[Treatment principles and outcome after fractures of the lateral humeral condyle in children]. / Therapieprinzipien und Outcome nach Frakturen des Condylus radialis im Wachstumsalter.

BACKGROUND: Fractures of the lateral humeral condyle with displacement (>2 mm; <2 mm articular gap) require open reduction and stabilization. Non-displaced fractures should be treated conservatively; however, there are difficulties in the differentiation of complete (potentially unstable) an incomplete (stable) articular fractures. The aim of this study was to analyze the frequency of conservative and operative treatment approaches as well as the accuracy of treatment decisions based on fracture stability displayed on repetitive X­rays. MATERIAL AND METHODS: A retrospective data analysis of all lateral humeral condyles in children <16 years old treated between 2005 and 2014 was carried out. The patients were classified according to the fracture stability at the time of the incident (primarily stable or unstable) and after 4 days (secondarily stable or unstable) using conventional X­ray images. RESULTS: A total of 89 fractures of the lateral humeral condyle were treated (mean age 6.4 years, range 0.9-14 years). Of the fractures 52 (58%) were initially not displaced and 37 (42%) were initially displaced. The latter underwent open reduction and stabilization by osteosynthesis (primarily stable). Of the 52 initially not displaced fractures 35 remained stable and conservative treatment in a plaster cast was performed (primarily and secondarily stable). In 8 out of 52 cases a secondary displacement (>2 mm articular gap) occurred after an average of 6 days (range 3-10 days) and operative treatment was initiated (primarily stable and secondarily unstable). No follow-up x­ray could be performed in 2 of the 52 fractures and at the end of treatment the fractures healed with displacement (primarily stable and secondarily unstable). In 7 of the 52 fractures operative treatment was performed although no displacement (primarily stable) was initially documented (overtreatment). The outcome of the whole study cohort was comparable with that described in the literature. CONCLUSION: Treatment decisions in pediatric lateral humeral condyle fractures are based on the primary and secondary fracture stability as observed in staged follow-up radiographs. Stable fractures, whether complete or incomplete, healed with good results after conservative treatment and overtreatment could be avoided. Unstable fractures, whether primary or secondary during the course, need to be recognized as such and operative treatment with a stable osteosynthesis must be initiated.

Coronary and carotid atherosclerosis in asymptomatic male marathon runners.

The aim of the study was to evaluate the diagnostic accuracy of carotid ultrasound (CU) to predict coronary atherosclerosis in asymptomatic male marathon runners. A total of 49 male marathon runners older than 45 years (mean age 53.3 ± 7.2 years, range 45-74 years) received CU and cardiac CT angiography (CTA) including calcium scoring (CS). Results of CU and CTA were classified binary: 1. Absence of atherosclerosis and 2. Presence of atherosclerosis. The extent of atherosclerosis was not primary end point of the study. Mean PROCAM score was 2.3% (SD 2.2, range 0.44%-12.34%). One person had to be excluded from analysis (one missing CT-scan). From the remaining 48 marathon runners, 17 (35.4%) had carotid atherosclerosis and 22 (45.8%) coronary atherosclerosis. Atherosclerosis in either exam was diagnosed in 27/48 (56.3%) marathon runners. Diagnostic accuracy of CU to predict coronary atherosclerosis was: sensitivity 54.55% (95% CI 32.2-75.6), specificity 80.8% (CI 60.6-93.4), positive predictive value 70.6 (CI 44.1-89.9), negative predictive value 67.7 (CI 48.6-83.3) with a positive likelihood ratio of 2.84 (CI 1.18-6.82) and a negative likelihood ratio of 0.56 (CI 0.34-0.92). Coronary and/or carotid atherosclerosis can be detected in more than 50% of male marathon runners aged older than 45 years. The diagnostic value of carotid ultrasound to predict coronary atherosclerosis is low but higher than the accuracy of rest- or stress-ECG. As outcome studies in sportsmen are still missing, the routine evaluation of the carotid arteries by ultrasound or even cardiac CT cannot be recommended at present. Furthermore, the incidence of atherosclerosis by our method in normal population is not known.

Clinically relevant variations of the superior thyroid cornu.

