Multisection Computed Tomography Research Articles

Diagnostic accuracy for coronary artery disease by computed tomography angiography as compared to conventional invasive angiography

Background: Emerging as a major cause of death and disability in the developing countries is coronary artery disease (CAD). Traditional coronary angiography has traditionally been the preferred diagnostic procedure for CAD. Non-invasive evaluation of coronary artery disease (CAD) using computed tomography (CT) coronary angiography shows promise. This observational study's goal is to assess the relative efficacy of noninvasive multi-section computed tomography (MSCT) coronary angiography vs invasive selective coronary angiography in detecting coronary stenosis.Method and patient: This observational study carried out in the Azadi teaching Hospital/Kirkuk between November 2021 to March 2022. Patients who suspected to have coronary artery disease underwent both CTCA and invasive coronary angiography in different centers in our country comparing and analyzing their results.Result: In total, 92 participants were enrolled in the trial. Patients had a mean age of 57.207.3 years, and men made up the vast majority of those who appeared (67.3 percent). Chest pain was the most common presenting complaint (94 percent). Patients exhibited a prevalence of 84% for HTN, 55% for hyperlipidaemia, 58% for diabetes, and 4% for ischemic heart disease. In addition, 50% of the patients are either current or former smokers. Half of the patients received 64-slice CT scans, nearly half had 128-slice scans, and 3.2% got 256-slice scans. CCTA's sensitivity was 100%, and its specificity was 66.7%. Positive predictive value for CCTA was 98.8 percent (meaning it correctly identified positive cases in 98.8 percent of patients) and negative predictive value was 100 percent, for a total diagnostic accuracy of 98.9 percent (which mean CCTA can exclude all negative cases and did not miss any case). When looking at individual arteries, the LAD artery was shown to be the most accurate, while the LCX artery was the least accurate (95.6 percent and 78.2 percent respectively). In terms of sensitivity, LAD performed at a 99.1% rate, while LMS performed at a 0% rate (33.3 percent). RCA had the most specificity (95.2 percent), whereas LAD had the lowest (88.8 percent) (40 percent). In order to determine what factors, influence CCTA positivity, we performed a binary logistic regression analysis for positive CCTA (negative as reference) with all variables from the studies. The results showed that IHD, lesions in the LAD artery, lesions in the LCX artery, and CT slice thickness (128 and 256 slices) all have a negative effect on CCTA (p0.05).Conclusions: When compared to traditional angiography, multi-slice computed tomography has demonstrated superior sensitivity and specificity for the identification of coronary artery disease.

Computed tomography imaging parameters of 82 Chinese patients with congenital microphthalmia

Objective: To observe computed tomography (CT) imaging parameters of congenitally blind microphthalmia in Chinese patients and to provide clinical reference data for the Chinese population. Methods: It was a retrospective study for a consecutive case series of congenitally blind microphthalmia from July 2011 to July 2013. All of the patients were diagnosed in the Ocular Plastic Department, Tongren Eye Center, Beijing Tongren Hospital. We employed multi-section helical CT imaging with a computer-aided design system to observe and measure the imaging features in 82 Chinese patients (85 eyes). The paired T-test was applied for comparing the axial lengths, transverse diameters, and vertical diameters between the both sides in patients with congenital microphthalmia. The Pearson correlation was used for analyzing the relationship between the axial length and the age of the patients. Results: In the 82 patients, the age ranged from 1 month to 40 years old. Forty-one patients were male and 41 were female. The disease was unilateral in 96.34% of the patients. The orbital cysts were observed in 12.94% of them, and 76.47% of them presented basic structures on the CT scan. The abnormalities of the lens (62.35% of the eyes) and vitreous (82.35% of the eyes) were observed. The mean maximum axial length of the affected eyes (85 eyes) was (14.52±0.56) mm and the mean axial length of the unaffected eyes (79 eyes) was (22.79±0.36) mm. There was significantly statistical difference in the ocular size between the affected and unaffected eyes (t= 1.156, P<0.001) . Conclusions: Congenitally blind microphthalmia is usually complicated with the abnormalities of the lens and vitreous. The ocular size decreases significantly. The results of the present study provide a clinical reference for evaluating congenitally blind microphthalmia.(Chin J Ophthalmol, 2018, 54: 199-204).

