A survey of 14 computed tomography scanners in Greece and 32 scanners in Italy: Examination frequencies, dose reference values, effective dose and doses to organs

Abstract

A survey of examination frequencies, dose reference values, effective doses and doses to organs involving 14 scanners from Greece and 32 scanners from Italy was carried out for the years 1999 and 2000. Examination frequencies per scanner and per year were found to be 3590 for Greece and 4520 for Italy. For the types of examinations considered, CDTI(W) and DLP measurements were taken. Also scan lengths used for the same types of examinations were monitored. For the same types of examinations effective doses were calculated by two methods, and it was found that their mean values ranged from 13.1 mSv for thoracic spine to 1.6 mSv for the brain examinations. From the data of the 14 Greek laboratories, doses to organs were calculated and it was found that the thyroid receives 50.2 +/- 19.8 mGy during a cervical spine examination while the gonads receive 17.8 +/- 6.9 mGy during a routine pelvis examination.

Effect of iterative reconstructions in low dose computed tomography

“…On the other hand, the mean DLP for abdominal CT (495.5 mGy.cm) is similar to the values reported by Papadimitriou et al (493 mGy.cm -551 mGy.cm) [8] . But in this study their values were based on CT scan of upper abdomen only and thus the region scanned was small.…”

“…The average CTDI value (7.42 mGy) in our study was lower than that reported by IAEA 16.2 mGy [7] and that by Papadimitriou et al (21 mGy) [8] . Torp et al [9] reported results from five countries in the Nordic region in which the weighted CTDI values ranged from 10.5 to 11.7 mGy.…”

“…In our study the mean DLP (286.3 mGy.cm) for CT of chest was significantly lower than the IAEA-recommended value of 455 mGy.cm [7] and the values reported by Papadimitriou et al -429 mGy.cm for centres in Greece and 483 mGy.cm for centres in Italy [8] . The DRL DLP in European guidelines for chest CT is 650 mGy.cm, which is approximately 56% higher than the corresponding value in our study.…”

Survey of computed tomography techniques and absorbed dose in Italian hospitals: a comparison between two methods to estimate the dose–length product and the effective dose and to verify fulfilment of the diagnostic reference levels

“…Where comparison is possible, the results of this and previous reports are summarised in Table 7. Only Papadimitriou et al [24] investigated all seven protocols covered here, although in a smaller number of cases.…”

Dose management in CT facility

“…Since it is not appropriate to set dose limits on medical exposures, DRL is a useful quantity that facilitates the investigation of dose levels in various CT procedures and permits comparison of performance between different scanners and techniques [22]. DRLs provide the means to improve patient protection, if it is required, identify poor performance and monitor CT performance in periodic measurements [24-27]. The foregoing discussion reveals the need for proper management of radiation dose in a CT facility.…”