PURPOSE: The superior thyroid cornu (STC) of the thyroid cartilage is a variable structure that maybe associated with different clinical symptoms. This study evaluates the three-dimensional anatomy of the STC. METHODS: Measurements were conducted on 97 CT scans (45 male and 52 female). The protocol models a vector from the base to the tip of the STC and references the cornu to the midline. From these data, the length (C), the rotation angle (γ), the inclination angle (ß), and the deviation of STC base (X 2) and tip (X 3) from the midline were measured. An additional measure of the medial inclination quotient (Q = X 3/X 2) was calculated. RESULTS: The STC has a mean length of 13.9 ± 3.26 mm. The male STC is more bent inwards (rotation angle (γ) 60.95° vs. 12.15°; p < 0.001), and the female STC is more steep (inclination angle (ß) 75.44° vs. 73.44°; p < 0.001). The mean Q in men was significantly lower (0.85 ± 0.15 vs. 0.97 ± 0.15; p < 0.001). An extreme medial deformation was found in 13.4 % of the patients. This variation is associated with Q ≤ 0.7, most of the time unilateral and more common in men (86.7 vs. 13.3 %). Furthermore, we can describe STC variations with close proximity to the common carotid artery or the cervical spine. CONCLUSIONS: The clinically most relevant variation of the STC seems to be the extreme medial deviation, which may lead to symptoms described with the superior thyroid cornu syndrome. The evaluation of Q in axial CT scans is easily done and may propose a helpful tool for clinical diagnostics.

[Strategies for paediatric spleen and liver injuries]. / Behandlungsstrategien bei Verletzungen von Milz und Leber im Kindesalter.

Traumatic injuries of the spleen and liver are typically caused by age-related falls or sports and traffic accidents. Today, the non-operative management for isolated injuries is established and evidence-based guidelines are available. The intact abdominal wall and the limited space within the peritoneum produce a compression which is the pathophysiological explanation for the limitation of the haemorrhage. Precondition for the non-operative therapy is the radiology-based classification of the injury (organ injury scale) and a haemodynamically stable patient. Haemodynamic stability is, if necessary maintained with blood transfusion, volume substitutes and the administration of catecholamines. In cases of hilar vascular injury and devascularisation or haemodynamic instability of the patient, despite utilisation of the measures mentioned above, urgent operative therapy needs to be performed. Organ sparing surgery is the therapy of choice for both liver and spleen. The spleen is required for the development of a competent immune system in the growing organism. Liver injuries can be further complicated by injury to the bile system, which might require operative reconstruction. If a patient suffers from multiple injuries and spleen or liver are involved, the decision on the management needs to be taken individually, no guidelines exist but the rate for operative therapy increases. Independent of the dimensions of injury, an experienced paediatric surgeon with his multidisciplinary team, considering the anatomic and age specific characteristics of a child, achieves the best therapeutic results.

Dual-energy CT for the characterization of urinary calculi: In vitro and in vivo evaluation of a low-dose scanning protocol.

The efficiency and radiation dose of a low-dose dual-energy (DE) CT protocol for the evaluation of urinary calculus disease were evaluated. A low-dose dual-source DE-CT renal calculi protocol (140 kV, 46 mAs; 80 kV, 210 mAs) was derived from the single-energy (SE) CT protocol used in our institution for the detection of renal calculi (120 kV, 75 mAs). An Alderson-Rando phantom was equipped with thermoluminescence dosimeters and examined by CT with both protocols. The effective doses were calculated. Fifty-one patients with suspected or known urinary calculus disease underwent DE-CT. DE analysis was performed if calculi were detected using a dedicated software tool. Results were compared to chemical analysis after invasive calculus extraction. An effective dose of 3.43 mSv (male) and 5.30 mSv (female) was measured in the phantom for the DE protocol (vs. 3.17/4.57 mSv for the SE protocol). Urinary calculi were found in 34 patients; in 28 patients, calculi were removed and analyzed (23 patients with calcified calculi, three with uric acid calculi, one with 2,8-dihyxdroxyadenine-calculi, one patient with a mixed struvite calculus). DE analysis was able to distinguish between calcified and non-calcified calculi in all cases. In conclusion, dual-energy urinary calculus analysis is effective also with a low-dose protocol. The protocol tested in this study reliably identified calcified urinary calculi in vivo.

Characterization of coronary atherosclerosis by dual-source computed tomography and HU-based color mapping: a pilot study.

