The association between insurance status and diagnostic imaging for acute abdominal pain among emergency department patients in the United States, 2005-2014.

Introduction and objectives: Acute abdominal pain (AAP) is one of the most common complaints in the emergency department (ED). Rapid diagnosis is essential and is often achieved through imaging. Computed tomography (CT) is widely considered an exemplary test in the diagnosis of AAP in adult patients. As previous studies show disparities in healthcare treatment based on insurance status, our objective was to assess the association between insurance status and frequency of CT ordered for adult patients presenting to the ED with AAP from 2005 to 2014. Methods: This study used the National Hospital and Ambulatory Medical Care Survey: Emergency Department Record (NHAMCS) database, which collects data over a randomly assigned 4 week period in the 50 states and DC, to perform an observational retrospective analysis of patients presenting to the ED with AAP. Patients with Medicaid, Medicare or no insurance were compared to patients with private insurance. The association between insurance status and frequency of CT ordered was measured by obtaining odds ratios along with 95% CIs adjusted for age, gender and race/ethnicity. Results: Individuals receiving Medicaid are 20% less likely to receive CT than those with private insurance (OR 0.8, CI 0.6-0.99, p = .046). Those on Medicare or who are uninsured have no difference in odds of obtaining a CT scan compared to patients with private insurance. Additional findings are that black patients are 42% less likely to receive a CT scan than white patients. Conclusions and implications: Patients on Medicaid are significantly less likely to receive a CT when presenting to the ED with AAP. Differences in diagnostic care may correlate to inferior health outcomes in patients without private insurance.

Radiologic assessment of gastric emptying of water-soluble contrast media: New data security from a longitudinal study. / Evaluación radiológica del vaciamiento gástrico de medio de contraste hidrosoluble: nuevos datos de seguridad de un estudio longitudinal.

BACKGROUND AND OBJECTIVES: Practice guidelines for preoperative fasting have not clearly established the fasting time needed after oral administration of water-soluble contrast media. The aim of this study was to determine the time required for the gastric emptying during the water-soluble contrast media in patients with acute abdominal pain. METHODS: This prospective longitudinal study included sixty-eight patients older than 18 years of age with acute abdominal pain, who required a water-soluble contrast media enhanced abdominal computed tomography study. Plain radiographs were obtained hourly until complete the gastric emptying. Patients with probable bowel obstruction were not included in the study. RESULTS: A total of 31 (45,6%), 54 (79,4%), and 64 (94,1%) patients achieved a complete gastric clearance of barium in 1, 2 and 3 hours, respectively. All patients achieved complete emptying of water-soluble contrast media within 6 hours. Gastric emptying time was not associated with gender (P=0,44), body mass index (P=.35), fasting time prior to water-soluble contrast media intake (P=0,12), administration of opioids in the emergency room (P=0,7), and the presence of comorbidities (P=0,36). CONCLUSION: Ninety-four percent of the patients with acute abdominal pain achieved complete gastric emptying within 3hours after the administration of water-soluble contrast media. All of them achieved complete gastric emptying within 6hours. The results suggested 6hours after oral intake of the contrast media is enough to complete transit of water-soluble contrast media through the stomach and avoid unnecessary risks.

Acute Abdomen in Pediatric Patients With Lassa Fever: Prevalence and Response to Nonoperative Management.

Few reports on the prevalence of acute abdomen (AAbd) in pediatric patients with Lassa fever (LF) are available, and no firm policy on its management exists. Here, we report on its prevalence in and the response to treatment among a cohort of children with confirmed LF. Six (10.3%) of 58 children with LF had AAbd, whereas 6 (2.8%) of 215 children with AAbd had LF. Nonoperative treatment was successful in 5 of the 6 children with both AAbd and LF. We conclude that AAbd is not uncommon in pediatric patients with LF, and it could be responsive to nonoperative treatment. Testing for LF in all children with febrile AAbd might be justified in areas in which LF is endemic.

Computed tomography as a first-line investigation for elderly patients admitted to a surgical assessment unit.

