MSCT肝脏体积测量研究

目的 评价MSCT测量肝脏体积(LV)各种方法的优劣及在肝移植中的应用价值.资料与方法 对18例肝移植受体术前行MSCT多期扫描.用手动法及半自动法测量LV,与术后即刻水测法所得LV进行相关分析、单因素方差分析及Bland-Altman检测,并分别记录两种方法测量LV所需时间.结果 手动法所测LV为(1369.8±186.7) cm3,半自动法所测体积为(1416.3±192.1) cm3,实际体积为(1383.1±196.1) cm3;术前CT手动法、半自动法测量体积与术后实际体积均有明显的相关性(r分别为0.969、0.978,P＜0.05);各方法所测体积与实际体积差异无明显统计学意义(F=0.016<0.05,P=0.985>0.05);手动法所测LV数值更接近实际体积,但平均时间为(24.5±5.7) min,较半自动法(9.6±1.8) min长.结论 MSCT半自动法LV测量减少了放射科医师的工作量,是一种较好的测量肝脏体积的方法.     

MSCT对外伤性肾上腺血肿的诊断价值

目的:总结外伤性肾上腺血肿的CT表现,探讨MSCT对外伤性肾上腺的诊断价值,提高诊断水平。方法:回顾性分析18例经临床确诊并治疗的外伤性肾上腺血肿患者的CT及临床资料。重点分析CT对血肿的检出率、血肿的形态、大小、密度及随时间推移血肿的变化特点。结果:18例均为单侧肾上腺血肿,其中左侧3例(16.67%),右侧15例(83.33%);18例均合并其他多部位挫裂伤或骨折。平扫下随血肿大小不同,其形态发生改变,边界多光整,平扫CT值等或略高于同侧肾实质。增强扫描后无强化,随时间推移,血肿密度发生变化,其CT值逐渐减低,体积变小,趋于椭圆形改变。结论:外伤性肾上腺血肿具有较为特征性的CT表现,外伤病史结合CT增强扫描有助于肾上腺血肿的定性诊断。     

MSCT对肾上腺病变的诊断价值

目的 :探讨MSCT在肾上腺病变中的应用价值。方法 :选取肾上腺疾病患者56例作为研究对象,分析其病变位置、大小及形状等CT影像特征。结果:56例中,经手术切除36例,穿刺活检4例,临床证实16例。经病理检查发现,腺瘤30例,CT表现为低密度结节且呈轻中度渐进性强化;髓样脂肪瘤5例,呈轻度强化,存在脂性混杂密度;囊肿4例,表现为液性密度,无强化,伴钙化包膜;嗜铬细胞瘤3例,表现为囊实性包块且实性部分强化明显;皮质腺癌2例,表现为低混杂密度,且不均匀强化;节细胞神经瘤2例,表现为"蜡滴样"软组织样密度轻度强化;血肿2例,转移瘤4例,结节状皮质增生4例。结论:MSCT扫描可有效定位及定性诊断肾上腺病变,但仍有部分不典型患者需根据临床病理确诊。     

兰州地区健康成人MSCT心肺血管测量及分析

目的利用多层螺旋CT(MSCT)测量兰州地区健康成人心肺血管管径及面积,制定本地区成人心肺大血管管径及面积的正常标准,并与既往文献报道的其他地区健康人的所测数据进行对比。方法选择常住于兰州,没有心肺疾患的健康体检者。按年龄分为:18~39岁(A组),40~60岁(B组),61~80岁(C组)。各组均包括男50例,女50例,共300例。采用平静呼吸状态下深吸气末时扫描,所得图像经工作站行3D重组后进行测量,所得结果行统计学分析。结果不同年龄组间,主肺动脉、右肺动脉、左肺动脉、升主动脉及降主动脉的管径及面积差异有统计学意义(P<0.05)。B组与C组中,主肺动脉、右肺动脉、左肺动脉的管径及面积具有明显的性别差异(P<0.05)。结论本实验为兰州地区成年人心肺动脉相关疾病的早期诊断提供了较好的影像学标准。与以往文献比较,兰州地区健康成人所测结果异于其他地区成人,推测与本地地理环境及空气质量有关。     

