Current usage of nonionic contrast.

All physicians who had billed Pennsylvania Blue Shield for at least three intravenous contrast studies during 1989 were surveyed on their use of nonionic versus ionic contrast. This surveyed group represents a diversity of hospital sizes, practice types, and group sizes. Of the 383 physician groups surveyed, responses were obtained from 285. The majority of the responding groups were radiologists (94.0%). Nonionic contrast is utilized in 41.3% of all intravenous studies. Radiologists use nonionic contrast in a much greater proportion than nonradiologists (P < 0.0001), with 17.6% of radiologists utilizing nonionic contrast in all of their patients. Conversely, 75% of nonradiologists utilize ionic contrast in all of their patients. For all physician groups surveyed, 40.3% utilize nonionic for at least 50%, while 27.6% use nonionics for more than 75% of their patients. The routine use of steroid premedication prior to the injection of ionic contrast is not a common practice. The increased utilization of nonionic contrast found in this survey may reflect the cross-section of physicians and practice types surveyed or may represent changing practice patterns among physicians utilizing contrast material.     

Use of informed consent for ionic and nonionic contrast media.

The use of informed consent before intravenous administration of contrast material remains a controversial issue. It involves explaining the risks of intravenous contrast material and obtaining the patient's permission for its use. All physician groups who had billed Pennsylvania Blue Shield for at least three intravenous contrast material-enhanced procedures performed in 1989 were surveyed. Informed consent was obtained from at least some patients by about two-thirds of physician groups before using intravenous contrast material, regardless of whether it was ionic or nonionic. Nonradiologists were more likely to obtain informed consent before the use of ionic contrast material than radiologists. Regardless of specialty, practices associated with larger hospitals (greater than 250 beds), larger physician groups (greater than 10), or a university used informed consent less often than smaller physician groups or those associated with a smaller hospital or a private practice. Though results may be affected by regional variation or increased usage since previous surveys, the use of informed consent before the intravenous injection of contrast material is a common practice; it is obtained in the majority of patients.     

National Trends in the Utilization of Skeletal Radiography From 2003 to 2015

PurposeExamine recent trends in the use of skeletal radiography and assess the roles of various nonradiologic specialties in the interpretations.MethodsMedicare Part B fee-for-service claims data files from 2003 to 2015 were analyzed for all Current Procedural Terminology, version 4 (CPT-4) procedure codes related to skeletal radiography. The files provide examination volume, and we calculated utilization rates per 1,000 Medicare beneficiaries. Medicare’s physician specialty codes were used to determine the specialties of the providers. Total utilization rate trends were analyzed, as well as those for radiologists and nonradiologists. We determined which nonradiologist specialties were the highest users of skeletal radiography. Medicare place-of-service codes were used to identify the locations where the services were provided.ResultsThe total utilization rate per 1,000 of skeletal radiography within the Medicare population increased 9.5% from 2003 to 2015. The utilization rate for radiologists increased 5.5% from 2003 to 2015 versus 11.1% for nonradiologists as a group. Among nonradiologist specialties in all health care settings over the study period, orthopedic surgeons increased 10.6%, chiropractors and podiatrists together increased 14.4%, nonphysician providers (primarily nurse practitioners and physician assistants) increased 441%, and primary care physicians’ rate decreased 33.5%. Although radiologists do almost all skeletal radiography interpretation in hospital settings, nonradiologists do the majority in private offices. There has been strong growth in skeletal radiography in emergency departments, but a substantial drop in inpatient settings.ConclusionsThe utilization of skeletal radiography has increased more rapidly among nonradiologists than among radiologists. This raises concerns about self-referral and quality.     

Day of Week,Site of Service,and Patient Complexity Differences in Venous Ultrasound Interpreted by Radiologists Versus Nonradiologists