Background Increases in life expectancy has meant that a higher proportion of patients presenting to surgical assessment units are now elderly. Abdominal computed tomography (CT) can provide early and accurate diagnosis in the elderly, even in the presence of incomplete clinical and biological findings. The aim of this study was to investigate the use of early CT imaging in elderly patients presenting directly to the surgical assessment unit. Materials and methods All consecutive patients aged 65 years and over admitted directly to the surgical assessment unit between January 2017 and April 2017 were identified. Data were collected on demographics, laboratory investigations, radiological investigations and hospital admission. The primary outcome measure was overall length of stay. Results A total of 200 consecutive patients were identified and included over a six-month period. This comprised 110 women and 90 men with a median age of 78 years (range 64-98 years). A total of 83 patients underwent CT on admission to the surgical assessment unit. White cell count (WCC) and C-reactive protein (CRP) results were significantly higher in patients undergoing CT (P = 0.001). Median length of stay for patients undergoing CT was 5 days (range 1-19 days). This was significantly lower than those patients not receiving CT imaging, at 6 days (range 1-105 days; P = 0.034). Discussion CT should be considered as a first-line investigation when elderly patients with an acute abdomen are admitted to surgical assessment units. Early CT can accelerate hospital discharge and decrease overall length of hospital stay.

Emergency assessment of patients with acute abdominal pain using low-dose CT with iterative reconstruction: a comparative study.

OBJECTIVES: To determine if radiation dose delivered by contrast-enhanced CT (CECT) for acute abdominal pain can be reduced to the dose administered in abdominal radiography (<2.5 mSv) using low-dose CT (LDCT) with iterative reconstruction algorithms. METHODS: One hundred and fifty-one consecutive patients requiring CECT for acute abdominal pain were included, and their body mass index (BMI) was calculated. CECT was immediately followed by LDCT. LDCT series was processed using 1) 40% iterative reconstruction algorithm blended with filtered back projection (LDCT-IR-FBP) and 2) model-based iterative reconstruction algorithm (LDCT-MBIR). LDCT-IR-FBP and LDCT-MBIR images were reviewed independently by two board-certified radiologists (Raters 1 and 2). RESULTS: Abdominal pathology was revealed on CECT in 120 (79%) patients. In those with BMI <30, accuracies for correct diagnosis by Rater 1 with LDCT-IR-FBP and LDCT-MBIR, when compared to CECT, were 95.4% (104/109) and 99% (108/109), respectively, and 92.7% (101/109) and 100% (109/109) for Rater 2. In patients with BMI ≥30, accuracies with LDCT-IR-FBP and LDCT-MBIR were 88.1% (37/42) and 90.5% (38/42) for Rater 1 and 78.6% (33/42) and 92.9% (39/42) for Rater 2. CONCLUSIONS: The radiation dose delivered by CT to non-obese patients with acute abdominal pain can be safely reduced to levels close to standard radiography using LDCT-MBIR. KEY POINTS: • LDCT-MBIR (<2.5 mSv) can be used to assess acute abdominal pain. • LDCT-MBIR (<2.5 mSv) cannot safely assess acute abdominal pain in obese patients. • LDCT-IR-FBP (<2.5 mSv) cannot safely assess patients with acute abdominal pain.

A randomised clinical trial of routine versus selective CT imaging in acute abdomen: Impact of patient age on treatment costs and hospital resource use.

OBJECTIVES: To evaluate the impact of patient age on hospital resource use and treatment costs of acute abdominal pain (AAP). MATERIALS AND METHODS: A total of 300 adult patients with AAP were randomised to either computed tomography (CT, n=150) or selective imaging practice (SIP, n=150) groups. Final analysis included 254 patients, 143 (42 patients ≥65years) in the CT and 111 (32 patients ≥65years) in the SIP group. All CT group patients underwent abdominal CT whereas in the SIP group, imaging was based on the clinical assessment. For each patient, the hospital length of stay (LOS), the numbers and costs of diagnostic and treatment procedures arising from AAP were calculated and registered. The incremental cost-effectiveness ratio (ICER) and bootstrapped cost-effectiveness acceptability curve (CEAC) were estimated for routine CT. RESULTS: Treatment costs, imaging costs and LOS increased in conjunction with aging in both study groups, and were generally higher in the CT group compared to the SIP group. In the SIP group, CT was undertaken in 34% (27/79) of the <65year olds but in 59% (19/32) of the older patients (≥65years) (p=0.02). The proportion of patients with non-specific abdominal pain was significantly lower in patients ≥65years than in their younger counterparts (p=0.04). In the routine CT group, the ICER of obtaining a specific diagnosis was 1682 € for patients <65years and 1055 € for patients ≥65years. According to CEAC estimation, routine CT for every patient with AAP has a 95% probability of being cost-effective if society is willing to pay 14087 € for an additional specific diagnosis for patients <65 years but only 4204 € in those ≥65years. CONCLUSION: Treatment costs of AAP increase in parallel with aging, and the costs are generally higher with routine CT compared to selective imaging. The probability of obtaining a specific diagnosis of AAP increases with aging. If obtaining a specific diagnosis is deemed crucial, then routine CT is more cost-effective in patients over 65 years compared to younger patients. Considering the diagnostic challenges of AAP in the elderly, liberal CT use can be advocated in this patient group.

