甲状腺良恶性病变的CT表现及其病理结果对比研究

目的分析甲状腺良恶性病变的CT表现及其病理结果关联性。方法回顾性分析我院2016年10月～2017年10月经手术病理证实的57例甲状腺良性肿瘤患者以及23例恶性肿瘤患者的临床资料,并对其术前CT表现与手术病理结果进行比较分析。结果 57例良性病变患者中,单侧发病占比70.18%(40/57),双侧发病占比29.82%(17/57),病灶总数为80个。23例恶性病变患者中,单侧发病占比95.65%(22/23),双侧发病占比4.35%(1/23),病灶总数为24个。边界不清、钙化发生率及囊性变发生率比较,良性病变者均明显低于恶性病变者,差异有统计学意义(P<0.05);恶性病变的强化程度、甲状腺包膜不完整性及淋巴转移发生率均高于良性病变,差异有统计学意义(P<0.05)。结论通过CT对甲状腺良恶性病变进行判断时,要依据病变密度、边界、钙化情况以及囊变情况、强化特征、包膜的完整性及周围淋巴结肿情况进行综合判断,有助于对疾病做出正确的鉴别与诊断。

Cavitary Pulmonary Metastases: CT Features and Their Correlation with the Pathology of the Primary Malignancy

Objective: To study CT features of cavitary pulmonary metastases and to investigate the pos- sible relationship between CT features and the pathology of the primary lesions. Methods: CT ?ndings of 131 cavitary metastatic nodules in 40 patients with pathologically-proved pulmonary metastases were retrospectively analyzed. A comparison between CT signs and the pathologic types of the primary tumors was made. Results: Cavitary metastases and multiple solid nodules coexisted in all patients. Cavitary metastases presented as bubble (n=41), irregular (n=33), cystic (n=26) or small circular (n=31) cavities, with even (n=61) or uneven (n=70) thickness of the cavity wall. Of 131 cavitary nodules, diameter less than 15 mm was seen in 44, between 15–25 mm in 66, 25–40 mm in 17 and larger than 40 mm in 4 respectively. And the wall thickness of the cavity below 4 mm, between 4–15 mm and over 15 mm was respectively seen in 69, 44 and 18 metastatic nodules. Cavitary pulmonary metastases mainly occurred in patients whose primary malignancy was squamous cell carcinoma (n=13) or adenocarcinoma (n=22). Both squamous cell carcinoma and adenocarcinoma had its own CT characteristics. The occurrence of cavity bore no relationship to its site in the lung. Conclusion: Cavitary pulmonary metastases carries certain CT features and its occurrence is related to the pathologic type of the primary malignancy.

Hepatic schwannoma:Imaging findings on CT,MRI and contrast-enhanced ultrasonography

A primary benign schwannoma of the liver is extremely rare and is difficult to preoperatively discriminate from a malignant tumor.We compared the imaging and pathological findings,and examined the possibility of preoperatively diagnosing a benign liver schwannoma.A 72-year-old woman was admitted to our hospital because of a 4.6-cm mass in the liver.A malignant tumor was suspected,and a right hepatectomy was performed.After this,the diagnosis of a primary benign schwannoma of the liver was made through pathological examination.Contrast-enhanced ultrasonography(CEUS) with Sonazoid showed minute blood flows into the septum and solid areas of the tumor in the vascular phase;most likely due to increased arterial flow associated with infiltration of chronic inflammatory cells.In the postvascular phase,CEUS showed contrast defect of cystic areas and delayed enhancement of solid areas;most likely due to aggregation of siderophores.Because discriminating between a benign and malignant schwannoma of the liver is difficult,surgery is generally recommended.However,the two key findings from CEUS may be useful in discriminating ancient schwannoma by recognizing the hemorrhage involved in the secondary degeneration and aggregation of siderophores.

