Interventional radiology at the meetings of the German Radiological Society from 1998 to 2008: evaluation of structural changes and radiation issues.

OBJECTIVES: Evaluation of structural changes and the weight given to radiation exposure of interventional radiology (IR) contributions at the Congress of the German Radiological Association from 1998 to 2008. METHODS: All IR abstracts were evaluated for type of contribution, design, imaging modality, and anatomic region. Weight given to radiation exposure was recorded as general statement, main topic and/or dose reduction. Statistical analysis included calculation of absolute/relative proportions of subgroups and ANOVA regression analyses. RESULTS: Out of 9,436 abstracts, 1,728 (18%) were IR-related. IR abstracts significantly rose to a maximum of 200 (20%) in 2005 (P = 0.048). While absolute numbers of scientific contributions declined, educational contributions significantly increased (P = 0.003). Computed tomography (CT) and magnetic resonance imaging (MRI) were the main IR imaging modalities, with growing use of CT (P = 0.021). The main body regions were vessels (45%) and abdomen (31%). Radiation exposure was addressed as a general statement in 3% of abstracts, as a main topic in 2%, and for dose reduction in 1%, respectively. During the study interval a significant growth of dose reduction abstracts was observed (P = 0.016). CONCLUSIONS: IR emerged as a growing specialty of radiology, with a significant increase in educational contributions. Radiation exposure was rarely in the focus of interest but contributions relating to dose reduction demonstrated a significant growth during the study period. Main Messages • Interventional radiology emerged as a growing specialty at the German radiological congress. • Significant increments of educational and prospective research contributions could be observed. • Despite a significant trend towards computed tomography, radiation exposure of IR was rarely in the focus of interest. • Contributions related to dose reduction demonstrated a significant growth during the study period.

Multidetector-CT angiography in pulmonary embolism-can image parameters predict clinical outcome?

OBJECTIVE: To assess if pulmonary CT angiography (CTA) can predict outcome in patients with pulmonary embolism (PE). METHODS: Retrospective analysis of CTA studies of patients with PE and documentation of pulmonary artery (PA)/aorta ratio, right ventricular (RV)/left ventricular (LV) ratio, superior vena cava (SVC) diameter, pulmonary obstruction index (POI), ventricular septal bowing (VSB), venous contrast reflux (VCR), pulmonary infarction and pleural effusion. Furthermore, duration of total hospital stay, necessity for/duration of ICU therapy, necessity for mechanical ventilation and mortality were recorded. Comparison was performed by logistic/linear regression analysis with significance at 5%. RESULTS: 152 patients were investigated. Mean duration of hospital stay was 21 ± 24 days. 66 patients were admitted to the ICU; 20 received mechanical ventilation. Mean duration of ICU therapy was 3 ± 8 days. Mortality rate was 8%. Significant positive associations of POI, VCR and pulmonary infarction with necessity for ICU therapy were shown. VCR was significantly associated with necessity for mechanical ventilation and duration of ICU treatment. Pleural effusions were significantly associated with duration of total hospital stay whereas the RV/LV ratio correlated with mortality. CONCLUSION: Selected CTA findings showed significant associations with the clinical course of PE and may thus be used as predictive parameters.

Intra-individual, randomised comparison of the MRI contrast agents gadobutrol and gadoterate in imaging the distal lower limb of patients with known or suspected osteomyelitis, evaluated in an off-site blinded read.

OBJECTIVE: To prove that 1.0 M gadobutrol provides superior contrast enhancement in suspicion of osteomyelitis of the feet compared with 0.5 M gadoterate. METHODS: MRI of feet was performed on 2 separate occasions. Independent injections of 1.0 M gadobutrol and 0.5 M gadoterate at doses of 0.1 mmol Gd/kg body weight were administered per patient. The interval between the two MR examinations was between 24 h and 7 days. Evaluation was performed in an off-site blinded read. RESULTS: 41 patients were eligible for efficacy analysis. Results of secondary efficacy variables did not show statistically significant differences. For the primary efficacy variable, a trend in favour of gadobutrol was seen in the full analysis set (ITT) population resulting in at least non-inferiority. In the per protocol (PP) analysis set gadobutrol had better contrast than gadoterate (Wilcoxon signed rank test, p = 0.0466). CONCLUSION: Imaging of the distal lower limb in this special patient population requires a large number of patients to obtain enough comparative images where non-contrast-agent-dependent factors do not disturb contrast agent efficacy. The ITT analysis showed at least non-inferiority of gadobutrol in comparison to gadoterate. The avoidance of imaging artefacts demonstrates a better outcome for gadobutrol.