Imaging assessment and clinical significance of pneumatosis in adult patients.

Gas detection in the bowel wall and in portomesenteric venous vessels in adults has long been related to intestinal infarction and poor outcome; many case reports have shown that pneumatosis may be associated with a large variety of pathological situations, ranging from absolutely benign and asymptomatic forms to abdominal catastrophes. Several studies have been conducted on this topic with different conclusions, probably due to differences in population so that the clinical value of these signs is still questioned. Intestinal pneumatosis, especially if presenting with a band-like pattern and if associated with portomesenteric vein gas, when observed in an acute abdominal setting should raise the suspicion of mesenteric infarct and prompt a careful search for other signs of intestinal involvement, so as not to miss cases of life-threatening intestinal infarct or allow them to further evolve into extensive necrosis with worse prognosis. In this review we illustrate the most relevant aspects of these debated but significant radiological signs.

The role of computed tomography in the preoperative assessment of gastrointestinal causes of acute abdomen in elderly patients.

Gastro-intestinal disorders in older patients is a medical emergency that requires immediate medical care. Chances of recovery improve with an early diagnosis and treatment. It might be caused by a number of different diseases, including perforations by foreign bodies, colon cancer, diverticulitis, ischemia. CT is often the initial modality used to assess patients with acute abdomen, the radiologist may be the first to suggest such a diagnosis. Computed tomography allows to identify the site of gastrointestinal perforations, of ischemia and to determine the most predictive signs in this diagnosis. The purpose of this study was to assess the diagnostic performance of CT gastrointestinal emergency of elderly patients with nontraumatic acute abdominal pain. The cases of 126 consecutively registered patients 65 years old or older presenting to the emergency department with acute abdominal pain and who underwent CT were retrospectively reviewed by two radiologists. Diagnostic accuracy was calculated according to the level of correctly classified cases in both the entire cohort and a surgical subgroup and was compared between readings. Agreement between each reading and the reference diagnosis and interobserver agreement were assessed with kappa statistics. In both the entire cohort (87.5% vs 85.3%, p = 0.07) and the surgical group (94% vs 91%, p = 0.15), there was no significant difference in CT accuracy between diagnoses made by the radiologist. Agreement between the CT diagnosis and the final diagnosis was excellent. In the care of elderly patients, CT is accurate for diagnosing the cause of acute abdominal pain, particularly when it is of gastrointestinal surgical origin. Thus CT interpretation should not be delayed until complete clinicobiologic data are available, and the images should be quickly transmitted to the emergency physician so that appropriate therapy can be begun.

Plain abdominal radiography in acute abdominal pain--is it really necessary?

The aims of this study are to audit the ordering of abdominal radiographs (AXR) in the emergency department (ED) and evaluate the current practices, knowledge and attitudes of emergency physicians with regard to ordering AXRs in patients presenting with acute abdominal pain. A retrospective study was undertaken at an ED of a tertiary hospital in Tasmania using clinical notes on patient presenting with acute abdominal pain who underwent an AXR. The study also included a short questionnaire, which assessed emergency physicians' knowledge of current imaging guidelines and clinical practice when ordering an AXR. During the study period, 108 patients satisfied the selection criteria, and the AXR was reported as normal in 76 % (n = 82; p value <0.05), non-specific in 12 % (n = 13; p value <0.05) and abnormal in 12 % (n = 13; p value <0.05) of patients. Of those patients, 25 % (n = 27) of the AXRs did not meet indications listed in the Diagnostic Imaging Pathways published by the Western Australia Department of Health and were found not to benefit patient care. Of the 19 doctors who completed the survey, only 16 % (n = 3) were aware of any clinical guidelines for imaging in this setting. Current guidelines should be followed when ordering imaging for patients with acute abdominal pain to minimise unnecessary patient radiation exposure, avoid delays in diagnosis and definitive patient management, reduce costs and therefore increase efficiency in ED.