To assess HU-based color mapping for characterization of coronary plaque, using intravascular ultrasound virtual histology (IVUS-VH) as a standard of reference. Dual-source computed tomography and IVUS-VH were prospectively performed in 13 patients. In five lesions, HU thresholds of the color-coding software were calibrated to IVUS-VH. In a 15-lesion verification cohort, volumes of vessel, lumen and plaque or percentages of lipid, fibrous and calcified components were obtained through use of pre-set HU cut-offs as well as through purely visual adjustment of color maps. Calibrated HU ranges for fatty or fibrous plaque, lumen and calcification were -10-69, 70-158, 159-436 and 437+. Using these cut-offs, HU-based analysis achieved good agreement of plaque volume with IVUS (47.0 vs. 51.0 mm(3)). Visual segmentation led to significant overestimation of atheroma (61.6 vs. 51.0 mm(3); P = 0.04) Correlation coefficients for volumes of vessel, lumen and plaque were 0.92, 0.87 and 0.83 with HU-based analysis or 0.92, 0.85 and 0.71 with visual evaluation. With both methods, correlation of percentage plaque composition was poor or insignificant. HU-based plaque analysis showed good reproducibility with intra-class correlation coefficients being 0.90 for plaque volume and 0.81, 0.94 or 0.98 for percentages of fatty, fibrous or calcified components. With use of optimized HU thresholds, color mapping allows for accurate and reproducible quantification of coronary plaque.

Noninvasive coronary angiography using 64-slice spiral computed tomography in an unselected patient collective: effect of heart rate, heart rate variability and coronary calcifications on image quality and diagnostic accuracy.

OBJECTIVE: The aim of this study was to assess the impact of heart rate, heart rate variability and calcification on image quality and diagnostic accuracy in an unselected patient collective. SUBJECTS AND METHODS: One hundred and two consecutive patients with known or suspected coronary artery disease underwent both 64-MSCT and invasive coronary angiography. Image quality (IQ) was assessed by independent observers using a 4-point scale from excellent (1) to non-diagnostic (4). Accuracy of MSCT regarding detection or exclusion of significant stenosis (>50%) was evaluated on a per segment basis in a modified AHA 13-segment model. Effects of heart rate, heart rate variability, calcification and body mass index (BMI) on IQ and accuracy were evaluated by multivariate regression. IQ and accuracy were further analysed in subgroups of significant predictor variables and simple regression performed to calculate thresholds for adequate IQ. RESULTS: Mean heart rate was 68.2+/-13.3 bpm, mean heart rate variability 11.5+/-16.0 beats per CT-examination (bpct) and median Agatston score 226.5. Average IQ score was 2+/-0.6 whilst diagnostic quality was obtained in 89% of segments. Overall sensitivity, specificity, PPV or NPV was 91.2%, 99.2%, 95.3% or 98.3%. According to multivariate regression, overall IQ was significantly related to heart rate and calcification (P=0.0038; P<0.0001). The effect of heart rate variability was limited to IQ of RCA segments (P=0.018); BMI was not related to IQ (P=0.52). Calcification was the only predictor variable with significant effect on the number of non-diagnostic segments (P<0.0001). In a multivariate regression, calcification was also the single factor with impact on diagnostic accuracy (P=0.0049). CONCLUSION: Whilst heart rate, heart rate variability and calcification all show an inverse correlation to IQ, severe calcium burden remains the single factor with translation of such effect into decrease of diagnostic accuracy.

Prevalence of Subclinical Coronary Artery Disease in Middle-Aged, Male Marathon Runners Detected by Cardiac CT.

PURPOSE: To evaluate the prevalence of coronary artery disease (CAD) in middle-aged, male marathon runners using coronary dual source CT angiography (DSCTA). MATERIALS AND METHODS: 50 male marathon runners older than 45 years (mean age: 52.7, standard deviation: 5.9 years, range: 45 to 67 years) received DSCTA including calcium scoring (CS) in addition to standard pre-participation screening. Based on standard risk factors, the risk for coronary events was calculated using the PROCAM score. Coronary status was defined using the following system: 1. absence of CAD (CS zero, no coronary plaques) 2. mild coronary atherosclerosis (CS > 0, coronary plaques with luminal narrowing < 50 %), 3. moderate coronary atherosclerosis (CS > 0, luminal narrowing > 50 %), 4. significant CAD (CS > 0, luminal narrowing > 75 %). RESULTS: The mean PROCAM score was 1.85 % (standard deviation = 1.56, range 0.39 to 8.47 %). 26/50 marathon runners had no atherosclerosis. 1 of the remaining 24 participants had significant CAD, 3 had moderate coronary atherosclerosis and 20 had mild coronary atherosclerosis. Treadmill exercise testing was unremarkable in terms of myocardial ischemia in all participants. Age, systolic blood pressure, personal minimum time, family history of cardiovascular disease and PROCAM score were factors associated with an increased risk for coronary atherosclerosis. CONCLUSION: Coronary atherosclerosis can be detected in almost 50 % of male marathon runners aged older than 45 years. In 24 % of the participants plaques were located in the proximal coronary system. However, only a minority of these persons have obstructive CAD. As expected, treadmill exercise testing failed to detect these persons that possibly have a higher risk for coronary events. KEY POINTS: • Coronary atherosclerosis can be detected in ~50 % of male marathon runners > 45 years. • Only a minority of these persons have obstructive CAD. • Treadmill exercise testing failed to detect these persons. • Cardiac CT might help to identify athletes with elevated risk for coronary events, especially in persons with a family history of coronary artery.

