MSCT重建技术在胰腺癌术前评估中的应用

目的 探讨多层螺旋CT（MSCT）重建技术在胰腺癌手术可切除性评估中的应用价值.方法 回顾性分析35例经手术证实的胰腺癌患者的多期增强CT图像及包括容积重建（VR）、多平面重建（MPR）、曲面重建（CPR）等的后处理方法,重点观察胰腺肿瘤与周围结构、邻近血管、胆管的关系,进行肿瘤能否手术切除的评估,并与实际手术的结果进行对比.结果 35例患者中9例共27支血管受侵犯;19例总胆管、12例胰管受侵犯;7例十二指肠受侵,2例胃后壁受侵,1例脾肿大伴区域性门脉高压;14例次胰头周围淋巴结肿大,4例次腹主动脉旁淋巴结肿大,3例肝转移.CT术前评估手术可切除21例,最终19例行胰腺癌根治术,2例行姑息术;术前评估手术不可切除14例,均行姑息术.根治术、姑息术术前评估与术后结果符合率分别为90％、88％.结论 MSCT重建技术能提高对胰腺癌局部侵犯、转移的诊断,可提高对肿瘤可切除性的评估.     

Assessment of coronary artery abnormalities by multislice spiral computed tomography in adolescents and young adults with Kawasaki disease

Multislice spiral computed tomography was performed in 16 adolescents and young adults who had Kawasaki's disease to assess coronary artery abnormalities. Adequate images were obtained for 96% of major coronary segments. The sensitivity of multislice spiral computed tomography to detect coronary artery aneurysms was 100%, and that for significant stenoses and occlusions was 87.5%, whereas false-positive results due to severe calcification was present in 5 arteries and those due to cardiac motion artifact were present in 2, resulting in a specificity of 92.5%.     

Imaging of calcified coronary arteries with multislice computed tomography

Reliable noninvasive detection of coronary artery disease is a prime goal in clinical cardiology. The aim of this study was to investigate the accuracy of multislice computed tomography in detecting coronary artery disease in correlation to the calcium score. Fifty patients with 61 stenoses > 50% and 41 occlusions underwent multislice computed tomography and conventional coronary angiography. Calcium scoring was calculated for the total coronary artery territory and patients were divided into 3 groups based on this score. Multislice computed tomography visualized 89% (365/500) of all coronary segments. The sensitivity and specificity for detection of stenoses > 50% or occlusion was 47%-92%, and 97%-100% for the calcium score. Forty of 500 segments were underestimated by multislice computed tomography, of which 39 were in the group with a calcium score > 400. Multislice computed tomography allows noninvasive angiographic evaluation of coronary artery disease with high diagnostic accuracy. However, the method strongly depends on the degree of vascular calcification and underestimates the degree of stenosis according to the calcium score. This new technology holds promise for noninvasive risk assessment in patients with known or suspected coronary artery disease.     

2型糖尿病合并冠心病患者行双源CT冠状动脉造影的对比研究

目的探讨双源CT冠状动脉造影在2型糖尿病合并冠心病患者诊断中的应用价值。方法选择临床确诊或疑诊冠心病的2型糖尿病患者88例行CT冠状动脉造影检查,并同期行选择性冠状动脉造影。双源CT的原始数据均行容积再现、曲面重组、最大密度投影及横断面重建。结果 352支血管中(直径≥2 mm),双源CT冠状动脉造影显示≥50%狭窄的血管为163支,占46.3%;选择性冠状动脉造影显示≥50%狭窄的血管为155支,占44.0%。与选择性冠状动脉造影对照分析,双源CT冠状动脉造影评价冠状动脉狭窄(≥50%狭窄)的敏感性、特异性、阳性预测值以及阴性预测值分别为92.3%、89.9%、87.7%和93.7%。结论双源CT冠状动脉造影是检测2型糖尿病患者冠状动脉狭窄的可靠方法。     