肾上腺结核的MSCT诊断及临床价值

目的:探讨肾上腺结核在MSCT薄层扫描上的影像学表现特点,判断病变的程度对临床治疗的价值。方法:回顾性分析经穿刺病理和治疗随访证实的10例肾上腺结核病例。行MSCT薄层平扫及增强扫描,分析病变的影像学表现特点。结果:10例患者中5例伴有肾上腺外其它部位的结核,其中肺结核3例,脾结核1例,肾结核1例。双侧肾上腺受累8例,单侧肾上腺受累2例,共18个病变。其中14个病变保持肾上腺轮廓呈多发结节状、三角形、类圆形,4个病变失去肾上腺轮廓呈类圆形肿块状。5个病变密度均匀,13个病变密度不均匀,其中8个病变中出现钙化。5个病变呈均匀性强化,13个病变呈不均匀性强化,其中9个病变呈周边环形强化。结论:MSCT薄层扫描能清晰的显示肾上腺结核的病变范围、程度及与周围组织器官的关系,对临床诊断和病变疗效的随访起着重要指导作用。     

MSCT对肾上腺较大肿瘤(直径≥4cm)的临床应用分析

目的:探讨多层螺旋CT(MSCT)对直径≥4cm的肾上腺肿瘤的临床应用价值。方法:回顾性分析23例经手术与病理证实的直径≥4cm的肾上腺肿瘤,观察其在螺旋CT上的征象。结果:结合多层面重建、三维容积重建等各种后处理技术,MSCT能清晰的显示直径≥4cm肾上腺肿瘤的大小、密度、强化程度以及与周围结构的关系。本组23例肾上腺肿瘤中,皮质腺瘤4例,嗜铬细胞瘤10例,肾上腺皮质癌、转移瘤、神经节细胞瘤、髓样脂肪瘤各2例,神经鞘瘤1例。结论:直径≥4cm肾上腺肿瘤的螺旋CT表现有一定的特征性,结合临床和生化检查,能对其做出正确诊断。MSCT对评价肿瘤与周围结构的关系和制定手术方案具有重要指导意义。     

肾上腺肿瘤的MSCT多期增强扫描应用价值

目的 探讨MSCT多期增强扫描对肾上腺肿瘤的诊断及鉴别价值.方法 收集经病理证实的肾上腺肿瘤患者70例共72个病灶的资料,包括醛固酮腺瘤23个、皮质醇腺瘤18个、嗜铬细胞瘤17个及转移瘤14个.结果 醛固酮腺瘤平扫CT均值≤20 HU,21个呈轻度均匀强化.皮质醇腺瘤平扫CT均值≤25 HU,12个呈中度均匀强化;15个嗜铬细胞瘤呈重度不均强化;12个转移瘤呈中度不均强化.动脉期强化率:醛固酮腺瘤＞嗜铬细胞瘤＞皮质醇腺瘤＞转移瘤;静脉期强化率:醛固酮腺瘤＞皮质醇腺瘤＞转移瘤,嗜铬细胞瘤＞转移瘤;相对造影剂清除率:醛固酮腺瘤＞皮质醇腺瘤＞嗜铬细胞瘤＞转移瘤.结论 肾上腺4种常见肿瘤的MSCT平扫、增强密度特征及其强化率、清除率存在差异,可作为这些肿瘤诊断及鉴别诊断的参考指标.     

MSCT对健康成人肩峰解剖形态的研究与分析

目的:应用MSCT对健康成人肩峰解剖形态进行分析及研究,进而对成人肩峰分型.方法:应用MSCT对76例20～75岁健康成年志愿者(其中男32例、女44例,并按年龄段分成20～39岁、40～59岁和60岁以上三组)共152个肩关节进行扫描,将原始数据进行容积再现(VR)、多平面重组(MPR)、最大密度投影(MIP)等后处...     

成人肾上腺神经母细胞瘤1例

患者男,50岁,因左腰痛半年入院,体检：腹平坦,左上腹压痛,无反跳痛,左肾叩击痛,实验室检查：ALB32．1．A／G0．89．HDL0．81。CT所见：左肾上极区域见以大小约9cm×8cm×8cm的混杂密度影,     