Clinicopathological and multisection CT features of primary pulmonary mucoepidermoid carcinoma

To delineate the multisection computed tomography (MSCT) features and the clinical characteristics of primary pulmonary mucoepidermoid carcinoma (PMEC). Prognostic factors were also analysed. A retrospective study was undertaken to investigate the medical records and MSCT performance of histopathologically confirmed PMECs from 2007 to 2015. A total of 83.3% of patients with high-grade PMECs were aged >40 years, whereas there were 1.5-times more women than men with low-grade PMECs. Cough (n=29) and haemoptysis (n=12) were the most common symptoms. Upon MSCT, 30 cases showed a round or lobulate mass, and few demonstrated bronchial-wall thickening or cavities. Distal obstruction (n=14) and "air crescent sign" (n=5) could be detected. Tumours showed mild (n=19), moderate (n=5), and marked enhancement (n=5). Moreover, 18 cases showed foci of low density in lesions. Mean survival for patients with low-grade PMECs was 59.2 months, whereas that for high-grade PMECs was 20.4 months; 3-year survival rates were 55% and 14%, respectively. Tumour staging was a significant independent predictor of survival according to the Cox proportional hazards model. High-grade PMECs occurred more frequently in patients aged >40 years and were more predominant in men. Young females were predisposed to having low-grade PMECs. MSCT revealed an oval or lobulate mass with mild enhancement, as manifested by calcification and visible mucus lakes, which may be suggestive of PMECs. Furthermore, a central nodule or mass may suggest low-grade PMECs; high-grade PMECs tend to be peripheral and associated with lymph-node metastasis. Pathological grade, lymph node metastasis, and TNM stage correlate with the survival of patients with PMEC.

Early detection of acute radiation-induced lung injury with multi-section CT perfusion imaging: An initial experience

To explore the value of 64-section computed tomography (CT) perfusion imaging (CTPI) in the early diagnosis of acute radiation-induced lung injury (ARILI). Fifty-one patients with oesophageal cancers or malignant thymomas received postoperative radiation therapy with a 60-62 Gy dose and underwent CTPI at pre- and post-radiation therapy time points (week 0, week 4, week 8, and week 12 respectively). The CTPI values were prospectively compared and analysed in order to evaluate the diagnostic utility of CTPI in the early diagnosis of ARILI. Eighteen cases (18/51) of ARILI were diagnosed. The mean values of relative regional blood flow (rrBF), relative regional volume (rrBV), and relative regional permeability surface (rrPS) in the ARILI group were correspondingly higher than those of the non-ARILI group. At week 4, rrBF, rrBV, and rrPS in the ARILI group were significantly higher than those at pre-radiation (each p < 0.05). In the non-ARILI group, rrBF and rrBV were higher than those at pre-radiation (each p < 0.05); however, rrPS was not statistically different from that of pre-irradiation. Applying the diagnostic threshold value of rrPS = 1.22, the sensitivity, specificity, and positive and negative predictive values of CTPI for early diagnosis of ARILI were better than those of CT. CTPI metrics may reflect haemodynamic changes in the post-irradiation lung and can detect cases of early ARILI that appear normal at CT. CTPI is a promising technique for early diagnosis of ARILI.

Practical Strategies to Reduce Pediatric CT Radiation Dose

The objective of this article is to provide a brief review of CT scanning radiation sensitivity in children and explain CT scan parameters that affect radiation dose. We discuss key factors influencing radiation dose and study quality and how these factors can be used to optimize scan protocols with the goal of reducing pediatric CT radiation dose without compromising diagnostic quality. Finally, we provide some practical tips for reducing radiation doses to children.

