Emergent and unusual presentations of endometriosis: pearls and pitfalls.

The purpose of this pictorial essay is to highlight atypical and unusual presentations of endometriosis that can be missed or misinterpreted in the emergency setting. Although endometriosis is a chronic disease, it can present acutely with symptoms and imaging mimicking more common acute gynecologic, gastrointestinal, or urinary conditions as well as neoplasms. Furthermore, patients may present emergently prior to an established diagnosis of endometriosis. Here, we present a range of cases including endometrioma rupture and infection, urinary tract involvement and obstruction, bowel obstruction, appendicitis, gastrointestinal infiltration, abdominal masses, and thoracic involvement. Pelvic ultrasound and MRI are the most valuable imaging modalities in the assessment of endometriosis. CT findings are non-specific, but given the widespread use of CT in emergency settings, it is important to recognize CT findings suggestive of the diagnosis in the right clinical setting.

Multimodality Imaging after Liver Transplant: Top 10 Important Complications.

Patients who have undergone liver transplant are now regularly seen in day-to-day radiology practice. All surgical techniques for liver transplant require arterial, portal venous, hepatic venous and caval, and biliary anastomoses. This review is focused on the 10 "not to be missed" complications of liver transplant that affect the health and life of the graft and graft recipient. Arterial complications are the most common and devastating. Early hepatic artery thrombosis may be catastrophic because the biliary tree is solely dependent on the hepatic artery after transplant and collateral vessels have not yet formed. In contrast, delayed hepatic artery thrombosis may be more insidious as collateral arteries develop. US findings of delayed hepatic artery thrombosis may be similar to those of hepatic artery stenosis and celiac artery stenosis. Splenic artery steal syndrome is an increasingly recognized cause of graft ischemia. Venous complications are much less common. Hepatic venous and caval complications are notable for their increased incidence in living-donor and pediatric transplants. Biliary complications often result from arterial ischemia. Biliary cast syndrome is a notable example in which ischemic biliary mucosa sloughs into and obstructs the duct lumens. Neoplasms also may occur within the hepatic graft and may be due to recurrent malignancy, posttransplant lymphoproliferative disorder, or metastases. US is the initial imaging modality of choice, particularly in the acute postoperative setting. Further evaluation with contrast-enhanced US, CT, or MRI; catheter angiography; endoscopic retrograde cholangiopancreatography; and/or nuclear medicine studies is performed as needed. An invited commentary by Bhargava is available online. Online supplemental material is available for this article. ©RSNA, 2022.

Interreader Concordance of the TI-RADS: Impact of Radiologist Experience.

OBJECTIVE. The objective of this article is to assess radiologist concordance in characterizing thyroid nodules using the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS), focusing on the effect of radiologist experience on reader concordance. MATERIALS AND METHODS. Three experienced and three less experienced radiologists assessed 150 thyroid nodules using the TI-RADS lexicon. Percent concordance was determined for various endpoints. RESULTS. Interreader concordance for the five TI-RADS categories was 87.2% for shape, 81.2% for composition, 76.1% for echogenicity, 72.9% for margins, and 69.8% for echogenic foci. Concordance for individual features was 96.3% for rim calcifications, 90.8% for macrocalcifications, 90.1% for spongiform, 83.5% for comet tail artifact, and 77.7% for punctate echogenic foci. Concordance for the TI-RADS level and recommendation for fine-needle aspiration (FNA) were 50.4% and 78.9%, respectively. Concordance was significantly (p < 0.05) higher for less experienced readers in identifying margins (84.3% vs 67.4%), echogenic foci (76.9% vs 69.3%), comet tail artifact (89.6% vs 79.2%), and punctate echogenic foci (85.3% vs 75.5%), and lower for peripheral rim calcifications (95.0% vs 97.8 %), but was not different (p > 0.05) for the remaining categories and features. CONCLUSION. A range of TI-RADS categories, features, and recommendations for FNA had generally moderate interreader agreement among six radiologists. Our results show that concordance for numerous characteristics was significantly higher for the less experienced versus the more experienced readers. These results suggest that less experienced readers relied more on the explicit TI-RADS criteria, whereas the experienced radiologists partially relied on their accumulated experience when forming impressions. However, the overall TI-RADS level and recommendation for FNA were unaffected, supporting the robustness of the TI-RADS lexicon and its continued use in practice.