肾上腺多层螺旋CT解剖学测量（附90例分析）

目的：采用多层螺旋CT薄层扫描测量肾上腺内、外肢厚度及同层面膈肌脚厚度,并对肾上腺的大体形态进行分类,为肾上腺疾病提供解剖学数据。方法：90例行CT增强扫描,用肝门静脉期（55s）采集数据,应用薄层横断面（2.0mm）重建及冠状面重建。测量肾上腺内、外肢厚度及同层面膈肌脚厚度,并对其进行统计学处理;采用冠状面观察肾上腺的大体形态。结果：左侧肾上腺内肢厚度（4.6±0.9）mm,外肢厚度（4.3±1.1）mm;右侧肾上腺内肢厚度（4.0±0.8）mm,外肢厚度（3.7±0.8）mm;左侧膈肌脚厚度（4.7±1.8）mm,右侧膈肌脚厚度（5.2±1.7）mm。冠状面观察,肾上腺的形态大体可分为3种类型。结论：肾上腺形态不一,但轮廓光整;冠状面重建能很好地显示肾上腺的形态类型。多层螺旋CT能准确测量肾上腺的内外肢厚度及膈肌脚厚度。     

Detection of pulmonary nodules by multislice computed tomography: improved detection rate with reduced slice thickness

The purpose of this study was to find out if the use of 1.25-mm collimated thin-slice technique helps to detect more small pulmonary lung nodules than the use of 5 mm. A total of 100 patient examinations that allowed a reconstruction of 1.25-mm slice thickness in addition to the standard of 5-mm slices were included in a prospective study. Acquisition technique included four rows of 1-mm slices. Two sets of contiguous images were reconstructed and compared with 1.25- and 5-mm slice thickness, respectively. Two radiologists performed a film-based analysis of the images. The size and the confidence of the seen nodules were reported. We did not perform a histological verification, according to the normal clinical procedure, although it would be optimal regarding research. Statistical analysis was performed by using longitudinal analysis described by Brunner and Langer [10]. In addition, sensitivity, specificity, negative predictive value and positive predictive value were calculated for each reader using the 1.25-mm sections as the gold standard. As an index for concordance the kappa value was used. A value of p<0.05 was regarded as significant. In 37 patients pulmonary nodules were detected. Twenty-four patients showed more than one nodule; among these, 7 patients had disseminated disease and were excluded from the study. Pulmonary nodules larger than 10 mm in size were equally well depicted with both modalities, whereas lesions smaller than 5 mm in size were significantly better depicted with 1.25 mm (p<0.05). Using 1.25 mm as the gold standard, sensitivity for 5-mm reconstruction interval was 88 and 86% for observers A and B, respectively. No false-positive results were reported for 5-mm sections. Interobserver agreement for nodule detection determined for 1.25-mm reconstruction intervals showed a k value of 0.753, indicating a good agreement, and 0.562 for 5-mm reconstruction intervals, indicating a moderate agreement. Brunner and Langer [10] analysis showed significant differences for slice thickness and no significant difference between the observers. Reduced slice thickness demonstrated an improvement of small nodule detection, confidence levels, and interobserver agreement. Application of thin-slice multidetector-row CT may raise the sensitivity for lung nodule detection, although the higher detection rate of smaller nodules has to be evaluated from a clinical perspective and remains problematic about how the detection of small nodules will effect patient outcome.     

Usefulness of multislice spiral computed tomography coronary angiography in patients with acute chest pain in the emergency department

Background

Despite reports that multislice spiral computed tomography (MSCT) has high sensitivity and specificity in preselected patient populations, the routine clinical feasibility and utility of MSCT coronary angiography in patients with acute chest pain in the emergency department remains uncertain.

Objectives

We sought to determine whether 16-slice MSCT coronary angiography can provide diagnostically useful images in patients with acute chest pain in the emergency department.

Methods

Ninety-eight patients in the emergency department (41 men, 57 women; mean age ± SD, 48.1 ± 11.9 y) with acute chest pain underwent MSCT coronary angiography. Coronary calcium (Agatston) scoring was performed, followed by contrast-enhanced MSCT. Images were evaluated for mean image quality (MIQ) and for degree of stenosis. These data were correlated with body mass index (BMI; in kg/m²), heart rate, beat-to-beat variation, and calcium score to assess their influence on image quality.

Results

The 28 patients (29%) with nondiagnostic MIQs had significantly higher BMIs (mean ± SD, 32.9 ± 9.1 vs 28.9 ± 6.7; P < 0.05) and heart rates (mean ± SD, 71.0 ± 11.9 beats/min vs 65.6 ± 9.9 beats/min; P < 0.05) than patients with diagnostic MIQs. Forty-five patients (46%) had at least 1 nondiagnostic coronary segment. These patients had significantly higher heart rates (mean ± SD, 70.5 ± 10.3 vs 64.1 ± 13.7; P < 0.05) than patients with only diagnostic-quality scans. Image quality correlated inversely and strongly with BMI and heart rate.

