[Radiological diagnosis of apophyseal injuries of the pelvic region]. / Radiologische Diagnostik von Apophysenverletzungen der Beckenregion.

Avulsion injuries of the pelvis are common sports-related findings in skeletally immature adolescent patients. They usually present as an avulsion of the unfused apophysis, resulting from forced muscular contraction during typical athletic movements or from chronic traction injuries. Acute apophyseal avulsion injuries are usually easily detected with radiography. Occasionally, advanced imaging such as ultrasound or magnetic resonance imaging is required in order to detect or fully assess the extent of injury. Chronic injuries can mimic aggressive entities, such as neoplasms and may thus cause difficulties in differential diagnosis. Profound knowledge of typical locations of apophyseal tendon attachment sites at the osseous pelvis and correct interpretation of imaging findings can facilitate accurate diagnosis. This article discusses the clinical and radiological findings of pelvic apophyseal avulsion injuries in pediatric patients and highlights potential complications and differential diagnoses.

Are patient and relationship variables associated with participation of intimate partners in couples research?

BACKGROUND: Recruitment of participants for studies focusing on couples facing illness is a challenging task and participation decline may be associated with nonrandom factors creating bias. This study examines whether patient and relationship characteristics are associated with partner participation in research. METHOD: Patients invited to participate in a cross-sectional study on adaptation and quality of life after renal transplantation were asked to forward information about an add-on study to their partners. RESULTS: A total of 456 participating patients had a partner; 293 of the partners showed interest in the study and 206 actually completed the questionnaire. Backward logistic regression analyses revealed that demographic, illness, and personal characteristics of the patient were not associated with partner interest in the study nor actual partner participation. However, partners who indicated interest in the study showed more active engagement toward the patients (as reported by the patients). Furthermore, patients of partners who actually completed the questionnaire reported less negative affect and higher relationship satisfaction than patients whose partner did not participate in the study. DISCUSSION: It is encouraging that of the large number of variables tested, only 2 were associated with the participation of partners. Nevertheless, well-functioning couples appear to be overrepresented in our study, calling for specific effort to include marital distressed couples in research focusing on dyadic adaptation to illness.

Image quality and radiation exposure with prospectively ECG-triggered axial scanning for coronary CT angiography: the multicenter, multivendor, randomized PROTECTION-III study.

OBJECTIVES: The purpose of this study was to evaluate image quality and radiation dose using a prospectively electrocardiogram (ECG)-triggered axial scan protocol compared with standard retrospective ECG-gated helical scanning for coronary computed tomography angiography. BACKGROUND: Concerns have been raised regarding radiation exposure during coronary computed tomography angiography. Although the use of prospectively ECG-triggered axial scan protocols may effectively lower radiation dose compared with helical scanning, it is unknown whether image quality is maintained in a clinical setting. METHODS: In a prospective, multicenter, multivendor trial, 400 patients with low and stable heart rates were randomized to either an axial or a helical coronary computed tomography angiography scan protocol. The primary endpoint was to demonstrate noninferiority in image quality with the axial scan protocol, which was assessed on a 4-point scale (1 = nondiagnostic, 4 = excellent image quality). Secondary endpoints included radiation dose and the rate of downstream testing during 30-day follow-up. RESULTS: Image quality in patients scanned with the axial scan protocol (score 3.36 ± 0.59) was not inferior compared with helical scan protocols (3.37 ± 0.59) (p for noninferiority <0.004). Axial scanning was associated with a 69% reduction in radiation exposure (dose-length product [estimated effective dose] 252 ± 147 mGy · cm [3.5 ± 2.1 mSv] vs. 802 ± 419 mGy · cm [11.2 ± 5.9 mSv] for axial vs. helical scan protocols, p < 0.001). The rate of downstream testing did not differ (13.8% vs. 15.9% for axial vs. helical scan protocols, p = 0.555). CONCLUSIONS: In patients with stable and low heart rates, the prospectively ECG-triggered axial scan protocol maintained image quality but reduced radiation exposure by 69% compared with helical scanning. Axial computed tomography data acquisition should be strongly recommended in suitable patients to avoid unnecessarily high radiation exposure.