CT and MR imaging of pancreatic cancer

Recent improvements in imaging techniques have made it possible to improve the diagnostic accuracy for detection, staging, and indicating surgical resectability of pancreatic cancer. The latest advance in the computed tomography technique, is the introduction of subsecond multislice helical scanning that improves z-axis resolution in the reformatted images and three-dimensional rendering with a large volume data. Magnetic resonance imaging provides versatile information including magnetic resonance cholangiopancreatography that allows noninvasive delineation of the pancreatic and biliary duct systems. The presence of pancreatic cancer may best be evaluated by dynamic computed tomography or dynamic magnetic resonance imaging with administration of intravenous contrast material. Both computed tomography and magnetic resonance imaging are valuable for the preoperative assessment of local invasion and vascular involvement. Multislice helical computed tomography is currently considered as the best single modality for the diagnosis of pancreatic cancer as it provides excellent image quality. When advanced magnetic resonance imaging equipment is used as a primary modality, in the future, it may have a possibility to replace other imaging modalities.     

Multislice CT angiography in the follow-up of fenestrated endovascular grafts: effect of slice thickness on 2D and 3D visualization of the fenestration stents

PURPOSE: To investigate the effect of multislice computed tomography (CT) protocols on the visualization of target vessel stents in patients with abdominal aortic aneurysm (AAA) treated with fenestrated endovascular grafts. METHODS: Twenty-one patients (19 men; mean age 75 years, range 63-86) undergoing fenestrated endovascular repair of AAA were retrospectively studied. Multislice CT angiography was performed with several protocols, and the section thicknesses used in each were compared to identify any relationship between slice thickness and target vessel stents visualized on 2-dimensional (2D) axial, multiplanar reformatted (MPR), and 3-dimensional (3D) virtual intravascular endoscopy (VIE) images. Image quality was assessed based on the degree of artifacts and their effect on the ability to visualize the configuration, intra-aortic location, and intraluminal appearance of the target vessel stents and measure their protrusion into the aortic lumen. RESULTS: There were 7 different multislice CT scanning protocols employed in the 21 patients (25 datasets, with 2 sets of follow-up images in 4 patients). The slice thicknesses and numbers (n) of studies included were 0.5 (n=3), 0.625 (n=6), 1.0 (n=1), 1.25 (n=9), 2.5 (n=3), 3.0 (n=1), and 5.0 mm (n=2). Of these CT protocols, images (especially 2D/3D reconstructions) acquired at 2.5, 3.0, and 5.0 mm were significantly compromised by interference from artifacts. Images acquired with a slice thickness of 1.0 or 1.25 mm were scored equal to or lower than those acquired with a submillimeter section thickness (0.5 or 0.625 mm), with minor degrees of artifacts resulting in acceptable image quality. CONCLUSION: Visualization of the target vessel stents depends on the appropriate selection of multislice CT scanning protocols. Our results showed that studies performed with a slice thickness of 1.0 or 1.25 mm produced similar image quality to those with a thickness of 0.5 or 0.625 mm. Submillimeter slices are not recommended in imaging patients treated with fenestrated stent-grafts, as they did not add additional information to the visualization.     

Assessment of myocardial viability in reperfused acute myocardial infarction using 16-slice computed tomography in comparison to magnetic resonance imaging

OBJECTIVES: The aim of this study was to examine if contrast-enhanced multislice spiral computed tomography (MSCT) is comparable to contrast-enhanced magnetic resonance imaging (MRI) for depiction of acute myocardial infarction (MI). BACKGROUND: Delayed-enhancement MRI of MI is well established, but there are no clinical reports about MSCT for this indication. Early perfusion deficit on MSCT has been reported to correlate with the presence of MI. METHODS: A total of 28 consecutive patients (23 men; 55.9 +/- 11.4 years) with reperfused MI underwent contrast-enhanced cardiac 16-slice MSCT. Images were acquired in the arterial phase and the late phase 15 min after administration of 120 ml contrast material. Within 5 days, patients underwent MRI after administration of 0.2 mmol Gd-dimeglumine/kg/bodyweight. All examinations were completed within two weeks after MI. The area of MI was compared between the different imaging techniques using Bland-Altman method and multivariate analysis. Agreement of the contrast enhancement patterns was evaluated with a weighted kappa test. RESULTS: Mean infarct size on MRI was 31.2 +/- 22.5% per slice compared with 33.3 +/- 23.8% per slice for late-enhancement MSCT and 24.5 +/- 18.3% per slice for early-perfusion-deficit MSCT. Bland-Altman data showed a good agreement between late-enhancement MRI and late-enhancement MSCT. Contrast enhancement patterns demonstrated an excellent agreement between late-enhancement MRI and late-enhancement MSCT (kappa = 0.878). The results were worse comparing MRI and early-phase MSCT (kappa = 0.635). CONCLUSIONS: Multislice spiral computed tomography allows for the assessment of acute MI. Late-enhancement MSCT appears to be as reliable as delayed contrast-enhanced MRI in assessing infarct size and myocardial viability in acute MI.     