Evaluation of contrast-enhanced helical hydro-CT in staging gastric cancer

AIM： TO discuss the helical computed tomography （CT） characteristics of gastric cancer and evaluate the diagnostic value of contrast-enhanced helical hydro-CT （HHCT） in staging gastric cancer. METHODS： A total of 50 patients with gastric cancer were included in this study. The CT findings in them were retrospectively analyzed and correlated with pathologic findings at surgery. All patients were preoperatively imaged by plain and contrast-enhanced helical CT afer orally ingesting 1 000-1 500 mL water. Peristalsis was minimized by intravenous administration of spasmolytics. RESULTS： The foci of gastric cancer became more prominent in all the 50 patients and showed strong enhancement in contrast-enhanced HHCT. The tumor was located at the gastric cardia in 14 cases, at the gastric fundus in 3 cases, at the gastric body in 8 cases, at the gastric antrum in 4 cases, at the gastric fundus and the body in 8 cases, at the gastric body and antrum in 11 cases, and at three segments of the stomach in 2 cases. The CT features of gastric cancer were focal or diffuse mural thickening, soft tissue mass, cancerous ulcer, stenosis of stomach, infiltration to adjacent tissues, lymph node and distant metastases. Strong contrast enhancement of the gastric wall was closely related to gastric cancer. The accuracy rate of contrast-enhanced HHCT in staging gastric cancer was 86% （43/50）. The detection rate of lymph node metastases by CT was 60% （12/20）. CONCLUSION： Contrast-enhanced HHCT is a reliable method to diagnose and stage gastric cancer.

Three-dimensional MR and axial CT colonography versus conventional colonoscopy for detection of colon pathologies

AIM： To evaluate the sensitivity and specificity of MR colonography （MRC） and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy. METHODS： Forty-two patients suspected of having colonic lesions, because of rectal bleeding, positive fecal occult blood test results or altered bowel habits, underwent the examinations. After insertion of a rectal tube, the colon was filled with 1000-1500 mL of a mixture of 9 g/L NaCI solution, 15-20 mL of 0.5 mmol/L gadopentetate dimeglumine and 100 mL of iodinized contrast material. Once colonic distension was achieved, three-dimensional gradient-echo （3D-GRE） sequences for MR colonography and complementary MR images were taken in all cases. Immediately after MR colonography, abdominal CT images were taken by spiral CT in the axial and supine position. Then all patients were examined by conventional colonoscopy （CC）. RESULTS： The sensitivity and specificity of MRC for colon pathologies were 96.4% and 100%, respectively. The percentage of correct diagnosis by MRC was 97.6%. The sensitivity and specificity of CT for colon pathologies were 92.8%, 100%, respectively. The percentage of correct diagnosis by CT was 95.2%. CONCLUSION： In detecting colon lesions, MRC achieved a diagnostic accuracy similar to CC. However, MRC is minimally invasive, with no need for sedation or analgesics during investigation. There is a lower percentage of perforation risk, and all colon segments can be evaluated due to multi-sectional imaging availability; intramural, extra-intestinal components of colonic lesions, metastasis and any additional lesions can be evaluated easily. MRC and CT colonography are new radiological techniques that promise to be highly sensitive in the detection of colorectal mass and inflammatory bowel lesions.

肺肉瘤样癌CT诊断与文献回顾

目的探讨肺肉瘤样癌(PSC)CT表现并对相关文献进行回顾。方法回顾性分析陕西省人民医院2015年1月至2020年3月住院诊治的10例PSC患者的CT表现、病理及免疫组化资料。结果10例患者均表现出肺内单发占位性病变,为周围性分布,其中右肺上叶2例,右肺下叶2例,左肺下叶2例,左肺上下叶跨叶生长4例;病灶最大直径10.8 cm,平均直径(5.3±3.7)cm;5例形态不规则,2例周围多发短毛刺,3例病变周围形成大小不等的空洞;增强扫描病变呈轻-中度不均匀强化改变,中央坏死区不强化。免疫组化显示:上皮细胞角蛋白(CK)、波形蛋白阳性7例,上皮细胞膜抗原(EMA)阳性3例。结论PSC在CT平扫及增强图像上具有一些特征表现,可为临床诊断提供帮助,明确诊断需结合病理及免疫组化。