Conclusions

Sixteen-slice MSCT coronary angiography cannot routinely provide diagnostically useful images in patients with acute chest pain in the emergency department.     

Impact of coronary calcium score on diagnostic accuracy of multislice computed tomography coronary angiography for detection of coronary artery disease

Background  The impact of the coronary calcium score on the diagnostic accuracy of multislice computed tomography (MSCT) to detect obstructive coronary stenoses remains controversial. Methods and Results  We examined 41 patients (mean Agatston score, 340 ± 530 [range, 0–2546]) with coronary artery disease with 16-slice MSCT and 60 patients (mean Agatston score, 446 ± 877 [range, 0–6264]) with 64-slice MSCT. MSCT scans were analyzed with invasive coronary angiography (CA) as the standard of reference. Lesions with luminal narrowing of 50% or greater were considered obstructive. In total, 9% and 2% of uninterpretable segments were excluded from analysis in patients examined with 16- and 64-slice MSCT, respectively. On a segment basis, the percentage of false-negative segments in the groups with Agatston scores of 0 to 100, 101 to 400, and greater than 400 with 16-slice MSCT were 0%, 5.3%, and 2.9% (P ± .0005), respectively; other comparisons of false-positive and false-negative segments were not significant. The sensitivity and specificity on a vessel and patient basis with 16- and 64-slice MSCT were not significantly different in different calcium score groups. Conclusions  A slight impact of coronary calcium was observed on the diagnostic accuracy of 16-slice MSCT CA on a segment basis, with no significant impact on a vessel and patient basis. No significant impact of coronary calcium was observed on the diagnostic accuracy of 64-slice MSCT CA on a segment, vessel, or patient basis. G.P. is financially supported by the Training Fellowship of the European Society of Cardiology and the Huygens Scholarship, The Netherlands. J.D.S. is financially supported by the Netherlands Heart Foundation, The Hague, The Netherlands (grant No. 2002B105).     

Evaluation of computed tomography coronary angiography in patients with a high heart rate using 16-slice spiral computed tomography with 0.37-s gantry rotation time

The aim of our study is to evaluate computed tomography (CT) coronary angiography in patients with a high heart rate using 16-slice spiral CT with 0.37-s gantry rotation time. We compare the image quality of patients whose heart rates were over 70 beats per minute (bpm) with that of patients whose heart rates were 70 bpm or less. Sixty patients with various heart rates underwent retrospectively ECG-gated multislice spiral CT (MSCT) coronary angiography. Two experienced observers who were blind to the heart rates of the patients evaluated all the MSCT coronary angiographic images and calculated the assessable segments. A total of 620 out of 891 (69.6%) segments were satisfactorily visualized. On average, 10.3 coronary artery segments per patient could be evaluated. In 36 patients whose heart rates were below 70 bpm [mean 62.2 bpm±5.32 (standard deviation, SD)], the number of assessable segments was 10.72±2.02 (SD). In the other 24 patients whose heart rates were above 70 bpm [mean 78.6 bpm±8.24 (SD)], the corresponding number was 9.75±1.74 (SD). No statistically significant difference was found in these two subgroups t test, P>0.05. The new generation of 16-slice spiral CT with 0.37-s rotation time can satisfactorily evaluate the coronary arteries of patients with high heart rates (above 70 bpm, up to 102 bpm).     

New identification possibilities with postmortem multislice computed tomography

Historically, radiographical identification has been done by comparing conventional antemortem and postmortem X-ray images. The advent of new technologies such as multislice computed tomography (MSCT) is making traditional antemortem examination increasingly less frequent. The authors present the results of MSCT study of 35 corpses, which demonstrated features potentially useful for identification purposes in ten cases. These features, which relate to abnormalities of postcranial bone as well as of the internal organs, are presented. Attempts were made to find any antemortem X-rays or MSCTs on the cases described to compare the two antemortem and postmortem images. Although antemortem imaging was recovered for only two cases (one case with a skeletal abnormality and one case with a visceral abnormality), it permitted for both cases the comparison of antemortem and postmortem MSCTs. Presented at the XXth Congress of International Academy of Legal Medicine, Budapest, Hungary, August 2006.     