Prognostic value of coronary computed tomographic angiography in patients with arterial hypertension.

Patients with arterial hypertension have a high risk of developing coronary artery disease (CAD), but noninvasive diagnosis of CAD remains difficult. We assessed the ability of coronary CT angiography (CCTA) to detect CAD and to predict subsequent cardiac events in hypertensive patients. We compared 906 hypertensive patients without known CAD undergoing CCTA with 906 matched normotensive patients. Besides calcium score and the degree of the most severe stenosis, the number of coronary segments with atherosclerotic changes was recorded. The primary endpoint was the occurrence of hard cardiac events defined as all cause death, nonfatal myocardial infarction or unstable angina requiring hospitalization. During a median follow-up of 29 months, there were 17 hard cardiac events in the hypertensive group and 13 events in the control group. The best predictor of events in hypertensive patients was the degree of the most severe stenosis (C-index 0.705, P < 0.001, both corrected for clinical risk). The annual event rate was 0.3% for patients without obstructive CAD and 1.5% for patients with obstructive CAD. In hypertensive patients without known CAD, coronary CT angiography allows for the identification of patients at high risk for incident cardiac events.

Prognostic value of coronary computed tomographic angiography in comparison with calcium scoring and clinical risk scores.

BACKGROUND: Several studies have demonstrated a high accuracy of coronary computed tomography angiography (CCTA) for detection of obstructive coronary artery disease (CAD), whereas some studies have also shown a good prediction of cardiac events. However, it remains to be proven whether CCTA is better predictive of events than conventional risk scores or calcium scoring. Therefore, we compared CCTA with calcium scoring and clinical risk scores for the ability to predict cardiac events. METHODS AND RESULTS: Patients (n=2223) with suspected CAD undergoing CCTA were followed up for a median of 28 months. The end point was the occurrence of cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and coronary revascularization later than 90 days after CCTA). Patients with obstructive CAD had a significantly higher event rate (2.9% per year; 95% confidence interval, 2.1 to 4.0) than those without obstructive CAD, having an event rate 0.3% per year (95% confidence interval, 0.1 to 0.5; hazard ratio, 13.5; 95% confidence interval, 6.7 to 27.2; P<0.001). CCTA had significant incremental predictive value when compared with calcium scoring, both with scores assessing the degree of stenosis (P<0.001) and with scores assessing the number of diseased coronary segments (P=0.027). CONCLUSIONS: In patients with suspected CAD, CCTA not only detects coronary stenosis but also improves prediction of cardiac events over and above conventional risk scores and calcium scoring. This may result in a reclassification of cardiovascular risk in a substantial proportion of patients.

Image quality and radiation exposure with a low tube voltage protocol for coronary CT angiography results of the PROTECTION II Trial.

OBJECTIVES: The purpose of this study was to evaluate image quality and radiation dose using a 100 kVp tube voltage scan protocol compared with standard 120 kVp for coronary computed tomography angiography (CTA). BACKGROUND: Concerns have been raised about radiation exposure during coronary CTA. The use of a 100 kVp tube voltage scan protocol effectively lowers coronary CTA radiation dose compared with standard 120 kVp, but it is unknown whether image quality is maintained. METHODS: We enrolled 400 nonobese patients who underwent coronary CTA: 202 patients were randomly assigned to a 100 kVp protocol and 198 patients to a 120 kVp protocol. The primary end point was to demonstrate noninferiority in image quality with the 100 kVp protocol, which was assessed by a 4-point grading score (1 = nondiagnostic, 4 = excellent image quality). For the noninferiority analysis, a margin of -0.2 image quality score points for the difference between both scan protocols was pre-defined. Secondary end points included radiation dose and need for additional diagnostic tests during follow-up. RESULTS: The mean image quality scores in patients scanned with 100 kVp and 120 kVp were 3.30 ± 0.67 and 3.28 ± 0.68, respectively (p = 0.742); image quality of the 100 kVp protocol was not inferior, as demonstrated by the 97.5% confidence interval of the difference, which did not cross the pre-defined noninferiority margin of -0.2. The 100 kVp protocol was associated with a 31% relative reduction in radiation exposure (dose-length product: 868 ± 317 mGy × cm with 120 kVp vs. 599 ± 255 mGy × cm with 100 kVp; p < 0.0001). At 30-day follow-up, the need for additional diagnostic studies did not differ (13.4% vs. 19.2% for 100 kVp vs. 120 kVp, respectively; p = 0.114). CONCLUSIONS: A coronary CTA protocol using 100 kVp tube voltage maintained image quality, but reduced radiation exposure by 31% as compared with the standard 120 kVp protocol. Thus, 100 kVp scan protocols should be considered for nonobese patients to keep radiation exposure as low as reasonably achievable. (Prospective Randomized Trial on Radiation Dose Estimates of Cardiac CT Angiography in Patients Scanned With a 100 kVp Protocol [PROTECTION II]; NCT00611780).

