Evidence-based guidelines for pediatric imaging: the example of the child with possible appendicitis

Evidence-based radiology: why and how?

PURPOSE

To provide an overview of evidence-based medicine (EBM) in relation to radiology and to define a policy for adoption of this principle in the European radiological community.

RESULTS

Starting from Sackett's definition of EBM we illustrate the top-down and bottom-up approaches to EBM as well as EBM's limitations. Delayed diffusion and peculiar features of evidence-based radiology (EBR) are defined with emphasis on the need to shift from the demonstration of the increasing ability to see more and better, to the demonstration of a significant change in treatment planning or, at best, of a significant gain in patient outcome. The "as low as reasonably achievable" (ALARA) principle is thought as a dimension of EBR while EBR is proposed as part of the core curriculum of radiology residency. Moreover, we describe the process of health technology assessment in radiology with reference to the six-level scale of hierarchy of studies on diagnostic tests, the main sources of bias in studies on diagnostic performance, and levels of evidence and degrees of recommendations according to the Centre for Evidence-Based Medicine (Oxford, UK) as well as the approach proposed by the GRADE working group. Problems and opportunities offered by evidence-based guidelines in radiology are considered. Finally, we suggest nine points to be actioned by the ESR in order to promote EBR.

CONCLUSION

Radiology will benefit greatly from the improvement in practice that will result from adopting this more rigorous approach to all aspects of our work.

Optimizing the role of imaging in appendicitis

Acute appendicitis is the most common acute abdominal condition that requires surgical intervention in childhood. From the diagnostic performance perspective, computed tomography (CT) has a significantly higher sensitivity than does ultrasound (US) for diagnosing appendicitis in children; from the safety perspective, however, one should consider the radiation associated with CT, especially in children. There is strong evidence supporting improved patient outcomes in children with suspected acute appendicitis who undergo CT scanning. Nevertheless, we should keep in mind that for a single abdominal CT study in a 5-year-old child, the lifetime risk of radiation-induced cancer would be 26.1 per 100,000 in female and 20.4 per 100,000 in male patients, based on probabilistic models designed with data from atomic bomb survivors. An integrated clinical-imaging approach, applying clinical scores that are able to predict which children with acute abdominal pain do or do not have a high probability of presenting with appendicitis may improve the effectiveness of the imaging diagnosis of appendicitis at the hospital level. Such an approach could avoid exposure of children who at low risk for appendicitis to unnecessary diagnostic tests and eventually, to radiation.

Fat-containing lesions revealed by CT in children with right lower quadrant pain

Suspected appendicitis is the most common indication for emergent abdominal surgery in children. The clinical diagnosis of appendicitis can be challenging, and CT is playing an increasing role in the evaluation of right lower quadrant pain. Occasionally, alternative diagnoses to appendicitis can be suggested on CT. The appreciation of a fat-containing lesion in the right lower quadrant will often allow a specific diagnosis. Importantly, many of these lesions are self-limited and treated nonoperatively. The purpose of this pictorial essay is to illustrate the spectrum of fat-containing lesions that can present as alternative diagnoses to appendicitis on CT scans performed for the evaluation of right lower quadrant pain in children.

Imaging challenges: a US perspective on controlling exposure to ionizing radiation in children with cancer

Issues pertaining to control of radiation dose exposures in pediatric imaging are on the forefront of patient care worldwide. Certain factors contribute to appropriate-or inappropriate-use of ionizing radiation in pediatric medical imaging. Such issues include naiveté regarding cancer risk and the role of medical imaging in its development, misinformation about exposure to ionizing radiation, resource availability, staffing, scheduling "snags," costs, limited evidence-based imaging practice information and shrinking funding. These issues will be introduced in this paper.

Current management of appendicitis

Appendicitis is the most common surgical disease of the abdomen in children. Pediatric appendicitis varies considerably in its clinical presentation, contributing to delay in diagnosis and increased morbidity. The methods of diagnosis and treatment of appendicitis also vary significantly among clinicians and medical centers according to the patient's clinical status, the medical center's capabilities, and the physician's experience and technical expertise. Recent trends include the increased use of radiologic imaging, minimally invasive and nonoperative treatments, shorter hospital stays, and home antibiotic therapy. Little consensus exists regarding many aspects of the care of the child with complicated appendicitis. This article examines the most debated aspects of the diagnosis and management of the diseased pediatric appendix.

Prospective comparison of helical CT of the abdomen and pelvis without and with oral contrast in assessing acute abdominal pain in adult Emergency Department patients

PURPOSE

This prospective study compares the agreement of nonenhanced helical computed tomography (NECT) with oral contrast-enhanced computed tomography (CECT) in Emergency Department (ED) patients presenting with acute abdominal pain.