Unenhanced spiral CT for evaluating acute appendicitis in daily routine. A prospective study

BACKGROUND/AIMS: The purpose of this study was to define in a routine setting the role of spiral computed tomography in patients with suspected acute appendicitis and to determine the effect of computed tomography on the treatment of such patients. METHODOLOGY: Appendiceal computed tomography was performed in 120 consecutive patients with acute appendicitis in the differential diagnosis, whose clinical findings were insufficient to perform surgery or to discharge from the hospital. Each scan was obtained in a single breath hold from the lower abdomen to the upper pelvis using a 5-mm collimation and a pitch of 1.6. Computed tomography results were correlated with surgical and pathologic findings at appendectomy or clinical follow-up. RESULTS: Eighty-eight of the 93 patients with acute appendicitis were correctly diagnosed by computed tomography, 24 of the 27 patients without acute appendicitis were correctly diagnosed by computed tomography (95% sensitivity, 89% specificity). Computed tomography signs of acute appendicitis included fat stranding (100%), enlarged appendix (> 6 mm) (97%), adenopathy (63%), appendicoliths (43%), abscess (10%), and phlegmon (5%). CONCLUSIONS: The use of spiral computed tomography in patients with equivocal clinical presentation suspected of having acute appendicitis led to a significant improvement in the preoperative diagnosis and a lower negative appendectomy rate. Appendiceal computed tomography is an accurate technique even if performed in the daily routine of scanning.     

Three-dimensional coronary anatomy in contrast-enhanced multislice computed tomography

A number of three-dimensional imaging modalities, such as magnetic resonance imaging, electron beam computed tomography, ultrasonography, and multislice computed tomography have been introduced in cardiovascular medicine. One of the most recently developed techniques, multislice computed tomographic coronary angiography, allows assessment of the small coronary vessels. The entire heart is scanned within a single breathhold and contrast-enhanced images are reconstructed through retrospective electrocardiographic gating. Instead of the conventional two-dimensional projection images, multislice computed tomographic data can be displayed in a three-dimensional, volume-rendered manner. This paper presents an overview of the cardiac and coronary morphology as it is imaged with contrast-enhanced multislice computed tomography. Further imaging characteristics of computed tomographic angiography are discussed.     

Extraluminal gastrointestinal stromal tumour in the second portion of the duodenum

The preoperative diagnosis of extraluminal gastrointestinal stromal tumours in the duodenum is difficult to establish due to their rare occurrence and the lack of pathognomonic signs. This report describes the case of a 61-year-old woman who suffered from an immunohistologically confirmed gastrointestinal stromal tumour in the second portion of the duodenum. Preoperative, abdominal, multislice computed tomography showed an extraluminal but intramural tumour located between the head of the pancreas and the duodenum. Rapid postprocessing analysis by three-dimensional, volume-rendered images revealed a strong arterial blood supply and an early draining vessel into the superior mesenteric vein during the portal-venous phase. The combination of endoscopic ultrasonography and non-invasive multislice computed tomography provided an early suggestion of gastrointestinal stromal tumour.     

Noninvasive assessment of coronary artery disease by multislice spiral computed tomography using a new retrospectively ECG-gated image reconstruction technique.