Prognostic value of coronary computed tomographic angiography in asymptomatic patients.

To assess the value of coronary computed tomographic angiography (CCTA) in the prediction of cardiac events in asymptomatic patients, 451 consecutive asymptomatic patients who underwent CCTA from December 2003 to November 2007 were retrospectively analyzed. The primary end point of the study was the occurrence of cardiac events, defined as cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and late revascularization (>90 days after CCTA) during a median follow-up period of 27.5 months. Secondary end points were the prevalence of nonobstructive coronary lesions and the number of patients reclassified regarding their cardiovascular risk. Two hundred twenty-nine patients (54%) had nonobstructive coronary lesions, and 107 patients (24%) obstructive coronary artery disease. During follow-up, there were 2 cases of unstable angina and 8 revascularizations for stable angina. Patients with obstructive coronary artery disease had a significantly higher event rate than those without obstructive CAD (risk ratio 13.9, 95% confidence interval 4.0 to 48.0). In 217 patients (48%), the clinically assessed cardiovascular risk could be reclassified by CCTA from intermediate or high to low risk. In conclusion, although the event rate was low in asymptomatic patients, CCTA could reliably predict further cardiac events and could reclassify 2/3 of patients regarding their cardiovascular risk.

Comparison of sequential and helical scanning for radiation dose and image quality: results of the Prospective Multicenter Study on Radiation Dose Estimates of Cardiac CT Angiography (PROTECTION) I Study.

OBJECTIVE: Concerns have been raised about the radiation exposure of coronary CT angiography (CTA). Recently, a prospective ECG-triggered sequential coronary CTA technique was developed to reduce exposure to ionizing radiation. The purpose of this analysis was to determine the impact of a sequential scanning technique on image quality and radiation dose in a prespecified subgroup analysis of the Prospective Multicenter Study on Radiation Dose Estimates of Cardiac CT Angiography I (PROTECTION I) Study when compared with a standard helical scanning technique. MATERIALS AND METHODS: This analysis comprises 685 64-MDCT coronary angiography studies of 47 international study sites in which the image quality was assessed by an experienced coronary CTA investigator using a 4-point score (1 = nondiagnostic, 4 = excellent image quality). Image quality was analyzed in all patients studied with the sequential scanning mode (n = 99) and in randomly selected patients of the population studied with the helical acquisition mode (n = 586). Radiation dose estimates were derived from the dose-length product (DLP) and a conversion coefficient for the chest (0.014 mSv x mGy(-1) x cm(-1)). RESULTS: Although the sequential scanning mode significantly reduced radiation dose estimates by 68% from 11.2 mSv for the helical mode to 3.6 mSv for the sequential mode (p < 0.001), the median diagnostic image quality scores were comparable in both groups. The median diagnostic score for both scanning modes was 3.5 (interquartile range: sequential vs helical mode, 3.25-3.75 vs 3.0-3.75, respectively; p = 0.62). CONCLUSION: The results of the PROTECTION I Study suggest that the prospective ECG-triggered sequential coronary CTA technique significantly reduces radiation dose without impairing image quality when compared with the standard retrospective helical data acquisition in patients with a low and stable heart rate.

Prognostic value of coronary computed tomographic angiography in diabetic patients without known coronary artery disease.

