Portal vein stenosis and occlusion stenting after liver transplantation in two adults

We report two cases of percutaneous transhepatic stenting of the portal vein to treat stenosis and occlusion disclosed 5 and 18 months, respectively, after orthotopic liver transplantation in two adult patients. If long-term patency is satisfactory, this technique should allow long-term management of portal vein stenosis and occlusion without the use of thrombolysis.     

肾动脉狭窄的肾脏CT血流灌注参数研究

目的:探讨利用CT血流灌注参数研究肾动脉狭窄患者肾脏血流状况。方法:高血压患者36人,分为肾动脉狭窄组(24人)和对照组(12人),进行肾脏CT电影扫描获得动态序列图像,通过AW影像工作站计算肾脏皮质血流灌注参数,分析肾脏皮质血流灌注与肾动脉狭窄的关系。结果:肾动脉狭窄>75%组肾皮质单位体积血流量(BF)(189.9±102.3ml/100g/min)低于对照组(308.4±99.9ml/100g/min),有显著差异(P=0.026)。肾动脉狭窄50%-75%组及狭窄>75%组肾皮质微血管容积(BV)(24.6±7.6ml/100g,21.4±12.6ml/100g)低于对照组(41.1±14.1ml/100g),有非常显著差异(P=0.008,0.001)。各组之间平均通过时间(MTT)、毛细血管表面通透性(PS)无显著性差异(P>0.05)。结论:明显肾动脉狭窄的肾脏皮质BF、BV下降,CT血流灌注参数可以为评估肾动脉狭窄的肾脏是否缺血提供帮助。     

Measuring portal venous perfusion with contrast-enhanced CT: comparison of direct and indirect methods

RATIONALE AND OBJECTIVES: Two algorithms can be used to measure portal venous perfusion (PVP) with contrast material-enhanced single-level liver computed tomography. The "direct" and "indirect" algorithms use data from the portal vein and aorta, respectively. This study compared PVP values obtained with direct and with indirect algorithms in a series of patients. MATERIALS AND METHODS: Both techniques were applied in 27 patients with cirrhosis (14 men and 13 women; mean age, 56.1 years +/- 9.4) and 18 control patients (seven men and 11 women; 52.8 years +/- 12.3). A single section through the liver was scanned after intravenous injection of ioversol (40-mL bolus; 320 mg of iodine per milliliter). RESULTS: Both techniques showed reduced PVP in patients with cirrhosis (0.63 for direct and 0.17 for indirect method) compared with control patients (1.06 and 0.26, respectively), but only the direct method agreed with physiologic expectations based on animal and human studies. In separating cirrhotic and control patients, the area under the receiver operating characteristic curve was significantly greater for the direct method (0.91 vs 0.78; P = .03). CONCLUSION: Both direct and indirect methods are feasible and distinguish well between cirrhotic and control patients, but the direct method is more physiologic and is preferable if portal venous data are available.     

Esophageal and gastric vasculature in children with extrahepatic portal hypertension: evaluation by intravenous CT portography

PURPOSE: To compare the findings related to esophageal/gastric varices and congestive gastropathy on intravenous computed tomography (CT) portography (CTP) and upper gastrointestinal endoscopy (UGIE) in children with extrahepatic portal venous obstruction (EHO) presented with hematemesis. METHODS/MATERIALS: Fifty pediatric patients (age < 15 years) with EHO (initially diagnosed on abdominal ultrasound) presented with hematemesis and underwent UGIE and intravenous CTP using a helical CT scanner. Axial sections of 2 mm each were obtained with a collimation of 2 mm and a table feed of 3 mm. CTP findings on these axial sections were compared with UGIE (gold standard). RESULTS: The sensitivity of CTP for detection of esophageal varices, gastric varices, and gastropathy was 32/33 (97%), 38/40 (95%), and 30/32 (93%), respectively. CTP showed false positivity as well, which was 5/17 (29%), 2/10 (20%), and 13/17 (76%) for esophageal varices, gastric varices, and gastropathy, respectively. On follow-up UGIE, the endoscopic features appeared in 14/19 (74%) of false positive patients. Therefore, false positivity for all the parameters on CTP when compared to the initial UGIE represented the changes in vasculature before they were endoscopically manifest. CONCLUSIONS: CTP was likely to pick up changes in esophageal and gastric vasculature earlier than UGIE in children with EHO presented with hematemesis.     