ObjectiveNationally, nonradiologists interpret an increasing proportion of lower extremity venous duplex ultrasound (LEVDU) examinations. We aimed to study day of week, site of service, and patient complexity differences in LEVDU services interpreted by radiologists versus nonradiologists.Materials and MethodsUsing carrier claims files for a 5% national sample of Medicare beneficiaries from 2012 to 2015, we retrospectively classified all LEVDU examinations by physician specialty (radiologist versus nonradiologist), day of week (weekday versus weekend), site of service, and patient Charlson Comorbidity Index (CCI) scores. Pearson’s χ² was used to test statistical significance.ResultsOf 760,433 LEVDU examinations for which provider specialty could be determined, 439,964 (58%) were interpreted by radiologists and 320,469 (42%) by nonradiologists. On weekends, radiologists interpreted 75% (66,094 of 88,244) and nonradiologists 25% (22,150 of 88,244) (P < .0001). Of LEVDU examinations interpreted by radiologists, 57% were performed in the inpatient or emergency department settings, and 70% of LEVDU examinations interpreted by nonradiologists were performed in the private office or outpatient hospital setting. Radiologists interpreted a slightly larger proportion (17%) of their examinations on patients with more comorbidities (CCI of ≥3) than nonradiologists (15%) (P < .0001).ConclusionCompared with nonradiologists, radiologists interpret a disproportionately larger share of weekend (versus weekday) LEVDU examinations and a considerably larger proportion in higher acuity settings. Additionally, the patients on whom they render services have more comorbidities. To optimize around-the-clock patient access to necessary imaging, emerging quality payment programs should consider the timing and sites of service, as well as patient complexity.     

Is terminology used effectively to convey diagnostic certainty in radiology reports?

RATIONALE AND OBJECTIVES: This study was performed to assess the extent of agreement among radiologists and nonradiologists in perception of diagnostic certainty conveyed by words and phrases commonly used in radiology reports. MATERIALS AND METHODS: The study was performed in a large academic radiology department. To determine the commonly used terminology for conveying diagnostic certainty in radiology reports, 12 randomly selected radiologists from six different subspecialties were interviewed. The authors identified the 15 most commonly used words and phrases and included these in random order in a questionnaire sent to all staff radiologists (n = 45) and to 158 referring physicians. Physicians were asked to rank the 15 phrases in order of the diagnostic certainty conveyed by each, from 1 (most certain) to 15 (least certain), using each number only once. The kappa statistic was used to assess agreement in rank order among physicians. RESULTS: The questionnaire response rate was 76% (n = 34) for radiologists and 49% (n = 78) for nonradiologists. There was excellent agreement among radiologists (kappa = 0.95) and nonradiologists (kappa = 0.93) in the rank order for the phrase diagnostic of. Although there was good agreement (kappa = 0.45) among radiologists for the word unlikely, agreement among nonradiologists was poor (kappa = 0.27). There was very poor agreement among all physicians for the rank order of the other 13 phrases. CONCLUSION: Among radiologists and nonradiologists, concordance was poor regarding the diagnostic certainty associated with phrases commonly used in radiology reports. Because poor agreement could lead to suboptimal quality of care, the standardization of terminology would benefit all parties.     

Physician Rating Websites: Do Radiologists Have an Online Presence?

PurposeGiven that patient satisfaction and provider transparency intersect on online physician-rating websites, we aimed to assess radiologist representation on these increasingly popular sites.MethodsFrom a directory of all Medicare participating physicians, we randomly selected 1,000 self-designated diagnostic radiologists and manually extracted their rating information from five popular online physician-review websites (HealthGrades, Healthcare Reviews, RateMDs, Kudzu, and Yelp). Using automated web “data-scraping” techniques, we separately extracted all radiologist and nonradiologist rating information from a single amenable site (Healthcare Reviews). Rating characteristics were analyzed.ResultsOf 1,000 sampled self-designated diagnostic radiologists representing all 50 states, only 197 (19.7%) were profiled on any of the five online physician-review websites. Only 24 (2.4%) were rated on two of the sites, and none was profiled on ≥3 sites. Of all 6,775 physicians listed on a single electronically interrogated site, only 30 (0.4%) were radiologists. With 28,555 (5.2%) of all 547,849 Medicare-participating physicians identified as diagnostic radiologists, radiologists were thus significantly underrepresented online (P < .0001). Although reviewed radiologists and nonradiologists were rated online by similar numbers of patients (1.13 ± 0.43 versus 1.03 ± 0.22, P = .22), radiologists were rated (on a low to high score of 1 to 10) significantly higher than nonradiologists (median 8.5 versus 5, P = .04).ConclusionsMost diagnostic radiologists are not profiled on common online physician-rating websites, and they are significantly underrepresented compared with nonradiologists. Reviewed radiologists, however, scored favorably. Given the potential for patient satisfaction scores and public domain information to affect referrals and future value-based payments, initiatives to enhance radiologists’ online presence are advised.     