The present study was designed to investigate the accuracy of multislice spiral computed tomography (MSCT) in detecting coronary artery disease, compared with coronary angiography (CAG), using a new retrospectively ECG-gated reconstruction method that reduced cardiac motion artifact. The study group comprised 54 consecutive patients undergoing MSCT and CAG. MSCT was performed using a SOMATOM Volume Zoom (4-detector-row, Siemens, Germany) with slice thickness 1.0 mm, pitch 1.5 (table feed: 1.5 mm per rotation) and gantry rotation time 500 ms. Metoprolol (20-60 mg) was administered orally prior to MSCT imaging. ECG-gated image reconstruction was performed with the reconstruction window (250 ms) positioned immediately before atrial contraction in order to reduce the cardiac motion artifact caused by the abrupt diastolic ventricular movement occurring during the rapid filling and atrial contraction periods. Following inspection of the volume rendering images, multiplanar reconstruction images and axial images of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) were obtained and evaluated for luminal narrowing. The results were compared with those obtained by CAG. Of 216 coronary arteries, 206 (95.4%) were assessable; 10 arteries were excluded from the analysis because of severe calcification (n=4), stents (n=3) or insufficient contrast enhancement (n=3). The sensitivity to detect coronary stenoses >or=50% was 93.5% and the specificity to define luminal narrowing <50% was 97.2%. The positive predictive value and the negative predictive value were 93.5% and 97.2%, respectively. The sensitivity was still satisfactory (80.6%) even when non-assessable arteries were included in the analysis. The new retrospectively ECG-gated reconstruction method for MSCT has excellent diagnostic accuracy in detecting significant coronary artery stenoses.     

64排螺旋CT在发绀型先天性心脏病肺血管成像中的应用

目的 评价64排螺旋CT(multislice spiral computed tomography,MSCT)对于发绀型先天性心脏病肺血管成像的临床应用价值.方法 回顾335例发绀型先天性心脏病患者的64排螺旋CT影像学资料,男218例,女117例,年龄1 d～37岁,中位年龄4岁.其中152例曾行手术治疗,另42例同时行血管造影术(cardioangiography,CAG)检查,对比其结果 并进行统计学分析.结果 152例患者经手术证实肺血管共有271处畸形.64排MSCT确诊258处畸形,符合率95.2%(258/271).42例患者经手术证实109处畸形,64排MSCT确诊102处畸形,符合率93.6%(102/109);CAG确诊106处畸形,符合率97.2%(106/109).MSCT和CAG对比,诊断符合率差异无统计学意义(P>0.05).结论 64排MSCT对发绀型先天性心脏病肺血管畸形的诊断有较高的符合率.且快捷、无创,具有较高的临床应用价值.     

Standard versus user-interactive assessment of significant coronary stenoses with multislice computed tomography coronary angiography

Forty-four patients in sinus rhythm with suspected coronary artery disease underwent 16-row multislice computed tomography coronary angiography and conventional coronary angiography. Two protocols for image analysis were applied to the multislice computed tomographic images: standard projections versus interactive postprocessing. The diagnostic accuracy of both methods for the detection of significant lesions (>50% lumen reduction) was compared with quantitative coronary angiography. Sensitivity and specificity were 58% and 96% and 96% and 97%, for standard projections and interactive postprocessing protocol, respectively.     

Comparison of radiation doses from multislice computed tomography coronary angiography and conventional diagnostic angiography.

OBJECTIVES: The aim of this study was to quantify and compare effective doses from conventional angiography and multislice computed tomography (MSCT) coronary angiography using a 16-slice scanner. BACKGROUND: Multislice computed tomography is now a viable modality for cardiac imaging. However, for any diagnostic use of ionizing radiation, the risk to the patient must be considered and justified. METHODS: Multislice computed tomography angiography and conventional angiography were used to assess 180 patients with suspected coronary artery disease. Estimates of effective dose were derived from exposure data recorded for each patient examination. For each modality, a comparable calculation technique was used, based on Monte Carlo modeling of the standard Cristy phantom. RESULTS: In a subset of 91 directly comparable patients the mean effective dose for MSCT coronary angiography was 14.7 mSv (SD 2.2) and that for conventional angiography was 5.6 mSv (SD 3.6). A significant difference in effective dose was seen between the two protocols. CONCLUSIONS: The mean effective dose for MSCT coronary angiography was significantly higher than that for conventional angiography. As MSCT cardiac scanners become increasingly available, operators must be aware of the radiation dose and the factors that affect it.     