Impact of routine contrast-enhanced CT on costs and use of hospital resources in patients with acute abdomen. Results of a randomised clinical trial.

OBJECTIVES: To evaluate the costs of treatment and use of hospital resources when comparing routine abdominal CT and selective imaging practice based on clinical assessment in patients with acute abdomen. METHODS: Altogether 300 patients with acute abdominal pain were randomised to computed tomography (CT, n = 150) or selective imaging practice (SIP, n = 150) groups. Final analysis included 254 patients, 143 in the CT and 111 in the SIP group. All CT group patients underwent contrast-enhanced abdominal CT within 24 h of admission. In the SIP group, imaging was individually tailored based on clinical assessment. The numbers of various examinations and procedures as well as costs of treatment arising from acute abdomen were calculated for each patient. Length of hospital stay was registered. RESULTS: Total treatment cost per patient was 1,202 euros () higher in the CT group compared to the SIP group (P = 0.002). The length of hospital stay was 1.2 days longer in the CT group (3.7 vs. 2.5 days, P = 0.010). Routine CT had no impact on ED discharge times. Imaging costs accounted for approximately 10 % of total costs. CONCLUSION: Routine abdominal CT results in higher treatment costs compared to selective use of imaging in patients with acute abdomen. KEY POINTS: • CT is widely used almost routinely in the diagnostics of acute abdomen. • Patients with acute abdomen were randomised to routine CT or selective imaging. • The treatment costs were significantly higher in the routine CT group. • Length of hospital stay was longer in the CT group. • Selective use of imaging may help control continuous increases of treatment costs.

The use of pre-operative computed tomography in the assessment of the acute abdomen.

INTRODUCTION: While there are a lot of data on the accuracy of computed tomography (CT) in diagnosing specific causes of an acute abdomen, there is very little information on the accuracy of CT in the acute general surgical admissions workload. We look at the diagnostic accuracy of CT in patients presenting with an acute abdomen who ultimately required a laparotomy. METHODS: Patients who underwent an emergency laparotomy between 2008 and 2010 at Eastbourne District General Hospital with pre-operative CT on the same admission were included in the study. The CT report was compared with the laparotomy and histology findings and, where a discrepancy existed, the original imaging was reviewed by a senior consultant blinded to the original report and laparotomy findings. RESULTS: A total of 196 emergency laparotomies were performed over the 2-year period, with 112 patients undergoing preoperative CT. Fifteen patients were excluded from the study due to missing notes. In the remaining 97 patients, 80 CT reports correlated with the final operative diagnosis, giving a diagnostic accuracy of 82%. Of these, the on-call registrar was the initial reporter in 37 scans, with a diagnostic accuracy of 78%. On review of the CT by a second consultant, this increased to 90 correlations, yielding an accuracy of 93%. Delay between CT and the operation did not significantly alter diagnostic accuracy, nor was there any statistically significant reduction in accuracy in reports issued by on-call registrars. CONCLUSIONS: On first reporting, CT misses 18% of diagnoses that ultimately require operative intervention. Reducing the threshold for obtaining a second consultant radiologist review significantly improves the diagnostic accuracy to 93%.

Imaging patients with acute abdominal pain.

UNLABELLED: Acute abdominal pain may be caused by a myriad of diagnoses, including acute appendicitis, diverticulitis, and cholecystitis. Imaging plays an important role in the treatment management of patients because clinical evaluation results can be inaccurate. Performing computed tomography (CT) is most important because it facilitates an accurate and reproducible diagnosis in urgent conditions. Also, CT findings have been demonstrated to have a marked effect on the management of acute abdominal pain. The cost-effectiveness of CT in the setting of acute appendicitis was studied, and CT proved to be cost-effective. CT can therefore be considered the primary technique for the diagnosis of acute abdominal pain, except in patients clinically suspected of having acute cholecystitis. In these patients, ultrasonography (US) is the primary imaging technique of choice. When costs and ionizing radiation exposure are primary concerns, a possible strategy is to perform US as the initial technique in all patients with acute abdominal pain, with CT performed in all cases of nondiagnostic US. The use of conventional radiography has been surpassed; this examination has only a possible role in the setting of bowel obstruction. However, CT is more accurate and more informative in this setting as well. In cases of bowel perforation, CT is the most sensitive technique for depicting free intraperitoneal air and is valuable for determining the cause of the perforation. Imaging is less useful in cases of bowel ischemia, although some CT signs are highly specific. Magnetic resonance (MR) imaging is a promising alternative to CT in the evaluation of acute abdominal pain and does not involve the use of ionizing radiation exposure. However, data on the use of MR imaging for this indication are still sparse. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/content/253/1/31/suppl/DC1.

