CT criteria for venous invasion in patients with pancreatic head carcinoma

The purpose of the study was to evaluate CT criteria for venous invasion in patients with potentially resectable carcinoma of the pancreatic head, with surgical and histopathological correlation. In 113 patients evaluated with spiral CT for suspected pancreatic head carcinoma, several CT criteria for venous invasion were scored prospectively for the portal vein (PV) and the superior mesenteric vein (SMV): length of tumour contact with PV/SMV (0 mm, < 5 mm, > 5 mm); circumferential involvement of the vein (0 degree, 0-90 degrees, 90-180 degrees, > 180 degrees); degree of stenosis; irregularity of the vessel margin; and tumour convexity towards vessel. 65 patients underwent surgery. Pancreatic head carcinoma was proven and pathology of the vascular margin was obtained in 50 of these patients. CT findings for single and combined criteria were correlated with pathology in these 50 patients, 30 of whom showed venous ingrowth. Invasion was found in all cases with SMV narrowing (n = 7), PV contour involvement > 90 degrees (n = 6), PV narrowing (n = 5) and PV wall irregularity (n = 3). The vascular ingrowth rate was 88% (15/17) for tumour concavity towards the PV or SMV. Poor predictors of ingrowth were length of tumour contact with PV > 5 mm (78% ingrowth, 14/18) and contour involvement of the SMV > 90 degrees (83% ingrowth, 10/12). Absence of vascular ingrowth could not be predicted in 100%. In conclusion, CT criteria can predict a high risk of invasion in potentially resectable tumours. Narrowing of the SMV and the PV seems the most reliable criterion, as well as circumferential involvement of the PV > 90 degrees. The best combination of criteria was tumour concavity with circumferential involvement > 90 degrees (sensitivity 60% and positive predictive value 90%).     

Pancreatic adenocarcinoma: signs of vascular invasion determined by multi-detector row CT

The purpose of this study was to analyse multi-detector row CT (MDCT) signs of peripancreatic arterial and venous invasion in pancreatic carcinoma. Among 101 patients with pancreatic carcinoma examined by MDCT, 54 candidates for surgery were pre-operatively evaluated for vascular invasion based on MDCT signs. The peripancreatic major vessels (including superior mesenteric artery, coeliac artery, common hepatic artery, superior mesenteric vein and portal vein) were examined carefully by surgeons during the operation. At surgical exploration, 78 of 224 vessels were invaded by tumour. The invaded peripancreatic major arteries (n = 29) and veins (n = 49) presented different MDCT signs: 43% of invaded veins (18/42, except for 7 occluded veins) were surrounded by tumour less than 50% of the vessel circumference compared with 97% (28/29) of the invaded arteries, which were surrounded by tumour more than 50% of the vessel circumference or were embedded in tumour (p<0.001). 69% (34/49) of the invaded veins had vascular stenosis or obliteration, compared with 41% (12/29) of the invaded arteries (p<0.05). Irregularity of the vein wall, 74% (31/42, except for 7 occluded veins); occurred more often than that of the artery wall, 45% (13/29) (p<0.05). In conclusion, the MDCT signs of peripancreatic arterial and venous invasion have different characteristics, which should be considered in pre-operative evaluation.     

胰腺癌:多排螺旋CT三期增强及曲面重建的评价

目的探讨多排螺旋CT三期扫描及曲面重建对胰腺癌显示与胰周血管侵犯评价的价值。方法对54例临床怀疑胰腺癌患者采用多排螺旋CT行薄层三期动态增强扫描,其中经手术或临床随访证实23例胰腺癌入选本研究,并采用胰腺期图像沿胰胆管以及胰周主要血管行曲面重建,分析肿瘤在三期图像上显示以及胰周血管受累情况。结果肿瘤于胰腺期图像上与胰腺实质密度差异最大,肿瘤-胰腺CT值差于动脉期、胰腺期及门脉期,分别为28.02±11.13,35.67±11.60和24.52±13.13,胰腺期高于动脉期和门脉期(p<0.01),而动脉期与门脉期差别无统计学意义(p>0.05)。曲面重建能直接显示肿瘤与周围解剖结构的关系以及血管受侵的情况。结合横断位图像,曲面重建共检出64条血管受侵,对6例手术患者血管无受累作出正确评价。结论多排螺旋CT动态增强胰腺期有利于肿瘤显示和胰周血管侵犯的评价。曲面重建可以直观显示肿瘤与周围结构的关系及血管受侵情况,并且能加强与临床医生间的信息传递。     

