Size, shape and age-related changes of the mandibular condyle during childhood

Objective: To determine age-related differences in the size and shape of the mandibular condyle in children to establish anatomical reference values. Methods: A total of 420 mandibular condyles in 210 children (mean age, 7years) were retrospectively analysed by using computed tomography (CT) imaging. The greatest left-right (LRD) and anterior-posterior (APD) diameters and the anteversion angles (AA) were measured by two readers. An APD/LRD ratio was calculated. The shape of the condyles was graded into three types on sagittal images. Correlations of parameters with the children's age were assessed by using Pearson's correlation analyses. Results: The LRD (mean, 14.1 ± 2.4mm), APD (mean, 7.3 ± 1.0mm) and LRD/APD ratio (mean, 1.9 ± 0.3) increased (r LRD = 0.70, p < 0.01; r APD = 0.56, p < 0.01; r rat = 0.28, p < 0.01) while the AA (mean, 27 ± 7°) decreased significantly (r antang = −0.26, p < 0.001) with age. The condylar shape as determined on sagittal images correlated significantly with age (r = 0.69, p < 0.05). Boys had significantly higher anteversion angles (p < 0.01), greater LRDs (p < 0.05) and greater mean ratios (p < 0.05). Conclusion: The mandibular condyle is subject to significant age-related changes in size and shape during childhood. As the size of the condyles increases with age, the anteversion angles decrease and the shape of the condyle turns from round to ova

Radiation dose values for various coronary calcium scoring protocols in dual-source CT

Purpose The purpose of this study was to assess the radiation dose and associated image noise of previously suggested calcium scoring protocols using dual-source CT. Methods One hundred consecutive patients underwent coronary calcium scoring using dual-source CT. Patients were randomly assigned to five different protocols: retrospective ECG-gating and tube current reduction to 4% outside the pulsing window at 120 (protocol A) and 100kV (B), prospective ECG-triggering at 120 (C) and 100kV (D), and prospective ECG-triggering at 100kV with attenuation-based tube current modulation (E). Radiation dose parameters and image noise were determined and compared. Results Protocol A resulted in an effective dose of 1.3±0.2mSv, protocol B in 0.8±0.2mSv, protocol C in 1.0±0.2mSv, protocol D in 0.6±0.1mSv, and protocol E in 0.7±0.1mSv. Effective doses were significantly lower (P<0.001) with 100kV when compared to 120kV protocols, and were significantly lower (P<0.001) for prospective versus retrospective ECG-gating. No significant difference was found between protocol D and E. Significant negative correlations were found between the CTDIvol and heart rate for both retrospective ECG-gating protocols (protocol A: r=−0.98, P<0.001; protocol B: r=−0.83, P<0.001). The mean image noise was 29.0±6.7HU, with no significant differences between the five protocols. The image noise was significantly correlated with the body weight (r=0.21, P<0.05) and BMI (r=0.31, P<0.01). Conclusions Effective dose of calcium scoring using dual-source CT ranges from 0.6 to 1.3mSv. Prospective triggering and lower tube voltage significantly reduces the radiation but yield similar image nois

Systematic analysis on the relationship between luminal enhancement, convolution kernel, plaque density, and luminal diameter of coronary artery stenosis: a CT phantom study

To systematically investigate into the relationships between luminal enhancement, convolution kernel, plaque density, and stenosis severity in coronary computed tomography (CT) angiography. A coronary phantom including 63 stenoses (stenosis severity, 10-90%; plaque densities, −100 to 1,000HU) was loaded with increasing solutions of contrast material (luminal enhancement, 0-700HU) and scanned in an anthropomorphic chest. CT data was acquired with prospective triggering using 64-section dual-source CT; reconstructions were performed with soft-tissue (B26f) and sharp convolution kernels (B46f). Two blinded and independent readers quantitatively assessed luminal diameter and CT number of plaque using electronic calipers. Measurement bias between phantom dimensions and CT measurements were calculated. Multivariate linear regression models identified predictors of bias. Inter- and intra-reader agreements of luminal diameter and CT number measurements were excellent (ICCs>0.91, p200HU. Measurement bias was significantly (p<0.01, each) correlated (ρ=0.37-55 and ρ=−0.70-85) with the differences between luminal enhancement and plaque density. In multivariate models, bias of luminal diameter assessment with CT was correlated with plaque density (β=0.09, p<0.05). Convolution kernel (β=−0.29 and −0.38), stenosis severity (β=−0.45 and −0.38), and luminal enhancement (β=−0.11 and −0.29) represented independent (p<0.05,each) predictors of measurement bias of luminal diameter and plaque number, respectively. Significant independent relationships exist between luminal enhancement, convolution kernel, plaque density, and luminal diameter, which have to be taken into account when performing, evaluating, and interpreting coronary CT angiograph

In vivo identification of uric acid stones with dual-energy CT: diagnostic performance evaluation in patients