The MSCT and MRI findings of collecting duct carcinoma

To characterize the multi-section computed tomography (MSCT) and magnetic resonance imaging (MRI) features of collecting duct carcinoma (CDC). Twenty patients with CDC were studied retrospectively using MSCT (n = 20), and MSCT and MRI (n = 5). MSCT and MRI were undertaken to investigate tumour location, size, radiodensity, cystic or solid appearance, calcification, capsule, signal, enhancement pattern, and metastases. Tumours (mean diameter 3.6 ± 1.7 cm) were solitary (20/20), solid (18/20), had cystic components (12/20), calcifications (12/20), poorly defined (18/20), were centred in the medulla (20/20), compressed the renal pelvis (12/20), and had lymph node metastases (2/20). On unenhanced computed tomography (CT), the radiodensity of the CDC was greater than that of the normal renal cortex or medulla (43.8 ± 2.4 versus 37.6 ± 5.1 or 32.6 ± 4.1, p = 0.041, n = 20). Five patients with CDC underwent MRI, which revealed cystic components (4/5), poorly defined CDC (5/5), and none of the patients had lymph node metastasis. The CDC was isointense on T1-weighted imaging, and iso- or hypointense on T2-weighted imaging. Enhancement was lower within the CDC than the renal cortex and medulla during all enhanced phases (p = 0.032, 0.001, 0.018, respectively, n = 20). CDC should be considered when a renal tumour is centred in the medulla, with increased radiodensity on unenhanced CT and reduced enhancement compared to the adjacent cortex or medulla.

The Correlation between MSCT for Lung Volume and Airway Measurements and Pulmonary Function Test

Objective To study the correlation between the airway dimensions from third to five generation of bronchi, and pulmonary function test(PFT) results in patients with chronic obstructive pulmonary disease(COPD) by using inspiratory and expiratory multisection computed tomography(MSCT). Materials and Methods The study included 19 patients with COPD who underwent both inspiratory and expiratory CT. For each patient, airway luminal areas and wall thickness from the third to fifth generations of RB1 and RB10 were measured. Correlations between these parameters and PFT results were evaluated. Results The correlation coefficients between airway luminal at expiratory CT and PFT results were higher than those for inspiratory CT, and improved as the airway size decreased from the third to the fifth generations. Conclusion Some parameters of airway luminal are significantly correlated with PFT. MSCT can be used to assess the pulmonary function of patients with COPD.

Dental Multisection CT for the Placement of Oral Implants: Technique and Applications

Dental computed tomography (CT) is a diagnostic examination for the preoperative evaluation of patients who will undergo placement of oral implants. It can be performed with multidetector CT or more recently with cone-beam CT. The growing older population and the consequent development of edentulism have increased the number of imaging studies performed for preoperative evaluation of dental implantation. Thus, radiologists are becoming more frequently involved in this type of testing. Dental CT is superior to conventional x-ray techniques because superimposition and distortion are eliminated; therefore, possible complications such as injury of the neurovascular bundle and perforation of the maxillary sinuses can be avoided. This noninvasive and fast method provides accurate information about the positions of important structures to allow one to determine the implant required. Dental CT enables analysis of the state, quality, and quantity of bone on two-dimensional and three-dimensional reformatted images, and its high spatial resolution allows exact measurements of the length and width of the alveolar ridge. Inclusion of all this information in the radiology report facilitates achievement of a successful implantation.

Multisection CT Protocols: Sex- and Age-specific Conversion Factors Used to Determine Effective Dose from Dose-Length Product