MATERIALS AND METHODS

One hundred eighteen patients presenting to the ED with acute abdominal pain undergoing CT were enrolled over a 13-month period using convenience sampling. Exclusion criteria included acute trauma, pregnancy, unstable patients, and patients suspected of having urinary calculi. Patients were scanned helically using 5-mm collimation before and approximately 90 min after oral contrast administration. Both exams were prospectively interpreted by different attending radiologists in a blinded fashion using an explicit data sheet specifying the presence or absence of 28 parameters relating to various common diagnoses.

RESULTS

The 118 patients had a mean age of 49 years, a male: female ratio of 7:13, and a median height, weight, and BMI of 166 cm, 80 kg, and 29, respectively. The most common indications for the study included appendicitis (32%) and diverticular disease (12%). Pain maximally localized to the right lower quadrant in 37% and the left lower quadrant in 21%. There were 21 patients that had significant disagreement of interpretations between NECT and CECT resulting in a simple agreement of 79% (95% CI: 70-87%). For specific radiologic parameters, agreement ranged from 77 to 100%. A post hoc agreement analysis was subsequently performed by two radiologists and only five paired scans were identified as discordant between the NECT and CECT. For only one of these patients did both radiologists agree that there was a definite discordant result between the two studies. A final unblinded consensus review demonstrated that much of the disagreement between the interpretations was related to interobserver variation.

CONCLUSION

There is 79% simple agreement between NECT and CECT in diagnosing various causes of acute abdominal pain in adult ED patients. Post hoc analysis indicates that a significant portion of the discordance was attributable to interobserver variability. This data suggests that NECT should be considered in adult ED patients presenting with acute abdominal pain.

Impact of radiologic imaging on the surgical decision-making process in suspected appendicitis in children

RATIONALE AND OBJECTIVES

To evaluate how the surgeons' decision-making process in appendicitis in children is affected by radiologic imaging.

MATERIALS AND METHODS

Prospective study including 593 children with suspected appendicitis was conducted. The surgeon's initial clinical disposition was recorded, designating the patient for operation, observation, or discharge. Thereafter, the patients were randomized to undergo either ultrasound only or ultrasound and abdominal computed tomography. The studies were evaluated by radiologists, who indicated if appendicitis was present or not. After radiology was completed, the surgeon re-examined the patient and made the final disposition. The change of disposition pathway was recorded. Final diagnoses were established by means of surgical, histopathologic, and/or clinical follow-up findings.

RESULTS

Two hundred forty-four patients had appendicitis. The initial clinical disposition called for 88 operations, 338 observations, and 167 discharges. In total, 347 patients had their treatment plan changed from the initial disposition, resulting in 252 operations, 65 observations, and 276 discharges. In 11 patients, an unnecessary operation was possibly avoided. In 28 patients who turned out to have appendicitis, a possible inappropriate discharge was avoided. Eighteen patients had a false-negative radiologic diagnosis. Of these, 17 underwent surgery because of convincing clinical findings. The difference between the impact on surgeons' decision-making between the two randomized groups was not substantially different. The negative appendectomy rate was 3.7%.

CONCLUSION

Radiologic imaging with ultrasound and/or computed tomography provides valuable guidance whether a patient should be discharged, observed, or given surgical treatment, leading to beneficial changes in management plan. Still, false-negative results may occur and a close clinical re-examination is of utmost importance for the appropriate final decision.

Suspected Appendicitis in Children: Diagnosis with Contrast-enhanced versus Nonenhanced Helical CT

PURPOSE

To compare the diagnostic accuracy of limited-area (lower abdominal) nonenhanced helical computed tomography (CT), intravenous contrast material-enhanced helical CT of the entire abdomen, and the combination of both.

MATERIALS AND METHODS

Three hundred six children suspected of having appendicitis, who were previously included in a prospective study, underwent limited-area nonenhanced helical CT of the lower abdomen and contrast-enhanced CT of the entire abdomen. No oral or rectal contrast material was administered. The CT scans were retrospectively reviewed by three independent readers both separately and together. The readers were blinded to all clinical information and to the results of previous ultrasonographic and CT examinations. Final diagnoses were established on the basis of surgical, histopathologic, or clinical follow-up findings. The Pearson chi(2) test was performed to compare values between groups. The Student two-sample t test was performed to determine statistically significant differences in age and sex.

RESULTS

One hundred twenty-nine patients (42%) had appendicitis. Readers diagnosed appendicitis with 66% pooled sensitivity and 96% pooled specificity with limited-area nonenhanced CT. With contrast-enhanced CT of the entire abdomen, appendicitis was diagnosed with 90% pooled sensitivity and 94% pooled specificity. With both sequences together, readers diagnosed appendicitis with 90% pooled sensitivity and 94% pooled specificity. The difference between the sensitivity of limited-area nonenhanced CT and that of contrast-enhanced CT was statistically significant (P <.001).

CONCLUSION

Sensitivity of helical CT for suspected appendicitis in children improved significantly with abdominal contrast-enhanced CT compared with limited-area nonenhanced CT. No further improvement in sensitivity was achieved with the combination of both sequences in comparison to that with contrast-enhanced CT alone.