多层螺旋CT检查对气道异物的诊断价值

目的：探讨多层螺旋CT对气道异物的诊断价值。方法对门诊收治疑似气管异物患者56例,给予多层螺旋CT检查,并与支气管镜检查作对照。结果多层螺旋CT检查共检出气道异物患者52例,1例误诊为肺炎,后经气管镜检查并取出异物,漏诊2例,假阳性1例。多层螺旋CT检查及气管镜对气道异物检出率差异无统计学意义（χ2＝0.61, P ＞0.05）。以支气管镜检查结果为金标准,螺旋 CT 灵敏度为96.23％,特异度为66.67％,诊断符合率为94.64％。结论多层螺旋CT检查气道异物,具有灵敏度高、符合率高特点,诊断时应结合病史、临床体征,以降低误诊率、漏诊率。儿童检查应以最低剂量扫描,避免辐射损伤。     

Contemporary approach to the diagnosis of non-massive pulmonary embolism

PURPOSE OF REVIEW: Minimally invasive diagnostic strategies for pulmonary embolism are in constant evolution, integrating new diagnostic tools along with the better use of clinical information. RECENT FINDINGS: In the past year, several reports have provided more data on the value of clinical signs and symptoms for diagnosing pulmonary embolism and improved clinical prediction rules for pulmonary embolism. Among the diagnostic tools, the use of multislice computed tomography of the chest received further validation, whereas the yield of bedside tests, such as the D-dimer test or alveolar dead-space measurement, have been further investigated. Furthermore, data linking good outcomes with appropriate diagnostic strategies in patients with suspected pulmonary embolism were reported this year for the first time. SUMMARY: These new data allow a more evidence-based and cost-effective approach to patients with suspected non-massive pulmonary embolism. Multislice computed tomography is replacing other imaging tests. More research should be performed on the role of lower limb venous compression ultrasonography, and on how to select patients in whom pulmonary embolism should be suspected and investigated.     

Preliminary experience in the assessment of aortic valve calcification by ECG-gated multislice spiral computed tomography

BACKGROUND: The aim was to correlate the degree of valvular calcification in patients with aortic stenosis determined by retrospectively electrocardiogram (ECG)-gated multislice spiral computed tomography with stenosis severity assessed by cardiac catheterization. METHODS: Prospective study on 41 patients (18 men, mean age 71+/-8 years) with aortic stenosis, who underwent four detector row multislice spiral computed tomography and cardiac catheterization. Severity of aortic stenosis was classified by cardiac catheterization. Aortic valve area, peak to peak and mean transvalvular gradients were correlated with the degree of calcification determined by multislice spiral computed tomography. Aortic valve calcification was assessed using aortic Agatston score, aortic mass score and aortic volume score. RESULTS: All measured aortic valve calcification scores were significantly higher in patients with severe aortic stenosis (n=29) than in patients with moderate (n=7) or mild aortic stenosis (n=5, p<0.001). Aortic valve calcification scores correlated significantly with aortic valve area (r=-0.49, p=0.001 for aortic mass score) and with peak to peak (r=0.68, p<0.001) and mean (r=0.60, p<0.001) transvalvular gradients. CONCLUSIONS: Severity of aortic valve calcification assessed by cardiac multislice spiral computed tomography is inversely related to aortic valve area and positively correlated with transvalvular gradients. Based on this preliminary data larger studies should be performed with echocardiography as a reference standard in order to validate this new information and its utility in the clinical management of the patient.     