OBJECTIVE: Diabetic patients have a high prevalence of coronary artery disease (CAD), but timely diagnosis of CAD remains challenging. We assessed the ability of coronary computed tomography angiography (CCTA) to detect CAD in diabetic patients and to predict subsequent cardiac events. RESEARCH DESIGN AND METHODS: We analyzed 140 diabetic patients without known CAD undergoing CCTA; 1,782 patients without diabetes were used as a control group. Besides calcium scoring and the degree of the most severe stenosis, the atherosclerotic burden score counting the number of segments having either a nonstenotic plaque or a stenosis was recorded. The primary end point was a composite of hard cardiac events defined as all-cause death, nonfatal myocardial infarction, or unstable angina requiring hospitalization. RESULTS: During a mean follow-up of 33 months, there were seven events in the diabetic group and 24 events in the control group. The best predictor in diabetic patients was the atherosclerotic burden score: the annual event rate ranged from 0.5% for patients with <5 lesions to 9.6% for patients with >9 lesions, resulting in a hazard ratio (HR) of 1.3 (95% CI 1.1-1.7) for each additional lesion (P = 0.005). For comparison, in nondiabetic patients the annual event rate ranged from 0.3 to 2.2%, respectively, resulting in an HR of 1.2 (95% CI 1.1-1.3, P < 0.001). The atherosclerotic burden score improved the prognostic value of conventional risk factors significantly (P < 0.001). CONCLUSIONS: In diabetic patients without known CAD, CCTA can identify a patient group at particularly high risk for subsequent hard cardiac events.

Impact of a reduced tube voltage on CT angiography and radiation dose: results of the PROTECTION I study.

OBJECTIVES: The aim of this study was to determine the impact of a reduced 100-kV tube voltage on image quality and radiation exposure in a pre-defined subgroup analysis of the international, multicenter radiation dose survey PROTECTION I (Prospective Multicenter Study on RadiaTion Dose Estimates Of Cardiac CT AngIOgraphy I) study. BACKGROUND: Cardiac computed tomography angiography (CCTA) has become a frequently used diagnostic tool in clinical practice. Despite continually improving CT technology, there remain concerns regarding the associated radiation exposure. A reduced tube voltage of 100 kV has been proposed as an effective means for dose reduction in nonobese patients. METHODS: The study assessed the relevant radiation dose parameters as well as quantitative and qualitative diagnostic image quality data in a subgroup of 321 patients (100 kV: 82 patients; 120 kV: 239 patients), who were scanned at study sites that applied a 100-kV tube voltage in at least 1 patient. Diagnostic image quality was assessed by an experienced CCTA investigator with a 4-point score (1: nondiagnostic to 4: excellent image quality). Effective radiation dose was estimated from the dose-length-product of each CCTA study. RESULTS: The use of the 100-kV scan protocol was associated with 53% reduction in CCTA median radiation dose estimates, when compared with the conventional 120-kV scan protocol (p < 0.001). Although image noise significantly increased by 26.3% with 100 kV, signal- as well as contrast-to-noise ratios also increased by 7.9% (p = 0.254) and 10.8% (p = 0.027), respectively. Reduction of tube voltage did not impair diagnostic image quality (median diagnostic score: 3.5 [3.25 to 3.75] vs. 3.5 [3.0 to 3.75] for 100 kV vs. 120 kV; p = 0.22). CONCLUSIONS: In this nonrandomized PROTECTION I dose survey, reducing the CCTA tube voltage to 100 kV in nonobese patients is associated with a significant reduction in radiation exposure while maintaining diagnostic image quality. Thus, the 100-kV scan technique should be considered for CCTA dose reduction in adequately selected patients.

Prognostic value of coronary computed tomographic angiography for prediction of cardiac events in patients with suspected coronary artery disease.