Use of coronary calcium score scans from stand-alone multislice computed tomography for attenuation correction of myocardial perfusion SPECT

Purpose To evaluate the use of CT attenuation maps, generated from coronary calcium scoring (CCS) scans at in- and expiration with a 64-slice CT scanner, for attenuation correction (AC) of myocardial perfusion SPECT images. Methods Thirty-two consecutive patients underwent ^99mTc-tetrofosmin gated adenosine stress/rest SPECT scan on an Infinia Hawkeye SPECT-CT device (GE Medical Systems) followed by CCS and CT angiography on a 64-slice CT. AC of the iteratively reconstructed images was performed with AC maps obtained: (a) from the “Hawkeye” low-resolution X-ray CT facility attached to the Infinia camera (IRAC); (b) from the CCS scan acquired on a 64-slice CT scanner during maximal inspiration (AC_INSP) and (c) during normal expiration (AC_EXP). Automatically determined uptake values of stress scans (QPS, Cedars Medical Sinai) from AC_INSP and AC_EXP were compared with IRAC. Agatston score (AS) values using AC_INSPversus AC_EXP were also compared. Results AC_INSP and AC_EXP resulted in identical findings versus IRAC by visual analysis. A good correlation for uptake values between IRAC and AC_INSP was found (apex, r=0.92; anterior, r=0.85; septal, r=0.91; lateral, r=0.86; inferior, r=0.90; all p<0.0001). The correlation was even closer between IRAC and AC_EXP (apex, r=0.97; anterior, r=0.91; septal, r=0.94; lateral, r=0.92; inferior, r=0.97; all p<0.0001). The mean AS during inspiration (319±737) and expiration(317±778) was comparable (p=NS). Conclusion Attenuation maps from CCS allow accurate AC of SPECT MPI images. AC_EXP proved superior to AC_INSP, suggesting that in hybrid scans CCS may be performed during normal expiration to allow its additional use for AC of SPECT MPI.     

Influence of intracoronary attenuation on coronary plaque measurements using multislice computed tomography: observations in an ex vivo model of coronary computed tomography angiography

Assessment of attenuation (measured in Hounsfield units, HU) of human coronary plaques was performed using multislice computed tomography (MSCT) in an ex vivo model. In three ex vivo specimens of left coronary arteries in oil, MSCT was performed after intracoronary injection of four solutions of contrast material (400 mgI/ml iomeprol). The four solutions were diluted as follows: 1/, 1/200, 1/80, and 1/20. All scans were performed with the following parameters: slices/collimation 16/0.75 mm, rotation time 375 ms. Each specimen was scored for the presence of atherosclerotic plaques. In each plaque the attenuation was measured in four regions of interest for lumen, plaque (non-calcified thickening of the vessel wall), calcium, and surrounding (oil surrounding the vessel). The results were compared with a one-way analysis of variance test and were correlated with Pearsons test. There were no significant differences in the attenuation of calcium and oil in the four solutions. The mean attenuation in the four solutions for lumen (35±10, 91±7, 246±18, 511±89 HU) and plaque (22±22, 50±26, 107±36, 152±67 HU) was significantly different between each decreasing dilution (p<0.001). The mean attenuation of lumen and plaque of coronary plaques showed high correlation, while the values were significantly different (r=0.73; p<0.001). Intracoronary attenuation modifies significantly the attenuation of plaques assessed with MSCT.     

First-pass perfusion computed tomography: Initial experience in differentiating adrenal adenoma from metastasis

Objective

To differentiate adrenal adenoma from metastasis in patients using perfusion computed tomography (PCT) imaging.

Methods

Thirty-two patients with adrenal masses underwent first-pass PCT imaging. Of these patients, twenty-one were diagnosed with adrenal adenoma, and the others with metastases. Perfusion maps of blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface-area production (PS) were generated with an Advantage Windows workstation using the CT perfusion 3.0 software (General Electric Medical Systems, Milwaukee, WI). Histopathologic sections immunostained for CD34 were quantitatively evaluated for microvessel density (MVD).

