Radiation dose measurement for patients undergoing common spine medical x-ray examinations and proposed local diagnostic reference levels

• Considerable variations in the radiological practice was revealed.
• Tube loading varied from 3 to 128 for lumbar AP and 3 to 200 for lumbar LAT.
• Huge discrepancies in ESDs for cervical Spine examinations were found.
• Max to min ratio of ESD in cervical AP and LAT were 136 and 820, respectively.
• ESDs for all projections were below EC and IAEA DRLs.

The main purposes of this study were to investigate patient dose in Spine radiographic examinations, as high dose procedures and propose the first LDRLs (Local Diagnostic Reference Levels) in Khuzestan region, southwest of Iran. ESD (Entrance Skin Dose) values of patients who underwent six spine radiographic procedures containing cervical (AP/LAT), thoracic (AP/LAT) and lumbar (AP/LAT), as high dose procedures, were evaluated. Patient doses were calculated from patient's individual anatomical data (weight, height and organ thickness) and exposure parameters (kVp, mAs, FFD and projection) based on the IAEA (International Atomic Energy Agency) Technical Report Series No.457. Indirect dosimetry method was conducted on 412 standard patients (57% men and 43% women) at seven high-patient-load hospitals. This survey reveals significant variations in the radiological practice. Despite large discrepancies found in the tube loadings (3–128 for lumbar AP and 3–200 for lumbar LAT), ESDs in all examinations were lower than the IAEA and EC (European Commission) DRLs (Diagnostic Reference Levels), 1.30, 1.65, 2.29, 3.09, 5, 7.5 mGy for cervical AP, cervical LAT, thoracic AP, lumbar AP, thoracic LAT and lumbar LAT respectively. Optimization of radiological practice could be accelerated by updating clinical audits and patient dose considerations, adequate training of students, implementation of systematic QA and QC programs and the use of qualified diagnostic medical physicists in the imaging sections. It is advisable that DRLs obtained in this study can be used as local DRL and dose surveys must be performed in all regions to establish NDRLs (National Diagnostic Reference Levels) in Iran. Also, national authorities must review periodically reference levels to ensure that it remains appropriate.