Posttraumatic appendicitis: further extending the extended Focused Assessment with Sonography in Trauma examination.

Several cases of appendicitis after blunt abdominal trauma have been reported in the literature. A 41-year-old man on a cruise ship began to experience acute abdominal pain several hours after cliff diving from a 20-ft height and landing hard against the water on his right side. The patient's symptoms were treated and he remained on the ship until its scheduled arrival in port 2 days later. In the emergency department, a bedside extended Focused Assessment with Sonography in Trauma (eFAST) examination showed no evidence of free fluid in the abdominal cavity, pericardial effusion, or pneumothorax. Next, an ultrasound of the right lower quadrant was performed, which revealed a 1.06 cm, noncompressible appendix consistent with appendicitis. Although physical examination remains the gold standard for evaluation of the acute abdomen, the presentation of acute appendicitis is historically unreliable and delays in its diagnosis can result in significant increases in morbidity and mortality. Ultrasonography has been shown to have clear value in the evaluation of the acute abdomen. It is the authors' opinion that ultrasonography may have an unrealized potential as a diagnostic tool for traumatic appendicitis in the trauma bay and as a triage tool for the cruise ship physician who must evaluate a patient with traumatic abdominal pain and determine the need for medical evacuation.

Lossy three-dimensional JPEG2000 compression of abdominal CT images: assessment of the visually lossless threshold and effect of compression ratio on image quality.

PURPOSE: To retrospectively determine the maximum compression ratio at which compressed images are indistinguishable from the original by using a three-dimensional (3D) wavelet algorithm. MATERIALS AND METHODS: The protocol of this study was approved by the local Institutional Review Board and informed consent was waived. Sixty emergency abdominal computed tomographic (CT) scans of patients (31 men, 29 women; mean age +/- standard deviation, 50.8 years +/- 20.1; range, 17-80 years) with acute abdominal pain were subjected to lossy irreversible three-dimensional Joint Photographic Experts Group 2000 (3D-JPEG2000) compression by using four compression ratios (4:1, 8:1, 12:1, and 16:1). Groups contained five patients for each of 12 common diagnoses for acute abdominal pain. Images were obtained by using a multidetector CT scanner (Sensation Cardiac 64; Siemens, Forcheim, Germany) with 3- and 6-mm-thick sections. Three radiologists independently compared one case-relevant image per patient with the original image at different compression ratios. They had to determine which image was the original by using a forced-choice, two-alternative model and to subjectively rank image quality. For analysis, a binomial test was used, a Bonferroni correction was applied, and a P value of .01 indicated a significant difference. RESULTS: Images compressed at ratios of 4:1 and 8:1 were visually indistinguishable and essentially indistinguishable, respectively, from the original images (P > .01 for all readers). For the 12:1 and 16:1 ratios, all readers definitively (P < .001) identified the original images. CONCLUSION: The highest 3D-JPEG2000 compression ratio for abdominal CT scans, at which compressed images are essentially indistinguishable from the original, is 8:1.

Abdominal CT scanning in reproductive-age women with right lower quadrant abdominal pain: does its use reduce negative appendectomy rates and healthcare costs?

