Addressing overutilization in medical imaging

Trends in diagnostic CT among fee-for-service enrollees, 2000-2011

OBJECTIVES

To examine trends in the use of diagnostic CT in aggregate and for 4 major body regions (abdomen/pelvis, head/neck, chest, and spine) in an 11-year US nationwide analysis.

METHODS

We summarize records from a large, mostly fee-for-service insurance claims database from 2000 to 2011.

RESULTS

Rates of diagnostic CT have increased substantially from 2000 to 2011; however, changes in rates are disparate for different age groups and body regions. As others have shown, there has been a notable increase in use of diagnostic CT from 2000 to 2011. However, from 2009 to 2011, diagnostic CT studies of the chest, abdomen/pelvis, and head/neck have leveled off or decreased, whereas CTs of the spine show a continued increase in many groups.

CONCLUSIONS

In general, the increase in the rate of CT study performance has slowed, whereas spine CT continued to escalate. Future research should consider whether the increase in use of spine CT leads to a benefit that outweighs the risk associated with the increased population-level cancer risk.

Screening cervical spine CT in the emergency department, phase 3: increasing effectiveness of imaging

PURPOSE

The aim of this study was to determine the effect of a clinical education initiative on the appropriate utilization of screening cervical spine CT in the emergency department. The purpose was to assess if clinical education can produce stricter adherence to the ACR Appropriateness Criteria and improve the utilization of screening CT examinations in the emergency department.

METHODS

Institutional review board approval was obtained for this HIPAA-compliant study. All adult patients presenting to a level 1 trauma center with blunt trauma prompting screening cervical spine CT were eligible. For each study, the requesting clinician completed a survey selecting all clinical indications. CT examinations were evaluated by a board-certified radiologist blinded to survey data. Results were compared with retrospective and prospective studies performed before the institution of the education initiative.

RESULTS

Of the 388 cervical spine CT examinations performed, 12 (3.1%) were positive for acute cervical spine injury, compared to only 1.0% before the clinical education program (phase 2). Of the 376 examinations without injury, 13% met all 5 National Emergency X-Radiography Utilization Study criteria for nonimaging (down from 16.1% in phase 2), and 15 (4%) required no imaging when both National Emergency X-Radiography Utilization Study and abbreviated Canadian cervical spine rule criteria were applied.

CONCLUSIONS

Implementation of a clinical education initiative resulted in improved adherence to ACR Appropriateness Criteria and improved clinical effectiveness of the studies by increasing fracture detection rate. Initiatives such as these could potentially influence imaging overutilization without burdening emergency department clinicians with excessive roadblocks to image ordering.

Emergency radiology elective improves second-year medical students' perceived confidence and knowledge of appropriate imaging utilization

RATIONALE AND OBJECTIVES

Given recent advances in and wider availability of complex imaging, physicians are expected to understand imaging appropriateness. We introduced second-year medical students to the American College of Radiology Appropriateness Criteria (ACR-AC) in an interactive case-based elective to demonstrate their use in imaging for common emergency department clinical complaints.

MATERIALS AND METHODS

Prospective pre- and post-test design assessed second-year medical students' performance on case-based knowledge applications and self-assessed confidence related to ACR-AC guidelines compared to second-year students participating in a different concurrent radiology elective. Students participated in a 3-day elective covering the ACR-AC, comparative effective imaging, and risks associated with imaging radiation exposure, with outcomes of perceived confidence using a 5-point Likert scale and knowledge of ACR-AC using case-based multiple choice questions. Analysis included computing mean scores and assessing effect sizes for changes in knowledge.

RESULTS

Before the elective, 24 students scored an average of 3.45 questions correct of 8 (43.1%). On course completion, students scored an average of 5.3 questions correct of the same questions (66.3%) (P < .001; effect size [Cohen's d] = 1.3940. In the comparison group, 12 students scored an average of 3.08 questions (38.5%) correctly pretest and 3.09 questions (38.6%) correctly post-test (P > .85; effect size = 0.008). Students' confidence in ordering appropriate imaging improved nearly 2-fold from a range of 1.9 to 3.2 (on a scale of 1.0 to 5.0) to a range of 3.7 to 4.5.

CONCLUSIONS

Following a short radiology elective, second-year medical students improved their knowledge of appropriate image utilization and perceived awareness of the indications, contraindications, and effects of radiation exposure related to medical imaging.

The influence of education on appropriateness rates for CT pulmonary angiography in emergency department patients

RATIONALE AND OBJECTIVES

To evaluate appropriate utilization rates for computed tomography (CT) pulmonary angiography (CTPA) in a tertiary center emergency department (ED), before and after a health care provider educational intervention.

MATERIALS AND METHODS

Institutional Review Board-approved retrospective study. Records for 100 consecutive CTPA studies ordered by the ED were retrieved from a radiology database. Appropriateness rates for the studies were determined using information from existing literature (clinical decision rules and society guidelines). Where pretest probability was not performed, it was calculated by the authors. After ED health care provider education regarding appropriateness guidelines through a dedicated lecture and question-and-answer session, appropriateness rates for another 100 consecutive CTPA ordered by the ED were calculated.

RESULTS

In the preeducational intervention, 1% of patients had Wells scores performed, 65% were women, and 29% were age <40 years. Before CTPA, 40% patients had d-dimer testing, 15% of patients had a "negative" d-dimer, 17% had alternative explanations for chest pain, and 76% had low or intermediate pretest probability. Appropriateness rates for CTPA was 7%, and 8% of studies were positive. Postintervention, no Wells scores were performed, 59% were women, and 34% <40 years. Before CTPA, 32% of patients had d-dimer, 16% had a "negative" d-dimer, 22% had alternative explanations for chest pain, and 84% had low or intermediate pretest probability. The appropriateness rate for CTPA was 6% and 10% of studies were positive.