CT assessment of the inferior peripancreatic veins: clinical significance

OBJECTIVE: The purpose of this study was to evaluate and clarify the clinical significance of CT scans of the inferior peripancreatic veins. MATERIALS AND METHODS: Forty-three patients with suspected pancreatic disease underwent three-phase helical CT (collimation, 5 mm; reconstruction, 2.5 mm; scan delay, 30, 60, and 150 sec). The frequency of visualization on CT of the anterior and posterior inferior pancreaticoduodenal veins, inferior pancreaticoduodenal vein, and first jejunal trunk was assessed and correlated with angiographic and pathologic findings. RESULTS: The frequency of visualization of normal inferior peripancreatic veins in patients (n = 22) with a normal portomesenteric vein was 36% for the anteroinferior pancreaticoduodenal vein, 36% for the posteroinferior pancreaticoduodenal vein, 59% for the inferior pancreaticoduodenal vein, and 100% for the first jejunal trunk. The smaller inferior peripancreatic veins were frequently not visualized when normal. In patients (n = 13) with pancreatic carcinoma involving the portosuperior mesenteric vein, all of the inferior peripancreatic veins were dilated and easily recognizable. When the tumor did not involve the portosuperior mesenteric vein but did involve the anteroinferior pancreaticoduodenal, posteroinferior pancreaticoduodenal, and inferior pancreaticoduodenal veins (n = 8), some of the other peripancreatic veins (first jejunal trunk, anterior and posterior superior pancreaticoduodenal veins, and gastrocolic trunk) were dilated. Dilatation indicated tumor extension to the third portion of the duodenum. In patients (n = 7) with involvement of the inferior pancreaticoduodenal vein, the first jejunal trunk, or both without the involvement of the portosuperior mesenteric vein, dilatation of the other peripancreatic veins (anteroinferior pancreaticoduodenal vein, posteroinferior pancreaticoduodenal vein, anterosuperior pancreaticoduodenal vein, posterosuperior pancreaticoduodenal vein, and gastrocolic trunk) indicated tumor invasion of only the second portion of the extrapancreatic nerve plexus (n = 4) and tumor invasion of both the second portion of the extrapancreatic nerve and the mesenteric root (n = 3). CONCLUSION: Dilatation of peripancreatic veins with nonvisualization of inferior peripancreatic veins suggests tumor invasion of peripancreatic tissue.     

Parathyroid lesions: characterization with dual-phase arterial and venous enhanced CT of the neck

This clinical report describes the enhancement characteristics of hypersecreting parathyroid lesions on dual-phase neck CT. We retrospectively analyzed the enhancement characteristics of 5 pathologically confirmed PTH-secreting lesions on dual-phase CT examinations. Attenuation values were measured for PTH-secreting lesions, vascular structures (CCA and IJV), and soft tissue structures (thyroid gland, jugulodigastric lymph node, and submandibular gland). From the attenuation values, "relative enhancement washout percentage" and "tissue-vascular ratio" were calculated and compared. All lesions decreased in attenuation from arterial to venous phase, while the mean attenuation values of other soft tissue structures increased. A high relative enhancement washout percentage was correlated with parathyroid lesions (P < .006). The tissue-CCA ratio and tissue-IJV ratio for PTH-secreting lesions in the arterial phase were statistically significantly higher compared with soft tissue structures (P < .05). If these results are validated in future larger studies, noncontrast and delayed venous phases of 4D-CT could be eliminated to markedly reduce radiation exposure.     

