PAFAH2 suppresses synchronized ferroptosis to ameliorate acute kidney injury.

Synchronized ferroptosis contributes to nephron loss in acute kidney injury (AKI). However, the propagation signals and the underlying mechanisms of the synchronized ferroptosis for renal tubular injury remain unresolved. Here we report that platelet-activating factor (PAF) and PAF-like phospholipids (PAF-LPLs) mediated synchronized ferroptosis and contributed to AKI. The emergence of PAF and PAF-LPLs in ferroptosis caused the instability of biomembranes and signaled the cell death of neighboring cells. This cascade could be suppressed by PAF-acetylhydrolase (II) (PAFAH2) or by addition of antibodies against PAF. Genetic knockout or pharmacological inhibition of PAFAH2 increased PAF production, augmented synchronized ferroptosis and exacerbated ischemia/reperfusion (I/R)-induced AKI. Notably, intravenous administration of wild-type PAFAH2 protein, but not its enzymatically inactive mutants, prevented synchronized tubular cell death, nephron loss and AKI. Our findings offer an insight into the mechanisms of synchronized ferroptosis and suggest a possibility for the preventive intervention of AKI.

Liver Stiffness Measured with Two-dimensional Shear-Wave Elastography Is Predictive of Liver-related Events in Patients with Chronic Liver Disease Due to Hepatis B Viral Infection.

Background Liver stiffness measurement has been proposed as a noninvasive marker for predicting liver-related complications of cirrhosis. Purpose To evaluate the predictive value of liver stiffness measurement by using two-dimensional (2D) shear-wave elastography (SWE) for liver-related events among patients with chronic hepatitis B. Materials and Methods This retrospective study recruited consecutive patients with chronic hepatitis B who were referred for liver biopsy between May 2011 and May 2015. All patients underwent 2D SWE before biopsy, and a subset of patients underwent transient elastography. Patients were followed up for 4 years through the electronic medical records or telephone interviews. Univariable and multivariable logistic regression analyses were used to determine prognostic factors. Accuracy of prognostic parameters was evaluated by using the area under the receiver operating characteristic curve (AUC). Results Among 430 patients (mean age, 38 years; range, 18-67 years) including 328 men and 102 women, 29 patients developed liver-related events. Multivariable analysis demonstrated that liver stiffness measured with 2D SWE, spleen longitudinal diameter at US, age, and albumin level were predictive factors of liver-related events. The AUC of the multivariable model was higher (0.89; 95% confidence interval [CI]: 0.86, 0.92) but not significantly different from that of 2D SWE (0.86; 95% CI: 0.82, 0.89; P = .23) and was significantly higher than that of the fibrosis stage (0.72; 95% CI: 0.68, 0.76; P < .001), the aspartate aminotransferase-to-platelet ratio index (0.80; 95% CI: 0.76, 0.84; P < .001), and the fibrosis-4 index (0.84; 95% CI: 0.80, 0.87; P = .02). In a subset of patients with available transient elastography (n = 188), the multivariable model, 2D SWE, and transient elastography showed comparable performance (AUC: 0.91 vs 0.86 vs 0.88, respectively). When inflammatory activity was considered, the multivariable model was highly accurate in patients with low-grade inflammation and normal levels of alanine aminotransferase (AUC: 0.97 and 0.94, respectively). Conclusion The multivariable model and two-dimensional shear-wave elastography are more accurate in predicting liver-related events than are the fibrosis stage and serum markers of liver fibrosis tests. © RSNA, 2020 Online supplemental material is available for this article.

How intrahepatic cholestasis affects liver stiffness in patients with chronic hepatitis B: a study of 1197 patients with liver biopsy.

OBJECTIVES: To evaluate the impact of intrahepatic cholestasis on liver fibrosis staging using liver stiffness measurements (LSM). METHODS: Between July 2011 and September 2016, a total of 1197 patients with chronic hepatitis B (CHB) infection were enrolled to collect clinical, biological, 2D shear wave elastography (SWE), and histological (METAVIR scoring system) data. LSM was compared in patients with normal total bilirubin (TB) versus abnormal TB for each group of fibrosis stage, alanine aminotransferase (ALT) levels, and inflammation grade. Logistic regression and ROC analyses were performed to assess the benefit of adding TB and to LSM for fibrosis staging. RESULTS: Nine hundred and seventy-three patients were analyzed. Within the same fibrosis stage, LSMs showed significantly higher value in patients with abnormal TB than those with normal TB. Increased LSM for abnormal TB was generally found within different sub-groups of patients (≤ F2 or ≥ F3; ALT < 2 × upper limit of normal (ULN) or ALT ≥ 2 × ULN; METAVIR activity grade ≤ 1 or ≥ 2). Patients with abnormal TB level showed higher optimal cutoff values: 10.46 kPa for ≥ F2, 10.94 kPa for ≥ F3, and 15.88 kPa for F4, than those with normal TB (7.62 kPa, 8.26 kPa, and 11.01 kPa, respectively). LSM assessed fibrosis stage (≥ F2, ≥ F3, F4) showed higher false positive rate in patients with abnormal TB level (44.6%, 45.1%, 39.6%) than those with normal TB (20.7%, 17.1%, 14.4%). However, the area under the ROC curve did not change appreciably when adding TB to LSM for fibrosis stage. CONCLUSION: Intrahepatic cholestasis showed slight effect on LSM in patients with CHB, also leading to overestimation of liver fibrosis stages. But adding TB level to LSM did not improve the overall diagnostic performance of liver fibrosis stage. KEY POINTS: • Intrahepatic cholestasis showed slight effect on liver stiffness measurements (LSMs) in chronic HBV patients. • Patients with abnormal total bilirubin (TB) level showed higher optimal cutoff values and false positive rate. • When taking into account intrahepatic cholestasis, the diagnostic performance of LSM for liver fibrosis staging in patients with chronic HBV infection will not improve.