CONCLUSION

A single educational intervention had no effect on appropriate utilization rates for CTPA. Repeated and sustained educational interventions may help improve imaging ordering pathways through the ED and other departments.

Survey of inappropriate use of magnetic resonance imaging

Objective

There are concerns that not all costly advanced imaging is appropriate. However, studies about the appropriateness of magnetic resonance imaging (MRI) are sparse. The aim of this study was to review various MRI examinations done at a university hospital to determine whether there is inappropriate use.

Methods

Altogether 150 common MRIs (upper abdomen or liver, lumbar spine, knee, head and head of children performed under anaesthesia, 30 each) were reviewed consecutively. The referrals and corresponding patient files were analysed by senior radiologists and the indications of the examinations were compared to the referral criteria.

Results

Seven per cent of the examinations were deemed inappropriate. All the MRIs of the head done on children were indicated. One to three examinations in all other subgroups were not indicated. The most common appropriate indications were ambiguous hepatic, pancreatic or adrenal lesions, prolonged lower back pain, suspicion of meniscus rupture, brain malignancy and developmental disorder of a child, respectively.

Conclusions

Although the proportion of inappropriate examinations was not high; financial issues and the growing number of patients referred for MRI are of concern. Education and regular use of up-to-date referral guidelines could help to further improve appropriateness.

Main Messages

•Seven per cent of the MRI examinations analysed were inappropriate at a university hospital.

•Everyday practices of a hospital may contribute to the level of appropriateness.

•A survey of indications for previous MRI examinations might be helpful in various institutions.

Ordering patterns for laboratory and radiology tests by students from different undergraduate medical curricula

BACKGROUND

The overuse of laboratory tests and radiology imaging and their possible hazards to patients and the health care system is observed with growing concern in the medical community. With this study the authors wished to determine whether ordering patterns for laboratory and radiology tests by medical students close to their graduation are related to undergraduate training.

METHODS

We developed an assessment for near graduates in the setting of a resident's daily routine including a consultation hour with five simulated patients, three hours for patient work up with simulated distracting tasks, and thirty minutes for reporting of patient management to a supervisor. In 2011, 60 students participated in this assessment: 30 from a vertically integrated (VI) curriculum (Utrecht, The Netherlands) and 30 from a traditional, non-VI curriculum (Hamburg, Germany). We assessed and compared the number of laboratory and radiology requests and correlated the results with the scores participants received from their supervisors for the facet of competence "scientifically and empirically grounded method of working".

RESULTS

Students from a VI curriculum used significantly (p < .01) less total laboratory requests (N = 283 versus N = 466) which correlated with their scores for a "scientifically and empirically grounded method of working" (Pearson's r = .572). A significantly (p < .01) higher number of radiology imaging was ordered with a large effect size (V = .618) by near graduates from a non-VI curriculum (N = 156 versus N = 97) even when this was not supporting the diagnostic process.

CONCLUSION

The focused ordering patterns from VI students might be a result of their early exposure to the clinical environment and a different approach to clinical decision making during their undergraduate education which further studies should address in greater detail.

Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain

PURPOSE

The purpose of this study was to investigate the correlation between model observer and human observer performance in CT imaging for the task of lesion detection and localization when the lesion location is uncertain.

METHODS

Two cylindrical rods (3-mm and 5-mm diameters) were placed in a 35×26 cm torso-shaped water phantom to simulate lesions with -15 HU contrast at 120 kV. The phantom was scanned 100 times on a 128-slice CT scanner at each of four dose levels (CTDIvol=5.7, 11.4, 17.1, and 22.8 mGy). Regions of interest (ROIs) around each lesion were extracted to generate images with signal-present, with each ROI containing 128×128 pixels. Corresponding ROIs of signal-absent images were generated from images without lesion mimicking rods. The location of the lesion (rod) in each ROI was randomly distributed by moving the ROIs around each lesion. Human observer studies were performed by having three trained observers identify the presence or absence of lesions, indicating the lesion location in each image and scoring confidence for the detection task on a 6-point scale. The same image data were analyzed using a channelized Hotelling model observer (CHO) with Gabor channels. Internal noise was added to the decision variables for the model observer study. Area under the curve (AUC) of ROC and localization ROC (LROC) curves were calculated using a nonparametric approach. The Spearman's rank order correlation between the average performance of the human observers and the model observer performance was calculated for the AUC of both ROC and LROC curves for both the 3- and 5-mm diameter lesions.

RESULTS

In both ROC and LROC analyses, AUC values for the model observer agreed well with the average values across the three human observers. The Spearman's rank order correlation values for both ROC and LROC analyses for both the 3- and 5-mm diameter lesions were all 1.0, indicating perfect rank ordering agreement of the figures of merit (AUC) between the average performance of the human observers and the model observer performance.

CONCLUSIONS

In CT imaging of different sizes of low-contrast lesions (-15 HU), the performance of CHO with Gabor channels was highly correlated with human observer performance for the detection and localization tasks with uncertain lesion location in CT imaging at four clinically relevant dose levels. This suggests the ability of Gabor CHO model observers to meaningfully assess CT image quality for the purpose of optimizing scan protocols and radiation dose levels in detection and localization tasks for low-contrast lesions.

CT for pediatric, acute, minor head trauma: clinician conformity to published guidelines

BACKGROUND AND PURPOSE

In 2001, pediatric radiologists participating in a panel discussion on CT dose reduction suggested that approximately 30% of head CT examinations were performed unnecessarily. With increasing concern regarding radiation exposure to children and imaging costs, this claim warrants objective study. The purpose of this study was to test the null hypothesis that 30% of head CT studies for clinical evaluation of children with acute, minor head trauma do not follow established clinical guidelines.