Clinical significance of CT-defined minimal ascites in patients with gastric cancer

AIM： To study the clinical significance of minimal ascites, which was only defined by the CT and whose nature was not determined preoperatively, in the relationship with the peritoneal carcinomatosis. METHODS： The medical records and the dynamic CT films of 118 patients with gastric cancer were reviewed. Factors associated with peritoneal carcinomatosis were analyzed in 40 patients who had CT-defined ascites of which the nature was surgically confirmed, RESULTS： Only 12.5-25% of the CT-defined minimal ascites, whose volume was estimated to be less than 50 mL, were associated with peritoneal carcinomatosis. When the estimated CT-defined ascitic volume was 50 mL or more, peritoneal carclnomatosis was identified in 75-100%. When CT-defined lymph node enlargements were not found beyond the regional gastric area, perigastric invasions were not suspected, and the size of tumor was less than 3 cm, peritoneal carcinomatosis seemed significantly less accompanied at the univariate analysis. However, except for the minimal volume of CT- defined ascites in comparison with the mild or more, other factors were not confirmed multivariately. CONCLUSION： In the patients with gastric cancer, CT- defined minimal ascites alone is rarely associated with peritoneal carcinomatosis, if it does not accompany other signs suggestive of malignant seeding. Therefore, consideration of active curative resection should not be hesitated, if CT-defined minimal ascites is the only delusive sign.

Value of Multi-slice spiral CT in diagnosis of malignant gastrointestinal stromal tumors

Objective： The aim of this study was to investigate the value of multi-slice spiral CT （MSCT） in the diagnosis of malignant gastrointestinal stromal tumors （GISTs）. Methods： Twenty-seven cases of MSCT images of malignant GIST proved by surgery and pathology were retrospectively analyzed. Both plain and enhanced CT scan was performed and multiplanar reconstruction was made in all cases. Results： The lesions originated from the stomach （n = 11）, small intestine （n = 9）, colon （n = 4）, rectum （n = 1）, and mesentery （n = 2）. The transverse diameters of mass were 4.2-22 cm, the edges clearly （n = 12）, unclearly （n = 15）. The mass were mainly irregular in shape Iobulated （n = 19）. The lesions were mainly heterogeneity on plain scan, moderate to marked enhancement in arterial phase and durative enhanced in venous phase. Cystic necrosis were observed in all the lesions, 9 cases were cystic and solid mixed mass. Hepatic metastases （n = 4）, pulmonary metastasis （n = 1）, lymphatic metastasis （n = 2） were detected. The accuracy rate of MSCT diagnosis for location and pathologic features of GISTs were 85.2% （23/27） and 77.8% （21/27）. Conclusion： Two-phase MSCT examination and axial images combined with multiplanar reconstruction images have important value for diagnosis of malignant GIST.

Tumor angiogenesis and dynamic CT in colorectal carcinoma: Radiologic-pathologic correlation

AIM: To investigate the correlation between microvessel density and spiral CT perfusion imaging in colorectal carcinoma. METHODS: Thirty-seven patients, with histologically proven colorectal carcinoma, underwent water enema spiral CT scan. The largest axial surface of the primary tumor was searched on unenhanced spiral CT images. At this level, the enhanced dynamic scan series was acquired. Time-density curves (TDC) were created from the region of interest drawn over the tumor, target artery by Toshiba Xpress/SX spiral CT with perfusion functional software. Then the perfusion was calculated. Microvessel density (MVD) was evaluated using immunohistochemical staining of surgical specimens with anti-CD34, and then MVD was correlated with perfusion. RESULTS: MVD of colorectal carcinomas was 33.11-173.44, mean 87.28, and perfusion was 15.60-64.80 mL/min/ 100 g, mean 39.74 mL/min/100 g. MVD and perfusion were not associated with invasive depth, metastasis and disease stage, and they all decreased with increasing Dukes' stage, but no significant correlation was found between them (r=0.18, P=0.29). CONCLUSION: There is no significant correlation between MVD and perfusion. Neovascularizaton and perfusion are highly presented in early colorectal carcinoma. CT perfusion imaging may be more suited for assessing tumorigenesis in colorectal carcinoma than histological MVD technique.