64层螺旋CT三维重建在肝脏门静脉右前支分段中的应用研究

目的利用64层螺旋CT三维重建技术观察肝脏门静脉右前支分支类型及亚段的解剖标志,为肝段划分提供准确的影像学依据。方法共165例腹部CT增强扫描资料,重组门静脉血管树,分析门静脉右前支分段的解剖标志并对右前支3级血管进行分型。结果 145例（87.9%）右前支门静脉3级分支之间存在一缺少血管的裂隙,此裂隙将右前支分为腹侧段和背侧段,其中42例腹侧段及背侧段分支间分别存在一缺少血管的裂隙,并再分为两个亚段;在这一裂隙中有一肝中静脉或肝右静脉走行。20例（12.1%）右前支分为上段和下段。右前支依据门静脉3级分支的不同分为5种类型,Ia型25.5%（42/165例）;Ib型43.6%（72/165例）;Ic型18.8%（31/165例）;IIa型7.9%（13/165例）;IIb型4.2%（7/165例）。结论 64层螺旋CT三维重建技术可以清晰显示门静脉右前支的分支类型及亚段解剖标志,为肝脏右前叶亚段手术提供可靠的影像学依据。     

Dynamic perfusion CT: optimizing the temporal resolution for the calculation of perfusion CT parameters in stroke patients

PURPOSE: To assess the influence of different temporal sampling rates on the accuracy of the results from cerebral perfusion CTs in patients with an acute ischemic stroke. MATERIAL AND METHODS: Thirty consecutive patients with acute stroke symptoms received a dynamic perfusion CT (LightSpeed 16, GE). Forty millilitres of iomeprol (Imeron 400) were administered at an injection rate of 4 ml/s. After a scan delay of 7s, two adjacent 10mm slices at 80 kV and 190 mA were acquired in a cine mode technique with a cine duration of 49 s. Parametric maps for the blood flow (BF), blood volume (BV) and mean transit time (MTT) were calculated for temporal sampling intervals of 0.5, 1, 2, 3 and 4s using GE's Perfusion 3 software package. In addition to the quantitative ROI data analysis, a visual perfusion map analysis was performed. RESULTS: The perfusion analysis proved to be technically feasible with all patients. The calculated perfusion values revealed significant differences with regard to the BF, BV and MTT, depending on the employed temporal resolution. The perfusion contrast between ischemic lesions and healthy brain tissue decreased continuously at the lower temporal resolutions. The visual analysis revealed that ischemic lesions were best depicted with sampling intervals of 0.5 and 1s. CONCLUSION: We recommend a temporal scan resolution of two images per second for the best detection and depiction of ischemic areas.     

CT blood pool enhancement in primates with lopromide-carrying liposomes containing soy phosphatidyl glycerol

RATIONALE AND OBJECTIVES: The purpose of this study was to determine the feasibility of using iodinated liposomes as blood pool agents for computed tomography (CT) in nonhuman primates. MATERIALS AND METHODS: Five normal adult baboons (15-21 kg) were anesthetized and intravenously injected with iopromide containing soy phosphatidyl glycerol liposomes with a diameter of 195 nm. Each animal received a dose of 300 mg total iodine per kilogram (46% encapsulation). RESULTS: The animals tolerated the injections well, experiencing no measurable electrocardiographic changes, and recovered uneventfully from anesthesia. Sequential helical CT scans of the baboons from the base of the skull to the symphysis pubis acquired up to 40 minutes after injection showed persistent blood pool enhancement. Maximum mean enhancement of major vascular structures was 106 HU at 1 minute after contrast medium injection. Mean blood pool enhancement was 76, 72, and 67 HU at 10, 20, and 40 minutes after injection, respectively. Liver and spleen were enhanced by 40 and 41 HU, respectively, 40 minutes after injection. No significant enhancement was measured in the brain and pancreas. CONCLUSION: Soy phosphatidyl glycerol with iopromide liposomes produces prolonged vascular enhancement and has potential as a blood pool CT contrast agent in primates.     