Dynamic MR urography in children with uropathic disease with a combined 2D and 3D acquisition protocol--comparison with MAG3 scintigraphy.

OBJECTIVE: The aim of this study was to evaluate combined two-dimensional (2D) and three-dimensional (3D) dynamic MR urography with respiratory compensation in children with anomalies of the genitourinary tract, allowing for computation of split renal function and assessment of urinary tract obstruction. METHODS: Dynamic MR urography was performed in 53 children (3 months-16 years of age) with anomalies of the urinary tract. A protocol for dynamic MR urography and nephrography was implemented at 1.5 T using a navigator-triggered 2D TurboFLASH sequence. Split renal function and contrast-medium excretion were assessed after the bolus injection of 0.05 mmol kg(-1) body weight of gadolinium dimeglumine. In the excretory phase, a 3D gradient-echo data set with high spatial resolution was acquired. In all patients, mercaptoacetyltriglycine (MAG3) scintigraphy was obtained as a reference standard. RESULTS: In all children, dynamic MR nephrography and urography could be performed with excellent compensation of breathing artefacts providing region of interest analysis in nearly identical kidney positions. The assessment of contrast-medium excretion into the ureter allowed for discrimination of functional from non-functional stenosis. Split renal function assessed by MRI showed an excellent agreement with the MAG3 reference standard with a correlation coefficient r = 0.95. Additionally recorded 3D data sets offered good depiction of anatomical anomalies in all patients. CONCLUSION: The proposed protocol provides a robust technique for assessment of ureteral obstruction and split renal function with compensation of breathing artefacts, short post-processing time and excellent 3D spatial resolution. ADVANCES IN KNOWLEDGE: The combined protocol of 2D and 3D MR urography is an efficient technique for assessment of renal morphology and function.

High-pitch computed tomography of the lung in pediatric patients: an intraindividual comparison of image quality and radiation dose to conventional 64-MDCT.

PURPOSE: The aim of this study was to investigate frequencies of typical artifacts in low-dose pediatric lung examinations using high-pitch computed tomography (HPCT) compared to MDCT, and to estimate the effective radiation dose (Eeff). MATERIALS AND METHODS: Institutional review board approval for this retrospective study was obtained. 35 patients (17 boys, 18 girls; mean age 112 ±â€Š69 months) were included and underwent MDCT and follow-up scan by HPCT or vice versa (mean follow-up time 87 days), using the same tube voltage and current. The total artifact score (0 - 8) was defined as the sum of artifacts arising from movement, breathing or pulsation of the heart or pulmonary vessels (0 - no; 1 - moderate; 2 - severe artifacts). Eeff was estimated according to the European Guidelines on Quality Criteria for Multislice Computed Tomography. The Mann-Whitney U test was used to analyze differences between the patient groups. The Spearman's rank correlation coefficient was used for correlation of ordinal variables. RESULTS: The scan time was significantly lower for HPCT compared to MDCT (0.72 ±â€Š0.13 s vs. 3.65 ±â€Š0.81s; p < 0.0001). In 28 of 35 (80 %) HPCT examinations no artifacts were visible, whereas in MDCT artifacts occurred in all examinations. The frequency of pulsation artifacts and breathing artifacts was higher in MDCT compared to HPCT (100 % vs. 17 % and 31 % vs. 6 %). The total artifact score significantly correlated with the patient's age in MDCT (r = - 0.42; p = 0.01), but not in HPCT (r = - 0.32; p = 0.07). The estimated Eeff was significantly lower in HPCT than in MDCT (1.29 ±â€Š0.31 vs. 1.47 ±â€Š0.37 mSv; p < 0.0001). CONCLUSION: Our study indicates that the use of HPCT has advantages for pediatric lung imaging with a reduction of breathing and pulsation artifacts. Moreover, the estimated Eeff was lower. In addition, examinations can be performed without sedation or breath-hold without losing image quality. KEY POINTS: • Fewer artifacts in pediatric lung imaging with HPCT• Reduced Eeff in HPCT• HPCT without sedation or breath-hold without loss of image quality.