Additional Surgery for Occult Risk Factors After Lobectomy in Solitary Thyroid Nodules is Predicted by Cytopathology Classification and Tumor Size.

OBJECTIVE: Clinical practice for differentiated thyroid cancer is moving towards lobectomy rather than total thyroidectomy in patients at low risk of recurrence. However, recurrence risk assessment depends on post-operative findings, while the surgical decision is based on preoperative factors. We determined the preoperative predictors of occult higher-risk pathology and rates of completion thyroidectomy among surgical candidates with nonbenign thyroid nodules 10 to 40 mm and no evidence of extrathyroidal extension or metastasis on preoperative evaluation. METHODS: Thyroid surgery cases at a single institution from 2005-2015 were reviewed to identify those meeting American Thyroid Association (ATA) criteria for lobectomy. ATA-based risk stratification from postoperative surgical pathology was compared to preoperative cytopathology, ultrasound, and clinical findings. RESULTS: Of 1,995 thyroid surgeries performed for nonbenign thyroid nodules 10 to 40 mm, 349 met ATA criteria for lobectomy. Occult high-risk features such as tall cell variant, gross extrathyroidal invasion, or vascular invasion were found in 36 cases (10.7%), while intraoperative lymphadenopathy led to surgical upstaging in 13 (3.7%). Intermediate risk features such as moderate lymphadenopathy or minimal extrathyroidal extension were present in an additional 44 cases. Occult risk features were present twice as often in Bethesda class 6 cases (35%) as in lower categories (12 to 17%). In multivariable analysis, Bethesda class and nodule size, but not age, race, sex, or ultrasound features, were significant predictors of occult higher-risk pathology. CONCLUSION: Most solitary thyroid nodules less than 4 cm and with cytology findings including atypia of undetermined significance through suspicious for papillary thyroid cancer would be sufficiently treated by lobectomy. ABBREVIATIONS: ATA = American Thyroid Association; CND = central neck dissection; DTC = differentiated thyroid cancer; ETE = extrathyroidal extension; FNA = fine needle aspiration; FTC/HCC = follicular thyroid carcinoma/Hurthle cell carcinoma; NIFTP = noninvasive follicular thyroid neoplasm with papillary-like nuclear features; OR = odds ratio; PTC = papillary thyroid cancer; US = ultrasound.

TIRADS Interobserver Variability Among Indeterminate Thyroid Nodules: A Single-Institution Study.

OBJECTIVES: A high proportion of cytologically indeterminate, Afirma Gene Expression Classifier "suspicious" thyroid nodules are benign. The Thyroid Imaging Reporting and Data System (TIRADS), was proposed by the American College of Radiology in 2017 to help classify thyroid nodules based on ultrasound characteristics in a standardized fashion to guide management. We aim to determine the interobserver variability of TIRADS classification among cytologically indeterminate and Afirma suspicious nodules. METHODS: We retrospectively queried cytopathology archives for thyroid fine-needle aspiration specimens obtained between February 2012 and September 2016 with associated (1) indeterminate diagnosis, (2) ultrasound imaging at our institution, (3) Afirma suspicious result, and (4) surgery at our institution. We compared the TIRADS variability of the 3 blinded radiologists using intraclass correlation coefficients. RESULTS: Our cohort consisted of 127 nodules. Intraclass correlation coefficients can be interpreted as follows: less than 0.4, poor; 0.4 to 0.59, fair; 0.6 to 0.74, good; 0.75 to 1.00, excellent. The intraclass correlation coefficients of the raw TIRADS score and category variability was 0.561 (95% confidence interval [CI]: 0.464-0.651) or fair and 0.547 (95% CI, 0.449-0.640) or fair, respectively. When analyzing composition, echogenicity, shape, margin, and echogenic foci, the ICCs were 0.552 (95% CI, 0.454-0.643), fair; 0.533 (95% CI, 0.432-0.627), fair; 0.359 (95% CI, 0.248-0.469), poor; 0.192 (95% CI, 0.084-0.308), poor; and 0.549 (95% CI, 0.451- 0.641), fair, respectively. CONCLUSIONS: Our results show that among the subset of cytologically indeterminate and Afirma suspicious nodules, TIRADS interobserver variability was fair. Shape and margin criteria were the biggest sources of disagreement. Large prospective studies are needed to evaluate the interobserver variability of TIRADS in this subset of thyroid nodules.