Comparison of unenhanced and contrast-enhanced spiral CT for assessing interval change in patients with colorectal liver metastases

RATIONALE AND OBJECTIVES: The purpose of this study was to determine whether the interval change in hepatic colorectal metastases as assessed with serial computed tomographic (CT) scans without contrast material enhancement differs from that as assessed using serial, portal dominant phase, contrast-enhanced CT scans. MATERIALS AND METHODS: Unenhanced and contrast-enhanced abdominal CT scans were obtained in 28 patients. Three radiologists separately reviewed serial unenhanced and contrast-enhanced studies to assess the interval change in liver metastases. These radiologists recorded total number of lesions, bidimensional measurements of the largest lesions (as many as three), and overall impressions regarding the interval change (none, worse, or better). RESULTS: Among the 84 judgments (28 patients x 3 radiologists), comparisons of unenhanced and contrast-enhanced CT studies were concordant in 60 assessments (71%). Nineteen (23%) showed mild disagreement. Of these, contrast-enhanced CT studies demonstrated disease stability when unenhanced CT studies demonstrated otherwise in 11 judgments, whereas unenhanced CT studies demonstrated stability when contrast-enhanced CT studies demonstrated otherwise in eight assessments. Furthermore, of the five marked disagreements, two resulted from a conclusion of interval improvement on unenhanced CT studies and a conclusion of interval worsening on contrast-enhanced CT studies, whereas three demonstrated the opposite. Neither set of serial CT studies systematically resulted in under- or overestimation of disease progression (McNemar Q test, P < .25). CONCLUSION: The authors found no consistent pattern to demonstrate that serial unenhanced or contrast-enhanced CT studies resulted in over- or underestimation of disease progression.     

Normative analysis of pulmonary vein drainage patterns on multidetector CT with measurements of pulmonary vein ostial diameter and distance to first bifurcation

RATIONALE AND OBJECTIVES: To document the frequency of normal and anomalous drainage patterns of the pulmonary veins, and to establish normal values for pulmonary vein ostial diameters, and distance to first bifurcation using multidetector computed tomography, as pertinent to ablation procedures for atrial fibrillation. MATERIALS AND METHODS: Two cardiothoracic radiologists retrospectively reviewed thin-section contrast material-enhanced multidetector computed tomography examinations of the thorax in 200 consecutive patients (38 females and 162 males), age 24-79 years (mean 52.8) referred for imaging before radiofrequency ablation therapy for atrial fibrillation. Pulmonary vein anatomy was based on both the number of venous ostia and the drainage patterns of pulmonary veins. Pulmonary vein ostial diameters and distance to first bifurcation of the four major pulmonary veins (right inferior and superior, left inferior and superior) and any additional pulmonary veins were measured at a workstation using both axial images and multiplanar reconstructions by two experienced cardiothoracic radiologists; the mean pulmonary vein diameter and the shortest distance to first bifurcation of the two measurements are reported. RESULTS: The majority of patients, 82% (164 patients) had four pulmonary veins, with a superior and inferior ostium on the right and a superior and inferior ostium on the left. Of the remainder, 9% (18 patients) had five veins, 4.5% (9 patients) had three veins, 3% (6 patients) had two anomalies each, and 0.5% (1 patient) had three anomalies. The middle lobe pulmonary vein drained into the right superior pulmonary vein in 83.5% of patients, directly into the left atrium in 11% of patients, and into the right inferior pulmonary vein in 5.5% of patients; 6.5% of patients had a single left pulmonary vein ostium. Mean pulmonary vein diameters with 95% confidence intervals at the ostia were as follows: right superior 17.6 (13.64-15.36) mm; left superior 16.6 (16.03-17.08) mm; right inferior 17.1 (16.58-17.55) mm; left inferior 14.8 (14.25-15.27) mm, and independent middle lobe 8.6 (8.27-8.86) mm. Mean distance to first bifurcation with 95% confidence intervals were: right superior 14.5 (17.02-18.23) mm; left superior 17.6 (16.63-18.53) mm; right inferior 7.0 (6.49-7.46) mm; left inferior 13.5 (12.83-14.16) mm, and independent middle lobe 8.4 (7.7-9.17) mm. CONCLUSION: Thin-section thoracic computed tomography demonstrates a greater variability of pulmonary venous drainage than previously described. There is greater variability of the right lung venous drainage compared to the left lung. Eighty-two percent of people have four standard pulmonary veins. There is significant variability in pulmonary vein diameter and distance to first bifurcation.     