MATERIALS AND METHODS

Retrospective review of 182 consecutive patients with acute, minor head trauma from February 2009 to January 2010 at a tertiary care children's hospital emergency department was performed, and clinician adherence to published clinical guidelines for children younger than 2 years and children 2-20 years of age was determined. The binomial test was used for a null hypothesis of 30% unnecessary examinations against the actual percentage of head CTs deemed unnecessary on the basis of established guidelines. Statistical testing was performed for children younger than 2 years and 2-20 years of age.

RESULTS

For children younger than 2 years of age, 2 of 78 (2.6%; 95% CI, 0.5%-8.3%) and, for children 2-20 years of age, 12 of 104 (11.5%; CI, 6.4%-18.7%) did not conform to established guidelines. These percentages were significantly less than the hypothesized value of 30% (P < .001).

CONCLUSIONS

Clinician conformity to published guidelines for use of head CT in acute, minor head trauma is better than suggested by a 2001 informal poll of pediatric radiologists.

Practice patterns in spine radiograph utilization among doctors of chiropractic enrolled in a provider network offering complementary care in the United States

OBJECTIVE

Nonspecific back pain is associated with high use of diagnostic imaging in primary care, yet current evidence suggests that routine imaging of the spine is unnecessary. The objective of this study is to describe current practice patterns in spine radiograph utilization among doctors of chiropractic enrolled in an American provider network.

METHODS

A cross-sectional analysis of administrative claims data from one of the largest providers of complementary health care networks for health plans in the United States was performed. Survey data containing provider demographics were linked with routinely collected data on spine radiograph utilization and patient characteristics aggregated at the provider level. We calculated rates and variations of spine radiographs over 12 months. Negative binomial regression was performed to identify significant predictors of high radiograph utilization and to estimate the associated incidence risk ratio.

RESULTS

Complete data for 6946 doctors of chiropractic and 249193 adult patients were available for analyses. In 2010, claims were paid for a total of 91542 new patient examinations and 23369 spine radiographs (including 17511 ordered within 5 days of initial patient examination). The rate of spine radiographs within 5 days of an initial patient visit was 204 per 1000 new patient examinations. Significant predictors of higher radiograph utilization rates included the following: practicing in the Midwest or South US census regions, practicing in an urban or suburban setting, chiropractic school attended, and being a male provider in full-time practice with more than 20 years of experience.

CONCLUSION

Chiropractic school attended and practice location were the most influential predictors of spine radiograph utilization among network chiropractors. This information may help to inform the development and evaluation of a tailored intervention to address overuse of radiograph utilization.

The assessment of function. Part II: clinical perspective of a javelin thrower with low back and groin pain

Assessment of an individual's functional ability can be complex. This assessment should also be individualized and adaptable to changes in functional status. In the first article of this series, we operationally defined function, discussed the construct of function, examined the evidence as it relates to assessment methods of various aspects of function, and explored the multi-dimensional nature of the concept of function. In this case report, we aim to demonstrate the utilization of a multi-dimensional assessment method (functional performance testing) as it relates to a high-level athlete presenting with pain in the low back and groin. It is our intent to demonstrate how the clinician should continually adapt their assessment dependent on the current functional abilities of the patients.

Effect of initial postoperative visit radiographs on treatment plans

BACKGROUND

It is a common practice among orthopaedic surgeons to make radiographs at the first outpatient postoperative visit after surgical repair of acute fractures. There is not much literature that investigates the benefits and necessity of such a practice. We hypothesized that the practice of routine postoperative radiographs is unnecessary and increases cost to the patients and the health-care system, increases radiation exposure, and provides no change in patient management.

METHODS

A retrospective review of patients sustaining acute fractures requiring operative fixation was done with the goal of determining how often a radiograph made at the first postoperative visit in the surgeon's office resulted in a change in patient management.

RESULTS

Fifteen (7.5%) of 200 fractures in 171 patients had a clinical indication for a radiograph because of an abnormal physical examination finding or history of additional trauma. Three (1.5%) of these fractures had a deviation from standard postoperative care; this deviation was a change in postoperative care on the basis of the patient history and physical examination rather than radiographs. One fracture (0.5%) had a radiographic change from the immediate postoperative radiograph to the clinic radiograph, yet did not have a change in treatment. The estimated average radiation exposure per radiograph was 0.164 mSv, and the average charge to the patient per radiograph was $335.13.

CONCLUSIONS

The majority of radiographs made at the first postoperative visit in the surgeon's office after acute fracture fixation did not result in a change in patient management and added substantial cost to the health-care system.

Cost-effectiveness of risk stratified followup after urethral reconstruction: a decision analysis

PURPOSE

We propose a novel risk stratified followup protocol for use after urethroplasty and explore potential cost savings.

MATERIALS AND METHODS

Decision analysis was performed comparing a symptom based, risk stratified protocol for patients undergoing excision and primary anastomosis urethroplasty vs a standard regimen of close followup for urethroplasty. Model assumptions included that excision and primary anastomosis has a 94% success rate, 11% of patients with successful urethroplasty had persistent lower urinary tract symptoms requiring cystoscopic evaluation, patients in whom treatment failed undergo urethrotomy and patients with recurrence on symptom based surveillance have a delayed diagnosis requiring suprapubic tube drainage. The Nationwide Inpatient Sample from 2010 was queried to identify the number of urethroplasties performed per year in the United States. Costs were obtained based on Medicare reimbursement rates.