Background: To prospectively investigate the in vivo diagnostic performance of dual-energy (DE) computed tomography (CT) for the differentiation between uric acid (UA)-containing and non-UA-containing urinary stones. Methods: DE CT scans were performed in 180 patients with suspected urinary stone disease using a dual-source CT scanner in the DE mode (tube voltages 80 and 140kV). Urinary stones were classified as UA-containing or non-UA-containing based on CT number measurements and DE software results. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) for the detection of UA-containing urinary stones were calculated using the crystallographic stone analysis as the reference standard. Results: DE CT detected 110/180 patients (61%) with urinary stone disease. In 53 patients, stones were sampled. Forty-four out of 53 stones (83%) were non-UA-containing; and nine stones (17%) were UA-containing. The software automatically mapped 52/53 (98%) stones. One non-UA-containing stone (UA, 2mm) was missed; one UA-containing stone (3mm) was misclassified by software analysis. The sensitivity, specificity, PPV, and NPV for the detection of UA-containing stones was 89% (8/9, 95% CI: 52-100%), 98% (43/44, 95% CI: 88-100%), 89% (8/9, 95% CI: 52-100%), and 98% (43/44, 95% CI: 88-100%). Conclusion: Our results indicate that DE dual-source CT permits for the accurate in vivo differentiation between UA-containing and non-UA-containing urinary stone

Coronary artery plaques and myocardial ischaemia

Objective: To prospectively examine coronary artery plaques as predictors of myocardial ischaemia using cardiac magnetic resonance (CMR). Methods: Fifty-two patients (46 men; age 64 ± 10) with suspected coronary artery disease (CAD) referred for catheter coronary angiography (CA) underwent CMR and computed tomography coronary angiography (CTCA). All coronary segments were evaluated for morphological stenosis based on CA. Any plaque according to its composition was assessed based on CTCA. Results: Numbers of total and calcified coronary artery plaques represented the best predictors of myocardial ischaemia (AUC = 0.87; [95%CI: 0.77-0.97] and AUC = 0.87; [95%CI: 0.77-0.96], respectively, p = 0.56) with the total plaque number significantly higher in patients with corresponding ischaemia than those without (p < 0.01, p < 0.05 adjusted for pre-test probability and stenosis). Compared with the AUC of coronary stenosis assessment by CA (AUC = 0.90; [95%CI: 0.80-1.00]), AUCs were equivalent using either the total number or the number of calcified plaques alone (p = 0.73 and p = 0.69). Multivariate logistic regression analyses demonstrated the total plaque number as an independent predictor of ischaemia (odds +20%; [95%CI: 1.096-1.368]), improving a model including clinical probability estimates of CAD (c-statistics, 0.66 to 0.89). Conclusion: Coronary artery plaque number according to CTCA is a significant, independent predictor of myocardial ischaemia with similar accuracy to stenosis assessmen

Synovitis maps for the assessment of inflammatory diseases of the hand

Objectives: To compare accuracy and review times of FLASH-MRI-derived synovitis maps (SM) with conventional MR images (cMRI) in the assessment of articular synovitis and tenosynovitis of the hand. Methods: 80 hands in 40 patients (mean age, 48years; range, 15-72years) were assessed for synovitis on cMRI and SM by two readers independently. Reporting times and diagnostic confidence (scale: 1 = least, 5 = most confident) were measured. Results from an assessment of a panel of senior musculoskeletal radiologists served as the standard of reference. Results: Sensitivity and specificity for the detection of articular synovitis were 0.91/1.00 (R1) and 1.00/0.67 (R2) on cMRI and 0.87/0.75 (R1) and 0.91/0.45 (R2) on SM and for the detection of tenosynovitis 0.95/0.63 (R1) and 0.67/0.79 (R2) on cMRI and 0.67/0.89 (R1) and 0.38/1.00 (R2) on SM. Mean review times (cMRI/SM, sec) were 142/37 (R1) and 167/25 (R2). Mean diagnostic confidence (cMRI/SM) was 3.7/3.4 (R1) and 3.2/3.5 (R2) for articular synovitis and 4.0/4.0 (R1), 3.3/3.7 (R2) for tenosynovitis. Conclusion: Synovitis maps provide a comparable diagnostic accuracy to conventional MR images in the assessment of articular synovitis and tenosynovitis of the hand. Because of short review times, synovitis maps provide a fast overview of locations with synovial enhancemen

Prevalence and morphology of coronary artery ectasia with dual-source CT coronary angiography

To assess the prevalence and morphological characteristics of coronary artery ectasia (CAE) with CT coronary angiography (CTCA) in comparison to conventional catheterangiography (CCA). Dual-source CTCA examinations from 677 consecutive patients (223 women; median age 57years) were retrospectively evaluated by two blinded observers for the presence of CAE defined as a diameter enlargement ≥1.5 times the diameter of adjacent normal coronary segments. Vessel diameters and contrast attenuation within and proximal to ectatic segments were measured. CCA was used to compare measurements obtained from CTCA with the coronary flow velocity by using the thrombolysis in myocardial infarction (TIMI) frame count. CTCA identified CAE in 20 of 677 (3%) patients. CCA was performed in ten of these patients. CAE diameter measurements with CTCA (10.0 ± 5.4mm) correlated significantly (r = 0.92, p < 0.001) with the CCA measurements (8.8 ± 4.9mm), but had higher diameters (levels of agreement: −1.0 to 3.4mm). Contrast attenuation was significantly lower in the ectatic (343 ± 63 HU) than in the proximal (394 ± 60 HU) segments (p < 0.01). The attenuation difference significantly correlated with the CAE ratio (r = 0.67, p < 0.01) and the TIMI frame count (r = 0.58, p < 0.05). The prevalence of CAE in a population examined by CTCA is around 3%. Contrast attenuation measurements with CTCA correlate well with the flow alterations assessed with CC