Pancreatic adenocarcinoma: A simple CT score for predicting margin-positive resection in patients with resectable disease

BackgroundNegative-margin status is a prognostic indicator for long-term survival following curative intent resection for pancreatic adenocarcinoma. Patients at increased risk for positive-margin resections may benefit from neoadjuvant chemotherapy prior to resection.MethodsWe retrospectively analyzed preoperative computed-tomography (CT) scans in 108 consecutive patients that underwent curative intent resection for a resectable pancreatic ductal adenocarcinoma from 2009 to 2016 in two academic hospitals. Two radiologists independently staged the tumor, including tumor location, size, and tumor-to-superior mesenteric/portal vein (SMV/PV) contact. Uni and multivariate analysis were performed to identify independent predictors of an R1 resection.ResultsTwenty-nine patients had an R1 resection (26.9%). Tumor size, location, and presence of tumor-to-SMV/PV contact were significantly associated with an R1 resection. In multivariate analysis, the independent parameters associated with resection status were: tumor size (R² = 9.7), and tumor location (neck R² = 6.6; pancreaticoduodenal interface R² = 4.4; uncinate process R² = 4.1), but not tumor-to-SMV/PV contact (R² = 0.1, p = 0.7). A simple CT score was built based on tumor size and location. Patients with an R0 resectability score ≥3, i.e. patients with tumor size ≥30 mm (except when tumor location is at the pancreatico-duodenal interface) or patients with tumor size ≥20 mm AND tumor located in the uncinate process or neck, were at high-risk of an R1 resection (AUC, 0.82; sensitivity, 79%; specificity, 76%). This score also showed good diagnostic performances for predicting an R1 resection involving the medial resection margin only (AUC, 0.85).ConclusionsA simple score based on tumor location and size can accurately predict patients at high-risk of an R1 resection.     

CT demonstration of central pulmonary venous and arterial occlusive diseases

Computed tomography was used to evaluate three patients with complicated pulmonary vascular patterns. The physiologic and anatomic changes seen on chest radiography were well defined by CT and in each case CT suggested the correct diagnosis.     

Pancreatic carcinoma: MR, MR angiography and dynamic helical CT in the evaluation of vascular invasion

OBJECTIVE: To assess the value of MR angiography in combination with contrast-enhanced MR imaging, and to compare MR imaging including MR angiography with dynamic contrast-enhanced dual phase helical CT in the preoperative assessment of vascular invasion in patients with suspected pancreatic carcinoma. METHODS AND MATERIAL: MR imaging only, MR imaging including MR angiography and dynamic contrast-enhanced dual phase helical CT images of 48 patients who were operated due to suspicion of pancreas cancer were correlated with the surgery results in terms of vascular invasion. Pathologic diagnosis were pancreatic adenocarcinoma in 31 patients of which nine had surgically confirmed vascular invasion. Sensitivity, specificity, predictive values (including 95% confidence intervals) and accuracy of MR imaging only, MR imaging including MR angiography and helical CT were calculated. RESULTS: Sensitivity, specificity, positive and negative predictive values and accuracy were 56, 100, 100, 85, 87%; 67, 100, 100, 88, 90% and 67, 100, 100, 88, 90%, respectively, for MR imaging only, MR imaging including MR angiography and helical CT in the adenocarcinoma group. The corresponding figures in the overall study group were 56, 97, 83, 90, 90%; 67, 97, 86, 93, 92% and 67, 97, 86, 93, 92%. Confidence intervals (95%) showed that the differences in the diagnostic efficacy of the techniques were not statistically significant in the overall study group, but the confidence intervals were undefined in the adenocarcinoma group due to the small sample size. CONCLUSION: Diagnostic efficacy of MR imaging when combined with MR angiography is equal to that of dynamic contrast-enhanced dual phase helical CT in the assessment of vascular invasion of pancreatic tumors.     

Pancreatic ductal adenocarcinoma showing iso-attenuation in early-phase contrast-enhanced CT: comparison with histopathological findings

PURPOSE: To clarify the CT characteristics and histopathological findings of pancreatic ductal adenocarcinomas that are not detected in early-phase contrast-enhanced CT images. MATERIALS AND METHODS: The CT findings of eight patients with histopathologically proven pancreatic carcinomas that were not detected in early-phase images following the rapid injection of contrast material were reviewed. The examinations consisted of pre-contrast-enhanced CT and multi-phase contrast-enhanced CT, with thin-section scanning in each patient. The CT findings were compared with those of the resected specimens. RESULTS: In all cases but one, the lesion was in the pancreatic head. In seven cases, the tumor did not appear as a focal area of hypoattenuation compared with surrounding pancreatic parenchyma in early-phase images, and in the remaining case, small areas of poor enhancement were observed. In late-phase images, hyperattenuated and isoattenuated areas were seen in six and two cases, respectively. In all but one case, the lesion was less than 40 mm in size. All lesions were composed of acinar tissues and tumor cells, and contained small amounts of mucin, necrotic tissue, and pus. The fibrous tissues were not abundant and were interlobular and/or relatively loose. CONCLUSION: Pancreatic ductal adenocarcinomas showing isoattenuation in early-phase images tend to be relatively mild lesions with scirrhous and/or desmoplastic changes.     

