were removed from these patients. In conclusion, IC-CEUS can greatly improve the ability to diagnose post-surgical GI fistulas and may also play an important role in interventional treatment and follow-up.

Intra-biliary contrast-enhanced ultrasound for evaluating biliary obstruction during percutaneous transhepatic biliary drainage: a preliminary study.

OBJECTIVES: The aimed of this study was to investigate the value of intra-biliary contrast-enhanced ultrasound (IB-CEUS) for evaluating biliary obstruction during percutaneous transhepatic biliary drainage (PTBD). MATERIALS AND METHODS: 80 patients with obstructive jaundice who underwent IB-CEUS during PTBD were enrolled. The diluted ultrasound contrast agent was injected via the drainage catheter to perform IB-CEUS. Both conventional ultrasound and IB-CEUS were used to detect the tips of the drainage catheters and to compare the detection rates of the tips. The obstructive level and degree of biliary tract were evaluated by IB-CEUS. Fluoroscopic cholangiography (FC) and computer tomography cholangiography (CTC) were taken as standard reference for comparison. RESULTS: Conventional ultrasound displayed only 43 tips (43/80, 53.8%) of the drainage catheters within the bile ducts while IB-CEUS identified all 80 tips (80/80, 100%) of the drainage catheters including 4 of them out of the bile duct (P<0.001). IB-CEUS made correct diagnosis in 44 patients with intrahepatic and 36 patients with extrahepatic biliary obstructions. IB-CEUS accurately demonstrated complete obstruction in 56 patients and incomplete obstruction in 21 patients. There were 3 patients with incomplete obstruction misdiagnosed to be complete obstruction by IB-CEUS. The diagnostic accuracy of biliary obstruction degree was 96.3% (77/80). CONCLUSION: IB-CEUS could improve the visualization of the drainage catheters and evaluate the biliary obstructive level and degree during PTBD. IB-CEUS may be the potential substitute to FC in the PTBD procedure.

CT and MR imaging characteristics of infantile hepatic hemangioendothelioma.

AIM: This study aims to analyze computed tomography (CT) and magnetic resonance (MR) imaging features of infantile hepatic hemangioendotheliomas before and after treatment. MATERIALS AND METHODS: CT and MR examinations of seven infants with biopsy proven hepatic hemangioendotheliomas were retrospectively analyzed. The distribution, number, size, imaging appearance, enhancement pattern and post-treatment changes of the tumors were evaluated. RESULTS: A total of 153 hepatic hemangioendotheliomas were detected on CT (111) and MR (42) imaging. In six infants, 109/111 (98.2%) tumors were hypodense and 2/111 (1.8%) lesions contained calcification on unenhanced CT. On MR imaging, all 42 lesions in one infant were heterogeneously T1-hypointense and T2-hyperintense compared to the normal liver parenchyma. Contrast-enhanced CT and MRI showed peripheral rim (51.6%), uniform (48.4%), fibrillary (33.3%), and nodular (28.8%) contrast enhancement in the hepatic arterial phase. Homogeneous (100%), rim (98.2%) and mixed enhancement patterns were noted in tumors <1.0cm, >2.0cm and 1.0-2.0cm in diameter respectively in the hepatic arterial phase. In three patients who underwent steroid therapy, follow-up CT examination demonstrated tumor size reduction and increased intra-tumoral calcification in two patients. CONCLUSION: Infantile hepatic hemangioendotheliomas show some typical imaging features and size-dependent pattern of contrast enhancement on CT and MR imaging, which allow accurate imaging diagnosis and post-treatment evaluation.

[Application of 64MDCT multislice perfusion imaging in colorectal carcinoma].

OBJECTIVE: To study the correlation of time-density curves (TDC), parameters revealed by 64-multidetector-row CT (64MDCT) perfusion imaging with clinicopathological factors (staging, serosal invasion, lymph node metastasis, distant metastasis and CEA) in colorectal carcinoma (CRC). METHODS: 64 MDCT perfusion imaging was performed in 33 patients with pathologically verified CRC. TDC was created from the region of interest (ROI) drawn over the tumor, target artery and vein by 64MDCT with perfusion functional software. The parameters of individual perfusion maps included blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability-surface area product (PS). Tumors were staged according to TMN classification. TDC was classified according to their shapes. The correlation between CT perfusion parameters and clinicopathological factors was studied. RESULTS: TDC of 64MDCT perfusion imaging could be classified into five types. TDC in different stages could demonstrate one or more types of the five types. There was no significant difference of CT perfusion parameters among different stages. BV and MTT were significantly higher in the patients with serosal invasion than in those without serosal invasion (t=-2.63,-2.24, P=0.0137, 0.0331, respectively). BV was significantly correlated with tumor size (r=0.41, P=0.02). BF and PS were not correlated with staging, serosal invasion, lymph node metastasis, distant place metastasis and CEA (all P>0.05). CONCLUSIONS: 64MDCT multislice perfusion imaging can reveal the blood perfusion of CRC and has potential value of clinical application.

Multiphasic MDCT in small bowel volvulus.