RESULTS

The 5-year cost of a symptom based, risk stratified followup protocol is $430 per patient vs $2,827 per patient using standard close followup practice. An estimated 7,761 urethroplasties were performed in the United States in 2010. Assuming that 60% were excision and primary anastomosis, and with more than 5 years of followup, the risk stratified protocol was projected to yield an estimated savings of $11,165,130. Sensitivity analysis showed that the symptom based, risk stratified followup protocol was far more cost-effective than standard close followup in all settings. Less than 1% of patients would be expected to have an asymptomatic recurrence using the risk stratified followup protocol.

CONCLUSIONS

A risk stratified, symptom based approach to urethroplasty followup would produce a significant reduction in health care costs while decreasing unnecessary followup visits, invasive testing and radiation exposure.

Physicians' beliefs about breast cancer surveillance testing are consistent with test overuse

BACKGROUND

Overuse of surveillance testing for breast cancer survivors is an important problem but its extent and determinants are incompletely understood. The objectives of this study were to determine the extent to which physicians' breast cancer surveillance testing beliefs are consistent with test overuse, and to identify factors associated with these beliefs.

METHODS

During 2009-2010, a cross-sectional survey of US medical oncologists and primary care physicians (PCPs) was carried out. Physicians responded to a clinical vignette ascertaining beliefs about appropriate breast cancer surveillance testing. Multivariable analyses examined the extent to which test beliefs were consistent with overuse and associated with physician and practice characteristics and physician perceptions, attitudes, and practices.

RESULTS

A total of 1098 medical oncologists and 980 PCPs completed the survey (response rate 57.5%). Eighty-four percent of PCPs [95% confidence interval (CI), 81.4%-86.5%] and 72% of oncologists (95% CI, 69.8%-74.7%) reported beliefs consistent with blood test overuse, whereas 50% of PCPs (95% CI, 47.3%-53.8%) and 27% of oncologists (95% CI, 23.9%-29.3%) reported beliefs consistent with imaging test overuse. Among PCPs, factors associated with these beliefs included smaller practice size, lower patient volume, and practice ownership. Among oncologists, factors included older age, international medical graduate status, lower self-efficacy (confidence in knowledge), and greater perceptions of ambiguity (conflicting expert recommendations) regarding survivorship care.

CONCLUSIONS

Beliefs consistent with breast cancer surveillance test overuse are common, greater for PCPs and blood tests than for oncologists and imaging tests, and associated with practice characteristics and perceived self-efficacy and ambiguity about testing. These results suggest modifiable targets for efforts to reduce surveillance test overuse.

Prediction of human observer performance in a 2-alternative forced choice low-contrast detection task using channelized Hotelling observer: impact of radiation dose and reconstruction algorithms

PURPOSE

Efficient optimization of CT protocols demands a quantitative approach to predicting human observer performance on specific tasks at various scan and reconstruction settings. The goal of this work was to investigate how well a channelized Hotelling observer (CHO) can predict human observer performance on 2-alternative forced choice (2AFC) lesion-detection tasks at various dose levels and two different reconstruction algorithms: a filtered-backprojection (FBP) and an iterative reconstruction (IR) method.

METHODS

A 35 × 26 cm(2) torso-shaped phantom filled with water was used to simulate an average-sized patient. Three rods with different diameters (small: 3 mm; medium: 5 mm; large: 9 mm) were placed in the center region of the phantom to simulate small, medium, and large lesions. The contrast relative to background was -15 HU at 120 kV. The phantom was scanned 100 times using automatic exposure control each at 60, 120, 240, 360, and 480 quality reference mAs on a 128-slice scanner. After removing the three rods, the water phantom was again scanned 100 times to provide signal-absent background images at the exact same locations. By extracting regions of interest around the three rods and on the signal-absent images, the authors generated 21 2AFC studies. Each 2AFC study had 100 trials, with each trial consisting of a signal-present image and a signal-absent image side-by-side in randomized order. In total, 2100 trials were presented to both the model and human observers. Four medical physicists acted as human observers. For the model observer, the authors used a CHO with Gabor channels, which involves six channel passbands, five orientations, and two phases, leading to a total of 60 channels. The performance predicted by the CHO was compared with that obtained by four medical physicists at each 2AFC study.

RESULTS

The human and model observers were highly correlated at each dose level for each lesion size for both FBP and IR. The Pearson's product-moment correlation coefficients were 0.986 [95% confidence interval (CI): 0.958-0.996] for FBP and 0.985 (95% CI: 0.863-0.998) for IR. Bland-Altman plots showed excellent agreement for all dose levels and lesions sizes with a mean absolute difference of 1.0% ± 1.1% for FBP and 2.1% ± 3.3% for IR.

CONCLUSIONS

Human observer performance on a 2AFC lesion detection task in CT with a uniform background can be accurately predicted by a CHO model observer at different radiation dose levels and for both FBP and IR methods.

Medical student radiology curriculum: what skills do residency program directors believe are essential for medical students to attain?

RATIONALE AND OBJECTIVES

The purpose of this study was to identify radiology topics considered essential by residency program directors who will be working with our graduates. Secondary goals were to survey their satisfaction with incoming residents' radiology knowledge, inquire if radiology training was provided in their programs, and identify differences among specialties.

MATERIALS AND METHODS

A questionnaire was mailed to all residency program directors in emergency medicine, family medicine, internal medicine, pediatrics, and general surgery programs that accepted our graduates between 2005 and 2010. Program directors were asked to rate a list of radiology knowledge and skills topics as essential or nonessential and to answer several questions regarding their residents and programs.

RESULTS

Ninety-nine surveys were completed (51.3% response rate). Seven skills were considered essential by 90% or more of all respondents. On average, program directors identified 18/28 topics as essential prior to beginning their residency. The mean number identified as essential did not differ by program (F4, 93 = 0.732, P = .572). Based on analyses of variance comparing each topic by program, the importance of six topics differed significantly. Program directors generally agreed that incoming residents had adequate radiology skills and knowledge when they started their residencies. One hundred percent of the responding emergency medicine, family medicine, and pediatrics programs and 70% to 80% of the general surgery and internal medicine programs provide radiology training.