Disparities over Time in Volume,Day of the Week,and Patient Complexity between Paracentesis and Thoracentesis Procedures Performed by Radiologists versus Those Performed by Nonradiologists

PurposeTo compare the disparities between the paracenteses and thoracenteses performed by radiologists with those performed by nonradiologists over time. Variables included the volume of procedures, the days of the week, and the complexity of the patient’s condition.Materials and MethodsUsing carrier claims files for a 5% national sample of Medicare beneficiaries from 2004 to 2016, paracentesis and thoracentesis examinations were retrospectively classified by physician specialty (radiologist vs nonradiologist), day of the week (weekday vs weekend), and the complexity of the patient’s condition (using Charlson comorbidity index scores). The Pearson chi-square and independent samples t-test were used for statistical analysis.ResultsBetween 2004 and 2016, the proportion of all paracentesis and thoracentesis procedures performed by radiologists increased from 70% to 80% and from 47% to 66%, respectively. Although radiologists increasingly performed more of both services on both weekends and weekdays, the share performed by radiologists was lower on weekends. For most of the first 9 years across the study period, radiologists performed paracentesis in patients with more complex conditions than those treated by nonradiologists, but the complexity of patients’ conditions was similar during recent years. For thoracentesis, the complexity of patients’ conditions was similar for both specialty groups across the study period.ConclusionsThe proportion of paracentesis and thoracentesis procedures performed in Medicare beneficiaries by radiologists continues to increase, with radiologists increasingly performing most of both services on weekends. Nonetheless, radiologists perform disproportionately more on weekdays than on weekends. Presently, radiologists and nonradiologists perform paracentesis and thoracentesis procedures in patients with similarly complex conditions. These interspecialty differences in timing and complexity of the patient’s condition differ from those recently described for several diagnostic imaging services, reflecting the unique clinical and referral patterns for invasive versus diagnostic imaging services.     

How Do Publicly Reported Medicare Quality Metrics for Radiologists Compare With Those of Other Specialty Groups?

PurposeTo characterize and compare the performance of radiologists in Medicare’s new Physician Compare Initiative with that of other provider groups.MethodsCMS Physician Compare data were obtained for all 900,334 health care providers (including 30,614 radiologists) enrolled in Medicare in early 2015. All publicly reported metrics were compared among eight provider categories (radiologists, pathologists, primary care, other medical subspecialists, surgeons, all other physicians, nurse practitioners and physician assistants, and all other nonphysicians).ResultsOverall radiologist satisfaction of all six Physician Compare Initiative metrics differed significantly from that of nonradiologists (all P ≤ .005): acceptance of Medicare-approved amount as payment in full, 75.8% versus 85.0%; Electronic Prescribing, 11.2% versus 25.1%; Physician Quality Reporting System (PQRS), 60.5% versus 39.4%; electronic health record participation, 15.8% versus 25.4%; receipt of the PQRS Maintenance of Certification Program Incentive, 4.7% versus 0.3%; and Million Hearts initiative participation, 0.007% versus 0.041%. Among provider categories, radiologists and pathologists demonstrated the highest and second-highest performance levels, respectively, for the two metrics (PQRS and MOC) with specialty-specific designs, but they ranked between fifth and eighth in all remaining non–specialty-specific metrics.ConclusionsThe performance of radiologists and pathologists in Medicare’s Physician Compare Initiative may relate to the extent to which metrics are tailored to the distinct aspects of their practices as diagnostic information specialists. If more physician participation in these programs is desired, more meaningful specialty-specific (rather than generic) metrics are encouraged.     

Turf wars in radiology: the overutilization of imaging resulting from self-referral

A recent report by the Medicare Payment Advisory Commission to Congress indicated that the utilization of diagnostic imaging is growing more rapidly than that of any other type of physician service. This has engendered concern among those who pay for health care. In this article, the authors review the role of self-referral in driving up imaging utilization.A number of studies of the self-referral factor in imaging have been conducted over the past three decades. These have consistently shown that when nonradiologist physicians operate their own imaging equipment and have the opportunity to self-refer, their utilization is substantially higher than among other physicians who refer their patients to radiologists. It has also been shown that the vast bulk of the recent increases in imaging utilization are attributable to nonradiologists who self-refer. The authors estimate that the cost to the American health care system of unnecessary imaging resulting from self-referral by nonradiologists is $16 billion per year.     

