Comparison of virtual computed tomography enteroscopy using carbon dioxide with small-bowel enteroclysis and capsule endoscopy in patients with small-bowel tuberculosis.

OBJECTIVE: Comparison of virtual CT enteroscopy (VCTE) using carbon dioxide with small-bowel enteroclysis (SBE) and capsule endoscopy (CE) in small-bowel tuberculosis (SBTB). METHODS: This prospective study comprised consecutive patients suspected to have SBTB. VCTE and SBE were performed on the same day and evaluated by independent radiologists. CE was performed within 2 weeks. VCTE was performed following insufflation of carbon dioxide via catheters in the jejunum and anorectum. A contrast-enhanced CT was followed by a delayed non-contrast CT. Image processing was done using virtual colonoscopy software. Findings on VCTE, SBE, and CE were compared. The final diagnosis of SBTB was based on either histopathological or cytological findings, response to antitubercular treatment, or a combination of these. RESULTS: Of the 55 patients in whom VCTE was performed, complete data was available in 52 patients. A final diagnosis of SBTB was established in 37 patients. All patients had VCTE and SBE. CE was performed in 34 patients. Adequate luminal distension was achieved in all patients with SBE and 35 patients with VCTE. SBE showed more strictures in jejunum (10.8%) and ileum (75.7%) compared with VCTE (jejunum, 8.1%, and ileum, 64.9%) and CE (jejunum, 5.9%, and ileum, 61.8%). However, difference was not statistically significant. VCTE revealed a greater length of strictures in both the jejunum and ileum compared with SBE and CE. CONCLUSION: VCTE allows adequate evaluation of the bowel in most patients with SBTB. It allows detection of greater length of abnormality in jejunum and ileum compared with SBE and CE. KEY POINTS: • The use of VCTE using CO2 bowel insufflation in patients with SBTB should be considered. • VCTE allows detection of a greater length of abnormality in the jejunum and ileum.

How accurate is the label "allergic to iodinated contrast agents"?

BACKGROUND: Iodinated contrast agents (ICAs) are crucial to the use of many imaging studies. Reported allergies to ICAs in the medical record can interfere with optimal diagnostic imaging workups. PURPOSE: To investigate the accuracy with which the label "allergic to ICAs" is applied. MATERIAL AND METHODS: The medical records of 500 patients labeled "allergic to ICAs" at a single tertiary care hospital were reviewed. Patients were separated into three groups based on documentation in their medical records, as follows: Group 1, documented hypersensitivity reaction to ICAs; Group 2, documented ICA exposure with non-hypersensitivity adverse event (Group 2a) or without documented reaction (Group 2b); and Group 3, no documented prior exposure to an ICA. We then further reviewed the EMR to determine whether or not patients had subsequent administration of an ICA, whether or not they were given specific premedication, and whether or not they had a subsequent ICA-related event. RESULTS: A total of 16.6% of patients (n = 83) listed as "allergic to ICAs" had a documented hypersensitivity reaction following ICA administration (Group 1) while 58.6% (n = 293) of patients (Group 2) had a documented exposure to ICAs with either: (i) a non-hypersensitivity adverse event (23.5%, n = 69) or (ii) no record of a reaction to ICAs (76.5%, n = 224). The remaining 24.8% (n = 124), Group 3, had no record of exposure to an ICA, yet still carried the label. CONCLUSION: The majority of patients carrying the label "allergic to ICAs" had no record of a prior hypersensitivity reaction to ICAs.

Long-term outcomes of transposed basilic vein arteriovenous fistulae.

