Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

AIM： To retrospectively analyze the imaging features of solid-pseudopapillary tumors （SPTs） of the pancreas on multi-detector row computed tomography （MDCT） and define the imaging findings suggestive of malignant potential. METHODS： A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations. RESULTS： Of the 24 cases of SPTs, 11 cases （45.8%） occurred in the pancreatic head and seven （29.1%） in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results （Kappa = 0.6, P 〈 0.05）. The size of SPTs ranged from 3 to 15 cm （mean, 5.8 cm）. When the size of the tumor was greater than 6 cm （including 6 cm）, the possibilities of vascular （8 vs 1） and capsular invasion （9 vs 0） increased significantly （P 〈 0.05）.Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors. CONCLUSION： Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyrna and nearby structures in SPTs of the pancreas can be accurately revealed by MDCT preoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.

Computed tomography diagnosed left ovarian venous thrombophlebitis after vaginal delivery:A case report

BACKGROUND Postpartum ovarian vein thrombophlebitis(POVT)is a rare but serious postpartum complication that affects mostly postpartum women.A high index of suspicion is required when faced with sudden postpartum abdominal pain.CASE SUMMARY A 25-year-old healthy woman who accepted a vaginal delivery procedure suffered fever(temperature 39.6℃)one day after delivery,accompanied with left lower abdominal pain.Physical examination indicated mild tenderness in the left lower abdomen,accompanied with rebound pain.The patient was confirmed to have left ovarian venous thrombosis with inflammation after receiving a multidetector row computed tomography scan.CONCLUSION POVT is a rare and dangerous postpartum complication.A high index of suspicion is required for the occurrence of ovarian venous thrombosis when faced with postpartum abdominal pain and fever.Early application of Doppler ultrasound,computed tomography,magnetic resonance imaging and other auxiliary examinations is conducive to timely and accurate diagnosis of POVT,thus reducing maternal mortality.

A spontaneous strangulated transomental hernia: Prospective and retrospective multi-detector computed tomography findings

Transomental hernias are among the rarest type of all internal hernias which overall account for less than 6% of small bowel obstructions. Most transomental hernias occurring in adults are either iatrogenic or post-traumatic. More rarely, a spontaneous herniation of small bowel loops may result from senile atrophy of the omentum. We report a case of an 86-year-old male who presented with signs and symptoms of small bowel obstruction but had no past surgical or traumatic abdominal history. At contrast-enhanced multi-detector row computed tomography(CT), a cluster of fluid-filled dilated small bowel loops could be appreciated in the left flank, with associated signs of bowel wall ischemia. Swirling of the mesenteric vessels could also be appreciated and CT findings were prospectively considered consistent with a strangulated small bowel volvulus. At laparotomy, no derotation had to be performed but up to 100 cm of gangrenous small bowel loops had to be resected because of a transomental hernia through a small defect in the left part of the greater omentum. Retrospective reading of CT images was performed and findings suggestive of transomental herniation could then be appreciated.

Utility of multi-detector row computed tomography angiography versus Doppler in localization of perforators of anterolateral thigh flaps

Aim:Anterolateral thigh(ALT)flap is widely used in reconstruction of various defects.Preoperative imaging facilitates perforator mapping,overcoming intraoperative uncertainty.The purpose of this study was to investigate the utility of multi-detector row computed tomography angiography(MDCTA)and a handheld Doppler in locating ALT perforators.Methods:Twenty patients were randomized into two groups.Group 1 patients received MDCTA and Doppler studies whereas Group 2 received only a Doppler study.The number,location,course,and source of all cutaneous and sizable perforators were compared with intraoperative findings.Surgeons’stress levels during flap harvest and flap harvest time were compared.Results:MDCTA findings correlated well with intraoperative findings for perforator type and segmental distribution with 100%concordance.Doppler alone had a 52%rate of concordance.The sensitivity and specificity for MDCTA in demonstrating the presence of perforators were 85.71%and 97.22%,respectively;whereas for Doppler alone the sensitivity and specificity were 80%and 87.91%,respectively.In demonstrating perforator source,MDCTA showed a sensitivity of 100%and specificity of 91.66%,with 100%accuracy.Sensitivity and specificity for sizable perforators were 90%each,with 88.88%accuracy.Doppler studies were unable to provide this information.Comparison of surgeon stress levels showed no differences between the two groups,although the time for flap harvest was significantly shorter in Group 1.Conclusion:MDCTA compared to Doppler is more sensitive,specific,and accurate with respect to location,course,and source of perforators.

MDCT angiography to evaluate the therapeutic effect of PTVE for esophageal varices

Abstract AIM:To evaluate the role of multi-detector row computed tomography(MDCT) angiography for assessing the therapeutic effects of percutaneous transhepatic variceal embolization(PTVE) for esophageal varices(EVs).METHODS:The subjects of this prospective study were 156 patients who underwent PTVE with cyanoacrylate for EVs.Patients were divided into three groups according to the filling range of cyanoacrylate in EVs and their feeding vessels:(1) group A,complete obliteration,with at least 3 cm of the lower EVs and peri-/EVs,as well as the adventitial plexus of the gastric cardia and fundus filled with cyanoacrylate;(2) group B,partial obliteration of varices surrounding the gastric cardia and fundus,with their feeding vessels being obliterated with cyanoacrylate,but without reaching lower EVs;and(3) group C,trunk obliteration,with the main branch of the left gastric vein being filled with cyanoacrylate,but without reaching varices surrounding the gastric cardia or fundus.We performed chart reviews and a prospective follow-up using MDCT images,angiography,and gastrointestinal endoscopy.RESULTS:The median follow-up period was 34 mo.The rate of eradication of varices for all patients was 56.4%(88/156) and the rate of relapse was 31.3%(41/131).The rates of variceal eradication at 1,3,and 5 years after PTVE were 90.2%,84.1% and 81.7%,respectively,for the complete group;61.2%,49% and 42.9%,respectively,for the partial group;with no varices disappearing in the trunk group.The relapsefree rates at 1,3 and 5 years after PTVE were 91.5%,86.6% and 81.7%,respectively,for the complete group;71.1%,55.6% and 51.1%,respectively,for the partial group;and all EVs recurred in the trunk group.Kaplan-Meier analysis showed P values of 0.000 and 0.000,and odds ratios of 3.824 and 3.603 for the rates of variceal eradication and relapse free rates,respectively.Cyanoacrylate in EVs disappeared with time,but those in the EVs and other feeding vessels remained permanently in the vessels without a decrease with time,which is important for the continued obliteration of the feeding vessels and prevention of EV relapse.CONCLUSION:MDCT provides excellent visualization of cyanoacrylate obliteration in EV and their feeding veins after PTVE.It confirms that PTVE is effective for treating EVs.