Intravascular contrast media. Ionic versus nonionic: current status

The development of LOCM is one of the most important medical discoveries made at the end of this century. In developing nonionic compounds, Almén showed that it was possible to decrease the osmolality by a factor of 2 and also thereby reduce the chemotoxicity by as much as a factor of 20. Serious adverse side effects after the intravascular administration of contrast material are caused by a combination of osmotoxic and chemotoxic properties of an individual contrast media molecule as well as the ionic composition of the agent when in solution. Worldwide clinical experience with the use of LOCM, ionic and nonionic, consistently has shown the new material to be safer and more comfortable in clinical practice. Some form of limited use of LOCM is now part of virtually every radiologist's daily practice, and the focus is turning to the low-risk-no-risk group. There are gray areas between risk categories, with some evidence even suggesting that the 20- to 40-year-old age group may be at risk to the same or even a greater degree than other commonly accepted risk groups such as the elderly. The future promises even better and safer but, in all likelihood, expensive, contrast agents for intravascular use. The ultimate decision on choice of contrast or the fate of LOCM rests with public policy makers, organized medicine, and the individual physician and patient. Based on penetration of the marketplace (nearly 50%) in terms of LOCM sales in 1990, there is a growing awareness within our specialty as well as the public sector of the improvements offered by LOCM. It is unlikely that a major conversion back to the universal use of HOCM will ever occur. As long as cost remains the major focus of the debate over the choice, however, physicians need to be informed advocates, familiar with the science, yet sensitive to the economic implications of the decisions they make to best serve the interests of their patients.     

Nonionic low-osmolality versus ionic high-osmolality contrast material for intravenous use in patients perceived to be at high risk: randomized trial.

To determine the cost-effectiveness of selective use of nonionic low-osmolality contrast material, the authors randomly assigned 955 patients to receive high-osmolality and 1,158 to receive low-osmolality intravenous contrast material. All patients had one or more of the following perceived risk factors for adverse reactions: prior reaction to contrast material, allergies, asthma, diabetes, cardiac or renal disease, anxiety, severe illness, and age greater than 50 years. The occurrence of any adverse event, need for therapy, or subjective symptoms was assessed in a double-blind fashion. An adverse reaction necessitating the attention of a physician occurred in 3.9% (n = 37) of patients in the high-osmolality and 0.9% (n = 10) of patients in the low-osmolality groups (P less than .000005). Therapy was administered to 1.4% (n = 13) and 0.5% (n = 6), respectively (P = .035). The difference was due to a reduction in urticaria and other mild anaphylactoid reactions. In a multivariate analysis, only prior reactions and allergy were independent risk factors. Selective use of intravenous nonionic contrast material is best justified in those with prior reactions, allergy, or asthma; at least 67% of reactions would be prevented.     

Medicare Policy Initiatives and the Relative Utilization of “Double-Scan” CT

PurposeCommonly called “double scans” by the media, combined pre- and postcontrast thoracic and abdominal CT examinations have been the focus of recent CMS policy initiatives. The aim of this study was to examine trends in the relative utilization of double-scan CT before and after 2006 legislation mandating relevant Medicare reporting initiatives.MethodsMedicare Physician Supplier Procedure Summary Master Files from 2001 through 2012 were used to identify claims for thoracic and abdominal CT examinations. Double-scan rates by billing physician specialty and place of service were analyzed over time. Rates of double-scan CT between radiologists and nonradiologists were compared using t tests.ResultsFrom 2001 to 2006, double-scan rates for thoracic and abdominal CT examinations declined by 1.7% and 7.5% for radiologists, respectively (from 6.0% to 5.9% and from 22.6% to 20.9%) but increased by 15.8% and 23.6% for nonradiologists (from 5.7% to 6.6% and from 28.8% to 35.6%). From 2006 through 2012, double-scan rates declined by 42.3% and 35.2% (from 5.9% to 3.4% and from 20.9% to 13.5%) for radiologists but only by 31.8% and 8.1% (from 6.6% to 4.5% and from 35.6% to 32.7%) for nonradiologists. Double-scan rates were significantly lower for radiologists than nonradiologists for all years for abdominal CT (P < .001) and for all years after 2006 legislation for thoracic CT (P < .05).ConclusionsReductions in thoracic and abdominal CT double-scan rates followed legislation mandating CMS initiatives designed to reduce costs and radiation. For nonradiologists, double-scan rates were consistently higher and declined more slowly than those for radiologists. Medicare policy initiatives directed toward imaging utilization seem to influence behavior differently for radiologists compared with nonradiologists.     