CONCLUSION

There is high agreement among program directors regarding imaging topics they consider essential. Topics considered essential by more than 60% should comprise our core curriculum for all students while less essential topics can be included in elective or program specific curricula.

Geographic and sociodemographic disparities in PET use by Medicare beneficiaries with cancer

PURPOSE

PET use for cancer care has increased unevenly, possibly because of regional health care market characteristics or underlying population characteristics. The aim of this study was to examine variation in advanced imaging use among individuals with cancer in relation to population and hospital service area (HSA) characteristics.

METHODS

A retrospective national study of fee-for-service Medicare beneficiaries with diagnoses of 1 of 5 cancers covered by Medicare for PET (2004-2008) was conducted. Crude and adjusted rates of PET, CT, and MRI were estimated for HSAs and sociodemographic subgroups. Generalized linear mixed models were used to assess the effects of race/ethnicity, area-level income, and HSA-level physician supply and spending on imaging utilization.

RESULTS

On the basis of an annual average of 116,452 beneficiaries with cancer, adjusted PET rates (imaging days per person-year) showed significantly higher use for whites compared with blacks in both 2004 (whites, 0.35 [95% confidence interval, 0.34-0.36]; blacks, 0.31 [95% confidence interval, 0.30-0.33]) and 2008 (whites, 0.64 [95% confidence interval, 0.63-0.65]; blacks, 0.57 [95% confidence interval, 0.55-0.59]). This trend was similar for the highest quartile of group-level median household income but was opposite for CT use, with blacks having higher rates than whites. The highest Medicare-spending HSAs had significantly higher adjusted PET rates compared with lower spending areas (0.57 [95% confidence interval, 0.55-0.60] vs 0.69 [95% confidence interval, 0.67-0.71] imaging days/person-year).

CONCLUSIONS

The use of PET among Medicare beneficiaries with cancer increased from 2004 to 2008, with higher rates observed among whites, among higher socioeconomic groups, and in higher Medicare spending areas. Sociodemographic differences in advanced imaging use are modality specific.

A text processing pipeline to extract recommendations from radiology reports

Communication of follow-up recommendations when abnormalities are identified on imaging studies is prone to error. The absence of an automated system to identify and track radiology recommendations is an important barrier to ensuring timely follow-up of patients especially with non-acute incidental findings on imaging examinations. In this paper, we present a text processing pipeline to automatically identify clinically important recommendation sentences in radiology reports. Our extraction pipeline is based on natural language processing (NLP) and supervised text classification methods. To develop and test the pipeline, we created a corpus of 800 radiology reports double annotated for recommendation sentences by a radiologist and an internist. We ran several experiments to measure the impact of different feature types and the data imbalance between positive and negative recommendation sentences. Our fully statistical approach achieved the best f-score 0.758 in identifying the critical recommendation sentences in radiology reports.

Declining trend in the use of repeat computed tomography for trauma patients admitted to a level I trauma center for traffic-related injuries

OBJECTIVE

To evaluate the trend in utilization of repeat (i.e. ≥2) computed tomography (CT) and to compare utilization patterns across body regions for trauma patients admitted to a level I trauma center for traffic-related injuries (TRI).

MATERIALS AND METHODS

We linked the Harborview Medical Center trauma registry (1996-2010) to the billing department data. We extracted the following variables: type and frequency of CTs performed, age, gender, race/ethnicity, insurance status, injury mechanism and severity, length of hospitalization, intensive care unit (ICU) admission and final disposition. TRIs were defined as motor vehicle collisions, motorcycle, bicycle and pedestrian-related injuries. Logistic regression was used to evaluate the association between utilization of different body region repeat (i.e. ≥2) CTs and year of admission, adjusting for patient and injury-related characteristics that could influence utilization patterns.

RESULTS

A total of 28,431 patients were admitted for TRIs over the study period and 9499 (33%) received repeat CTs. From 1996 to 2010, the proportion of patients receiving repeat CTs decreased by 33%. Relative to 2000 and adjusting for other covariates, patients with TRIs admitted in 2010 had significantly lower odds of undergoing repeat head (OR=0.61; 95% CI: 0.49-0.76), pelvis (OR=0.37; 95% CI: 0.27-0.52), cervical spine (OR=0.23; 95% CI: 0.12-0.43), and maxillofacial CTs (OR=0.24; 95% CI: 0.10-0.57). However, they had higher odds of receiving repeat thoracic CTs (OR=1.86; 95% CI: 1.02-3.38).

CONCLUSION

A significant decrease in the utilization of repeat CTs was observed in trauma patients presenting with traffic-related injuries over a 15-year period.

Insight into the sharing of medical images: physician, other health care providers, and staff experience in a variety of medical settings

BACKGROUND

Scant knowledge exists describing health care providers' and staffs' experiences sharing imaging studies. Additional research is needed to determine the extent to which imaging studies are shared in diverse health care settings, and the extent to which provider or practice characteristics are associated with barriers to viewing external imaging studies on portable media.

OBJECTIVE

This analysis uses qualitative data to 1) examine how providers and their staff accessed outside medical imaging studies, 2) examine whether use or the desire to use imaging studies conducted at outside facilities varied by provider specialty or location (urban, suburban, and small town) and 3) delineate difficulties experienced by providers or staff as they attempted to view and use imaging studies available on portable media.

METHODS

Semi-structured interviews were conducted with 85 health care providers and medical facility staff from urban, suburban, and small town medical practices in North Carolina and Virginia. The interviews were audio recorded, transcribed, then systematically analyzed using ATLAS.ti.