Multiplanar display of spiral CT data of the pulmonary hila in patients with lung cancer : Preliminary observations

Spiral or helical computed tomography (CT)-generated multiplanar reconstructions were used in the radio-logical assessment of the pulmonary hila in patients with central lung cancer. Twelve patients with non-small-cell lung cancer and hilar abnormalities were examined with contrast-enhanced spiral CT. Studies were performed on a Siemens Somatom S or Plus-S scanner using either a 24- or 32-second spiral. The study volume was from the arch of the aorta to the inferior pulmonary veins done in a single breath-hold, using 4-mm collimation, and reconstructed at 2-mm intervals. We assessed the quality of vascular enhancement and of multiplanar reconstructions. Bronchoscopic, surgical, and pathological findings were correlated. Excellent vascular opacification and good-quality reconstructions were obtained in all patients. No interscan motion was detected. No problems were encountered with the breathholding technique or in the reconstruction of images, even in patients with poor respiratory function. Multiplanar reconstructions were useful for the evaluation of mediastinal including vascular and airways invasion, for optimal definition of lymph node groups, for the planning of bronchoscopically guided biopsy, as well as for endobronchoscopic laser coagulation therapy and surgical treatment. Spiral CT-generated multiplanar reconstructions of the hila are helpful for staging, solving problems, guiding bronchoscopy, and planning surgery. Even patients with limited respiratory reserve can successfully complete the examination.     

Subtle Pleural Metastasis without Large Effusion in Lung Cancer Patients: Preoperative Detection on CT

Objective

We wanted to describe the retrospective CT features of subtle pleural metastasis without large effusion that would suggest inoperable lung cancer.

Materials and Methods

We enrolled 14 patients who had open thoracotomy attempted for lung cancer, but they were proven to be inoperable due to pleural metastasis. Our study also included 20 control patients who were proven as having no pleural metastasis. We retrospectively evaluated the nodularity and thickening of the pleura and the associated pleural effusion on the preoperative chest CT scans. We reviewed the histologic cancer types, the size, shape and location of the lung cancer and the associated mediastinal lymphadenopathy.

Results

Subtle pleural nodularity or focal thickening was noted in seven patients (50%) having pleural metastasis and also in three patients (15%) of control group who were without pleural metastasis. More than one of the pleural changes such as subtle pleural nodularity, focal thickening or effusion was identified in eight (57%) patients having pleural metastasis and also in three patients (15%) of the control group, and these findings were significantly less frequent in the control group patients than for the patients with pleural metastasis (p = 0.02). The histologic types of primary lung cancer in patients with pleural metastasis revealed as adenocarcinoma in 10 patients (71%) and squamous cell carcinoma in four patients (29%). The location, size and shape of the primary lung cancer and the associated mediastinal lymphadenopathy showed no significant correlation with pleural metastasis.

Conclusion

If any subtle pleural nodularity or thickening is found on preoperative chest CT scans of patients with lung cancer, the possibility of pleural metastasis should be considered.     