Contrast media in venous digital angiography: ionic or non-ionic?

Nonionic contrast media (cm) are more and more widely employed in vascular radiology. These cm are the choice in some conventional arteriographies owing to their better tolerability. In intravenous digital subtraction angiography (DSA) the analysis of the personal material and of the literature allows to state that: the image quality with ionic and non ionic cm is similar; the tolerability of nonionic cm is slightly superior; the cardiac and renal toxicity of nonionic cm is slightly lower; reactions to nonionic cm take place with a lower frequency; the price of nonionic cm is considerably higher. Therefore nonionic cm seem to be slightly superior to ionic agents on the basis of these data and they should be theoretically preferred. The only doubt to their routine use in intravenous DSA is the high cost. Therefore we prefer to employ them in risk patients only, as ionic cm in current use are safe and cheap.     

Diagnostic CT scans: assessment of patient, physician, and radiologist awareness of radiation dose and possible risks

PURPOSE: To determine the awareness level concerning radiation dose and possible risks associated with computed tomographic (CT) scans among patients, emergency department (ED) physicians, and radiologists. MATERIALS AND METHODS: Adult patients seen in the ED of a U.S. academic medical center during a 2-week period with mild to moderate abdominopelvic or flank pain and who underwent CT were surveyed after acquisition of the CT scan. Patients were asked whether or not they were informed about the risks, benefits, and radiation dose of the CT scan and if they believed that the scan increased their lifetime cancer risk. Patients were also asked to estimate the radiation dose for the CT scan compared with that for one chest radiograph. ED physicians who requested CT scans and radiologists who reviewed the CT scans were surveyed with similar questions and an additional question regarding the number of years in practice. The chi(2) test of independence was used to compare the three respondent groups regarding perceived increased cancer risk from one abdominopelvic CT scan. RESULTS: Seven percent (five of 76) of patients reported that they were told about risks and benefits of their CT scan, while 22% (10 of 45) of ED physicians reported that they had provided such information. Forty-seven percent (18 of 38) of radiologists believed that there was increased cancer risk, whereas only 9% (four of 45) of ED physicians and 3% (two of 76) of patients believed that there was increased risk (chi(2)(2) = 41.45, P <.001). All patients and most ED physicians and radiologists were unable to accurately estimate the dose for one CT scan compared with that for one chest radiograph. CONCLUSION: Patients are not given information about the risks, benefits, and radiation dose for a CT scan. Patients, ED physicians, and radiologists alike are unable to provide accurate estimates of CT doses regardless of their experience level.     

Comparison of omnipaque with hypaque in temporomandibular arthrography

Decreasing or alleviating pain experienced by some patients during or after temporomandibular arthrography would make this relatively inexpensive and highly accurate technique more attractive. This is particularly true for those patients without access to MR or those whose referring physicians prefer arthrography to other techniques for diagnosing internal derangements. Ionic and nonionic contrast agents were compared in a randomized, double-blind trial to determine if pain could be decreased by using a nonionic contrast material. Forty patients received either Omnipaque 300 (nonionic, iohexol) or Hypaque 60 (ionic, diatrizoate meglumine). Radiographs were assessed for diagnostic quality, and patients were asked to note their level of discomfort. No significant differences between the agents were detected. Maximal discomfort was noted at 24 hr. Discomfort was classified as none, mild, or moderate, with no patients describing marked discomfort. This study does not support the use of nonionic contrast agents over the less expensive ionic agents for decreasing pain or improving film quality in temporomandibular joint arthrography.     

Unique Medicare Beneficiaries Served: A Radiologist-Focused Specialty-Level Analysis

PurposeThe aims of this study were to compare the number of unique Medicare fee-for-service beneficiaries served by radiologists and other physicians and to identify characteristics of radiologists serving the most number of unique patients.MethodsMedicare Physician and Other Supplier Public Use Files were used to identify all physicians who provided services to Medicare fee-for-service beneficiaries for the entirety of 2013. The average number of unique beneficiaries served was computed per specialty. The number of unique beneficiaries served was further stratified among radiologists in terms of physician and practice characteristics.ResultsAmong 56 unique physician specialties, diagnostic radiologists on average served the most unique beneficiaries (3,150 ± 2,344). Among radiologists, the number of unique beneficiaries varied in association with numerous characteristics and was larger for male (3,214) versus female (2,521) radiologists, rural (3,551) versus urban (3,092) radiologists, nonacademic (3,427) versus academic (1,932) radiologists, generalist (3,866) versus subspecialist (1,981) radiologists, and radiologists in the South (3,716) versus other geographic regions (range, 2,432-3,217). The number of unique beneficiaries served increased significantly with smaller group practice size (2,218 for ≥100 group members versus 3,669 for ≤9 members). Among subspecialists, the number of unique beneficiaries was largest for breast imagers (2,594).ConclusionsThe large number of unique beneficiaries served by radiologists highlights their important role in orchestrating patient care and their immense opportunities to expand the face of the specialty. An understanding of which radiologists serve the largest numbers of unique patients may help radiology practices target patient engagement and other Imaging 3.0™ efforts.     