RESULTS

Physicians at family and pediatric medicine practices rely primarily on written reports for medical studies other than X-rays; and thus do not report difficulties accessing outside imaging studies. Subspecialists in urban, suburban, and small towns view imaging studies through internal communication systems, internet portals, or portable media. Many subspecialists and their staff report experiencing difficulty and time delays in accessing and using imaging studies on portable media.

CONCLUSION

Subspecialists have distinct needs for viewing imaging studies that are not shared by typical primary care providers. As development and implementation of technical strategies to share medical records continue, this variation in need and use should be noted. The sharing and viewing of medical imaging studies on portable media is often inefficient and fails to meet the needs of many subspeciality physicians, and can lead to repeated imaging studies.

Prereferral MRI use in patients with musculoskeletal tumors is not excessive

BACKGROUND

Inappropriate MRI use has been targeted as a particular area of concern in orthopaedics, but it is unclear whether and to what extent its use is inappropriate in musculoskeletal oncology.

QUESTIONS/PURPOSES

We therefore evaluated the incidence and cost of inappropriate prereferral MRI among patients with musculoskeletal tumors.

METHODS

We retrospectively identified 920 patients treated in a musculoskeletal oncology clinic between 2009 and 2010. We accepted as necessary any MRI for a primary bone sarcoma, for biopsy-proven soft tissue sarcomas, for soft tissue masses greater than 5 cm in diameter, for soft tissue masses deep to the fascia, for painful soft tissue masses, and for growing soft tissue masses. Patients without these criteria were reviewed by a team of musculoskeletal oncologists to determine the necessity. The criteria for a repeat MRI were failure to show the tumor, lack of gadolinium contrast, lack of T1 or T2 MRI sequence, or poor image quality. Cost was determined using 2010 Medicare reimbursement rates.

RESULTS

Of 920 patients, 320 (35%) arrived with a prereferral MRI study. Eight of the 320 (3%) studies were unnecessary, and 12 (4%) were necessary but were repeated. The cost was $11,474, which averages to $574 per study and $36 of waste per patient referred with an MRI study.

CONCLUSIONS

Based on our data, we judged MRI use before referral to our tertiary center as not excessive. This is likely attributable, in part, to the relatively low use of MRI in our referral base. Inappropriate MRI use in patients with tumors may not be as widespread as previously reported.

LEVEL OF EVIDENCE

Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Minimising medically unwarranted computed tomography scans

As computed tomography (CT) is such a superb diagnostic tool and individual CT risks are small, whenever a CT scan is clinically warranted, the CT benefit/risk balance is by far in the patient's favour. However, if a CT scan is not clinically warranted, this balance shifts dramatically. It is likely that at least 25% of CT scans fall into this latter category, in that they could either be replaced with alternative imaging modalities or could be avoided entirely. Use of clinical decision rules for CT usage represents a powerful approach for slowing down the increase in CT usage, because they have the potential to overcome some of the major factors that result in some CT scans being undertaken when they may not be clinically helpful.

Justifying referrals for paediatric CT

• The system of radiation protection assumes a linear dose-response relationship with no threshold for low doses and dose rate exposures. This is based on epidemiological evidence at higher doses. • Hence there is a small theoretical risk of carcinogenesis attributable to low doses of ionising radiation. This risk is associated with any diagnostic imaging procedure involving radiation. • Radiosensitivity declines with age, so children are more susceptible to radiation risks than adults. Females are more radiosensitive than males. • The radiation protection system is based on the assumption that radiation risk is cumulative over a lifetime. • For an individual, a justified, optimised computed tomography (CT) scan will result in more benefit than harm. A doctor must justify the necessity for a CT scan before referring an individual for imaging.

Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework

Background

The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without x-rays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine x-rays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays.

Methods

Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF.

Results

Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied ( social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors ( social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays ( belief about capabilities); and guideline awareness and agreements ( knowledge).

Conclusions

Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theory-based survey to help identify potential targets for behavioral-change strategies.

Combating overutilization: radiology benefits managers versus order entry decision support

Radiology benefits managers (RBMs) and computerized decision support offer different advantages and disadvantages in the efforts to provide appropriate use of radiology resources. RBMs are effective in their hard-stop ability to reject inappropriate studies, incur a significant cost, and interpose an intermediary between patient and physician. Decision support is a more friendly educational product, but has not been implemented for all clinical indications and its efficacy is still being studied.

Environmental causes of breast cancer and radiation from medical imaging: findings from the Institute of Medicine report

Susan G. Komen for the Cure asked the Institute of Medicine (IOM) to perform a comprehensive review of environmental causes and risk factors for breast cancer. Interestingly, none of the consumer products (ie, bisphenol A, phthalates), industrial chemicals (ie, benzene, ethylene oxide), or pesticides (ie, DDT/DDE) considered could be conclusively linked to an increased risk of breast cancer, although the IOM acknowledged that the available evidence was insufficient to draw firm conclusions for many of these exposures, calling for more research in these areas. The IOM found sufficient evidence to conclude that the 2 environmental factors most strongly associated with breast cancer were exposure to ionizing radiation and to combined postmenopausal hormone therapy. The IOM's conclusion of a causal relation between radiation exposure and cancer is consistent with a large and varied literature showing that exposure to radiation in the same range as used for computed tomography will increase the risk of cancer. It is the responsibility of individual health care providers who order medical imaging to understand and weigh the risk of any medical procedures against the expected benefit.

The effect of imaging on the clinical management of breast pain

BACKGROUND

Breast pain is a common complaint to primary care and breast specialists. Literature recommends imaging to provide reassurance of benign etiology. The effect of imaging on reassurance and subsequent healthcare utilization has not been described.

OBJECTIVE

To determine if initial imaging for breast pain reduces subsequent utilization.

DESIGN

Retrospective cohort study at a hospital-based breast health practice.