Estimation of radiation exposure of prospectively triggered 128-slice computed tomography coronary angiography.

PURPOSE: To estimate the effective dose of prospectively triggered computed tomography coronary angiography (CTCA) in step-and-shoot (SAS) mode, depending on the tube current and tube voltage modulation. MATERIALS AND METHODS: For dose measurements, an Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to ICRP 103. Exposure was performed on a 128-slice single source scanner providing a collimation of 128 × 0.6 mm and a rotation time of 0.38 seconds. CTCA in the SAS mode was acquired with variation of the tube current (160, 240, 320 mAs) and tube voltage (100, 120, 140 kV) at a simulated heart rate of 60 beats per minute and a scan range of 13.5 cm. RESULTS: Depending on gender, tube current and tube voltage, the effective dose of a CTCA in SAS mode varies from 2.8 to 10.8 mSv. Due to breast tissue in the primary scan range, exposure in the case of females showed an increase of up to 60.0 ± .4% compared to males. The dose reduction achieved by a reduction of tube current showed a significant positive, linear correlation to effective dose with a possible decrease in the effective dose of up to 60.4% (r = 0.998; p = 0.044). Disproportionately high, the estimated effective dose can be reduced by using a lower tube voltage with a dose reduction of up to 52.4%. CONCLUSION: Further substantial dose reduction of low-dose CTCA in SAS mode can be achieved by adapting the tube current and tube voltage and should be implemented in the clinical routine, i. e. adapting those protocol parameters to patient body weight.

Automatic bone and plaque removal using dual energy CT for head and neck angiography: feasibility and initial performance evaluation.

PURPOSE: We sought to evaluate the feasibility and efficiency of dual energy (DE) bone and plaque removal in head and neck CT angiography. MATERIALS AND METHODS: 20 patients with suspected carotid stenoses received head and neck DE-CTA as part of their pre-interventional workup. Visual grading using multiplanar reformations (MPR), thick slab maximum intensity projections (MIP) and quantitative vessel analysis (QVA) of stenoses was performed prior and after DE bone removal. Results were evaluated for the detection of relevant stenoses (vessel area reduction >70%). Vessel segmentation errors were analyzed. RESULTS: Segmentation errors occurred in 19% of all vessel segments. Nevertheless, most post-bone removal artifacts could be recognized using the MPR technique for reading. Compared to MPR reading prior to bone removal, sensitivity, specificity, positive and negative predictive values after bone removal were 100%, 98%, 88% and 100% for MPR reading and 100%, 91%, 63% and 100% for exclusive MIP reading, respectively. There was a good agreement between the QVA results prior and post-DE plaque removal (r(2)=0.8858). CONCLUSION: DE bone and plaque removal for head and neck angiography is feasible and offers a rapid and highly sensitive overview over vascular head and neck studies. Due to a slightly limited specificity of the MIP technique due to segmentation errors, possible stenoses should be verified and graded using MPR techniques.

Image quality analysis to reduce dental artifacts in head and neck imaging with dual-source computed tomography.

PURPOSE: Important oropharyngeal structures can be superimposed by metallic artifacts due to dental implants. The aim of this study was to compare the image quality of multiplanar reconstructions and an angulated spiral in dual-source computed tomography (DSCT) of the neck. MATERIALS AND METHODS: Sixty-two patients were included for neck imaging with DSCT. MPRs from an axial dataset and an additional short spiral parallel to the mouth floor were acquired. Leading anatomical structures were then evaluated with respect to the extent to which they were affected by dental artifacts using a visual scale, ranging from 1 (least artifacts) to 4 (most artifacts). RESULTS: In MPR, 87.1 % of anatomical structures had significant artifacts (3.12 +/- 0.86), while in angulated slices leading anatomical structures of the oropharynx showed negligible artifacts (1.28 +/- 0.46). The diagnostic growth due to primarily angulated slices concerning artifact severity was significant (p < 0.01). CONCLUSION: MPRs are not capable of reducing dental artifacts sufficiently. In patients with dental artifacts overlying the anatomical structures of the oropharynx, an additional short angulated spiral parallel to the floor of the mouth is recommended and should be applied for daily routine. As a result of the static gantry design of DSCT, the use of a flexible head holder is essential.