Automated Framework for Digital Radiation Dose Index Reporting From CT Dose Reports

• Published in: American journal of roentgenology (1976) Vol. 197; no. 5; pp. 1170 - 1174
• Main Authors: SHIH, George, ZHENG FENG LU, ZABIH, Ramin, KENNEDY, Devin, LOFTUS, Michael, SHIH, Wei-Jen, OSBORNE, Joseph, NICKOLOFF, Edward, SCHWARTZ, Lawrence
• Format: Journal Article
• Language: English
• Published: Reston, VA American Roentgen Ray Society 01-11-2011
• Subjects: Applied radiobiology (equipment, dosimetry...); Automation; Biological and medical sciences; Biological effects of radiation; Fundamental and applied biological sciences. Psychology; Humans; Internet; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Miscellaneous. Technology; Phantoms, Imaging; Radiation Dosage; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Radiometry - methods; Software; Tissues, organs and organisms biophysics; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed; United States; United States; Human; CT; Radiation dose; Radiobiology; Radiodiagnosis; Medical imagery; Computerized axial tomography; Dosimetry; Radiation exposure (person); reporting; Automatic processing
• ISSN: 0361-803X; 1546-3141
• DOI: 10.2214/AJR.11.6650

Radiation exposure from CT studies has increased over the past 30 years in the United States and now constitutes approximately 50% of the radiation dose index administered in the health care setting. Tracking CT dose index (CTDI) is cumbersome because it relies on a manufacturer-generated screen capture, which contains the estimated dose index exposure for the patient. The radiation dose index information is not digital but, rather, is "burned" into the image (i.e., not in numeric form, not as part of the image header or elsewhere associated with the study), making it difficult to automatically share these data with other information systems. The purpose of the dose index reporting application (DIRA) we developed for CT is to extract the radiation dose index information from the CTDI reports to eventually perform automated quality control, promote radiation safety awareness, and provide a longitudinal record of patient-specific health care-related radiation exposure.
A random selection of 518 CTDI reports were processed by the DIRA and the dose index information was extracted. CTDI reports using a standard DICOM C-STORE to the DIRA allow an automated process to compile radiation dose index and patient information in a Web-based framework using a structured query language (SQL) database.
Our initial tests showed that the DIRA accurately extracted dose index information from 518 of 518 CTDI reports (100%). Because the extracted CTDI descriptor-dose-length product-is based on standard CTDI measurements obtained using fixed-size cylindric polymethylmethacrylate phantoms, preliminary studies have been performed to correct for patient size by applying correction factors derived from CTDI measurements using a range of phantom sizes from 6 to 32 cm in diameter. Our system provides a way to automatically track CTDI on existing CT scanners and does not rely on the DICOM SR Dose Index Report standard, which is available on only the newest CT scanners.
A modular and vendor-independent DIRA system can be integrated with any existing CT scanner. This system greatly facilitates digital dose index reporting and makes it possible to provide a longitudinal record of the health care radiation exposure estimate in an individual patient's health record.