Radiomics machine learning algorithm facilitates detection of small pancreatic neuroendocrine tumors on CT.

PURPOSE: The purpose of this study was to develop a radiomics-based algorithm to identify small pancreatic neuroendocrine tumors (PanNETs) on CT and evaluate its robustness across manual and automated segmentations, exploring the feasibility of automated screening. MATERIALS AND METHODS: Patients with pathologically confirmed T1 stage PanNETs and healthy controls undergoing dual-phase CT imaging were retrospectively identified. Manual segmentation of pancreas and tumors was performed, then automated pancreatic segmentations were generated using a pretrained neural network. A total of 1223 radiomics features were independently extracted from both segmentation volumes, in the arterial and venous phases separately. Ten final features were selected to train classifiers to identify PanNETs and controls. The cohort was divided into training and testing sets, and performance of classifiers was assessed using area under the receiver operator characteristic curve (AUC), specificity and sensitivity, and compared against two radiologists blinded to the diagnoses. RESULTS: A total of 135 patients with 142 PanNETs, and 135 healthy controls were included. There were 168 women and 102 men, with a mean age of 55.4 ± 11.6 (standard deviation) years (range: 20-85 years). Median PanNET size was 1.3 cm (Q1, 1.0; Q3, 1.5; range: 0.5-1.9). The arterial phase LightGBM model achieved the best performance in the test set, with 90 % sensitivity (95 % confidence interval [CI]: 80-98), 76 % specificity (95 % CI: 62-88) and an AUC of 0.87 (95 % CI: 0.79-0.94). Using features from the automated segmentations, this model achieved an AUC of 0.86 (95 % CI: 0.79-0.93). In comparison, the two radiologists achieved a mean 50 % sensitivity and 100 % specificity using arterial phase CT images. CONCLUSION: Radiomics features identify small PanNETs, with stable performance when extracted using automated segmentations. These models demonstrate high sensitivity, complementing the high specificity of radiologists, and could serve as opportunistic screeners.

CT of gallbladder cancer and its mimics: a pattern-based approach.

On computed tomography (CT), gallbladder pathology may be detected incidentally or as the etiology of symptoms that prompted imaging. Accurate pathologic diagnosis can be challenging, however, due to overlapping appearances of malignant and benign gallbladder disease. This pictorial essay takes a pattern-based approach to CT of the gallbladder, to help the radiologist formulate the proper differential diagnosis.

Role of MDCT angiography in selection and presurgical planning of potential renal donors.