PATIENTS

Women referred for breast pain from 2006-2009.

MAIN MEASURES

Imaging ordered at initial provider visit; clinical utilization, defined as the number of follow-up visits, diagnostic imaging studies, and biopsies completed within 12 months following initial visit.

KEY RESULTS

Sixty-percent of women were age 40 or younger, 87% were from racial/ethnic minority groups. Twenty-five percent had imaging ordered at initial visit. Of those who received initial imaging, 75% had normal radiographic findings, yet 98% returned for additional evaluation. In adjusted analyses, women with initial imaging had increased clinical services utilization (OR 25.4, 95% CI: 16.7, 38.6). Women with normal clinical breast exams who received initial imaging exhibited increased odds for subsequent clinical services utilization (OR 23.8, 95% CI: 12.9, 44.0). Six cancers were diagnosed; imaging in the absence of clinical breast exam abnormalities did not result in any cancer identification.

CONCLUSIONS

Initial imaging for women with breast pain increased the odds of subsequent clinical utilization and did not increase reassurance in ruling out malignancy.

Advanced imaging: use and misuse

SUMMARY

The primary purpose of diagnostic imaging is to enable clinicians to make correct decisions about a patient's diagnosis and severity of its condition and, thereby, to contribute to effective and efficient treatment. Advanced imaging modalities are inherently better detectors of morphological lesions than radiography; hence, they offer the possibility of more accurate diagnosis and staging, with correspondingly better patient outcomes. However, there is a lack of evidence that better outcomes are being realised for veterinary patients. Furthermore, increased use of advanced imaging carries the possibility of increased misuse, primarily through unnecessary studies that contribute little to patient management other than increased costs.

SCOPE

This article is intended to be relevant to all veterinary species. Advanced imaging of cats is not sufficiently developed as a specific discipline that a balanced review could be based purely on feline examples or references.

Utilization effect of integrating a chest radiography room into a thoracic surgery ward

PURPOSE

Bedside chest radiography (CXR) represents a substantial fraction of the volume of medical imaging for inpatient health care facilities. However, its image quality is limited compared with posterior-anterior/lateral (PA/LAT) acquisitions taken in radiographic rooms. The aim of this study was to evaluate the utilization of bedside CXR and other chest imaging modalities before and after placing a radiography room within a thoracic surgical inpatient ward.

METHODS

All patient admissions (n = 3,852) to the thoracic surgical units between April 1, 2007, and December 31, 2010, were retrospectively identified. All chest imaging tests performed for these patients, including CT scans, MRI, ultrasound, and bedside and PA/LAT radiography, were counted. The primary outcome measure was chest imaging utilization, defined as the number of chest examinations per admission, before and after the establishment of the digital radiography room on January 10, 2010. Statistical analysis was performed using an independent-samples t test to evaluate changes in chest imaging utilization.

RESULTS

A 2.61-fold increase in the number of PA/LAT CXR studies per admission (P < .01) and a 1.96-fold decrease in the number of bedside CXR studies per admission (P < .01) were observed after radiography room implementation. The number of chest CT, MRI, and ultrasound studies per admission did not change significantly.

CONCLUSIONS

Establishing a radiography room physically within thoracic surgery units or in close proximity can significantly shift CXR utilization from bedside to PA/LAT acquisitions, which may enable opportunities for improvement in efficiency, quality, and safety in patient care.

Assessing the recommendations for the use of diagnostic imaging in clinical practice guidelines

Accuracy is the primary evidence assessed when diagnostic imaging is evaluated in clinical practice guidelines. However, recommendations to not use diagnostic imaging are usually based not on its accuracy but on its lack of utility, that is its low Level 4 efficacy. If there is good clinical evidence that diagnostic imaging will not be useful in a clinical situation, the recommendation not to use it should be strong even if the evidence for its accuracy is of poor quality.

Accuracy, risk and the intrinsic value of diagnostic imaging: a review of the cost-utility literature

RATIONALE AND OBJECTIVES

The aim of this study was to systematically review the reporting of the value of imaging unrelated to treatment consequences and test characteristics in all imaging-related published cost-utility analyses (CUAs) in the medical literature.

MATERIALS AND METHODS

All CUAs published between 1976 and 2008 evaluating diagnostic imaging technologies contained in the CEA Registry, a publicly available comprehensive database of health related CUAs, were screened. Publication characteristics, imaging modality, and the inclusion of test characteristics including accuracy, costs, risks, and the potential value unrelated to treatment consequences (eg, reassurance or anxiety) were assessed.

RESULTS

Ninety-six published CUAs evaluating 155 different imaging technologies were included in the final sample; 27 studies were published in imaging-specialized journals. Fifty-two studies (54%) evaluated the performance of a single imaging modality, while 44 studies (46%) compared two or more different imaging modalities. The most common areas of interest were cardiovascular (45%) and neuroradiology (17%). Forty-two technologies (27%) concerned ultrasound, while 34 (22%) concerned magnetic resonance. Seventy-nine (51%) technologies used ionizing radiation. Test accuracy was reported or calculated for 90% (n = 133 and n = 5, respectively) and assumed perfect (reference test or gold-standard test without alternative testing strategy to capture false-negatives and false-positives) for 8% (n = 12) of technologies. Only 22 studies (23%) assessing 40 imaging technologies (26%) considered inconclusive or indeterminate results. The risk of testing was reported for 32 imaging technologies (21%). Fifteen studies (16%) considered the value of diagnostic imaging unrelated to treatment. Four studies incorporated it as quality-of-life adjustments, while 10 studies mentioned it only in their discussions or as a limitation.