Results

The perfusion parameters such as BV, BF and PS were statistically significant different between the two groups, with adenomas showing higher mean BV (12.18 versus 3.86), BF (97.51 versus 45.99) and PS (21.73 versus 10.93) compared with metastases (p < 0.05). For BV, a cutoff point of 7.30 was found to have a sensitivity of 95.2% and a specificity of 100% to differentiate between adenoma and metastasis. The sensitivity and specificity were 81.0 and 80.0%, respectively, for BF with a cutoff point of 71.96; and 85.7 and 86.7%, respectively, for PS with a cutoff point of 12.70 to differentiate adenoma and metastasis. A comparison of MVD counts from adenomas with those from metastases showed a significant difference (p < 0.05). However, no significant differences were observed in the four perfusion parameters and MVD between lipid rich and lipid poor adenomas.

Conclusion

PCT may be useful for evaluating the neovascularization of adrenal masses and differentiating adenoma from metastasis on the basis of PCT parameters. Adenomas show higher BV, BF and PS compared with metastases. According our data, the optimal threshold BV is 7.30, resulting in a sensitivity of 95.2% and a specificity of 100% for the differentiation of adenoma from metastasis. Adrenal adenomas have similar hemodynamic profiles, which are apparently independent of the lipid content of an adenoma.     

Influence of convolution filtering on coronary plaque attenuation values: observations in an ex vivo model of multislice computed tomography coronary angiography

Attenuation variability (measured in Hounsfield Units, HU) of human coronary plaques using multislice computed tomography (MSCT) was evaluated in an ex vivo model with increasing convolution kernels. MSCT was performed in seven ex vivo left coronary arteries sunk into oil followingthe instillation of saline (1/∞) and a 1/50 solution of contrast material (400 mgI/ml iomeprol). Scan parameters were: slices/collimation, 16/0.75 mm; rotation time, 375 ms. Four convolution kernels were used: b30f-smooth, b36f-medium smooth, b46f-medium and b60f-sharp. An experienced radiologist scored for the presence of plaques and measured the attenuation in lumen, calcified and noncalcified plaques and the surrounding oil. The results were compared by the ANOVA test and correlated with Pearson’s test. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The mean attenuation values were significantly different between the four filters (p < 0.0001) in each structure with both solutions. After clustering for the filter, all of the noncalcified plaque values (20.8 ± 39.1, 14.2 ± 35.8, 14.0 ± 32.0, 3.2 ± 32.4 HU with saline; 74.7 ± 66.6, 68.2 ± 63.3, 66.3 ± 66.5, 48.5 ± 60.0 HU in contrast solution) were significantly different, with the exception of the pair b36f–b46f, for which a moderate-high correlation was generally found. Improved SNRs and CNRs were achieved by b30f and b46f. The use of different convolution filters significantly modifief the attenuation values, while sharper filtering increased the calcified plaque attenuation and reduced the noncalcified plaque attenuation.     

Value of multislice computed tomography angiography of the thorax in preparation for catheter ablation for the treatment of atrial fibrillation: the impact of unexpected cardiac and extracardiac findings on patient care

Objective

In patients referred for catheter ablation for the treatment of atrial fibrillation, multislice computed tomography angiography of the thorax is routinely performed to assess pulmonary vein anatomy. We sought to investigate the incidence of unexpected cardiac and extracardiac findings in this select patient population and to establish how these findings influence subsequent patient care.

Methods

Ninety-five patients (mean age 62 ± 10 years, 35% female) referred to our institution for ablation therapy for atrial fibrillation between July 2003 and October 2007 underwent multislice computed tomography angiography of the thorax. Radiologists interpreted all images. Need for additional testing, consultation and eventual diagnosis were assessed by electronic record review.

Results

A total of 83 (5 cardiac, 78 extracardiac) unexpected findings were observed in 50/95 (53%) of patients. The findings prompted 23 additional tests (5 cardiac, 18 noncardiac) in 15/95 (16%) of patients and 8 subsequent referrals in 7/95 (7%) patients. In 6 patients the findings significantly altered future patient care and resulted in postponement of ablation therapy in 4 patients. In 2 patients, extracardiac findings (pulmonary emboli and adenocarcinoma of the lung) were of potentially life-saving consequence.

Conclusions

In patients undergoing multislice computed tomography angiography of the thorax in anticipation of planned catheter ablation therapy for the treatment of atrial fibrillation, unexpected findings are common and of potentially significant value. In comparison, there is a higher prevalence of unexpected extracardiac, rather than cardiac findings. Further investigation of these findings may lead to postponement of ablation therapy, but may also be of potentially lifesaving consequence.