OBJECTIVE: The purpose of this study was to determine the prevalence and types of renal and extrarenal abnormalities that preclude renal donation or lead to alteration of the surgical approach on the basis of abdominal CT angiography (CTA) in a large group of potential renal donors. MATERIALS AND METHODS: In this retrospective study, 654 potential renal donors undergoing dual-phase CTA were identified from January 2005 to January 2009. The CT reports were systemically reviewed by two radiologists to determine the presence of renal and extrarenal abnormalities. The operative notes of the renal donors were reviewed by one radiologist to determine whether the presence of renal pathology had affected the surgical approach. In the candidates who did not proceed to kidney donation, the reasons that precluded kidney donation were abstracted from the transplant database. RESULTS: Four hundred seventeen potential donors (269 men and 385 women; mean age, 44.0 years; age range, 17-79 years) proceeded to renal donation and 237 did not. The most common renal abnormalities were cysts (34%) and renal stones (4.4%). Renal artery disease was identified in 3.4% of potential donors, including renal artery stenosis, possible fibromuscular dysplasia, and renal artery aneurysm. Suspicious renal masses were incidentally found in 0.5% of potential donors. The most common extrarenal pathology was an incidental adrenal nodule (2.6%). Other significant extrarenal pathology identified included gallbladder mass (0.2%), Crohn disease (0.2%), ovarian mass (0.2%), and possible sarcoidosis (0.2%). Although renal and extrarenal abnormalities were present in 41% of potential renal donors, abnormalities seen on CT only contributed to exclusion of 27 potential donors (4.1%). The most common reason for exclusion was the presence of renal stones or scarring (1.8%). Significant CT findings also contributed to the selection of the right kidney in 29 donors, most commonly due to presence of ipsilateral vascular disease or complex left vascular anatomy. CONCLUSION: Renal parenchymal and vascular abnormalities are common in asymptomatic potential kidney donors. Although most of these represent incidental CT findings, abnormalities can exclude potential renal donors and alter the surgical approach in a small minority of cases.

Do ACR TI-RADS scores demonstrate unique thyroid molecular profiles?

PURPOSE: The present study aimed to examine the molecular profiles of cytologically indeterminate thyroid nodules stratified by American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) categories and to determine whether certain ultrasonographic features display particular molecular alterations. METHODS: A retrospective review was conducted of cases from January 1, 2016 to April 1, 2018. Cases with in-house ultrasonography, fine-needle aspiration Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) diagnoses, molecular testing, and surgery were included. All cases were diagnosed as TBSRTC indeterminate categories. The ultrasound studies were retrospectively reviewed and assigned TI-RADS scores (TR1-TR5) by board-certified radiologists. The final diagnoses were determined based on the surgical resection pathology. Binary logistic regression analysis was used to study whether demographic characteristics, TI-RADS levels, and TBSRTC diagnoses were associated with ThyroSeq molecular results. RESULTS: Eighty-one cases met the inclusion criteria. RAS mutations were the most common alteration across all TI-RADS categories (TR2 2/2; TR3 10/19, TR4 13/44, and TR5 8/16), and did not stratify with any particular TI-RADS category. Only TR4 and TR5 categories displayed more aggressive mutations such as BRAFV600E and TERT. ThyroSeq results were positively correlated with thyroid malignancy when non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was categorized in the malignant category (odds ratio [OR], 6.859; P<0.01), but not when NIFTP was removed from the malignancy category. Echogenicity scores were found to be negatively correlated with ThyroSeq results in thyroid nodules (OR, 0.162; P<0.01). CONCLUSION: Higher-risk molecular alterations tended to stratify with the higher TI-RADS categories.

Evaluation of ACR TI-RADS cytologically indeterminate thyroid nodules and molecular profiles: a single-institutional experience.

INTRODUCTION: The American College of Radiology (ACR) Thyroid Imaging Reporting and Data Systems (TI-RADS) was developed to standardize thyroid ultrasound reports and predict the likelihood of malignancy. In our study, we aimed to correlate indeterminate thyroid fine needle aspiration cytology cases with preceding ultrasound (US) ACR TI-RADS scores and concurrent molecular testing results to examine how well the use of the ACR TI-RADS in our institution predicted which patients with indeterminate cytology might harbor molecular alterations. MATERIALS AND METHODS: We performed a retrospective review of thyroid nodules. Patients with US reports that included TI-RADS scores, fine needle aspiration specimens with indeterminate cytology (Bethesda class III-V), and molecular testing results were included. RESULTS: A total of 46 indeterminate cytology cases had had preceding US reports with TI-RADS scores and molecular testing (Bethesda class III, n = 37; Bethesda class IV, n = 6; Bethesda class V, n = 3). Most of the indeterminate cases had had a TI-RADS score of TR4 (31 of 46; 67.39%) or TR5 (9 of 46; 19.57%). RAS mutations were the most common alteration (n = 12). Of the 46 cases, 22 (47.85%) showed no alterations. Ten cases proceeded to surgery, of which seven displayed malignancies. CONCLUSIONS: Molecular testing in cytologically indeterminate thyroid nodules provided valuable information for TR4 and TR5 lesions; however, the TR2 and TR3 lesions often had no molecular alterations. These findings highlight the potential value of including US imaging features when assessing the significance of indeterminate cytology findings.