Variability of clinical CT perfusion measurements in patients with carotid stenosis

Introduction CT perfusion imaging (pCT) may be used to detect and monitor hemodynamic abnormalities due to cerebrovascular disease. The magnitude of variability in clinical measurements has been insufficiently evaluated. The purpose of this study was to measure the long-term variability of clinical pCT measurements in patients with cerebrovascular disease. Methods pCT parameters were calculated for the cerebral hemisphere contralateral to a carotid stenosis before and after stent treatment of stenosis in 33 consecutive patients. Mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) calculated from pCT data from both a small and large region of interest (ROI) using both manual and automated methods were compared before and after stent treatment. Differences between the first and second measurement were tested for statistical significance with at-test. Variability was calculated as the standard deviation of the differences divided by the mean of the pre- and post-stent treatment values. To adjust for proportional bias, the Bland–Altman analysis was applied. Results The differences between the two measurements of MTT, CBF, and CBV averaged 2.5 to 7.7% when a manual method was used and was higher with automatic methods (p > 0.07). The variability of the values was 18% for MTT, 19% for CBV, and 25% for CBF with the large ROI and the manual method of calculation. The magnitude was larger when the small ROI and automatic methods were employed. Conclusion Longitudinal measurements of MTT, CBV, or CBF by pCT may vary by 20–25%. To detect changes in treatment-related changes in perfusion, pCT studies must be designed to achieve statistical significance based on this variability.     

Follow-up CT Evaluation of the Mural Changes in Active Takayasu Arteritis

Objective

We wanted to evaluate the mural changes by CT on the follow-up examination of patients with active Takayasu arteritis.

Materials and Methods

The study included 18 patients, (4 males and 14 females), with active Takayasu arteritis. A total of 44 CT examinations were done during the follow-up period (mean: 55.6 months). At the time of the last follow-up CT, the disease, on the basis of the erythrocyte sedimentation rate (ESR), was found to be inactive in five patients and the disease was active and persistent in 13 patients. The thickness and CT attenuation of the aortic wall on the precontrast, arterial and venous phases were measured on the initial and the follow-up CT examinations. The ratio of the mural attenuation over that of the back muscle on the initial CT was compared with the ratio found on the follow-up CT.

Results

The initial CT findings included high density and calcifications of the aortic wall in the precontrast images and a thickened wall with enhancements in the arterial and the venous phases. A low-attenuation ring was demonstrated in the venous phase in 15 patients (83%). On the follow-up evaluation, the mean mural thickness decreased significantly from 4.1 mm to 2.4 mm. The mean mural attenuation ratio in the venous phase decreased significantly from 1.9 to 1.3 (p = 0.001). The low attenuation ring was identified in seven patients (39%) who had only with active, persistent Takayasu arteritis.

Conclusion

The mural changes demonstrated by the follow-up CT evaluations for the patients with active Takayasu arteritis included a decrease of the mural thickness and enhancement, disappearance of the low-attenuation ring on the venous phase, and an increase of the mural attenuation and calcification on the precontrast phase.     

Acute epiploic appendagitis: CT findings in 33 cases

Acute epiploic appendagitis (AEA) is a benign self-limiting process presenting with acute abdominal pain often misdiagnosed clinically as either diverticulitis or appendicitis, but which has a pathognomonic CT appearance. The CT findings in 33 adult patients diagnosed by CT over a 33-month period as having AEA were retrospectively reviewed. The study group included 24 men and 9 women, with a mean age of 44.6 years. The mean age of the male patients was lower than that of the female patients, 40.9 vs 54.7 years. All patients presented with acute abdominal pain, mainly in the left (n=21) and right (n=9) lower quadrants, with localized tenderness in all patients and peritoneal irritation in 15 of them. Low-grade fever was found in 8 patients and mild leukocytosis in 16. Characteristic CT findings of an oval fatty mass with central streaky densities and surrounded by mesenteric stranding adjacent to the serosal surface of the colon were seen in all cases. Additional findings included mural thickening of the juxtaposed colon in 16 patients and peritoneal fluid in 7. One patient underwent surgery on the basis of an erroneous diagnosis of acute appendicitis. As CT is often used nowadays to evaluate various acute abdominal complaints, it may be the first imaging modality by which AEA is diagnosed. AEA should be included in the differential diagnosis in young male patients with localized left lower abdominal pain and tenderness. Electronic Publication     

Myoepitheliomas of the soft palate: helical CT findings in two patients.