CONCLUSIONS

The intrinsic value of imaging (the value of imaging unrelated to treatment) has not been appropriately defined or incorporated in the existing cost-utility literature, which could be due to a lack of evidence on the issue. Thus, more research is needed on metrics for a more comprehensive evaluation of diagnostic imaging. Similarly, the incorporation of variations in imaging tests accuracy, inconclusive results and associated risks has lacked uniformity in the cost-utility literature. Acknowledgment of these characteristics in future cost-utility publications will enhance their value and provide results that more closely resemble routine clinical practice.

CT urography for hematuria

Hematuria can signify serious disease such as bladder cancer, upper urinary tract urothelial cell carcinoma (UUT-UCC), renal cell cancer or urinary tract stones. CT urography is a rapidly evolving technique made possible by recent advances in CT technology. CT urography is defined as CT examination of the kidneys, ureters and bladder with at least one series of images acquired during the excretory phase after intravenous contrast administration. The reasoning for using CT urography to investigate hematuria is based on its high diagnostic accuracy for urothelial cell carcinoma (UCC) and favorable comparison with other imaging techniques. The optimum diagnostic imaging strategy for patients with hematuria at high-risk for UCC involves the use of CT urography as a replacement for other imaging tests (ultrasonography, intravenous urography, or retrograde ureteropyelography) and as a triage test for cystoscopy, resulting in earlier diagnosis and improved prognosis of bladder cancer, UUT-UCC, renal cell cancer and stones. Current problems with CT urography for investigating hematuria might be solved with a formative educational program simulating clinical reporting to reduce reader error, and a new technique for image-guided biopsy of UUT-UCC detected by CT urography for histopathological confirmation of diagnosis and elimination of false-positive results. CT urography is recommended as the initial imaging test for hematuria in patients at high-risk for UCC.

Cancer risks associated with external radiation from diagnostic imaging procedures

The 600% increase in medical radiation exposure to the US population since 1980 has provided immense benefit, but increased potential future cancer risks to patients. Most of the increase is from diagnostic radiologic procedures. The objectives of this review are to summarize epidemiologic data on cancer risks associated with diagnostic procedures, describe how exposures from recent diagnostic procedures relate to radiation levels linked with cancer occurrence, and propose a framework of strategies to reduce radiation from diagnostic imaging in patients. We briefly review radiation dose definitions, mechanisms of radiation carcinogenesis, key epidemiologic studies of medical and other radiation sources and cancer risks, and dose trends from diagnostic procedures. We describe cancer risks from experimental studies, future projected risks from current imaging procedures, and the potential for higher risks in genetically susceptible populations. To reduce future projected cancers from diagnostic procedures, we advocate the widespread use of evidence-based appropriateness criteria for decisions about imaging procedures; oversight of equipment to deliver reliably the minimum radiation required to attain clinical objectives; development of electronic lifetime records of imaging procedures for patients and their physicians; and commitment by medical training programs, professional societies, and radiation protection organizations to educate all stakeholders in reducing radiation from diagnostic procedures.

Growth in the use of PET for six cancer types after coverage by medicare: additive or replacement?

BACKGROUND

In July 2001, PET became a covered service for Medicare beneficiaries when used for the diagnosis, staging, and restaging of non-small-cell lung, esophageal, colorectal, and head and neck cancers as well as lymphoma and melanoma. Whether physicians use PET as a replacement for or in addition to CT, MRI, or bone scintigraphy (BS) is uncertain.

METHODS

A 20% sample of Medicare fee-for-service beneficiaries aged > 64 years from 2004 through 2008 was used. Annually for each cancer type, a cohort of patients was created defined as having at least one admission with a primary cancer diagnosis or two nonhospital claims with a cancer diagnosis ≥7 days apart per calendar year. Each year, imaging claims and claim-days were counted by modality and cancer type. The sequence of PET use was examined as before, after, or instead of other imaging.

RESULTS

About 125,000 beneficiaries (2.5% of the cohort) met the cancer definition each year. In 2008, the combined annual imaging days per person-year were 2.3 for CT, 0.49 for MRI, 0.70 for PET, and 0.13 for BS. The annual rates of imaging from 2004 to 2008 increased by 0.5% for CT, 3.2% for MRI, and 18.0% for PET (range, 14.6%-19.9% by cancer type) and decreased by 12.7% for BS. The growth in PET use was not associated with meaningful changes in body CT. In 2007 and 2008, body CT preceded PET within 30 days in about half of patients, whereas PET preceded CT in only 22%.

CONCLUSIONS

Several years after its introduction, PET continued to grow rapidly, with evidence that it is replacing BS. Growth of PET occurred without evidence of a decline in body CT. About half of PET use occurred shortly after body CT, suggesting an additive or final arbiter role.

Compendium of national guidelines for imaging of the pediatric patient

BACKGROUND

Diagnostic imaging plays an integral role in diagnosing and managing many pediatric disorders, but there is growing concern in both the medical community and the general public about the long-term health effects of ionizing radiation in children, as well as utilization of imaging evaluation. These concerns, coupled with increasing pressure to reduce national health care spending, underscore the need for an assessment of readily available guidelines, especially evidence-based guidelines, for imaging in children.

OBJECTIVE

To generate a list of national medical organization-endorsed guidelines with provisions for imaging the pediatric patient.

MATERIALS AND METHODS

Several resources, including the National Guideline Clearinghouse (NGC) and the Web sites of major medical organizations, were searched for documents that contained specific recommendations for imaging in the pediatric population.

RESULTS

A total of 155 guidelines from 40 medical organizations met inclusion criteria and are represented in our compendium.

CONCLUSIONS

The compendium generated in this study can be used to direct clinical care, inform policy development and improve education of health care personnel. Additionally, the compendium can be used to identify areas of redundancy or deficiency, which may stimulate the reassessment of existing recommendations as well as the creation of new guidelines.