PATIENT DOSE MEASUREMENTS FROM FEMORAL ANGIOGRAPHY

Investigation of patient dose from femoral angiography requires detail ed logging of dose-area product (DAP) measurements, which is time-cons uming and only possible on small numbers of patients. A simple model f or the femoral angiogram study consists of two regions; lower limbs an d torso. The experimental phantom was the abdominal and pelvic section s of a Rando phantom, and two 10 cm diameter water filled cylinders to represent a lower limb. DAP rate during screening, and the DAP per sp ot film exposure were obtained in two rooms. Total DAP values were mea sured on 100 patients in each room. The median screening time and numb er of spot film exposures were divided between the two regions. The DA P from screening and spot films for each region was estimated by combi ning the phantom and patient data. The total DAP predicted by the mode l agreed to within 7% of the median DAP from the patient studies. Conv ersion to effective dose gave 9.0 mSv for the newer room compared with 2.8 mSv for the older room. In the newer room it was estimated that d igital spot film exposure contributed 88% of the total effective dose. In the same room, exposure of the torso contributed 98% of the total effective dose. The model will enable interpretation of total DAP meas urements made from femoral angiogram studies without the need for deta iled DAP measurements on every patient. Attempts to reduce patient dos e from femoral angiography must concentrate on reduction of the number and dose per exposure from abdominal and pelvic digital spot films.