To determine conversion factors for the new International Commission on Radiological Protection (ICRP) publication 103 recommendations for adult and pediatric patients and to compare the effective doses derived from Monte Carlo calculations with those derived from dose-length product (DLP) for different body regions and computed tomographic (CT) scanning protocols. Effective dose values for the Oak Ridge National Laboratory phantom series, including phantoms for newborns; 1-, 5-, and 10-year-old children; and adults were determined by using Monte Carlo methods for a 64-section multidetector CT scanner. For each phantom, five anatomic regions (head, neck, chest, abdomen, and pelvis) were considered. Monte Carlo simulations were performed for spiral scanning protocols with different voltages. Effective dose was computed by using ICRP publication 60 and publication 103 recommendations. The calculated effective doses were compared with those derived from the DLP by using previously published conversion factors. In general, conversion factors determined on the basis of Monte Carlo calculations led to lower values for adults with both ICRP publications. Values up to 33% and 32% lower than previously published data were found for ICRP publication 60 and ICRP publication 103, respectively. For pediatric individuals, effective doses based on the Monte Carlo calculations were higher than those obtained from DLP and previously published conversion factors (eg, for chest CT scanning in 5-year-old children, an increase of about 76% would be expected). For children, a variation in conversion factors of up to 15% was observed when the tube voltage was varied. For adult individuals, no dependence on voltage was observed. Conversion factors from DLP to effective dose should be specified separately for both sexes and should reflect the new ICRP recommendations. For pediatric patients, new conversion factors specific for the spectrum used should be established.

Diagnostic Imaging of Colorectal Liver Metastases with CT, MR Imaging, FDG PET, and/or FDG PET/CT: A Meta-Analysis of Prospective Studies Including Patients Who Have Not Previously Undergone Treatment

To obtain diagnostic performance values of computed tomography (CT), magnetic resonance (MR) imaging, fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET), and FDG PET/CT in the detection of colorectal liver metastases in patients who have not previously undergone therapy. A comprehensive search was performed for articles published from January 1990 to January 2010 that fulfilled the following criteria: a prospective study design was used; the study population included at least 10 patients; patients had histopathologically proved colorectal cancer; CT, MR imaging, FDG PET, or FDG PET/CT was performed for the detection of liver metastases; intraoperative findings or those from histopathologic examination or follow-up were used as the reference standard; and data for calculating sensitivity and specificity were included. Study design characteristics, patient characteristics, imaging features, reference tests, and 2 × 2 tables were recorded. Thirty-nine articles (3391 patients) were included. Variation existed in study design characteristics, patient descriptions, imaging features, and reference tests. The sensitivity estimates of CT, MR imaging, and FDG PET on a per-lesion basis were 74.4%, 80.3%, and 81.4%, respectively. On a per-patient basis, the sensitivities of CT, MR imaging, and FDG PET were 83.6%, 88.2%, and 94.1%, respectively. The per-patient sensitivity of CT was lower than that of FDG PET (P = .025). Specificity estimates were comparable. For lesions smaller than 10 mm, the sensitivity estimates for MR imaging were higher than those for CT. No differences were seen for lesions measuring at least 10 mm. The sensitivity of MR imaging increased significantly after January 2004. The use of liver-specific contrast material and multisection CT scanners did not provide improved results. Data about FDG PET/CT were too limited for comparisons with other modalities. MR imaging is the preferred first-line modality for evaluating colorectal liver metastases in patients who have not previously undergone therapy. FDG PET can be used as the second-line modality. The role of FDG PET/CT is not yet clear owing to the small number of studies. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100729/-/DC1.

Overranging at Multisection CT: An Underestimated Source of Excess Radiation Exposure

To reconstruct the first and last sections of a helical computed tomographic (CT) scan, the scan length is automatically extended beyond the planned image boundaries, a phenomenon known as overranging. With common 16-section CT scanning protocols, the overrange length is between 3 and 6 cm. For scanners with 64 or more sections, this length will be much greater, since overranging increases as pitch or detector collimation increases. Manufacturers have equipped the latest generation of CT scanners (128 sections or more) with overrange dose-reducing innovations that reduce overranging by typically up to 50%, which in the best cases reduces overranging to that of the previous scanner models (64 sections). To reduce the impact of overranging on radiosensitive organs just outside the planned scan region, it is best to use an axial protocol rather than a helical protocol. If this is not an option, lowering the pitch or the detector collimation will significantly reduce overranging. Finally, CT examinations should be planned in such a way that radiosensitive organs are as far as possible from the imaged volume.