Intrahepatic portal venous variations: demonstration by helical CT during arterial portography

PURPOSE: We assessed the prevalence and types of intrahepatic portal venous variations by helical computed tomography performed with arterial portography (CTAP). METHODS: In 192 patients without evidence of vascular invasion or distortion, CTAP images were reviewed retrospectively to identify portal venous variations. RESULTS: Of the 192 patients examined, 10 (5.2%) had trifurcation, 5 (2.6%) had a right posterior segmental branch arising from the main portal vein, 5 (2.6%) had an absence of the horizontal segment of the left portal vein, and 1 (0.5%) had an absence of the left lateral segmental portal branch. Of the patients without a horizontal segment, two had a right-sided ligamentum teres associated with malposition of the gallbladder, while another had complete ramification of intrahepatic portal branches from an umbilical vein-like segment. In the patient missing the left lateral segmental branches, the right portal vein segments were subcapsularly located. CONCLUSION: Variations of the intrahepatic portal veins can be recognized on CTAP imaging. tomography-Portal vein, computed tomography.     

Normal and variant coronary arterial and venous anatomy on high-resolution CT angiography

OBJECTIVE: This article displays the normal and variant anatomy of the coronary arteries and subjacent cardiac veins using a high-resolution 64-MDCT scanner. CONCLUSION: Knowledge of the anatomy of the coronary arteries and subjacent cardiac veins as displayed with maximum intensity and volume-rendered projections is important for correct image interpretation of coronary CT angiography examinations.     

MDCT in Pancreatic adenocarcinoma: prediction of vascular invasion and resectability using a multiphasic technique with curved planar reformations

OBJECTIVE: The objective of our study was to determine the negative predictive value of MDCT with curved planar reformations for detecting vascular invasion and predicting overall resectability in patients with pancreatic adenocarcinoma. MATERIALS AND METHODS: Imaging findings related to vascular invasion and overall tumor resectability in 25 patients who underwent contrast-enhanced biphasic MDCT evaluation were correlated with actual vessel invasion and overall resectability determined at surgery and pathologic examination. The presence of vascular invasion was assessed in 110 major peripancreatic vessels in 22 patients who underwent resection. RESULTS: On MDCT, 23 (92%) of 25 patients were deemed to have resectable pancreatic adenocarcinoma. The tumors in the remaining two (8%) were considered not resectable because of the presence of vascular invasion (which was confirmed in only one patient at surgery). Of those 23 patients deemed to be candidates for curative resection on the basis of MDCT results, 20 were found to have resectable adenocarcinoma at time of surgery, yielding a negative predictive value for MDCT of 87% (20/23 patients) for overall resectability. In the other three patients, adenocarcinoma was deemed to be unresectable because of small metastases to the liver (two patients) or to the peritoneum (one patient) discovered at surgery. For detection of vascular invasion, MDCT yielded a negative predictive value of 100% (108/108 vessels) with no false-negative findings and an accuracy of 99% (109/110 vessels) with 108 true-negative findings, one true-positive finding, and one false-positive finding. CONCLUSION: Our preliminary data on MDCT show that the technique has excellent negative predictive value for vascular invasion and good negative predictive value for overall tumor resectability in patients with pancreatic adenocarcinoma, suggesting an improvement over previous results reported using single-detector CT. The problem of undetected micrometastases to the liver and peritoneum remains.     

肠系膜上动、静脉血栓形成的CT诊断

肠系膜上动、静脉血栓形成临床上比较少见，由于其症状和体征不典型，常易误诊，且死亡率较高。笔者遇到9例经CT发现的肠系膜上静脉血栓形成和4例肠系膜上动脉血栓形成病例，并经临床、手术及病理证实，现报告如下。