Survey on the use of pulmonary scintigraphy, spiral CT and conventional pulmonary angiography for suspected pulmonary embolism in the British Isles

AIM: To determine current clinical practice in the radiological diagnosis of acute pulmonary embolism and assess the use of spiral volumetric computed tomography. METHOD: A survey of 327 acute hospitals including cardiothoracic and orthopaedic tertiary referral centres was undertaken to assess current utilization of lung scintigraphy, spiral computed tomography and pulmonary angiography in the investigation of suspected pulmonary embolism. Responses were received from 215/327 (66%) centres. RESULTS: Lung scintigraphy was provided by 208 hospitals (144 on-site and 64 off-site). Spiral CT services were provided by 111 (52%) hospitals (on- or off-site), 142 (66%) units had access to angiographic facilities. Sixty-three centres out of 215 (29%) offered both on-site lung scintigraphy and spiral CT while only 41/215 (19%) hospitals were able to undertake all three tests on-site. On average, 501 perfusion (Q) or ventilation-perfusion (V/Q) scintigrams were performed per hospital per year with 26 spiral CT studies and just 4.6 pulmonary angiograms. CONCLUSION: These data suggest that lung scintigraphy is frequently the only imaging test in patients other than chest radiography, despite the large number of indeterminate results reported in most series.     

Value of axial and coronal maximum intensity projection (MIP) images in the detection of pulmonary nodules by multislice spiral CT: comparison with axial 1-mm and 5-mm slices

The purpose of this study was to investigate the diagnostic accuracy of non-overlapping 10-mm axial and coronal maximum intensity projections (MIP) in comparison with standard axial 1-mm and 5-mm slices in the detection of pulmonary nodules. Sixty patients with suspected nodules who underwent multislice spiral CT of the chest were evaluated. Axial 1-mm and 5-mm slices as well as non-overlapping 10-mm axial/coronal MIPs were interpreted independently by three blinded radiologists. After initial review, a retrospective consensus session was performed for agreement on final nodule counts using the axial 1-mm slices as gold standard. Small nodules of less than 5 mm in size were most accurately detected by the axial MIPs. Receiver operating characteristic (ROC) analysis of these small nodules showed that 5-mm slices were not capable of a statistically significant differentiation of nodules from other focal lesions in two observers (p=0.034 and p=0.012, respectively) whereas 1-mm slices and coronal/axial MIPs did allow a statistically significant differentiation in all observers (p<0.001). Nodules larger than 5 mm were equally well depicted with all modalities. Non-overlapping 10-mm axial MIPs improve the accuracy in the detection of small pulmonary nodules.     

小细胞肺癌的CT征象和血管生成(VEGF、MVD)相关性研究

目的探讨小细胞肺癌(SCLC)的CT征象和血管内皮生长因子(VEGF)、微血管密度(MVD)的相关性。方法收集资料完整的37例小细胞肺癌,回顾性分析CT征象;应用免疫组化方法(S-P法)检测标本中的VEGF、MVD的含量,统计分析其相关性。结果37例小细胞肺癌中VEGF阳性表达为83.78%(31/37)、MVD平均为51.75±16.97;VEGF阳性组MVD为53.45±13.58,VEGF阴性组MVD为39.16±15.39,2组间有差异(P<0.05);小细胞肺癌的CT征象:肿瘤直径≥3cm、分叶征、肺门纵隔淋巴结大、强化程度与MVD含量密切相关(P<0.05)。结论通过小细胞肺癌的CT征象可以评价其组织中VEGF、MVD的表达及血管生成情况,进一步判断小细胞肺癌的恶性程度、转移、预后成为可能。     

Quantification of left ventricular function and mass in cardiac Dual-Source CT (DSCT) exams: comparison of manual and semiautomatic segmentation algorithms