Coronary Artery Stenosis in High-risk Patients: 64–Section CT and Coronary Angiography—Prospective Study and Analysis of Discordance

To assess the diagnostic accuracy of multisection (64-section) computed tomography (CT) versus coronary angiography in detection of and assignment of grades for coronary artery stenoses in a high-risk population and to investigate causes for discordance between the two. The protocol was approved by the local ethics committee. Patients gave informed consent. The study included 114 patients (103 men, 11 women; mean age, 63 years +/- 8.2 [standard deviation]) with potential myocardial ischemia. Multisection CT images were interpreted independently by two radiologists with unequal experience in reading coronary CT angiograms. Diagnostic performance of 64-section CT in detection of stenoses of 50% or more was assessed per patient, per artery, and per segment. Interrater agreement was assessed by using the Cohen kappa coefficient. Agreement between 64-section CT and coronary angiography for assigning grades to stenoses was assessed by using Bland-Altman analysis. Sixty-eight percent of patients had stenoses of 50% or more. Good interrater agreement was found, with kappa values of 0.77-0.85. For the most experienced radiologist, the sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were 73.4%, 95.0%, 14.7, and 0.28 per segment, 95.2%, 94.7%, 18.0, and 0.05 per artery, and 100%, 89.2%, 9.26, and zero per patient, respectively. Discordance between 64-section CT and coronary angiography was related to either under- or overestimation of the degree of stenosis, anatomic misclassification, and coronary artery segments that were not assessable at 64-section CT. Bland-Altman analysis showed poor agreement, especially for intermediate stenosis (mean bias, 1.3%; 95% limits of agreement: -27.3%, 29.9%). Despite excellent sensitivity and negative likelihood ratios in a per-patient or per-vessel analysis, some coronary artery stenosis remained misdiagnosed with 64-section CT, resulting in limited sensitivity on a per-segment basis owing to anatomic discordance and failure to accurately quantify intermediate stenosis.

Nondestructive Insights into Composition of the Sculpture of Egyptian Queen Nefertiti with CT

To assess the conservation status of, to gain information on the creation of, and to provide surface reformations of the core and the surface of the bust of the pharaoh-queen Nefertiti, considered to be one of the greatest treasures of ancient Egyptian art, with computed tomography (CT). Multisection CT was performed with 0.6-mm section thickness. Two- and three-dimensional reformations were made to depict the core and the surface separately. The stucco layer on the face and the ears was very thin, a maximum of 1-2 mm thick. The rear part of the reconstructed crown showed two thick stucco layers of different attenuation values, indicating that a multistep process was used to create the sculpture. Within the stucco, a great number of air-equivalent hypoattenuating areas, filamentous fissures parallel to the surface, and an inhomogeneous bonding between the layers were delineated. Nefertiti's inner face was not anonymous, but rather delicately sculpted by the royal sculptor Thutmose. The comparison to the outer face revealed differences, including the angles of the eyelids, creases around the corners of the mouth on the limestone surface, and a slight bump on the ridge of the nose. According to the beauty ideals of the Amarna period, the differences had positive and negative effects and can be read as signs of individualization of the sculpture. The potential material-related weaknesses of the sculpture that were revealed at imaging necessitate careful handling, with the avoidance of any focal pressure and shearing forces in the crown and the shoulders. CT imaging revealed construction techniques in Nefertiti's bust that had implications for conservation, as well as for an understanding of the artistic methods used in the creation of this masterpiece of art of the 18th dynasty.

Airway Dimensions at Inspiratory and Expiratory Multisection CT in Chronic Obstructive Pulmonary Disease: Correlation with Airflow Limitation