Cumulative effective dose associated with radiography and CT of adolescents with spinal injuries.

OBJECTIVE: The purpose of this study was to analyze the quantity and distribution of cumulative effective doses in diagnostic imaging of adolescents with spinal injuries. MATERIAL AND METHODS: At a level 1 trauma center from July 2003 through June 2009, imaging procedures during initial evaluation and hospitalization and after discharge of all patients 10-20 years old with spinal fractures were retrospectively analyzed. The cumulative effective doses for all imaging studies were calculated, and the doses to patients with spinal injuries who had multiple traumatic injuries were compared with the doses to patients with spinal injuries but without multiple injuries. The significance level was set at 5%. RESULTS: Imaging studies of 72 patients (32 with multiple injuries; average age, 17.5 years) entailed a median cumulative effective dose of 18.89 mSv. Patients with multiple injuries had a significantly higher total cumulative effective dose (29.70 versus 10.86 mSv, p < 0.001) mainly owing to the significantly higher CT-related cumulative effective dose to multiple injury patients during the initial evaluation (18.39 versus 2.83 mSv, p < 0.001). Overall, CT accounted for 86% of the total cumulative effective dose. CONCLUSION: Adolescents with spinal injuries receive a cumulative effective dose equal to that of adult trauma patients and nearly three times that of pediatric trauma patients. Areas of focus in lowering cumulative effective dose should be appropriate initial estimation of trauma severity and careful selection of CT scan parameters.

CT angiography in suspected pulmonary embolism: impact of patient characteristics and different venous lines on vessel enhancement and image quality.

OBJECTIVE: The objective of our study was to compare image quality, patient characteristics, and different catheters in pulmonary CT angiography (CTA) performed with bolus tracking and z-axis automated tube current modulation (ATCM) in patients with suspected pulmonary embolism. SUBJECTS AND METHODS: One hundred twenty-six patients were referred to undergo pulmonary CTA with bolus tracking and ATCM. Besides patient characteristics, the type, position, size, and side of venous catheters were documented. Pulmonary vessel enhancement and image noise were quantified; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective vessel contrast was assessed by two radiologists in consensus. RESULTS: Patient age showed a moderate but significant positive correlation to vessel enhancement (r = 0.244, p = 0.006), CNR (r = 0.178, p = 0.046), and subjective image quality (r = 0.344, p < 0.001). Patient weight revealed a significant negative correlation to vessel enhancement (r = -0.496, p < 0.001), SNR (r = -0.446, p < 0.001), CNR (r = -0.425, p < 0.001), and subjective image quality (r = -0.422, p < 0.001). In univariate analysis, SNR and CNR were significantly higher in patients who received contrast medium through peripheral catheters (30 +/- 13 and 27 +/- 13, respectively) than in those in whom central catheters were used (22 +/- 8 and 19 +/- 7, p = 0.041 and p = 0.029, respectively). Neither patient sex nor catheter size, position, or side had any significant impact on image quality. CONCLUSION: Patient age and weight showed significant impact on vascular attenuation and image quality in pulmonary CTA with bolus tracking and ATCM, whereas patient sex and different peripheral catheters did not significantly influence image parameters.

[Endosonography -- an additional diagnostic possibility in the differentiation between the two common types of primary hyperaldosteronism]. / Endosonographie -- eine zusätzliche diagnostische Möglichkeit bei der Differenzierung der beiden häufigsten Formen des primären Hyperaldosteronismus.

BACKGROUND: Primary aldosteronism is an important and one of the few potentially curable forms of secondary hypertension. The distinction between aldosterone-producing adenoma (APA) and idiopathic adrenal hyperplasia (IHA) may be difficult, but establishing the correct diagnosis is essential because surgery is only effective in patients with adrenal adenoma. CASE REPORT: The case of a 65-year-old man with long-term hypertension due to an APA is reported. The routine laboratory tests displayed an elevated plasma aldosterone/renin quotient as well as an elevated 24-h urinary excretion of aldosterone and its metabolites. The serum aldosterone concentration did not decrease normally in the saline suppression test. The posture testing demonstrated an increase in aldosterone. These facts might lead to the conclusion of an IHA. Magnetic resonance imaging (MRI) of the adrenal glands revealed no abnormalities. Because of the unusual combination of laboratory findings and radiologic results an endosonographic examination of the adrenal glands was performed which yielded a unilateral adrenal adenoma. With establishing this diagnosis, curative surgery became possible. CONCLUSION: This case demonstrates that in the differential diagnosis of primary aldosteronism, endosonography is more important than previously discussed. It may be helpful in the differentiation of an unusual constellation of laboratory and radiologic findings.