Infection rates of rifampin/gentamicin-coated Titan Coloplast penile implants. Comparison with Inhibizone-impregnated AMS penile implants.

INTRODUCTION: It is a common practice to soak Titan(®) Coloplast penile implants in antibiotic solution prior to implantation. Experience with Inhibizone impregnation suggests that rifampin coating significantly reduces infection rates of penile implant surgery. In this article we describe the results of coating Titan Coloplast penile implants with rifampin/gentamicin solution. AIM: To compare infection rates of Titan(®) Coloplast penile implants coated with vancomycin/gentamycin, rifampin/gentamicin, and Inhibizone-impregnated American Medical Systems (AMS) penile implants. METHODS: Chart review was done for all Mentor/Coloplast and AMS implant surgeries performed at our center between the dates January 1, 2002 and February 8, 2010. Infection rates for Titan(®) Coloplast penile implants coated with vancomycin/gentamycin, rifampin/gentamicin, and Inhibizone-impregnated (AMS) penile implants were compared. MAIN OUTCOME MEASURES: Infection rates for penile implants coated with different antibiotics. RESULTS: Infection rates for Titan(®) Coloplast penile implants coated with vancomycin/gentamycin and Inhibizone-impregnated (AMS) penile implants was 4.4% and 1.3%, respectively (P = 0.05). None of the rifampin/gentamicin-coated Titan(®) Coloplast penile implants have developed infection. Rifampin is the common antibiotic both in rifampin/gentamicin-coated Coloplast implants and Inhibizone(®) . The infection rate in this combined rifampin/gentamicin-coated Titan Coloplast implants and Inhibizone-coated AMS implants group was 0.63% (P = 0.03). CONCLUSION: Both rifampin/gentamicin-coated Titan(®) Coloplast penile implants and Inhibizone-impregnated (AMS) penile implants appear to have lower infection rates compared with vancomycin/gentamycin-coated Titan(®) Coloplast penile implants The present study does not suggest superiority of rifampin/gentamicin-coated Titan(®) Coloplast penile implants or Inhibizone-impregnated (AMS) penile implants but we strongly suggest that all Titan(®) Coloplast penile implants should be coated with rifampin/gentamicin solution.

Can ultrasound be used as the primary screening modality for the localization of parathyroid disease prior to surgery for primary hyperparathyroidism? A review of 440 cases.

BACKGROUND/AIMS: Sestamibi scintigraphy and neck ultrasonography have both been proposed as screening modalities for the detection of abnormal parathyroid glands in patients with primary hyperparathyroidism. As a result, many surgeons use both techniques prior to surgery. The goal of this study was to independently evaluate both ultrasound and sestamibi as single-modality preoperative screening tools for primary hyperparathyroidism. METHODS: A retrospective review of consecutive patients who underwent surgery for primary hyperparathyroidism from January 1999 to December 2009. Imaging results were compared to surgical findings. RESULTS: 440 patients were found to meet inclusion criteria. Sensitivities for correct localization of a single parathyroid adenoma for sestamibi versus ultrasound were: 83% (95% CI 78-86) versus 72% (95% CI 67-76). Ultrasound operator had no influence on sensitivity, and ultrasound identified nodular thyroid disease in 31% of patients. CONCLUSION: Ultrasonography alone can be used as the primary screening modality in patients with primary hyperparathyroidism. Ultrasound sensitivity is conserved despite operator variability, and identifies concomitant thyroid pathology.