To analyze the relationship between airflow limitation and airway dimensions from the third to the fifth generation of bronchi in patients with chronic obstructive pulmonary disease (COPD) by using inspiratory and expiratory multisection computed tomography (CT). This retrospective study was approved by the institutional review board, which waived the need for informed consent. The study included 50 patients with COPD who underwent both inspiratory and expiratory 64-detector CT. In each patient, mean values of airway luminal areas from the third to the fifth generation of three bronchi (right B1, right B10, and left B3) were measured at inspiratory CT (IA3, IA4, and IA5) and expiratory CT (EA3, EA4, and EA5). To evaluate the change of the airway luminal area between inspiration and expiration, the ratio of expiratory to inspiratory airway luminal area in each generation was calculated (EA3/IA3, EA4/IA4, and EA5/IA5). Correlations between airway dimensions and pulmonary function test results were evaluated. The correlation coefficients between airway luminal area measured at expiratory CT and the forced expiratory volume in 1 second (FEV(1)) were higher than those for inspiratory CT and improved as the airway size decreased from the third to the fifth generation (IA3, r = .02; IA4, r = .18; IA5, r = .26; EA3, r = .09; EA4, r = .40; EA5, r = .63). EA5/IA5 had the highest correlations with FEV(1) (r = .72, P < .001). There were no significant correlations between EA3/IA3 and pulmonary function test results. Airway lumen measured at expiratory CT was more closely related to expiratory airflow measurements than was lumen measured at inspiratory CT. In addition, the changes of airway luminal area between inspiration and expiration were strongly related to airflow limitation.

Intraductal Papillary Mucinous Neoplasm of the Pancreas: Assessment of the Likelihood of Invasiveness with Multisection CT

To evaluate the capabilities of multisection computed tomography (CT) in determining the likelihood of invasiveness of intraductal papillary mucinous neoplasm (IPMN). The institutional review board approved this research and waived informed consent from the patients. Two radiologists blinded to the pathologic assessment of malignancy or parenchymal invasion of IPMN retrospectively evaluated CT images of 61 consecutive surgically resected tumors (26 adenomas, 15 noninvasive carcinomas, and 20 invasive carcinomas) in patients who underwent multiphase contrast material-enhanced CT with 0.5- or 1-mm collimation. The findings were statistically analyzed by using univariate and multivariate analyses, with the optimal cutoff levels of each continuous parameter determined by generating receiver operating characteristic curves. The following findings showed significant differences among the three groups: maximum diameter of the main pancreatic duct (MPD), size (length of major axis) of the largest mural nodule in the MPD or in any associated cystic lesion, abnormal attenuating area in the surrounding parenchyma, calcification in the lesion, protrusion of the MPD into the ampulla of Vater, and bile duct dilatation. An MPD diameter of 6 mm or larger, a mural nodule of 3 mm or larger, and an abnormal attenuating area were independently predictive of malignancy. A mural nodule of 6.3 mm or larger in the MPD and an abnormal attenuating area were independently predictive of parenchymal invasion. According to these criteria, the sensitivity, specificity, and accuracy for identifying malignancy were 83%, 81%, and 82% and for identifying parenchymal invasion were 90%, 88%, and 89%, respectively. Multisection CT is useful for distinguishing among adenoma, noninvasive carcinoma, and invasive carcinoma in patients with IPMN.

Diagnostic Performance of 16- and 64-Section Spiral CT for Coronary Artery Bypass Graft Assessment: Meta-Analysis

To perform a meta-analysis to evaluate the accuracy of 16- and 64-section spiral computed tomography (CT) to help assess coronary artery bypass grafts (CABGs). The MEDLINE, Cochrane library, and BioMed Central databases were searched for relevant original articles published up to May 2007. Major criteria for article inclusion were that it (a) used multisection CT as a diagnostic test for the assessment of significant lesions (occlusion or >50% stenosis) of CABG, (b) used a 16- or 64-section scanner, and (c) used coronary angiography as the reference standard. After data extraction, the analysis was performed according to a random-effects model. Between-study statistical heterogeneity was also assessed by using the Cochran Q chi(2) test. Of 158 screened articles, 15 fulfilled all inclusion criteria. Graft assessability (including distal anastomosis) ranged from 78%-100% among all included studies (mean, 92.4%; 90% with 16- and 96% with 64-section CT; P < .001). Statistical heterogeneity was observed for specificity and positive likelihood ratio (LR), justifying the use of the random-effects model. The analysis, pooled from 15 studies (723 patients, 2023 CABGs), provided the following results for the assessment of graft obstruction (occlusion and >50% stenosis): sensitivity, 97.6% (95% confidence interval [CI]: 96%, 98.6%); specificity, 96.7% (95% CI: 95.6%, 97.5%); positive predictive value, 92.7% (95% CI: 90.5%, 94.6%); negative predictive value, 98.9% (95% CI: 98.2%, 99.4%); positive LR, 23.42 (95% CI: 13.69, 40.07); negative LR, 0.045 (95% CI: 0.028, 0.071); and diagnostic odds ratio, 780.32 (95% CI: 379.12, 1606.1). Multisection CT provided high accuracy for the evaluation of CABG obstruction in assessable conduits, and might be used as a noninvasive tool for the evaluation of suspected graft dysfunction in patients who are at high risk for complications from coronary angiography.

