Relative accuracy of emergency CT in adults with non-traumatic abdominal pain

Tailored versus fixed scan delay in contrast-enhanced abdominal multi-detector CT: An intra-patient comparison of image quality

PURPOSE

To perform anintra-patient comparison betweena single-pass protocol (SP) and a portal venous phase (PVP) by means ofboth quantitative and qualitative analysis of image quality.

METHODS

Forty patients (31 M; 9F; aged 20-77 years; BMI 23 ± 4 Kg/m²) underwent both a SP and a PVP using a 64-rows multi-detector CT with a median interval time of 56 days (range5-903). All patients underwent i.v. bolus injection (2.0 cc/sec) of 1.7 cc/Kg of a non ionic iodinated contrast-media (370 mgI/ml) with scan delays of 67 ± 8 and 90 s for the SP and the PVP, respectively. Signal- (SNR) and contrast-to-noise ratios (CNR) were calculated for most visceral organs and for both abdominal aorta (AA) and main portal vein (MPV). For qualitative analysis, reproduction of abdominal viscera and vascular structures was blindly evaluated and inter-observer agreement calculated by the weighted Cohen k-analysis.

RESULTS

Attenuation values (H.U.) of AA (232 ± 53vs180 ± 36) and MPV (215 ± 39vs187 ± 42) were significantly (p < 0.001) higher in the SP than in PVP, respectively. At qualitative analysis, reproduction of mostabdominal viscerawas also significantly sharper (p < 0.001) with the SP than the PVPwith inter-observer agreement scores (k)ranging from 0.60 to 0.88 for all but one imaging criteria.

CONCLUSIONS

As the SP resulted in a significantly higher vascular enhancement and in a sharper reproduction of most abdominal viscera, it may be better suited than a PVP for the CT evaluation of non traumatic acute abdomen.

ACR Appropriateness Criteria® Postmenopausal Acute Pelvic Pain

Acute pelvic pain is a common presenting complaint in both the emergency room and outpatient settings. Pelvic pain of gynecologic origin in postmenopausal women occurs less frequently than in premenopausal women; however, it has important differences in etiology. The most common causes of postmenopausal pelvic pain from gynecologic origin are ovarian cysts, uterine fibroids, pelvic inflammatory disease, and ovarian neoplasm. Other etiologies of pelvic pain are attributable to urinary, gastrointestinal, and vascular systems. As the optimal imaging modality varies for these etiologies, it is important to narrow the differential diagnosis before choosing the initial diagnostic imaging examination. Transabdominal and transvaginal ultrasound are the best initial imaging techniques when the differential is primarily of gynecologic origin. CT with intravenous (IV) contrast is more useful if the differential diagnosis remains broad. MRI without IV contrast or MRI without and with IV contrast, as well as CT without IV contrast may also be used for certain differential considerations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Association of Pain Location With Computed Tomography Abnormalities in Emergeny Department Patients With Abdominal Pain

BACKGROUND

Over the last decade the usage of computed tomography (CT) imaging has risen dramatically in emergency department (ED) patients with abdominal pain. Recognizing the potential disadvantages of overuse of CT imaging, efforts are being made to reduce imaging.

OBJECTIVE

We determined the operating characteristics for location of abdominal pain for the entities of acute appendicitis, diverticulitis, and intestinal obstruction. We hypothesized that patients with pain localized to the upper abdomen would be less likely to have CT abnormalities than those with lower abdominal pain.

METHODS

This is a prospective, observational registry of ED patients with abdominal pain, performed in an academic, suburban ED with an annual census of 110,000. Presence of clinically significant CT abnormalities (e.g., appendicitis, diverticulitis, bowel obstruction) were recorded along with clinical variables including laboratory values, vital signs, reported location of pain, location of tenderness on examination, and physician pretest probability.

RESULTS

A convenience sample of 1154 patients was enrolled. Of all patients, 273 cases (24%) had abnormal CT results, including appendicitis (n = 95), diverticulitis (n = 133), and bowel obstruction (n = 49). Right upper quadrant pain was negatively associated with abnormal CT (p = 0.02). Clinician gestalt was highly specific, but lacked sensitivity for the diagnosis of appendicitis, diverticulitis, and obstruction. Twenty-four percent of patients diagnosed with appendicitis had no right lower quadrant pain or tenderness, and 7% of patients with diverticulitis had no left lower quadrant pain or tenderness.