Current status of low dose multi-detector CT in the urinary tract

Over the past several years,advances in the technical domain of computed tomography(CT) have influenced the trend of imaging modalities used in the clinical evaluation of the urinary system.Renal collecting systems can be illustrated more precisely with the advent of multi-detector row CT through thinner slices,high speed acquisitions,and enhanced longitudinal spatial resolution resulting in improved reformatted coronal images.On the other hand,a significant increase in exposure to ionizing radiation,especially in the radiosensitive organs,such as the gonads,is a concern with the increased utilization of urinary tract CT.In this article,we discuss the strategies and techniques availablefor reducing radiation dose for a variety of urinary tractCT protocols with metabolic clinical examples.We also reviewed CT for hematuria evaluation and related scan parameter optimization such as,reducing the number of acquisition phases,CT angiography of renal donors and lowering tube potential,when possible.

关于多排螺旋CT剂量的探讨

随着螺旋CT探测器排数的增加 ,病人所受辐射剂量也出现了新的变化。本文就多排螺旋CT的剂量表征、测量进行了探讨 ,对其临床诊断剂量参考水平进行了调研。分析了多排螺旋CT管球对热容量的要求以及其剂量效率的变化。最后提出了在不降低影像质量的情况下如何降低病人剂量的方法。

透明血管型Castleman病的多排螺旋CT影像学特征

目的 探讨Castleman病(CD)的多排螺旋CT(MDCT)影像学特点。方法 收集18例CD患者的病例资料,其中12例同时行MDCT平扫和多期增强检查,2例行MDCT平扫检查,4例行MDCT多期增强检查,收集患者的临床、影像及病理类型资料,比较影像资料中病灶部位、形态、平扫特点、强化程度以及强化方式等特征。结果 18例CD患者,发生部位在胸部9例、腹部4例、颈部2例、盆腔2例以及多部位1例;17例为单中心型(UCD),1例为多中心型(MCD);18例CD病理类型均为透明血管型(HVV);术前正确诊断4例、误诊5例、不定性诊断9例;14例MDCT平扫表现为6例不均质,6例合并钙化,2例边缘模糊,1例多发软组织密度肿块,其余表现为质地均匀、边缘清楚的单发软组织密度结节或肿块;16例多期增强扫描表现为病灶动脉期呈中度或显著强化,静脉期及延迟期呈显著强化,其中11例可见瘤周滋养血管。结论 CD在MDCT上多为密度均质、边界清楚的孤立性软组织结节或肿块,增强扫描显示显著强化及瘤周滋养血管。

尘肺高分辨率CT表现特征及病理、生理学基础

因职业环境造成的尘肺常见有矽肺、煤尘肺和石棉肺等,病理改变主要为结节和纤维化。尘肺的影像学检查方法有平片和CT,高分辨率CT、多层螺旋CT及其后处理技术更有利于观察细微病变,适用于尘肺早期诊断。多层螺旋CT功能成像可进一步了解尘肺病人肺功能的改变。

食管癌多层螺旋CT灌注成像研究现状

食管癌是常见的恶性肿瘤之一。多层螺旋CT灌注成像作为一种无创手段,可以在活体状态下评价其微循环。近年来,CT灌注成像在食管癌的微循环评价、放化疗的疗效判断方面取得进展。本文着重综述多层螺旋CT灌注成像技术在食管癌中的应用研究现状。

CT-scan vs.3D surface scanning of a skull:first considerations regarding reproducibility issues

Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques are more and more commonly employed,surprisingly little information is known about the quality rendering of digitalized three-dimensional(3D)models provided by each of them.This paper presents findings related to the measurement precision of 3D models obtained through observation of a study case,where a fractured skull reconstructed by an anthropologist was digitalized using both post-mortem imaging methods.Computed tomography(CT)scans were performed using an 8-row MDCT unit with two different slice thicknesses.The variability of 3D CT models superimposition allowed to assess the reproducibility and robustness of this digitalization technique.Furthermore,two 3D surface scans were done using a professional high resolution 3D digitizer.The comparison of 3D CT-scans with 3D surface scans by superimposition demonstrated several regions with significant differences in topology(average difference between+1.45 and-1.22 mm).When comparing the reproducibility between these two digitalizing techniques,it appeared that MDCT 3D models led in general to greater variability for measurement precision between scanned surfaces.Also,the reproducibility was better achieved with the 3D surface digitizer,showing 3D models with fewer and less pronounced differences(from+0.32 to-0.31 mm).These experiments suggest that MDCT provides less reproducible body models than 3D surface scanning.But further studies must be undertaken in order to corroborate this first impression,and possibly explain the reason for these findings.