The need for reliable, long-term hemodialysis vascular access remains critical. To determine the long-term outcomes of transposed basilic vein arteriovenous fistulae (BVT) and their comparability with other vascular accesses, we determined retrospectively the primary and secondary patency rates in 58 BVT and in a total of 58 arteriovenous fistulae (AVF) and arteriovenous grafts (AVG) at a single center. Fifty-eight BVT were placed in 57 individuals, 69% after prior vascular access failure. Ten BVT failed before initial use and 2 patients expired with functioning accesses before dialysis initiation. In all 58 BVT, 46.8+/-10.8% functioned at 3 years, with median survival 30.8 months. Limiting analyses to the 46 BVT that were ultimately accessed, 3-year primary and secondary patency rates were 38.3+/-7.7% and 56.5+/-12.6%, respectively. Lower ejection fraction (p=0.054) and greater numbers of prior permanent dialysis catheters (p=0.005) were present in those with failed BVT. Compared with AVF, BVT had similar 3-year primary and secondary patency rates. The secondary patency rate was significantly better for BVT vs. AVG over the observation period; at 3 years, the rates were 56.5+/-12.6% vs. 9.1+/-6.0% (p=0.002), respectively. Basilic vein arteriovenous fistulae are valuable hemodialysis accesses. Although nearly 20% of newly placed BVT will not function before first use, those that are functional have median survivals exceeding 6 years, and 38% will not require intervention within 3 years of initial use.

Percutaneous radiologic gastrostomy versus percutaneous endoscopic gastrostomy: a comparison of indications, complications and outcomes in 370 patients.

OBJECTIVE: Percutaneous access to the stomach can be achieved by endoscopic or fluoroscopic methods. Our objective was to compare indications, complications, efficacy and outcomes of these two techniques. METHODS: Records of 370 patients with feeding tubes placed either endoscopically by gastroenterology, or fluoroscopically by radiology, at our university-based tertiary care center over a 54-month period were reviewed. RESULTS: 177 gastrostomies were placed endoscopically and 193 fluoroscopically. Nutrition was the most common indication in each group (94 and 92%), but the most common underlying diagnosis was neurologic impairment in the endoscopic group (n=89, 50%) and malignancy in the fluoroscopic group (n=134, 69%) (p<0.001). Complications in the first 30 days were more common with fluoroscopic placement (23% versus 11%, p=0.002), with infection most frequent. Correlates of late complications were inpatient status (OR 0.26, 95%CI: 0.13-0.51) and a diagnosis of malignancy (OR 2.2, 95%CI: 1.03-4.84). Average follow-up time was 108 days in the fluoroscopic group and 174 days in the endoscopic group. CONCLUSIONS: Both endoscopic and fluoroscopic gastrostomy tube placement are safe and effective. Outpatient status was associated with greater early and late complication rates; minor complications such as infection were greater in the fluoroscopic group, while malignancy was associated with late complications.

Monitoring of clinical imaging guidelines part 3: norms, standards, and regulations.

It is known that the use of imaging in clinical situations is not always optimal, leading to suboptimal health care and potential radiation risk. There may be overuse of imaging, underuse, or use of the wrong modality. The use of clinical imaging guidelines is likely to improve the use of imaging, but roadblocks exist. Some of these relate to regulatory oversight and mandates. There is wide variation by country and region in the regulatory setting, ranging from actual absence of regulatory authorities to mandated availability of clinical imaging guidelines in the European Community. Collaborative efforts to ensure that clinical imaging guidelines are at least available is a good starting point. Regulatory oversight and support are necessary to ensure the use of clinical imaging guidelines. Regulations should address 3 areas: availability, clinical utilization, and adherence to and revision of guidelines. The use of both internal and external audits, with the aim of both use of and adherence to guidelines and quality improvement, is the best tool for enhancing use. The major challenges that need to be addressed, collaboratively, to ensure the dissemination and use of clinical imaging guidelines are the development of regulations, of regulatory structures that can be effectively deployed, and of benchmarks for adherence and for utility.

Clinical imaging guidelines part 4: challenges in identifying, engaging and collaborating with stakeholders.

