Shift in imaging modalities of the urinary tract over a 25-year period and its impact on ionizing radiation doses given to patients.

OBJECTIVES: To explore the shift in imaging modalities used when examining the urinary tract over the period 1979-2003 and to see how this shift, together with a radiation protection policy, have influenced the doses of ionizing radiation used. MATERIAL AND METHODS: Activity reports from a department of radiology were reviewed. Relevant radiation dose estimates were obtained from the Norwegian Radiation Protection Authority. RESULTS: Ultrasound (US) was introduced in 1983 and has been increasingly used since then. MRI was introduced in 1992 and has been used to some extent when examining the urinary tract. The use of i.v. pyelography decreased by 50% during the review period and the use of plain radiographs remained practically unchanged. The number of CT examinations increased until 1983, but decreased thereafter. The total number of examinations of the urinary tract has increased during the review period, but the radiation doses given have decreased. CONCLUSIONS: The introduction of US and MRI, together with a radiation protection policy, have reduced the ionizing radiation doses given to this population, in spite of an increase in the total number of examinations of the urinary tract.

Shift in imaging modalities of gastrointestinal tract through 25 years and its impact on patient ionizing radiation doses.

We wanted to explore the shift in modalities when diagnosing the gastrointestinal tract through the last three decades and see how this has influenced on the radiation doses given to this patient population. Activity reports from a central hospital in the years of 1979-2003 have been reviewed. The x-ray based modalities have decreased, while there has been a marked increase in colonoscopies, gastroscopies, ultrasound, and magnetic resonance cholangiopancreatography. This has caused a reduction in collective effective radiation dose of 54%.

Radiology quality assurance in a developing country setting: the 11-valent pneumococcal conjugate vaccine trial, Bohol, Philippines.

The endpoint used for a phase 3 pneumococcal conjugate vaccine (PCV) trial in Bohol, Philippines was radiographic consolidation. Only one (Bohol Regional Hospital, BRH) of the four surveillance hospitals had a quality control/quality assurance program (QC/QA) prior to the trial. QC/QA was initiated in the three private hospitals. Radiologists from BRH evaluated radiographs from all hospitals based on recommended standards. Four thousand nine hundred and eighty nine films were analyzed. In 2000, the proportion of good quality films was 65% and 29% in BRH and private hospitals, respectively. By 2004, these increased to 92% and 79%, respectively. Poor film quality was commonly due to absence of collimation and poor contrast. The regular QC/QA implementation was necessary to improve film quality and was particularly important in our PCV trial that used X-ray proven consolidation as an endpoint.

Shift in imaging modalities of the spine through 25 years and its impact on patient ionizing radiation doses.

STUDY DESIGN: Retrospective. OBJECTIVE: To explore the shift in modalities when diagnosing the spine in the years 1979-2003. To see how this shift, together with a radiation protective policy, have influenced on the ionizing radiation doses. SUMMARY OF BACKGROUND DATA: The shift from CT/myelography to MR when diagnosing the spine is well known. To what extent this has changed the radiation doses has to our knowledge not yet been published. METHODS: Activity reports from a department of radiology have been reviewed. Relevant radiation doses estimates have been obtained from the Norwegian Radiation Protection Authority. RESULTS: MRI was introduced in 1992 and has been used increasingly since then. Conventional X-ray to the spine has been practically unchanged. Myelography and CT decreased markedly after the introduction of MRI. The total number of examinations of the spine has increased, but the radiation doses given have decreased since 1993. CONCLUSIONS: The introduction of MRI together with a radiation protective policy have reduced the ionizing radiation doses given to this population, in spite of an increase in the total number of examinations of the spine.

Standardized interpretation of paediatric chest radiographs for the diagnosis of pneumonia in epidemiological studies.

BACKGROUND: Although radiological pneumonia is used as an outcome measure in epidemiological studies, there is considerable variability in the interpretation of chest radiographs. A standardized method for identifying radiological pneumonia would facilitate comparison of the results of vaccine trials and epidemiological studies of pneumonia. METHODS: A WHO working group developed definitions for radiological pneumonia. Inter-observer variability in categorizing a set of 222 chest radiographic images was measured by comparing the readings made by 20 radiologists and clinicians with a reference reading. Intra-observer variability was measured by comparing the initial readings of a randomly chosen subset of 100 radiographs with repeat readings made 8-30 days later. FINDINGS: Of the 222 images, 208 were considered interpretable. The reference reading categorized 43% of these images as showing alveolar consolidation or pleural effusion (primary end-point pneumonia); the proportion thus categorized by each of the 20 readers ranged from 8% to 61%. Using the reference reading as the gold standard, 14 of the 20 readers had sensitivity and specificity of > 0.70 in identifying primary end-point pneumonia; 13 out of 20 readers had a kappa index of > 0.6 compared with the reference reading. For the 92 radiographs deemed to be interpretable among the 100 images used for intra-observer variability, 19 out of 20 readers had a kappa index of > 0.6. CONCLUSION: Using standardized definitions and training, it is possible to achieve agreement in identifying radiological pneumonia, thus facilitating the comparison of results of epidemiological studies that use radiological pneumonia as an outcome.