Pathological and High Resolution CT Findings in Churg-Strauss Syndrome

Objective To investigate the Churg-Strauss syndrome （CSS） associated lung involvement, concentrating on clinical characteristics, pathological findings of tung involvements, response to treatment, and prognosis. Methods We retrospectively analyzed the characters of the clinical manifestations, thin-section CT and pathological findings of CSS. The study involved 16 patients. Clinical data were obtained by chart review All patients underwent transbronchial lung biopsy （TBLB）. Six of them underwent surgical lung biopsy as well. Results The patients included 7 men and 9 women, aged from 14 to 61 years （median, 47.5 years）. Extrathoracic organs involved included nervous system （7/16） and skin （5/16）. Respiratory symptoms included cough （12/16）, exertional dyspnea （11/16）, hemoptysis （4/16）, and chest pain （3/16）. CT findings included bilateral ground-glass opacities （12 / 16）, bilateral patchy opacities （12 / 16）, and centrilobular nodules （6/16）. The pathological findings of TBLB demonstrated increased eosinophils （3/16）, vasculitis （3/16）, and interstitial pneumonia （16/16）. The pathological fmdings of surgical lung biopsy of 6 cases showed necrotizing vasculitis in 4 cases, capillaries in 5, eosinophilic pneumonia in 3, granulomas in 2, and airway abnormalities in 3. All patients improved in symptoms after therapy during the study period （range, 3 to 51 months; median, 15 months）. Conclusions Asthma may be present in CSS patient when there is bronchial involvement. Grotmd-glass opacities and consolidation seen on high-resolution CT reflect the presence of eosinophilic pneumonia, vasculitis, and pulmonary alveolar hemorrhage. TBLB has significant limitations for the diagnosis of CSS. Early diagnosis and therapy can result in satisfactory prognosis.

CT-maximum intensity projection is a clinically useful modality for the detection of gastric varices

AIM： To evaluate the efficacy of CT-maximum intensity projection （CT-MIP） in the detection of gastric varices and their infiowing and outflowing vessels in patients with gastric varices scheduled to undergo balloonoccluded retrograde transvenous obliteration （B-RTO）. METHODS： Sixteen patients with endoscopically confirmed gastric varices were included in this study. All patients were evaluated with CT-MIP using threedimensional reconstructions, before and after B-RTO. RESULTS： CT-MIP clearly depicted gastric varices in 16 patients （100%）, the left gastric vein in 6 （32.5%）, the posterior gastric vein in 12 （75.0%）, the short gastric veins in 13 （81.3%）, gastrorenal shunts in 16 （100%）, the hemiazygos vein （HAZV） in 4 （25.0%）, the pericardiophrenic vein （PCPV） in 9 （56.3%）, and the left inferior phrenic vein in 9 patients （56.3%）. Although flow direction itself cannot be determined from CT-MIP, this modality provided clear images of the inflowing and the outflowing vessels. Moreover, in one patient, short gastric veins were not seen on conventional angiographic portography images of the spleen, but were clearly revealed on CT-MIP. CONCLUSION： We suggest that CT-MIP should be considered as a routine method for detecting and diagnosing collateral veins in patients with gastric varices scheduled for B-RTO. Furthermore, CT-MIP is more useful than endoscopy in verifying the early therapeutic effects of B-RTO.