The purpose of our study was to evaluate reliability of left ventricular (LV) function and mass quantification in cardiac DSCT exams comparing manual contour tracing and a region-growing-based semiautomatic segmentation analysis software. Thirty-three consecutive patients who underwent cardiac DSCT exams were included. Axial 1-mm slices were used for the semiautomated technique, and short-axis 8-mm slice thickness multiphase image reconstructions were the basis for manual contour tracing. Left ventricular volumes, ejection fraction and myocardial mass were assessed by both segmentation methods. Length of time needed for both techniques was also recorded. Left ventricular functional parameters derived from semiautomatic contour detection algorithm were not statistically different from manual tracing and showed an excellent correlation (p<0.001). The semiautomatic contour detection algorithm overestimated LV mass (180.30±44.74 g) compared with manual contour tracing (156.07±46.29 g) (p<0.001). This software allowed a significant reduction of the time needed for global LV assessment (mean 174.16±71.53 s, p<0.001). Objective quantification of LV function using the evaluated region-growing-based semiautomatic segmentation analysis software is feasible, accurate, reliable and time-effective. However, further improvements are needed to equal results achieved by manual contour tracing, especially with regard to LV mass quantification.     

Lung scintigraphy with nonspecific human immunoglobulin G (<Superscript>99m</Superscript>Tc-HIG) in the evaluation of pulmonary involvement in connective tissue diseases: correlation with pulmonary function tests (PFTs) and high-resolution computed tomography (HRCT)

Purpose In patients with connective tissue diseases (CTD), the early detection and evaluation of the severity of the pulmonary involvement is mandatory. High-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) are considered to be valuable noninvasive diagnostic modalities. Radiopharmaceuticals have also been used for this purpose. Our aim was the evaluation of technetium-labeled human polyclonal immunoglobulin G (HIG) lung scintigraphy in the early detection and assessment of the severity of the pulmonary involvement in CTD patients. Methods Fifty-two nonsmoking CTD patients were studied by PFTs, HRCT, and HIG. According to PFTs, patients were divided in group A (impaired PFTs—abnormal pulmonary function) and group B (normal pulmonary function). Semiquantitative analysis was done on HIG and HRCT and corresponding scores were obtained. Results Significant difference was found between HIG scores in the two groups (0.6 ± 0.07 vs 0.51 ± 0.08, P < 0.001). There was a statistically significant negative correlation between HIG scores and PFTs results and a positive correlation between HIG and HRCT scores. HIG demonstrated similar clinical performance to HRCT. At the best cut-off levels of their score (0.56 and 7, respectively), HIG had a superior sensitivity (77.5 vs 57.5%) with lower specificity (75 vs 91.7%). The combination of the two methods increased the sensitivity of abnormal findings at the expense of specificity. Conclusions HIG scintigraphy can be used in the early detection and evaluation of the severity of the pulmonary involvement in CTD, whereas, when used in combination with HRCT, the detection of affected patients can be further improved.     

SCTAP对肝癌检测和治疗的临床应用价值

目的：评价螺旋CT经动脉门静脉造影（SCTAP）对肝癌的检测和治疗的临床应用价值。方法：比较23例肝局灶性病变采用SCTAP、常规CT、DSA显示病灶个数的差异性,分析肝局灶性病变SCTAP影像学征象。结果：SCTAP较常规CT及DSA对显示小于30．0mm病灶数及小于10．0mm病灶数差异有高度显著性（P＜0．01）或有显著性（P＜0．05）,而对大于30．0mm病灶的显示,差异无显著性（P＞0．05）。病灶周边可有门脉供血而内部无门脉供血是肝癌的特征性表现。SCTAP为肝癌的可切除性判断及介入治疗方案的选择提供了有价值的信息。结论：SCTAP与常规CT、DSA比较,对小肝癌或微小肝癌的检测具有极高的敏感性,结合其它影像学手段,可明显提高其特异性。对于肝癌治疗方案的选择,SCTAP具有较大的临床应用价值。