We describe the enhancement patterns of myoepithelioma in two patients with a soft palate mass. In the first case, helical CT revealed a faintly enhancing mass. Histologically, the tumor was composed of plasmacytoid cells in a background of rich myxoid stroma. Immunostaining for CD34 showed scanty blood vessels. In the second case, helical CT revealed an intensely enhancing mass. Histologically, the mass was a cellular tumor with fibrous stroma. Immunostaining for CD34 also showed frequent blood vessels.     

Difficulties in the diagnosis of appendicitis: review of CT and US images

To determine the reasons for missing a distended appendix, we discuss cases of acute appendicitis in which either or both computed tomography (CT) and/or ultrasonography (US) initially failed to detect distended appendix. In some cases, distended appendices that were undetected on US were easily detected by CT, and vice versa. Failure to detect a distended appendix does not always eliminate the possibility of acute appendicitis.     

Aortic dissection following coronary artery bypass surgery: Diagnosis by CT

We describe an unusual case of aortic dissection causing spinal cord infarction. The dissection arose from an intimal tear at the suture line of a coronary artery bypass graft. CT was used to diagnose the dissection and to demonstrate its extension to the aortoiliac bifurcation and innominate artery and its rupture into the left pleural cavity. The most common causes of intimal tears following cardiac bypass surgery are aortic cross-clamping, aortic cannulation, and injury during suturing of the graft to the aorta. An underlying disease of the aorta such as atherosclerosis, cystic medial necrosis, or aortitis is commonly present. CT is an accurate and safe means of detecting aortic dissections following cardiac surgery, and is also useful in assessing the extent of the dissection and identifying its rupture into the pleural or pericardial cavity.     

Duplication of the Extrahepatic Bile Duct in Association with Choledocholithiasis as Depicted by MDCT

We report here on an extremely rare case of duplicated extrahepatic bile ducts that was associated with choledocholithiasis, and this malady was visualized by employing the minimum intensity projection images with using multi-detector row CT. The presence of duplicated extrahepatic bile ducts with a proximal communication, and the ducts were joined distally and they subsequently formed a single common bile duct, has not been previously reported.     

门静脉支架联合125I粒子条植入治疗门脉癌栓12例

目的 介绍用门静脉支架联合125I粒子条对合并门脉癌栓的肝癌患者的综合治疗方法.方法 汇集自2014年以来中国医科大学附属盛京医院放射科收治的肝癌合并门脉癌栓的患者12例,分析其临床、影像、实验室检查资料,完成经皮经肝门静脉穿刺及支架联合125I粒子条植入术,统计手术的可行性、安全性及并发症,讨论支架的通畅情况及患者的生存情况.结果 手术成功12例(100％),2例支架未开通,其中1例并发穿刺点出血,1例并发呕血.10例患者接受随访,平均随访时间8.0个月(2～15个月),平均生存时间8.0个月(2～15个月).术后3、6和9个月及1年生存率分别为7/9、7/9、5/8和3/6.门脉支架平均通畅时间7.5个月(0～15个月).术后3、6和9个月、1年门静脉通畅率分别为7/9、6/9、5/8和3/6.随访期内共8例患者行后续TACE治疗,共行TACE 18例次,术后肝功能稳定.结论 门静脉支架联合125I粒子条植入可以降低癌栓分级、维持支架通畅、保证门脉供血、扩大TACE适应证,对合并门脉癌栓的肝细胞癌患者具有较大的综合治疗价值.