Nationwide surveys of chest, abdomen, lumbosacral spine radiography, and upper gastrointestinal fluoroscopy: a summary of findings

Clinical application of a gadolinium-based capsule as an MRI contrast agent in slow transit constipation diagnostics

BACKGROUND

As a traditional method for the assessment of colon dynamics, radio-opaque markers (ROMs) are limited in clinical use because of their ionizing radiation. We compared the accuracy and applicability of gadolinium-based capsules with ROMs in the measurement of colon dynamics in healthy controls and slow transit constipation (STC) patients.

METHODS

Seven patients with STC and nine healthy controls under a normal diet orally consumed ROMs and gadolinium-based capsules simultaneously. All subjects underwent X-ray and magnetic resonance imaging (MRI). Healthy control images were acquired at 12, 24, and 48 h, and STC patient images were acquired at 24, 48, and 72 h. The scores based on the position of the labeling capsules and ROMs in the colon and the colon transit times (CTTs) in the two groups were compared.

KEY RESULTS

The CTTs obtained via the ROMs were 34.7±17.4 and 67.3±6.5 h in the healthy controls and STC patients, respectively (P<.05). The CTTs obtained via MRI were 30.9±15.9 and 74.1±7.2 h in the healthy controls and STC patients, respectively (P<.05). The CTTs of the STC patients were significantly longer than the healthy controls. The correlation (r_s ) between the scores based on the position of the labeling capsule and ROMs in the healthy group and the STC patients was .880 (P<.05) and .889 (P<.05), respectively.

CONCLUSIONS AND INFERENCES

As a MRI contrast label, gadolinium-based capsules exhibit results comparable to ROMs in colon motility measurements.

Mechanisms of low back pain: a guide for diagnosis and therapy

Chronic low back pain (CLBP) is a chronic pain syndrome in the lower back region, lasting for at least 3 months. CLBP represents the second leading cause of disability worldwide being a major welfare and economic problem. The prevalence of CLBP in adults has increased more than 100% in the last decade and continues to increase dramatically in the aging population, affecting both men and women in all ethnic groups, with a significant impact on functional capacity and occupational activities. It can also be influenced by psychological factors, such as stress, depression and/or anxiety. Given this complexity, the diagnostic evaluation of patients with CLBP can be very challenging and requires complex clinical decision-making. Answering the question "what is the pain generator" among the several structures potentially involved in CLBP is a key factor in the management of these patients, since a mis-diagnosis can generate therapeutical mistakes. Traditionally, the notion that the etiology of 80% to 90% of LBP cases is unknown has been mistaken perpetuated across decades. In most cases, low back pain can be attributed to specific pain generator, with its own characteristics and with different therapeutical opportunity. Here we discuss about radicular pain, facet Joint pain, sacro-iliac pain, pain related to lumbar stenosis, discogenic pain. Our article aims to offer to the clinicians a simple guidance to identify pain generators in a safer and faster way, relying a correct diagnosis and further therapeutical approach.

Mechanisms of low back pain: a guide for diagnosis and therapy

Chronic low back pain (CLBP) is a chronic pain syndrome in the lower back region, lasting for at least 3 months. CLBP represents the second leading cause of disability worldwide being a major welfare and economic problem. The prevalence of CLBP in adults has increased more than 100% in the last decade and continues to increase dramatically in the aging population, affecting both men and women in all ethnic groups, with a significant impact on functional capacity and occupational activities. It can also be influenced by psychological factors, such as stress, depression and/or anxiety. Given this complexity, the diagnostic evaluation of patients with CLBP can be very challenging and requires complex clinical decision-making. Answering the question "what is the pain generator" among the several structures potentially involved in CLBP is a key factor in the management of these patients, since a mis-diagnosis can generate therapeutical mistakes. Traditionally, the notion that the etiology of 80% to 90% of LBP cases is unknown has been mistaken perpetuated across decades. In most cases, low back pain can be attributed to specific pain generator, with its own characteristics and with different therapeutical opportunity. Here we discuss about radicular pain, facet Joint pain, sacro-iliac pain, pain related to lumbar stenosis, discogenic pain. Our article aims to offer to the clinicians a simple guidance to identify pain generators in a safer and faster way, relying a correct diagnosis and further therapeutical approach.

Chest X-ray screening examinations among French uranium miners: exposure estimation and impact on radon-associated lung cancer risk

BACKGROUND

Medical surveillance of uranium miners can include periodic chest X-ray examinations. This study aimed to assess the X-ray exposure due to occupational health monitoring in the French cohort of uranium miners, and to test whether consideration of this additional radiation exposure impacts the excess risk of lung cancer death associated with radon exposure.