OBJECTIVE: Evaluate the use of MDCT with 3D CT angiography (CTA) and CT portal venography (CTPV) reconstruction for the diagnosis of small bowel volvulus (SBV). METHODS: Multiphasic MDCT findings in nine patients (seven males and two females, age range 2-70) with surgically proven SBV were retrospectively reviewed. Non-contrast and double phase contrast enhanced MDCT including 3D CTA and CTPV reconstruction were performed in all the patients. Two experienced abdominal radiologists evaluated the images and defined the location, direction and degree of SBV. RESULTS: On axial MDCT images, all cases show segmental or global dilatation of small intestine. Other findings include circumferential bowel wall thickening in eight cases, halo appearance and hyperemia in seven cases, whirl sign in six cases, beak-like appearance in six cases, closed loops in six cases and ascites in one case. CTA/CTPV showed abnormal courses involving main trunks of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in seven cases, with or without distortion of their tributaries. Normal course of SMA but abnormal course of SMV was seen in the other two cases. Of all the nine cases, whirl sign was seen in six cases and barber's pole sign in five cases. Dilated SMV was observed in eight cases and abrupt termination of SMA was found in one case. Compared with surgical findings, the location, direction and degree of SBV were correctly estimated in all cases based on CTA/CTPV. CONCLUSION: Multiphasic MDCT with CTA/CTPV reconstruction can play an important role in the diagnosis of SBV. The location, direction and degree of SBV can all be defined preoperatively using this method.

Evaluation of angiogenesis in colorectal carcinoma with multidetector-row CT multislice perfusion imaging.

To evaluate the correlation between 64 multidetector-row CT (64MDCT) perfusion imaging in colorectal carcinoma and microvessel density (MVD) and vascular endothelial growth factor (VEGF), 64MDCT perfusion imaging was performed in 33 patients with pathologically verified colorectal carcinoma. These images were analyzed with perfusion functional software, and time-density curves (TDC) were created for the region of interest (ROI) encompassing the tumor, the target artery and vein. The individual perfusion maps generated indicated blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS). MVD and VEGF were evaluated by immunohistochemical staining with anti-CD34 and anti-VEGF, respectively. Correlations between MVD or VEGF with CT perfusion parameters and clinicopathological factors (Dukes' stages, invasion depth, and lymph node and liver metastasis) were also investigated. MVD in the colorectal carcinoma was 22.61+/-9.01 per x200 field. The scores obtained for VEGF expression were 4.15+/-1.09. VEGF staining was positive in 25 of 29 tumors (86.2%). There was no significant correlation between the presence of MVD, VEGF expression and clinicopathological factors (P>0.05). There was also no correlation between MVD, VEGF expression, and any dynamic CT parameters (P>0.05). The BV and MTT were significantly higher in tumors demonstrating serous coat invasion than in those without it (t=-2.63, -2.24, P=0.0137, 0.0331, respectively). BV was also significantly correlated with tumor size (r=0.41, P=0.02). Neither BF nor PS was correlated with clinicopathological factors. In conclusion, 64MDCT perfusion imaging, MVD, and VEGF may reflect angiogenic activity, but no significant correlation among these factors.

[CT diagnosis of midgut malrotation].

OBJECTIVE: To explore the diagnostic value of CT in midgut malrotation. METHODS: The CT appearances of 16 patients with midgut malrotation were analyzed retrospectively. RESULTS: The features of CT manifestation in 16 cases were as follows: (1) Horizontal part of duodenum could not reach medioventral line or could reach it but encircled right-down behind the superior mesenteric artery(SMA). (2) Ectopic ileocecal junction. (3) Jejunum located in right-middle abdomen while ileum in left abdomen. (4) A clockwise or counterclockwise rotation of the superior mesenteric vein (SMV) around the SMA. (5) Mid-gut volvulus.(6)Accompanied by other malformations. CONCLUSION: Ambulation of duodenum, location of the small intestine and colon as well as anatomical position of mesenteric vessels should be intensively observed in order to exclude midgut malrotation.

[Evaluation of microvessel density and vascular endothelial growth factor in colorectal carcinoma with 64-multidetector-row CT perfusion imaging].

OBJECTIVE: To evaluate the correlation of 64-multidetector-row CT (64MDCT) perfusion imaging with microvessel density(MVD) and vascular endothelial growth factor(VEGF) in colorectal carcinoma. METHODS: 64MDCT perfusion imaging was performed in 33 patients with pathologically verified colorectal carcinoma. Time-density curves (TDC) were created from the region of interest (ROI) drawn over the tumor, target artery and vein by 64MDCT with perfusion functional software. The individual perfusion maps generated were for blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability-surface area product (PS). MVD and VEGF expression of surgical specimens were examined by immunohistochemical staining with anti-CD34, anti-VEGF monoclonal antibody. MVD and VEGF were compared among the different types of TDC in colorectal carcinoma. The correlation of CT perfusion parameters with MVD and VEGF was also examined. RESULTS: TDC of colorectal carcinoma was divided into five types according to their shapes. MVD in the colorectal carcinoma was 22.61+/-9.01. VEGF staining was found in 25 of 29 tumors (86.2%). The score of VEGF expression was 4.15+/-1.09. No significant differences of MVD and VEGF expression among TDC types were found (F=2.59, 1.11, P>0.05). There were also no correlations of MVD and VEGF expression with any dynamic CT parameters (P>0.05). CONCLUSION: 64MDCT perfusion imaging, MVD and VEGF may reflect angiogenic activity, but no significant correlations are found among them.