National dose reference levels in computed tomography-guided interventional procedures-a proposal.

OBJECTIVES: To establish national reference levels (RLs) in interventional procedures under CT guidance as required by the 2013/59/Euratom European Directive. METHODS: Seventeen categories of interventional procedures in thoracic, abdominopelvic, and osteoarticular specialties (percutaneous infiltration, vertebroplasty, biopsy, drainage, tumor destruction) were analyzed. Total dose length product (DLP), number of helical acquisitions (NH), and total DLP for helical, sequential, or fluoroscopic acquisitions were recorded for 10 to 20 patients per procedure at each center. RLs were calculated as the 3rd quartiles of the distributions and target values for optimization process (TVOs) as the median. RLs and TVOs were compared with previously published studies. RESULTS: Results on 5001 procedures from 49 centers confirmed the great variability in patient dose for the same category of procedures. RLs were proposed for the DLPs and NHs in the seventeen categories. RLs in terms of DLP and NH were 375 mGy.cm and 2 NH for spinal or peri-spinal infiltration, 1630 mGy.cm and 3 NH for vertebroplasty, 845 mGy.cm and 4 NH for biopsy, 1950 mGy.cm and 8 NH for destruction of tumors, and 1090 mGy.cm and 5 NH for drainage. DLP and NH increased with the complexity of procedures. CONCLUSIONS: This study was the first nationwide multicentric survey to propose RLs for interventional procedures under CT guidance. Heterogeneity of practice in centers were found with different levels of patient doses for the same procedure. The proposed RLs will allow imaging departments to benchmark their practice with others and optimize their protocols. KEY POINTS: • National reference levels are proposed for 17 categories of interventional procedures under CT guidance. • Reference levels are useful for benchmarking practices and optimizing protocols. • Reference levels are proposed for dose length product and the number of helical acquisitions.

Correction to: National dose reference levels in computed tomography-guided interventional procedures-a proposal.

The original version of this article, published on 02 May 2020, unfortunately contained a mistake.

Magnetic Resonance Imaging of Parotid Gland Tumors: Dynamic Contrast-Enhanced Sequence Evaluation.

OBJECTIVE: The aim of the study was to evaluate dynamic contrast-enhanced magnetic resonance (MR) imaging in the characterization of parotid gland tumors. METHODS: Fifty-five parotid lesions in 55 patients were retrospectively included. Two observers interpreted 2 reading protocols derived from all MR imaging in 2 distinct sessions, independently and blinded. Benign versus malignant distinction was carried out for protocol 1 (without contrast administration) and protocol 2 (with dynamic contrast-enhanced sequence). Histopathological results after surgical resection were used as the criterion standard. Diagnostic accuracy was compared between protocols using McNemar test. A P values of less than 0.05 indicated significant difference. RESULTS: There was no intraobserver statistical discordance between protocols for both observers (P = 0.27 and P = 1). Interobserver reliability showed moderate agreement for protocol 1 (κ = 0.591; 95% confidence interval [CI], 0.376-0.806) and 2 (κ = 0.463, 95% CI, 0.226-0.701). Intraobserver reliability showed moderate agreement for observer 1 (κ = 0.507; 95% CI, 0.279-0.736) and 2 (κ = 0.477; 95% CI, 0.241-0.712). CONCLUSIONS: Magnetic resonance imaging protocol including dynamic sequence for the characterization of parotid gland lesion yielded nonsignificant increases in sensitivity, specificity, or positive predictive values, and negative predictive values over noninjected protocol.

Acquired pulmonary artery pseudoaneurysms: a pictorial review.

Pulmonary artery pseudoaneurysms (PAPs) are uncommon but potentially lethal. They may be incidentally discovered on imaging, or following massive haemoptysis if they rupture, with high risk of mortality. The most frequent causes of PAP are trauma and infectious disease. Vasculitis, in particular Behçet's disease, neoplasm, congenital disease and pulmonary hypertension are rarer causes of PAP. A PAP can be suspected from chest X-ray and contrast CT, but requires confirmation by CT angiography. Arteriography is no longer performed for diagnostic purposes, but can be useful in preparing endovascular occlusion of the PAP. In rare cases, surgery is necessary. The aim of this pictorial review was to illustrate the most common causes of acquired PAPs.