Splenic sequestration in the adult: cross sectional imaging appearance of an uncommon diagnosis.

Acute splenic sequestration crisis, the sudden pooling of red blood cells in the spleen, is an emergent process typically seen in children with homozygous sickle cell disease. Splenic sequestration has rarely been reported in adults with heterozygous sickle cell conditions, including sickle cell beta(+)-thalassemia disease (HbS/ß+-thalassemia). Here we present a case of a 32-year-old man with HbS/ß+-thalassemia who suffered an acute splenic sequestration crisis. We review the CT and ultrasound appearance of splenic sequestration, which include splenic enlargement and an irregular rim of hypoenhancing or hypoechoic tissue at the periphery of the spleen, and discuss imaging differential considerations. To our knowledge, this is only the nineteenth case of acute splenic sequestration to be reported in an adult with HbS/ß+-thalassemia in the English literature, and only the second case in which ultrasound findings are reported.

Asymptomatic Abdominal Aortic Aneurysm: Standardizing Reporting Recommendations at a Large Multistate Radiology Practice.

OBJECTIVE: Although often asymptomatic at initial diagnosis, abdominal aortic aneurysms (AAAs) require careful surveillance to prevent rupture, with rupture-associated mortality rates as high as 90%. The purpose of this study was to explore if a performance improvement initiative implemented across a large radiology practice successfully increased inclusion of best practice recommendations (BPRs) within the radiology report across the practice. METHODS: After BPRs for asymptomatic AAA surveillance were developed, a structured reporting macro for follow-up recommendation was integrated into dictation software. Following a training period, inclusion of recommendations within the radiology report was monitored across 345 facilities within the practice. Performance was reported on scorecards distributed monthly. To measure practice improvement, inclusion of appropriate recommendation in radiology reports postimplementation was compared with pre-implementation data. RESULTS: During the period before AAA BPRs implementation, from 64,090 consecutive cross-sectional radiology reports reviewed during a 6-month period, 855 incidental AAAs (1.3%) were identified, with 783 aneurysms measuring 2.6 to 5.4 cm requiring imaging surveillance; only 17 (2.1%) included follow-up recommendations within the radiology report. Postimplementation, 2,641 of 148,807 cross-sectional imaging studies were positive for 2.6- to 5.4-cm AAAs requiring further management; 1,533 (58.0%) of these radiology reports included follow-up imaging recommendations (97.0% of which followed our AAA BPRs). DISCUSSION: Quality improvement initiatives to develop BPRs for AAA surveillance and include these recommendations within the radiology report can be successfully implemented across large practices and are imperative to ensure imaging surveillance and avert AAA rupture.

Ultrasound Studies of COVID-19-Positive Patients and Patient Under Investigation: Pandemic Experience of Body Imaging Division at a Tertiary Medical Center.

ABSTRACT: This retrospective study shares our departmental experience of screening of ultrasound (US) requests, triaging of studies, and abbreviated US protocols implemented during the COVID-19 pandemic. For US studies requested in April and May 2020, the following data were collected: type of study, indication, COVID-19 status (positive or patient under investigation [PUI]), decision to perform study, US findings, and location of patient. A total of 196 US studies in 150 patients were included. The median age of patients was 60 years (female: 46.7% [70/150]). At the time of study request, 83 patients (55.3%) were COVID-19-positive and 67 (44.7%) were PUI, of which 8 (11.9%) tested positive after waiting for test result. The most frequently requested study was venous extremity Doppler (51%), followed by right upper quadrant (20.4%), renal (11.7%), and liver duplex (6.6%). After radiologist screening and triage of US requests, 156 studies were performed (79.6%), 15 were postponed until COVID test result (7.6%), and 40 were not performed after discussion with ordering provider (20.4%). Notably, 40.1% of studies performed on COVID-19-positive patients yielded pathological findings, most frequently deep venous thrombosis (18.1%), medical renal disease (7.6%), and gall bladder sludge (5.7%). Abbreviated US protocols were used in 29.4% of studies. In conclusion, US study screening and triage played an important role to optimize care of COVID-19 patients and PUIs.