The diagnosis and classification of inguinal and femoral hernia on multisection spiral CT

To assess the contribution of high-quality multiplanar reconstructions of the groin from multisection computed tomography (CT) to the accurate diagnosis of inguinal and femoral hernias. Twenty-eight patients who had undergone both a contrast-enhanced CT and a herniorrhaphy were identified from hospital records. Seventeen were excluded, as the images did not include the groin area. The remaining 11 images were re evaluated on a workstation without knowledge of the surgical findings and the hernias were identified and classified using the axial data and coronal and sagittal reconstructions. Anatomical structures and radiological details that hindered or aided this classification were recorded. Hernias were identified in nine out of the 11 patients. Of the seven inguinal hernias, six were identified with the correct side recorded in each case. Of the four patients with surgical data that distinguished direct from indirect inguinal hernias, the correct diagnosis was provided in all cases using CT. Of the four patients with a femoral hernia CT was used to correctly classify three. Among the three available planes, the axial was particularly poor for the identification of the inguinal ligament compared with the other planes. In contrast, the coronal views were very useful in the evaluation of femoral hernias. The high-resolution coronal and sagittal images available from multisection CT now permit the accurate diagnosis of groin hernias. Using simple anatomical criteria, direct and indirect inguinal hernias and femoral hernias can be reliably distinguished, abolishing the need for surrogate markers, which was hitherto necessary.

Coronary Arteries: Diagnostic Performance of 16- versus 64-Section Spiral CT Compared with Invasive Coronary Angiography—Meta-Analysis

To perform a meta-analysis to compare the diagnostic performance of 16- versus 64-section computed tomography (CT) for the diagnosis of coronary artery disease (CAD). The MEDLINE database was searched for relevant original articles. Criteria for inclusion of articles were (a) use of multisection spiral CT as a diagnostic test for obstructive CAD, (b) use of the newer generation of multisection spiral CT (16 or 64 section) scanners, and (c) use of coronary angiography as the reference standard for diagnosing obstructive CAD (>50% diameter stenosis was selected as the cutoff criterion for diagnosis of CAD). After data extraction, the analysis was performed according to a random-effects model. Between-study statistical heterogeneity also was assessed by using Cochran Q chi(2) tests. Of 328 identified relevant articles, 37 fulfilled all inclusion criteria, with data available for a patient-based analysis in 28. The patient-based analysis included pooled data from 16 studies, corresponding to 1292 patients who underwent 16-section spiral CT, and from 12 studies, corresponding to 695 patients who underwent 64-section spiral CT. Respectively, the results for 16-section CT versus 64-section CT were 95% (95% confidence interval [CI]: 93%, 96%) versus 97% (95% CI: 95%, 98%) for sensitivity (P = .03), 69% (95% CI: 66%, 73%) versus 90% (95% CI: 86%, 93%) for specificity (P < .001), 79% (95% CI: 76%, 82%) versus 93% (95% CI: 91%, 96%) for positive predictive value (PPV) (P < .001), 92% (95% CI: 88%, 94%) versus 96% (95% CI: 92%, 98%) for negative predictive value (P < .001), and 72.05 (95% CI: 31.35, 165.56) versus 181.82 (95% CI: 88.70, 372.71) for diagnostic odds ratio (P = .1). Sixty-four-section spiral CT has significantly higher specificity and PPV on a per-patient basis compared with 16-section CT for the detection of greater than 50% stenosis of coronary arteries. http://radiology.rsnajnls.org/cgi/content/full/2453061899/DC1.