The effective development and use of clinical imaging guidelines requires an understanding of who the stakeholders are, what their interests in the process are, and what roles they should play. If the appropriate stakeholders are not engaged in the right roles, it is unlikely that clinical imaging guidelines will be successfully developed, relied on, and actually used. Some stakeholders are obvious: for the development of clinical imaging guidelines, both imagers and those who request examinations, such as general practitioners, internists, and medical specialists, must be involved. To gain acceptance, other relevant groups are stakeholders, including medical societies, other health care professionals, insurers, health IT experts and vendors, and patients. The role of stakeholders must be dictated by their specific interest. For some, involvement in the creation of guidelines is the right role. For others, such as regulators or insurers, reviews or invitations to comment are required, and for others, such as medical educators, it is probably sufficient to provide information and create awareness. Only through a careful consideration of who the stakeholders are and what are their interests are the successful development, acceptance, and use of clinical imaging guidelines likely to occur. Future efforts must focus on collaboration, particularly among groups that create clinical imaging guidelines and those that can support their use, and on regulatory roles and mandates.

Clinical imaging guidelines part 2: Risks, benefits, barriers, and solutions.

A recent international meeting was convened by two United Nations bodies to focus on international collaboration on clinical appropriateness/referral guidelines for use in medical imaging. This paper, the second of 4 from this technical meeting, addresses barriers to the successful development/deployment of clinical imaging guidelines and means of overcoming them. It reflects the discussions of the attendees, and the issues identified are treated under 7 headings: ■ Practical Strategy for Development and Deployment of Guidelines; ■ Governance Arrangements and Concerns with Deployment of Guidelines; ■ Finance, Sustainability, Reimbursement, and Related Issues; ■ Identifying Benefits and Radiation Risks from Radiological Examinations; ■ Information Given to Patients and the Public, and Consent Issues; ■ Special Concerns Related to Pregnancy; and ■ The Research Agenda. Examples of topics identified include the observation that guideline development is a global task and there is no case for continuing it as the project of the few professional organizations that have been brave enough to make the long-term commitment required. Advocacy for guidelines should include the expectations that they will facilitate: (1) better health care delivery; (2) lower cost of that delivery; with (3) reduced radiation dose and associated health risks. Radiation protection issues should not be isolated; rather, they should be integrated with the overall health care picture. The type of dose/radiation risk information to be provided with guidelines should include the uncertainty involved and advice on application of the precautionary principle with patients. This principle may be taken as an extension of the well-established medical principle of "first do no harm."

Frequently asked questions: iodinated contrast agents.

Although iodinated contrast agents are safe and widely used, adverse events occur and questions remain about their use, safety, and interactions. Some questions are easily answered and others still require extensive investigation. For one frequent question--is informed consent necessary before all contrast media injections--the simple answer is no. Another question concerns use of contrast media in patients with prior reactions or allergies. Contrast agents can be safely used in such patients, but special care must be taken to be aware of what the previous reaction was and to be ready to treat any reaction. The protective role of pre-treatment with steroids is well established for minor reactions, but they may not prevent major reactions. It is important to realize that even life-threatening, anaphylactoid reactions are not the result of a true allergy to contrast media. Many questions arise about contrast agent-induced nephropathy. Baseline serum creatinine values should be obtained in patients who are at risk, not all patients. The incidence and natural history of contrast agent-induced nephropathy remain unclear. It occurs only in patients with compromised renal function before contrast agent injection, but even patients with normal serum creatinine levels can have renal dysfunction. Calculated creatinine clearance is a better way to determine risk and to follow this complication. The outcome in almost all patients is benign, with progression to end-stage renal disease being rare. The major risk factors, in addition to renal dysfunction, are long-standing diabetes mellitus, dehydration, and use of other nephrotoxic medications. Recent work in preventing and ameliorating contrast agent-induced nephropathy with N-acetyl cysteine, substitution of an isosmolal nonionic contrast agent, and various hydration regimens has been promising. Another common concern is use of iodinated contrast agents in pregnant or breast-feeding women. In both cases, there is no evidence of harm to the fetus or infant, but it is prudent to weigh the theoretical risks and benefits and avoid contrast agent administration unless it is truly necessary.

Clinicians' perceptions of the value of ventilation-perfusion scans.