OBJECTIVES: We assessed the rate of cardiac events after detection or exclusion of obstructive coronary artery disease (CAD) by coronary computed tomography angiography (CCTA). BACKGROUND: Several studies have demonstrated a high diagnostic accuracy of CCTA for detection of obstructive CAD compared with invasive angiography, but data regarding the clinical prognostic value of CCTA are limited. METHODS: In all, 1,256 consecutive patients with suspected CAD undergoing 64-slice CCTA in our institution between October 2004 and September 2006 were observed prospectively for the occurrence of severe cardiac events (cardiac death, myocardial infarction, or unstable angina requiring hospitalization: primary study end point) and all cardiac events (additionally including revascularization >90 days after CCTA). The observed rate of all cardiac events was compared with the event rate predicted by the Framingham risk score. Obstructive CAD was defined as > or = 50% diameter stenosis in any coronary artery. RESULTS: During a median follow-up of 18 months (interquartile range 14 to 25 months), the overall rates of severe and all cardiac events were 0.6% and 1.8%, respectively. In 802 patients without obstructive CAD, there were 4 cardiac events, of which 1 was severe, whereas in 348 patients with obstructive CAD, there were 17 cardiac events, of which 5 were severe. The difference between the 2 groups was highly significant both for severe events (odds ratio: 17.3, 95% confidence interval: 3.6 to 82.5) and for all cardiac events (odds ratio: 16.1, 95% confidence interval: 7.2 to 36.0; both p < 0.001). The rate of all cardiac events in patients without obstructive CAD was significantly lower than predicted by the Framingham risk score (p = 0.01). CONCLUSIONS: In patients with suspected CAD, CCTA has a significant prognostic impact on the prediction of cardiac events for the subsequent 18 months. The exclusion of obstructive CAD by CCTA identifies a patient population with an event risk lower than predicted by conventional risk factors.

Feasibility of dual-source cardiac CT angiography with high-pitch scan protocols.

BACKGROUND: Cardiac CT angiography (CCTA) has become a frequently used diagnostic tool in clinical practice, but concern remains about the radiation exposure. Because of the second x-ray acquisition system, dual-source CT systems might allow for high-pitch CT data acquisition and thus for examination of the whole heart during a single heart beat, with the potential for radiation dose reduction. OBJECTIVE: We assessed the feasibility of a high-pitch scan mode with a dual-source CT system. METHODS: High-pitch modes were used in patients undergoing CCTA with a dual-source CT system. Diagnostic image quality for cardiac structures and coronary arteries was assessed. Radiation dose was estimated from the scanner-generated dose-length product (DLP). RESULTS: CCTA was performed in 14 patients during a single heart beat applying a pitch value of 3.4. Mean heart rate during examination was 56.4+/-8.1 beats/min. Diagnostic image quality for the assessment of larger cardiac structures was obtained in all patients, whereas diagnostic image quality could be achieved in 82% of all coronary segments. With a mean DLP of 145+/-47 mGy x cm, the resulting estimated radiation dose was 2.0+/-0.7 mSv. CONCLUSIONS: This proof-of-concept study shows the ability of dual-source CT scanners to scan the whole heart during one single heart beat at low radiation dose.

Trends in radiation protection in CT: present and future status.

With the introduction of modern multislice scanner generations, computed tomography (CT) has emerged as a useful tool for evaluation of the coronary arteries. A common application of coronary CT angiography (CCTA) is the examination of patients with intermediate pretest probability for obstructive coronary artery disease. Despite the widespread use of cardiac CT examinations in clinical practice, concern remains about the exposure to ionizing radiation and its potential hazards. Therefore, radiation dose and strategies for dose reduction have become an important focus of interest. Several smaller analyses have shown an effective radiation dose between 6.4 and 27.8 mSv for spiral CCTA image acquisition. The international Prospective Multicenter Study On RadiaTion Dose Estimates Of Cardiac CT AngIOgraphy I (PROTECTION I) study, the largest observational study on radiation dose estimates of cardiac CT so far, determined radiation dose estimates of CCTA, as well as the effect of different strategies to reduce dose in clinical practice. The median dose-length-product of 1965 CCTA examinations was 885 mGy x cm, which corresponds to a median estimated effective radiation dose of 12 mSv. However, a large variation in dose between study sites was observed, indicating a large potential to reduce dose for individual sites. Several dose-saving scanning techniques and algorithms have been developed. This article discusses these strategies as well as their effect on radiation dose and image quality. Because the contrast-enhanced CT angiography is the largest part of the total study dose, the following described strategies focus on radiation dose reduction for CCTA image acquisition.