METHOD

X-ray exposure due to occupational health monitoring was estimated retrospectively based on review of a sample of miners' medical records and bibliographic data. Four exposure scenarios were designed, differing in their assumptions about the type of procedures performed, their frequency, and the lung dose delivered. Radon exposure and lung doses from exposure to α-particle emitters and external γ rays have previously been individually assessed. Exposure-risk and dose-risk relations were estimated by Poisson regression with a linear excess relative risk (ERR) model.

RESULTS

The cohort included 5086 miners with a mean follow-up duration of 30.1 years. The mean number of chest X-ray examinations ranged from 15.1 in the lowest to 34 in the highest-exposure scenario, and produced a mean cumulative lung dose ranging from 4.6 to 34.2 mGy. The role of occupation-related imaging screening X-ray procedures in total equivalent lung dose appeared insignificant compared to α-emitter exposure. X-ray exposure was not associated with lung cancer mortality risk. The ERR associated with radon remained significantly positive when X-ray exposure was included in the multivariate analysis.

CONCLUSIONS

X-ray exposure did not confound the exposure-risk relation between radon and lung cancer.

Effective dose assessment for participants in the National Lung Screening Trial undergoing posteroanterior chest radiographic examinations

OBJECTIVE

The National Lung Screening Trial (NLST) is a multicenter randomized controlled trial comparing low-dose helical CT with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004, when 53,454 participants had been randomized at 33 screening sites. The objective of this study was to determine the effective radiation dose associated with individual chest radiographic screening examinations.

SUBJECTS AND METHODS

A total of 73,733 chest radiographic examinations were performed with 92 chest imaging systems. The entrance skin air kerma (ESAK) of participants' chest radiographic examinations was estimated and used in this analysis. The effective dose per ESAK for each examination was determined with a Monte Carlo-based program. The examination effective dose was calculated as the product of the examination ESAK and the Monte Carlo estimate of the ratio of effective dose per ESAK.

RESULTS

This study showed that the mean effective dose assessed from 66,157 postero-anterior chest examinations was 0.052 mSv. Additional findings were a median effective dose of 0.038 mSv, a 95th percentile value of 0.136 mSv, and a fifth percentile value of 0.013 mSv.

CONCLUSION

The effective dose for participant NLST chest radiographic examinations was determined and is of specific interest in relation to that associated with the previously published NLST low-dose CT examinations conducted during the trial.

Patient radiation doses in interventional cardiology in the U.S.: advisory data sets and possible initial values for U.S. reference levels

PURPOSE

To determine patient radiation doses from interventional cardiology procedures in the U.S and to suggest possible initial values for U.S. benchmarks for patient radiation dose from selected interventional cardiology procedures [fluoroscopically guided diagnostic cardiac catheterization and percutaneous coronary intervention (PCI)].

METHODS

Patient radiation dose metrics were derived from analysis of data from the 2008 to 2009 Nationwide Evaluation of X-ray Trends (NEXT) survey of cardiac catheterization. This analysis used identified data and did not require review by an IRB. Data from 171 facilities in 30 states were analyzed. The distributions (percentiles) of radiation dose metrics were determined for diagnostic cardiac catheterizations, PCI, and combined diagnostic and PCI procedures. Confidence intervals for these dose distributions were determined using bootstrap resampling.

RESULTS

Percentile distributions (advisory data sets) and possible preliminary U.S. reference levels (based on the 75th percentile of the dose distributions) are provided for cumulative air kerma at the reference point (K(a,r)), cumulative air kerma-area product (P(KA)), fluoroscopy time, and number of cine runs. Dose distributions are sufficiently detailed to permit dose audits as described in National Council on Radiation Protection and Measurements Report No. 168. Fluoroscopy times are consistent with those observed in European studies, but P(KA) is higher in the U.S.

CONCLUSIONS

Sufficient data exist to suggest possible initial benchmarks for patient radiation dose for certain interventional cardiology procedures in the U.S. Our data suggest that patient radiation dose in these procedures is not optimized in U.S. practice.

Appropriate use of lumbar imaging for evaluation of low back pain

Use of lumbar spine imaging, particularly advanced imaging, continues to grow rapidly in the United States. Many lumbar spine imaging tests are obtained in patients who have no clinical symptoms or risk factors suggesting a serious underlying condition, yet evidence shows that this routine imaging is not associated with benefits, exposes patients to unnecessary harms, and increases costs. This article reviews current trends and practice patterns in lumbar spine imaging, direct and downstream costs, benefits and harms, current recommendations, and potential strategies for reducing imaging overuse.

Considerations and preliminary design of patient exposure registry

To aid in protecting patients from unnecessary exposures and to reduce radiation burdens to the public, a system for tracking a patient's medical exposure history and related radiation doses would be a useful tool. A patient-centred exposure registry, the Patient Exposure Registry (PER), is a mechanism that provides this tracking. This article outlines the objectives of the proposed Canadian PER together with considerations and preliminary design of the registry. Implementation strategy is discussed. The strategy will allow many initiatives progressing in parallel such as backward data mining and forward development in order to make this important registry a reality in the near future.