Incidental detection of cancers and other non-cardiac abnormalities on coronary multislice computed tomography

The investigators prospectively examined 625 consecutive patients who underwent coronary multislice computed tomography (MSCT) for suspected coronary artery disease (CAD) and evaluated the presence or absence of cancers and other noncardiac abnormalities on the original transverse sectional images of MSCT. Eight patients with known cancers were excluded from the analysis. The remaining 617 patients (344 men, 273 women; mean age 66 +/- 12 years) were analyzed. Cancers were found in 7 patients (1.13%) on the multislice computed tomographic images, including 4 lung cancers (0.65%), 2 thyroid cancers (0.32%), and 1 hepatic cancer (0.16%). In addition, nonmalignant abnormalities (nodules, tumors, or lymphadenopathies) were also found in 142 patients (23.01%), consisting of 58 postinflammatory lung nodules (9.40%), 49 hepatic cysts or hemangiomas (7.94%), 18 benign thyroid tumors (2.92%), 12 mediastinal lymphadenopathies (1.94%), 4 benign mammary gland tumors (0.65%), and 1 esophageal submucosal tumor (0.16%). In conclusion, cancers and other noncardiac abnormalities are often found in patients who undergo coronary MSCT for suspected CAD. Because patients who undergo coronary MSCT for suspected CAD are mostly elderly and therefore may have unrecognized cancers or other noncardiac abnormalities, care should thus be taken not to overlook these abnormalities when analyzing the multislice computed tomographic images.     

Detection of choledocholithiasis: comparison of unenhanced spiral CT, US, and ERCP

BACKGROUND/AIMS: ERCP is an established method for the diagnosis and treatment of common bile duct stones, however, it is invasive, time-consuming, and expensive. The purpose of this study was to determine whether unenhanced spiral CT and US, compared with ERCP, have sufficient sensitivity and negative predictive value to be useful screening techniques in patients suspected of having choledocholithiasis. METHODOLOGY: Over a period of 2 years, 82 patients with clinically suspected choledocholithiasis underwent unenhanced spiral computed tomography and US immediately before undergoing endoscopic retrograde cholangiopancreatography. CT/US scans and ERCP images were evaluated for the presence of bile duct stones, ampullary stones, and extrahepatic biliary dilatation. RESULTS: Unenhanced spiral computed tomography (US) depicted common bile duct stones in 24 (23) of 28 patients found to have stones at endoscopic retrograde cholangiopancreatography. Five patients had stones impacted at the ampulla, all (two) of which were detected with CT (US). Computed tomography (US) had a sensitivity of 86% (82%) and a specificity of 98% (98%) in the diagnosis of choledocholithiasis. CONCLUSIONS: Both unenhanced spiral CT and US are useful for evaluating suspected common bile duct stones. Unenhanced spiral CT is especially useful when the patient is likely to have ampullary stones and is a safe, more available and less expensive alternative to magnetic resonance cholangiography.     

Accuracy of multislice computed tomography in the preoperative assessment of coronary disease in patients with aortic valve stenosis.

OBJECTIVES: To evaluate multislice computed tomography (MSCT) as an alternative to coronary angiography, we prospectively studied its diagnostic accuracy for the detection of significant coronary artery lesions in patients with significant aortic valve stenosis undergoing valve surgery. BACKGROUND: In patients with aortic valve stenosis, coronary angiography is still recommended before surgery. Multislice computed tomography is a promising noninvasive technique for the detection of significant coronary artery lesions. METHODS: Fifty-five consecutive patients scheduled for coronary angiography in the preoperative assessment of aortic valve stenosis underwent 16-slice MSCT 24 h before coronary angiography. We analyzed coronary lesions, image quality, and arterial calcium score. RESULTS: The sensitivity of the MSCT-based strategy in detecting significant stenosis was 100%, and its specificity 80%. The positive and negative predictive values were respectively 55% and 100%. For calcium scores <1,000 (77% of patients), MSCT detected all patients without coronary artery disease, enabling conventional coronary angiography to be avoided in 35 of 55 cases (80%). For calcium scores >1,000, MSCT enabled conventional coronary angiography to be avoided in only 6% of cases, either because significant stenosis was found with a possible indication of revascularization, or because the examination was not interpretable. CONCLUSIONS: The results of this initial experience in relatively few patients suggest that MSCT-based coronary angiography may serve as an alternative to invasive coronary angiography to rule out significant coronary artery disease in patients scheduled for elective aortic valve replacement. Larger studies are necessary to fully explore the potential of coronary MSCT to improve preoperative risk stratification.