Efficacy and safety of digital subtraction angiography with special reference to contrast agents

We evaluated the diagnostic accuracy and complications of digital subtraction angiography (DSA) in a series of clinical trials conducted on patients primarily with cerebral vascular disease and those evaluated before and after surgery or percutaneous transluminal angioplasty. Double-blind studies of the carotid-vertebral arteries of 300 of the 2,200 patients using DSA imaging and a variety of ionic and nonionic contrast agents showed that although subjects tolerated the injection of nonionic contrast better than ionic, nonionic contrast administration did not lead to better image quality. Of 764 patients receiving ionic contrast media, 3.3% had mild-to-serve adverse reactions; of 350 injected with nonionic contrast agents, 1.7% had mild-to-severe adverse reactions. If the sole consideration is safety, use of ionic contrast media is justified.     

Turf wars in radiology: The quality of interpretations of imaging studies by nonradiologist physicians—a patient safety issue?

Previous publications have demonstrated that in side-by-side testing, radiologists clearly outperform nonradiologist physicians at interpreting plain radiographs. Other articles, mostly in the nonradiologic literature, have shown that in actual practice settings, nonradiologist physicians make frequent errors in image interpretation. On the other hand, several other studies have concluded that such errors are infrequent and generally do not affect patient outcomes. However, most of the latter studies have had methodologic flaws. Radiologists need to be aware of the evidence that exists in the medical literature on errors made by nonradiologists in image interpretation and to bring it to the attention of hospital authorities or medical policy-making groups that are charged with improving patient safety.     

Prevention of adverse reactions to contrast media by means of general anesthesia?

Adverse reactions to systemically administered contrast media are a threat to patients as well as the responsible physician. Non-ionic media produce less side effects due to the lower osmolarity and an advantageous chemical structure. Suggested prophylactic measures include the intravenous administration of H1- and H2-receptor blockers the administration of corticosteroids, sedatives and general anaesthesia. General anaesthesia not necessarily protects from a reaction to either ionic or nonionic compounds and bears its own risks.     

Nonradiologists as second readers for intraluminal findings at CT colonography

RATIONALE AND OBJECTIVES: Multiple trials have documented wide interobserver variability between radiologists interpreting computed tomography colonography (CTC) exams. We sought to determine if nonradiologists could learn to interpret intraluminal findings at CTC with a high degree of sensitivity to determine if they could play a role as second readers in interpreting CTC exams. MATERIALS AND METHODS: Seven nonradiologists (five medical students, two radiologic technologists) undertook self-directed CTC training using a teaching file of 50 cases; thereafter, each reader blindly interpreted 50 cases with colonoscopic correlation (30 positive, 20 negative). Results were compared with a previously studied cohort of radiologists. The two technologists additionally repeated the exam after 6 weeks of clinical experience. RESULTS: The sensitivity of nonradiologists for small (5-9 mm) polyps, large (>9 mm) lesions, and cancers was similar to that of radiologists (0.45 versus 0.63, 0.74 versus 0.71, and 0.80 versus 0.88, respectively). After 6 weeks of clinical experience as second readers, the accuracy of one technologist significantly improved (from 74% to 90%, P = .008), whereas accuracy of the other tended toward improvement (from 74% to 86%%, P = .25). Nonradiologists detected, on average, 6/36 additional polyps (17%) missed by any radiologist, and the sensitivity of 5/7 nonradiologists was significantly greater than at least one of the radiologists (P = .05). CONCLUSION: Nonradiologists can perform similarly to radiologists in interpreting intraluminal findings at CTC, with nonradiologist performance improving even after experience with more than 100 cases. Skilled nonradiologists may play a vital role as a second reader of intraluminal findings or by performing quality control of examinations before patient dismissal.