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.

Two-dimensional shear-wave elastography and conventional US: the optimal evaluation of liver fibrosis and cirrhosis.

PURPOSE: To evaluate the individual and combined performances of two-dimensional (2D) shear-wave elastography (SWE) and conventional ultrasonography (US) in assessing liver fibrosis and cirrhosis to determine when 2D SWE should be added to routine US. MATERIALS AND METHODS: This prospective study was approved by the institutional ethics committee, and the patients provided written informed consent. Between April 2012 and March 2013, conventional US and 2D SWE examinations were performed in 198 patients (mean age, 37.7 years; age range, 18-67 years) with chronic liver disease. Liver biopsy was used as a reference standard for 167 patients; the other 31 patients had decompensated liver cirrhosis. Receiver operating characteristic (ROC) curves were obtained to assess the diagnostic performance. Differences between the areas under the ROC curves (AUCs) were compared by using a Delong test. RESULTS: Two-dimensional SWE was significantly superior to US in diagnosis of significant fibrosis (score of F2 or greater) (AUC, 0.862 vs 0.725; P = .001) and early cirrhosis (score of F4) (AUC, 0.926 vs 0.789; P = .007). Combining 2D SWE with US did not increase the performance of depicting either significant fibrosis or liver cirrhosis (P = .713 and 0.410, respectively) relative to 2D SWE alone. There was no significant difference between 2D SWE and US in diagnosis of decompensated cirrhosis (AUC, 0.878 vs 0.925; P = .323). In addition, combining 2D SWE with US did not increase the performance relative to that of US alone (P = .372). CONCLUSION: Conventional US is sufficient to detect decompensated cirrhosis. Two-dimensional SWE is significantly superior to US in detecting liver fibrosis. Combining 2D SWE and US did not improve the diagnostic performance for either fibrosis or cirrhosis.

Sonographic features of thoracoabdominal wall metastases of liver cancer after liver transplantation.

Objective: Sonographic features are not well-defined in thoracoabdominal wall metastases (TAWM) of liver cancer after liver transplantation (LT), which is one of the most important reasons affecting the long-term survival of transplant recipients. The purpose of this study was to analyze the sonographic features of TAWM from liver cancer after LT and to identify the role of ultrasound (US) in the differential diagnosis between TAWM and benign lesions of the thoracoabdominal wall after LT. Methods: This retrospective study included 1,999 LT recipients between January 2008 and July 2021. Clinical characteristics and sonographic features of 32 patients with thoracoabdominal wall lesions were analyzed. The types of thoracoabdominal wall lesions were studied, and the US findings of benign and malignant lesions were compared. Whether TAWM from liver cancer after LT exhibited any distinctive sonographic appearance was evaluated. Results: All seven malignant cases were metastases from liver cancer. The benign group included 13 cases of thoracoabdominal wallencapsulated effusion/hematoma, nine of abdominal incisional hernia, and three of thoracoabdominal wall inflammatory mass. Sonographic features were significantly different between two groups. Compared with the benign group, metastases lesions were frequently located in the parietal peritoneum/pleura (4/7 vs 1/25, p = 0.009), fewer lesions were located at abdominal incisions (3/7 vs 23/25, p = 0.012), all metastatic lesions were hypoechoic (7/7 vs 5/25, p = 0.001), and most lesions had blood flow signals (4/7 vs 3/25, p = 0.026). Additionally, most metastatic cases had intrahepatic lesions (4/7 vs 1/25, p = 0.004) and multiple extrahepatic solid lesions in the abdomen (6/7 vs 0/25, p = 0.000). Conclusions: Compared with benign lesions, TAWM of liver cancer after LT exhibited unique sonographic features.

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.

Can ultrasonography differentiate anastomotic and non-anastomotic biliary strictures after orthotopic liver transplantation- a single-center experience.

PURPOSE: To evaluate the role of ultrasonography (US) in differentiating anastomotic biliary strictures (AS) and non-anastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT). METHOD: This retrospective study included 1259 OLT recipients between 2005-2018. Seventy-six with anastomotic strictures (AS) and 103 with non-anastomotic strictures (NAS) were analyzed. The reference standard was cholangiography. The sensitivity, specificity, accuracy of US was evaluated. RESULTS: There were significant differences between AS and NAS groups (p < 0.001) for skipped and irregular dilatation of intrahepatic bile duct and visualization of hilar biliary lumen. The better US imaging feature for NAS was poorly visualized and non- visible hilar bile duct luminal contour. The sensitivity, specificity and accuracy were 94.2 %, 84.2 % and 88.9 % respectively. Combined two predictors greatly increased the specificity to 93.4 % while diminished its sensitivity and accuracy. CONCLUSION: US is useful and efficient to differentiate AS and NAS after OLT.

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.

[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.

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.

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.