Automated lung segmentation algorithm for CAD system of thoracic CT

Objective: To design and test the accuracy and efficiency of our lung segmentation algorithm on thoracic CT image in computer-aided diagnostic (CAD) system, especially on the segmentation between left and right lungs. Methods: We put forward the base frame of our lung segmentation firstly. Then, using optimal thresholding and mathematical morphologic methods, we acquired the rough image of lung segmentation. Finally, we presented a fast self-fit segmentation refinement algorithm, adapting to the unsuccessful left-right lung segmentation of thredsholding. Then our algorithm was used to CT scan images of 30 patients and the results were compared with those made by experts. Results: Experiments on clinical 2-D pulmonary images showed the results of our algorithm were very close to the expert’s manual outlines, and it was very effective for the separation of left and right lungs with a successful segmentation ratio 94.8%. Conclusion: It is a practicable fast lung segmentation algorithm for CAD system on thoracic CT image.

A comparative study on CT imaging and pathologic presentation of the periphery of hepatocellular carcinoma using in vivo specimens of liver transplantation

Objective:To examine CT and pathologic presentations of the periphery of hepatocelllar carcinoma (HCC) by using in vivo liver specimens from orthotopic liver transplantation (OLT) and to see whether there is any correlation between them. Materials and Methods:Forty-two patients with HCC confirmed by pathology and liver transplantation were included. Plain CT scan covering the whole liver was done, followed by arterial and portal venous phase scanning. The delay time was 25 s and 60 s after injection of contrast medium. Fresh liver samples were evaluated, sliced and stained with HE and the standard immunoperoxidase method using facterⅧrelated antigen (F8RA) monoclonal antibody to study CT presentation of the periphery of tumor and compare them with pathologic findings. Results: (1) Tumors with clear boundaries on CT scan reflected the presence of tumor capsules in pathologic sections. Most tumors with unclear boundaries had no capsules and grew in an invasive pattern; (2) Tumors with unclear boundaries or high density on dynamic enhancement usually had abundant newborn vessels in the periphery and were poorly differentiated, while those with low density had few newborn vessels and were well differentiated; (3) When microvessel density (MVD) was>30, the occurrence of intrahepatic daughter foci was higher. Conclusion: (1) CT morphologic classification of the HCC periphery can well reflect the intactness of tumor capsules, which is helpful for preoperative assessment of tumor infiltration and cancer cell grading; (2) CT enhancement presentation of the HCC periphery in arterial and portal phases may reflect pathologic changes and help predict the prognosis at large.

Multi-phase post-mortem CT-angiography： a pathologic correlation study on cardiovascular sudden death

Multi-phase post-mortem CT-angiography （MPMCTA） has the great potential to increase the quality of the postmortem investigation, especially in the area of sudden death; however, its role as routine complement to the pathology toolbox is still questioned as it needs to be further standardized. The aim of this study is to investigate the contribution of MPMCTA in cases of sudden unexplained death in adults and in particular in sudden cardiovascular death. Sixty-eight sudden unexpected deaths of adults were investigated at our institution between 2012 and 2013. Ten cases underwent MPMCTA and autopsy and were included in the study. Before the angiographic step by complete filling of the vascular system, prior to any manipulation of the body, a non-contrast CT-scan was carried out. Image reconstructions were performed on a CT workstation （Vitrea） and two radiologists experienced with post mortem imaging interpreted the MPMCTA findings. In all 10 cases, we could state a good correlation between combination of post-mortem CT and MPMCTA and autopsy procedures, confirming a high diagnostic sensitivity. With this case series we want to illustrate the advantages offered by performing MPMCTA when facing a sudden death, regardless of specific suspicion for acute coronary syndrome or other vascular or ischemic disease.

Comparative analysis of CT and pathological findings of peripheral nerve sheath tumors

Objective: To improve the qualitative diagnosis of peripheral nerve sheath tumors by computed tomography (CT). Methods: CT findings of 64 cases of pathologically confirmed nerve sheath tumors were compared with the pathological findings of the tumors. Results: Low density of the tumors shown in plain CT images was related to dominating reticular structure in the tumor as found pathologically. Tumors with intact capsule found by pathological findings were shown with smooth margin in CT images. Inhomogeneous density and enhancement of the tumors in CT images was related to tumor necrosis, liquefaction and cystic degeneration, and inhomogeneous enhancement also involved the reticular structure. Conclusion: Nerve sheath tumors are characterized by distribution along the nerves, lower density than that of muscles in plain CT images, and inhomogeneous enhancement in enhanced CT, which can help differentiate nerve sheath tumors from other soft tissue tumors. When nerve sheath tumors lack distinctive CT features, the diagnoses have to depend on their pathological findings.