Although acute appendicitis is the most frequent cause of the acute abdomen in the United States, its accurate diagnosis in reproductive-age women remains difficult. Problems in making the diagnosis are evidenced by negative appendectomy rates in this group of 20 per cent to 45 per cent. Abdominal CT scanning has been used in diagnosing acute appendicitis, but its reliability and usefulness remains controversial. There is concern that the use of CT scanning to make this diagnosis leads to increased and unwarranted healthcare charges and costs. The purpose of our study is to determine if abdominal CT scanning is an effective test in making the diagnosis of acute appendicitis in reproductive-age women (age, 16-49 years) with right lower quadrant abdominal pain and to determine if its use is cost-effective. From January 2003 to December 2006, 439 patients were identified from our academic surgical database and confirmed by chart review as undergoing an appendectomy with a pre- or postoperative diagnosis of acute appendicitis. Data, including age, presence and results of preoperative abdominal CT scans, operative findings, and pathology reports were reviewed. Comparison of patients receiving a preoperative CT scan with those who did not was performed using chi-squared analysis. In the subgroup of reproductive-age women, there was a significant difference in negative appendectomy rates of 17 per cent in the group that received abdominal CT scans versus 42 per cent in the group that did not (P < 0.038). After accounting for the patient and insurance company costs, abdominal CT scan savings averaged $1412 per patient. Abdominal CT scanning is a reliable, useful, and cost-effective test for evaluating right lower quadrant abdominal pain and making the diagnosis of acute appendicitis in reproductive-age women.

[Impact of computed tomography on patient's care in nontraumatic acute abdomen: 90 patients]. / Contribution du scanner à la prise en charge des tableaux abdominaux aigus non traumatiques: étude de 90 patients.

OBJECTIVES: To determine the contribution of computerized tomography (CT) to the management of nontraumatic acute abdomen, to evaluate interobserver agreement and the contribution of CT to cost control, to look for the predictive factors of CT. PATIENTS: and method. Ninety prospectively included patients, admitted for nontraumatic acute abdomen and examined by a surgeon, received CT examination. Diagnosis and treatment 1) envisioned before and 2) defined after CT, and 3) finally retained were compared, and the interobserver agreement was calculated after the second reading. The predictive value of the clinical and biological criteria as well as the radiological criteria characterizing these patients was sought. RESULTS: CT was contributive in 68.9% of cases, with a reliable diagnosis and treatment strategy, defined after CT examination, for 92.2% and 90%, respectively. Interobserver agreement was 93.3%. CT contributed to reducing costs in 15.5% of patients, for an additional cost estimated at 104-139 euros. The positive predictive factors of the CT contribution were age over 70 years, localized symptoms, fever, and high CRP. CONCLUSION: In agreement with the literature, in our study CT appears to be a choice examination to guide patient care in nontraumatic acute abdomen.

Derivation of a clinical guideline for the assessment of nonspecific abdominal pain: the Guideline for Abdominal Pain in the ED Setting (GAPEDS) Phase 1 Study.

OBJECTIVE: The purpose of this study was to identify a clinical guideline for the evaluation of nonspecific abdominal pain (NSAP) using history, physical examination, laboratory analysis, acute abdominal series (AAS) radiographs, and nonenhanced helical computed tomography (NHCT) clinical predictor variables (CPVs). SETTING: The setting of this study was at an urban emergency department (ED) with 70,000 yearly visits. METHODS: This is an institutional review board-approved, prospective, observational study. The primary outcome variable was urgent intervention (UI), defined as a diagnosis requiring surgical or medical treatment to prevent death or major morbidity. Subjects underwent prompted history, physical, laboratory studies, AAS, and NHCT and were followed up to 6 months for ultimate diagnosis and outcome. CPVs were subjected to classification and regression tree analysis. RESULTS: One hundred sixty-five subjects were analyzed. Thirteen percent of subjects required UI within 24 hours of presentation; an additional 34% underwent elective interventions that mitigated morbidity or mortality. Four guideline models were generated. Model 1 consisted of history and physical, with a sensitivity of 25%, a specificity of 92%, a positive likelihood ratio of 3.17, and a negative likelihood ratio of 0.81. Model 2 consisted of model 1 with laboratory, with a sensitivity of 39%, a specificity of 88%, a positive likelihood ratio of 3.25, and a negative likelihood ratio of 0.69. Model 3 consisted of model 2 with AAS, with a sensitivity of 56%, a specificity of 81%, a positive likelihood ratio of 2.94, and a negative likelihood ratio of 0.54. Model 4 comprised all inputs, including NHCT, with a sensitivity of 92%, a specificity of 90%, a positive likelihood ratio of 9.2, and a negative likelihood ratio of 0.089. NHCT was the single most accurate CPV for UI. CONCLUSIONS: No clinical guideline was identified exclusive of NHCT that possessed adequate sensitivity for exclusion of UI. NHCT is a rational choice for decision support in the evaluation of NSAP and is likely the single most useful diagnostic adjunct available to augment the clinical evaluation.