Superior vena cava obstruction evaluation with MDCT.

OBJECTIVE: The purpose of this article is to review the CT findings associated with superior vena cava obstruction and to illustrate collateral venous pathways bypassing the obstruction as shown on MDCT. CONCLUSION: Multiple collateral venous pathways can form to bypass an obstruction of the superior vena cava. With its ability to acquire near isotropic data, MDCT allows high-quality reformations and thus exquisitely displays these venous collaterals and has the potential to aid in planning therapy to bypass the obstruction.

Incidental thyroid nodules on chest CT: Review of the literature and management suggestions.

OBJECTIVE: This article will review the current literature regarding the detection of thyroid nodules with an emphasis on CT diagnosis. We will also discuss management strategies. CONCLUSION: With advances in cross-sectional imaging, the detection of incidental thyroid nodules has increased significantly. Detection of thyroid nodules is common on chest CT that is being performed for unrelated reasons. The workup of these nodules can be timeconsuming and expensive.

The pre-CT checklist: A simple tool to improve workflow and patient safety in an outpatient CT setting.

PURPOSE: We aim to share our experience with implementation of a simple checklist to improve workflow and safety in patients scheduled for outpatient CT. METHODS: After identification of several recurrent problems leading to study delays or cancellation, a pre-CT checklist to be used by designated CT technologist in advance of patients' scheduled appointment was designed with input from CT technologists, radiologists, schedulers and nurses. RESULTS: Implementation of the checklist led to further actions in 25.9% of cases. The most common actions were calls to referring providers to modify or clarify an order (24.3%), followed by verification of proper premedication in patients with allergy to iodinated contrast (12.7%) and contacting the radiologist for protocolling (12.7%). CONCLUSIONS: Implementation of a pre-CT checklist that can be tailored to individual practices has potential to improve patients' safety and experience as well as providing a more efficient clinical operation. SUMMARY SENTENCE: We present an easy-to-implement checklist to maximize CT throughput in an outpatient setting that can be customized to the needs of individual institutions and has the potential to improve patients' safety and experience.

Decreasing Duplicative Imaging: Inpatient and Emergency Medicine Abdominal Ultrasound Within 72 Hours of Abdominal CT.

PURPOSE: The aim of this project was to reduce abdominal ultrasound examinations in patients who had undergone abdominal CT within 72 hours previously. METHODS: A best practice advisory (BPA) was created in the electronic medical record to advise against the use of abdominal ultrasound in adult inpatients and emergency department patients who had undergone abdominal CT within the preceding 72 hours. Acceptable acknowledgment reasons to proceed with the order were made available if providers chose to override. Frequency of BPA firing and subsequent ordering behavior were evaluated 6 months after integration of the BPA into the electronic medical record. Chart review was conducted for 100 patients whose orders were placed through an override of the alert to determine if the ultrasound study added value and for all patients whose ultrasound studies were canceled to confirm that patient care was not compromised by omitting the ultrasound study. RESULTS: In the first 6 months, a total of 614 inpatient and emergency department abdominal ultrasound orders triggered the BPA. A total of 16% of orders (n = 96) were canceled by the provider after the BPA, reflecting 518 overrides. The majority of retained orders were to evaluate the gallbladder (44% [227 of 518]). Chart review confirmed utility for gallbladder imaging and that the canceled ultrasound examinations would not have contributed value to patients' care. CONCLUSIONS: A recently performed abdominal CT scan may obviate the need for inpatient and emergency department abdominal ultrasound, particularly in the setting of hospital-acquired acute kidney injury. A BPA resulted in only 16% of orders' being canceled, whereas chart review revealed a much larger opportunity to avoid duplicative imaging.