CONCLUSIONS

Localization of abdominal pain by history or physical examination is not sufficient to accurately diagnose intra-abdominal pathology, especially cases of acute appendicitis, diverticulitis, or intestinal obstruction.

Generalist versus Abdominal Subspecialist Radiologist Interpretations of Abdominopelvic Computed Tomography Performed on Patients with Abdominal Pain and its Impact on the Therapeutic Approach

Introduction:

Abdominal pain is one of the most common patient complaints in the emergency department (ED) and abdominopelvic computed tomography (ACT) scan plays an important role in evaluation of these patients.

Objective:

The aim of this study was to determine the differences between interpretations by generalist radiologists and abdominal subspecialist radiologists regarding the abdominopelvic computed tomography (ACT) of patients who were admitted to the Emergency Department (ED) and to investigate its effect on the patients’ therapeutic approach.

Methods:

The records of 16452 patients who were admitted to the emergency department with complaint of abdominal pain between January 2015 and April 2017 were reviewed, retrospectively. Out of these patients, 245 (1.5%) underwent ACT for differential diagnosis and among them, 137 (0.8%) patients had their ACT reports evaluated by generalist radiologists in 45 minutes and by abdominal subspecialist radiologist 8–12 hours later and were included in the study. Patients were divided into three groups according to the effect of ACT reports on the performed treatment. Group 1: no effect on planned treatment, group 2: minor effect on planned treatment, which did not result in a change in the treatment process and group 3: major effect on planned treatment approach, which resulted in a change in the treatment process. These changes included at least one of the two criteria: changing the indication of surgery from emergency surgery to elective surgery and/or discharge of the patient from the ED, when actually hospitalization was required.

Results:

Out of the 137 patients, 87 (63.5%) were male, 50 (36.5%) were female and the patients’ mean age was 56 (27–93) years. There were 117 (85.4%) patients in group 1, 15 (10.9%) patients in group 2, and 5 (3.7%) patients in group 3. We determined minor inconsistency between the reports in group 2 and major inconsistency in group 3. Patients in group 3 suffered from delayed surgical intervention due to inconsistency of the CT reports resulting in prolonged hospital stay and increased morbidity. In 17 patients (four patients in Group 1 and 13 patients in Group 2) treatment plan was changed due to CT results; and while surgical treatment was planned for them prior to CT scan, they were discharged with medical treatment after that and overtreatment was prevented.

Conclusion:

Contribution of abdominal radiologists to evaluation of ACT images in the ED would reduce the inconsistency in ACT reports and prevent the patients from receiving insufficient treatment or overtreatment.

Effects of eliminating routine use of oral contrast for computed tomography of the abdomen and pelvis: A pilot study

INTRODUCTION

Computed tomography (CT) of the abdomen and pelvis using only intravenous contrast has been shown to have a high degree of accuracy in evaluating abdominal pain. The aim of this study was to determine the effect on time to completion of study, time to radiologist read, and length of stay in the emergency department (ED) of implementing a protocol that stopped the routine use of oral contrast for CT of the abdomen and pelvis.

METHODS

This was a single-center, retrospective cohort study. All patients ≥18 years of age who presented to the ED and required a CT of the abdomen and pelvis during the hours 0700-1500 were included. There were two one-month study periods, before and after implementing a protocol that specified oral contrast should only be used for CT scans of the abdomen and pelvis if body mass index <25 kg/m² or age < 30 years, or if there was history of inflammatory bowel disease, gastrointestinal surgery, or suspected bowel malignancy.

RESULTS

During the pre- and post-implementation periods, there were 93 and 83 patients, respectively, with mean times to CT completion of 158 min and 135 min, representing a reduction of 23 min (15%). The mean lengths of stay in the pre- and post-implementation periods were 365 min and 336 min, a decrease of 29 min (8%).

CONCLUSION

A protocol without the routine use of oral contrast for CT of the abdomen and pelvis can result in improved time to completion and ED length of stay.