Pulmonary Nodules: Interscan Variability of Semiautomated Volume Measurements with Multisection CT—Influence of Inspiration Level, Nodule Size, and Segmentation Performance

To prospectively assess the precision of semiautomated volume measurements of pulmonary nodules at low-dose multi-detector row computed tomography (CT) and to investigate the influence of nodule size, segmentation algorithm, and inspiration level. This study had institutional review board approval; written informed consent was obtained from all patients. Between June 2004 and March 2005, 20 patients (15 men, five women; age range, 40-84 years; mean age, 57 years) referred for chest CT for known lung metastases underwent two additional low-dose chest CT examinations without contrast material (collimation, 16 x 0.75 mm). Between these examinations, patients got off and on the table to simulate the conditions for a follow-up examination. Noncalcified solid pulmonary nodules between 15 and 500 mm(3) that did not abut vessel or pleura were measured in both studies by using widely applied commercial semiautomated software. Interscan variability was established with the Bland and Altman approach. The impact of nodule shape (spherical or nonspherical) on measurement variability was assessed by using one-way analysis of variance, while the contributions of mean nodule volume and change in lung volume were investigated with univariate linear regression for completely (group A) and incompletely (group B) segmented nodules. Two hundred eighteen eligible nodules (volume range, 16.4-472.7 mm(3); 106 spherical, 112 nonspherical) were evaluated. The 95% confidence interval for difference in measured volumes was -21.2%, 23.8% (mean difference, 1.3%). The precision of nodule segmentation was highly dependent on nodule shape (P < .001) and was weakly related to inspiration level for completely segmented nodules (r = -0.20; P < .047), while mean nodule volume did not show any effect (P = .15 and P = .81 for group A and B nodules, respectively). Variation of semiautomated volume measurements of pulmonary nodules can be substantial. Segmentation represents the most important factor contributing to measurement variability, while change in inspiration level has only a weak effect for completely segmented nodules.

Is It Possible to Recognize Pulmonary Infarction on Multisection CT Images?

To retrospectively determine sensitivity and specificity of four findings for distinguishing pulmonary infarction from other causes of peripheral pulmonary consolidations on multidetector computed tomographic (CT) images, with other CT and clinical findings as reference. Institutional review board approved the study and waived informed consent. Three independent radiologists blindly analyzed selected multisection CT images of 50 pulmonary infarctions-not showing direct arterial signs of pulmonary embolism-and 100 peripheral consolidations of other origins. Readers analyzed four findings: triangular shape, vessel sign (defined as presence of an enlarged vessel at the apex of consolidation), central lucencies, and air bronchograms. Interobserver agreement; frequency on CT images with and without infarct; and sensitivity, specificity, and positive likelihood ratio (LR) for diagnosis of pulmonary infarction were assessed for each finding. One hundred fifty peripheral consolidations were analyzed in 134 (75 men, 59 women) patients (mean age, 55.9 years+/-17.4 [standard deviation] vs 54.7+/-19.9; P=.71). Interobserver agreement was good for central lucencies and air bronchograms and poor to moderate for the other two findings (kappa<0.61). Compared with CT images without infarct, CT images with infarct had a higher frequency of vessel sign (32% [16 of 50] vs 11% [11 of 100], P=.029) and central lucencies (46% [23 of 50] vs 2% [two of 100], P<.001) and a lower frequency of air bronchograms (8% [four of 50] vs 40% [40 of 100], P=.003). Frequency of triangular shape was similar in both groups (52% [26 of 50] vs 40% [40 of 100], P=.17). Positive LR was 23.0 for central lucencies, 2.9 for vessel sign, 1.3 for triangular shape, and 0.2 for air bronchograms. Presence of central lucencies had 98% specificity and 46% sensitivity for pulmonary infarction. When the vessel sign and negative air bronchogram were combined with central lucencies, specificity increased to 99% but sensitivity decreased to 14%. Central lucencies in peripheral consolidations are highly suggestive of pulmonary infarction.