RATIONALE: The goal of this investigation was to understand clinicians' perceptions of the probability of pulmonary embolism as a function of V/Q scan results of normal, low, intermediate, and high probability. METHODS: A questionnaire was developed and distributed to 429 clinicians at a single academic medical center. The response rate was 44% (188 of 429). The questions included level of training, specialty, probability of PE given 1 of the 4 V/Q scan results, and estimations of the charges for V/Q scanning and pulmonary angiography, and estimations of the risks of pulmonary angiography. RESULTS: The medians and ranges for the probability of pulmonary embolism given a normal, low, intermediate, and high probability V/Q scan result were 2.5% (0-30), 12.5% (0.5-52.5), 41.25% (5-75), and 85% (5-100), respectively. Eleven percent (21 of 188) of the respondents listed the probability of PE in patients with a low probability V/Q scan as being 5% or less, and 33% (62 of 188) listed the probability of PE given an intermediate probability scan as 50% or greater. The majority correctly identified the rate of serious complications of pulmonary arteriography, but many respondents underestimated the charge for V/Q scans and pulmonary arteriography. CONCLUSIONS: A substantial minority of clinicians do not understand the probability of pulmonary embolism in patients with low and intermediate probability ventilation-perfusion scans. More quantitative reporting of results is recommended. This could be particularly important because VQ scans are used less frequently but are still needed in certain clinical situations.

2013 appropriate utilization of cardiovascular imaging: a methodology for the development of joint criteria for the appropriate utilization of cardiovascular imaging by the American College of Cardiology Foundation and American College of Radiology.

The American College of Radiology (ACR) and the American College of Cardiology Foundation (ACCF) have jointly developed a method to define appropriate utilization of cardiovascular imaging. The primary role of this method is to create a series of documents to define the utility of cardiovascular imaging procedures in relation to specific clinical questions, with the aim of defining what, if any, imaging tests are indicated to help to determine diagnosis, treatment, or outcome. The methodology accomplishes this aim through the application of systematic evidence reviews integrated with expert opinion by means of a rigorous Delphi process. By obtaining broad input during the development process from radiologists, cardiologists, primary care physicians, and other stakeholders, these documents are intended to provide practical evidence-based guidance to ordering providers, imaging laboratories, interpreting physicians, patients, and policymakers as to optimal cardiovascular imaging utilization. This document details the history, rationale, and methodology for developing these joint documents for appropriate utilization of cardiovascular imaging.

2013 appropriate utilization of cardiovascular imaging: a methodology for the development of joint criteria for the appropriate utilization of cardiovascular imaging by the American College of Cardiology Foundation and American College of Radiology.

The American College of Radiology (ACR) and the American College of Cardiology Foundation (ACCF) have jointly developed a method to define appropriate utilization of cardiovascular imaging. The primary role of this method is to create a series of documents to define the utility of cardiovascular imaging procedures in relation to specific clinical questions, with the aim of defining what, if any, imaging tests are indicated to help to determine diagnosis, treatment, or outcome. The methodology accomplishes this aim through the application of systematic evidence reviews integrated with expert opinion by means of a rigorous Delphi process. By obtaining broad input during the development process from radiologists, cardiologists, primary care physicians, and other stakeholders, these documents are intended to provide practical evidence-based guidance to ordering providers, imaging laboratories, interpreting physicians, patients, and policymakers as to optimal cardiovascular imaging utilization. This document details the history, rationale, and methodology for developing these joint documents for appropriate utilization of cardiovascular imaging.

ACR Appropriateness Criteria® acute chest pain--suspected pulmonary embolism.

Pulmonary embolism (PE) remains a common and important clinical condition that cannot be accurately diagnosed on the basis of signs, symptoms, and history alone. In the absence of high pretest probability and with a negative high-sensitivity D-dimer test, PE can be effectively excluded; in other situations, diagnostic imaging is necessary. The diagnosis of PE has been facilitated by technical advancements and multidetector computed tomography pulmonary angiography, which is the major diagnostic modality currently used. Ventilation and perfusion (V/Q) scans remain largely accurate and useful in certain settings. Lower-extremity ultrasound can substitute by demonstrating deep vein thrombosis; however, if negative, further studies to exclude PE are indicated. In all cases, correlation with the clinical status, particularly with risk factors, improves not only the accuracy of diagnostic imaging but also overall utilization. Other diagnostic tests have limited roles. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The development and review of the guidelines include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.