Four-Dimensional Computerized Tomography (4D-CT) Reconstruction Based on the Similarity Measure of Spatial Adjacent Images

Objective:To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods:A motor driven sinusoidal motion platform made in house was used to create one-dimensional periodical motion that was along the longitudinal axis of the CT couch. The amplitude of sinusoidal motion was set to an amplitude of ±1 cm. The period of the motion was adjustable and set to 3.5 s. Phantom objects of two eggs were placed in a Styrofoam block, which in turn were placed on the motion platform. These objects were used to simulate volumes of interest undergoing ideal periodic motion. CT data of static phantom were acquired using a multi-slice general electric (GE) LightSpeed 16-slice CT scanner in an axial mode. And the CT data of periodical motion phantom were acquired in an axial and cine-mode scan. A software program was developed by using VC++ and VTK software tools to resort the CT data and reconstruct the 4D-CT. Then all of the CT data with same phase were sorted by the program into the same series based on the similarity principle of spatial adjacent images and mutual information measure among them, and 3D reconstruction of different phase CT data were completed by using the software. Results:All of the CT data were sorted accurately into different series based on the similarity principle of spatial adjacent images and mutual information measures among them. Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were reduced significantly, and all of the sorted CT series result in a 4D-CT that reflected the characteristic of the periodical motion phantom. Conclusion:Time-resolved 4D-CT reconstruction can be implemented with any general multi-slice CT scanners based on the similarity principle of spatial adjacent images and mutual information measure.The process of the 4D-CT data acquisition and reconstruction were not restricted to the hardware or software of the CT scanner and has the feasibility ,which extensive applicability.

Large cell carcinoma of lung: analysis of CT signs and review of the literature

Objective: Large cell carcinoma of lung is a very rare tumor. The clinical characteristics and CT imaging feature of large cell carcinoma of lung were discussed in this article. Methods: Eight cases of large cell carcinoma of lung proven by post-operational pathology were retrospectively analyzed from 2000 to 2005 and the literature on it was reviewed. Results: All 8 cases were men. The average age of patients was 64.88 years. Seven cases were smokers. Six cases had obvious chest stuffy, short breath, thrill dry cough. Hereinto 3 cases had cardinal red blood sputum. CT images of large cell carcinoma of lung were represented as single and peripheral mass or nodule. The distribution of large cell carcinoma of lung was short of some rule. 75% focus had clear finitude. One case showed internal calcification and 2 cases showed cavity. They did not show internal fat density. Conclusion: Large cell carcinoma of lung is difficult to be diagnosed before operation. Its CT finding is nonspecific.

