ASSESSMENT OF OCCUPATIONAL EXPOSURE IN THE MAIN PAEDIATRIC INTERVENTIONAL RADIOLOGY PROCEDURES.

The aim of this study is to evaluate the personal dose equivalent Hp(10) in the most frequent (non-cardiac) paediatric interventional radiology (PIR) procedures: central venous catheters (CVC), hepatic/biliary and sclerotherapy interventions. i2 active solid-state dosemeters placed over the lead apron were used to monitor the exposure of three interventional radiologists over 18 months. A database was created to register all procedures performed by each radiologist (including the type of procedure and the kerma-area product, PKA). The mean Hp(10) per procedure for CVC, sclerotherapy and hepatic/biliary interventions was respectively 0.01 ± 0.01 mSv, 0.18 ± 0.13 mSv and 0.12 ± 0.06 mSv (k = 2). A similar value of Hp(10)/PKA was found despite the type of procedure or the patient weight (~10 µSv/Gy·cm2). There was high variability among individual interventions, probably due to the variable level of complexity, which led to uncertainties in the measurements' mean higher than those associated with the dosemeter's angular and energy dependence. i2 therefore proved suitable for monitoring Hp(10) in PIR procedures.

Concurrent Cerebral, Splenic, and Renal Infarction in a Patient With COVID-19 Infection.

INTRODUCTION: Thrombotic events are potentially devastating complications of coronavirus disease 2019 (COVID-19) infection. Although less common than venous thromboembolism, arterial thrombosis has been reported in COVID-19 cohorts in almost 3% of patients. We describe a patient with COVID-19 infection and concurrent cerebral and noncerebral infarction. CASE REPORT: A 53-year-old man with history of COVID-19 pneumonia was admitted to a primary stroke center for speech disturbances and left hemiplegia. Urgent laboratory tests showed a great increase of inflammatory and coagulation parameters as D-dimer, ferritin, interleukin-6 and C-reactive protein. Neuroimaging found occlusion of the M1 segment of the right middle cerebral artery with early signs of ischemic stroke. He received intravenous thrombolysis and mechanical thrombectomy. Abdominal computed tomography discovered a splenic infarction with hemorrhagic transformation and bilateral renal infarction. Urgent angiography showed an associated splenic pseudoaneurysm, which was embolized without complications. He was treated with intermediate-dose anticoagulation (1 mg subcutaneous enoxaparin/kg/24 h), acetylsalicylic acid 100 mg and 5 days of intravenous corticosteroids. In the following days, inflammatory markers decreased so anticoagulant treatment was stopped and acetylsalicylic acid 300 mg was prescribed. His condition improved and he was discharged to a rehabilitation facility on hospital day 30. CONCLUSION: In this case, a patient with multiple thrombotic events in the acute phase of COVID-19 infection, the delimitation of the inflammatory state through analytical markers as D-dimer helped to individualize the antithrombotic treatment (full anticoagulation or anticoagulation at intermediate doses plus antiplatelet treatment as used in our patient) and its duration. However, more data are needed to better understand the mechanisms and treatment of stroke in patients with COVID-19 infection.

Occupational doses to the eye lens in pediatric and adult noncardiac interventional radiology procedures.

PURPOSE: To assess occupational lens exposure in a mixed interventional radiology department, comparing pediatric and adult procedures. To analyze the correlation between the lens dose and the doses measured at the chest and collar level and the kerma-area product (PKA ). METHODS: For 17 months, three radiologists performing both pediatric and adult interventions were monitored by means of 14 dosimeters per worker: 12 single-point optically stimulated luminescent (OSL) dosimeters calibrated in terms of Hp (0.07) were placed on the inside and outside of two pairs of lead glasses, one for pediatric procedures and one for adult interventions; another whole-body OSL dosimeter calibrated in terms of Hp (10) was placed over the thyroid shield; finally, an additional active solid-state dosimeter, also calibrated for Hp (10), was worn on the chest, over the apron. Furthermore, a database was created to register the demographic and dosimetric data of the procedures, as well as the name of the radiologist acting as first operator. RESULTS: For the three radiologists, who performed 276-338 procedures/year (20% pediatric), cumulative annual doses to the left bare eye exceeded 20 mSv (21-61 mSv). Considering the glasses' protection, annual doses exceeded 6 mSv (13-48 mSv) for both eyes. No important differences were observed in lens dose per procedure between pediatric and adult interventions (0.16 vs 0.18, 0.12 vs 0.09, and 0.07 vs 0.07 mSv), although lens dose per PKA was 4.1-4.5 times higher in pediatrics (5.8 vs 1.3, 3.3 vs 0.8, and 2.6 vs 0.6 µSv/Gy·cm2 ) despite a similar use of the ceiling-suspended screen. Lens doses were highly correlated with collar readings (with Pearson coefficients [r] ranging from 0.86 to 0.98) and with chest readings (with r ranging from 0.75 to 0.93). However, slopes of the linear regressions varied greatly among radiologists. CONCLUSIONS: There is real risk of exceeding the occupational dose limit to the eye lens in mixed interventional radiology rooms if radiation protection tools are not used properly. Regular monitoring of the lens dose is recommended, given lens exposure might easily exceed 6 mSv/yr. Using a collar dosimeter for this purpose might be suitable if it is preceded by an individualized regression analysis. The same radiation protection measures should be applied to interventional radiologists regardless of whether they are treating pediatric or adult patients.

Local diagnostic reference levels for paediatric non-cardiac interventional radiology procedures.

PURPOSE: To establish local diagnostic reference levels (DRLs) for non-cardiac interventional procedures in paediatrics. METHODS: The type of procedure, the patient's weight and age and dose-related data from 279 interventions was recorded in a database completed by interventional radiologists, radiographers and technicians of the Medical Physics department. These procedures were classified into 14 categories and 6 weight ranges. Local DRLs were proposed for those ranges in which a sample of at least 15 patients could be gathered and were calculated as the third quartile (Q3) of the air kerma-area product (PKA) values. The Q3 of the fluoroscopy time (FT) and number of digital subtraction angiography (DSA) images were also obtained. Finally, the correlation between PKA and weight was analysed. RESULTS: Local DRLs are proposed for three types of procedures: hepatic/biliary interventions (5-15 kg, 1304 cGy·cm2; 15-30 kg, 2121 cGy·cm2), sclerotherapy procedures (15-30 kg, 704 cGy·cm2; 30-50 kg, 4049 cGy·cm2; 50-80 kg, 3734 cGy·cm2) and central venous catheter (CVC) procedures (5-15 kg, 84 cGy·cm2). Hepatic/biliary interventions showed a moderate correlation (r = 0.61), while sclerotherapy procedures presented a poor correlation (r = 0.34) between PKA and weight, possibly due to the PKA dependence on the complexity level. Regarding CVC procedures, a clearly higher correlation was found when the fluoroscopy PKA value was normalised to the FT (r = 0.85 vs r = 0.35). CONCLUSIONS: The results support the feasibility of establishing DRLs for the most common procedures (sclerotherapy, hepatic/biliary and CVC interventions) despite the small number of paediatric interventions.