USING OF MULTISLICE HELICAL CT COLONOGRAPHY IN PATIENTS WITH MALIGNANT LESIONS OF COLON

Objoctive To investigate the techniques and clinical applications ofmultislice helical computed tomography （CT） colonography in colonic lesions. Methods Fifty-nine patients with malignant lesions of colon underwent volume scanning using multislice helical CT. Four types of reconstruction including CT virtual colonoscopy （CTVC）, shaded surface display （SSD）, Raysum, and multiple planar reconstruction （MPR） were used for image post-processing. The results were compared with those of colonoscopy and pathology. Results Multislice helical CT colonography detected 54 colorectal carcinomas, 4 adenomas with focal carcinoma, 1 non-Hodgkin＇s lymphoma （NHL）. The lesions＇ number, size, location, morphology, stricture of intestinal cavity, infiltration, and metastasis were shown satisfactorily by multislice helical CT colonography. Whole colon could be shown in all patients. CT colonography displayed 4 synchronous colonic tumors, 1 ascending colon carcinoma combined with left renal carcinoma among 54 patients with colonic carcinomas. The accuracy of location of CT colonography was 100%. There were 9 cases that CT showed the tumor location was different from the finding of conventional colonoscopy, while all of the CT location were proven exact by operation. CT colonography also displayed the infiltration of serous layer and fatty tissue in 45 cases; 21 cases matched the pathological results in all the 24 cases of suspicious lymph node metastasis, the sensitivity was 87.5%, the specificity was 90.6%; 9 cases hepatic metastasis, 2 ovarian metastasis, and 1 double adrenal gland metastasis. Conclusions Multislice helical CT colonography is effective in preoperative diagnosis, location, stage, and making treatment plan of colorectal carcinoma. It can display the portion not seen during colonoscopy and may have an adjunctive role.

A Correlative Study of CT, MR and Pathology in Rabbit Liver after Embolization by a China-Formulated Lipiodol Emulsion

OBJECTIVE To explore the MR characteristics following lipiodol retention in rabbit liver and to evaluate the sensitivity of CT （CT value 〉400 HU） and MR in displaying the hepatic degeneration and necrosis following embolization. METHODS Thirty-two rabbits were randomly divided into 3 groups. In the control group （n=8）, 2 ml of normal saline was injected into the right branch of the portal vein. In the first experimental group（n= 12）, 4 ml of lipiodol emulsion was injected into the main portal vein. In the second experimental group （n= 12）, 2 ml of lipiodol emulsion was injected into the right branch of the portal vein. CT and MR images were obtained before and after surgery in each group. The histopathologic condition was determined for all liver tissue specimens. RESULTS In the control group, CT and MR did not show any significant changes in the livers after surgery. After the operations in the experimental groups, the regional CT attenuation was 601±101 HU in the largest slice, which had no abnormal signals on T1Wl and T2Wl. In the first group, histologic examinations showed there were concentrated lipiodol droplets around the portal areas. In the second group, serious degeneration and necrosis in the right hepatic lobe occurred in 9 rabbits. T1Wl displayed homogenous or non-homogenous low signals and T2Wl mainly displayed a high signal. However, these pathologic changes did not appear on CT scanning due to high attenuation of the lipiodol. CONCLUSION There were no remarkable hepatic changes on MR in rabbits following good retention of the formulated lipiodol emulsion mixture of lipiodol and urografin（CT value 〉 400 HU）. MR displayed serious degeneration and necrosis of the liver following embolization.

The Use of Multislice Spiral CT to Predict the Resectability of Central Lung Cancer： Correlation with Pathologic and Surgical Findings

OBJECTIVE To assess the accuracy of multi-slice spiral CT （MSCT） with imaging reconstruction in judging central pulmonary vascular involvement from central lung cancer, and to explore its ability to predict the resectability of lung cancer. METHODS MSCTs were conducted on 48 patients who were diagnosed preoperatively with central lung cancer. Images of pulmonary arteries and veins that might affect Iobectomy or pneumonectomy were reconstructed by means of imaging processing techniques. Then the relationship of the tumor to the vessels was assessed prospectively on both axial CT images and axial CT images plus reconstructed images（CT-RI） in comparison to subsequent pathologic and surgical findings. RESULTS MSCTs were obtained on all 48 patients whom 42 underwent thoracotomy, Iobectomy or pneumonectomy. Compared with the axial CT images, CT-RI was more accurate in judging the relationship of the central pulmonary vessels to the tumor based on subsequent pathologic 78 vessels studied and surgical findings （186 vessels studied）（0.01 〈P〈0.05）. The sensitivity and positive predictive value of unresectability of the vessels were all remarkably higher with CT-RI （P〈0.01）. CONCLUSION MSCT with imaging reconstruction can improve the recognition of neoplastic invasion of central pulmonary vessels. It can be used to predict preoperatively the resectability of central lung cancer and to plan surgery.