The Added Value of Prostate Magnetic Resonance Imaging to Patient Selection.

INTRODUCTION: There has been a rapid increase in the utilization of magnetic resonance imaging (MRI) for prostate cancer detection. The objective of this study was to measure the increase in utilization of MRI before prostate biopsy and the effects on the distribution of Prostate Imaging Reporting and Data System (PI-RAD) scores and Gleason grades over a 5-year interval in an integrated health system. METHODS: The authors conducted a retrospective analysis of prostate MRI studies prior to biopsy in the calendar years of 2017 and 2022. Peak PI-RADS score, peak Gleason grade of suspected prostatic lesions, and the number of biopsy cores were collected from radiology reports and pathology reports from patients' electronic health records, respectively. All statistical tests were 2-tailed with a significance level set at p < 0.05. Categorical data analyses were performed using Mann-Whitney tests. Continuous data analyses were performed using t-tests. RESULTS: The total number of prostate MRIs and the number of MRIs with subsequent biopsy respectively increased by 178% and 215% over a 5-year interval (2017-2022). There was a higher proportion of MRI studies with an associated biopsy given a PI-RADS score of ≥ 3 (91%) and a Gleason grade of ≥ 7 (61%) in 2022 than in 2017 (PI-RADS: 75%; Gleason: 28%). CONCLUSIONS: Increased utilization of prostate MRI has been associated with a higher proportion of biopsies with high PI-RADS and Gleason scores consistent with improved patient selection in this integrated health system.

Moderate to severe hepatic steatosis on computerized tomography imaging: Prevalence in obese Pacific Islanders and Asians.

Background and Aim: Hepatic steatosis (HS) is common worldwide, but there is little data on the prevalence of HS in Pacific Islanders (PIs) and Asians within the United States. Our aim was to compare prevalence of HS in obese 18-50-year-olds of Asian and PI ethnicity who underwent computerized tomography (CT). Methods: We performed a retrospective analysis of all members of an integrated healthcare system who self-identified as Asian or PI, were between the ages of 18 and 50 years, had a body mass index (BMI) ≥ 30, and underwent a CT scan that included the liver during 2021, resulting in 748 subjects. Imaging was analyzed using a method sensitive and specific for moderate to severe HS. Additionally, multiple binary logistic regression was performed to explore the relationship between HS and HbA1c, BMI, and age. Results: Of the 748 patients, 311 (41.6%) had HS. We found no significant difference in the prevalence of HS between Asians and PIs (χ2 1 = 1.3, P = 0.25), between Asian and PI men (χ2 1 = 2.8, P = 0.096), or between Asian and PI women (χ2 1 = 0.053, P = 0.82). Higher odds of HS was associated with increasing BMI (OR = 1.08; 95% CI: 1.06-1.11; P < 0.001) and HbA1c (OR = 1.15; 95% CI: 1.04-1.26; P = 0.00489), but HS was not associated with age in this age range (OR = 0.993; 95% CI: 0.973-1.01; P = 0.46). Conclusion: Moderate to severe HS is very common in obese Asian and PI adults, and occurs at similar rates in these ethnicities. Abdominal CT imaging presents an opportunity to diagnose HS and provides relevant information to patients and healthcare providers.

Comparison of Mammography AI Algorithms with a Clinical Risk Model for 5-year Breast Cancer Risk Prediction: An Observational Study.

Background Although several clinical breast cancer risk models are used to guide screening and prevention, they have only moderate discrimination. Purpose To compare selected existing mammography artificial intelligence (AI) algorithms and the Breast Cancer Surveillance Consortium (BCSC) risk model for prediction of 5-year risk. Materials and Methods This retrospective case-cohort study included data in women with a negative screening mammographic examination (no visible evidence of cancer) in 2016, who were followed until 2021 at Kaiser Permanente Northern California. Women with prior breast cancer or a highly penetrant gene mutation were excluded. Of the 324 009 eligible women, a random subcohort was selected, regardless of cancer status, to which all additional patients with breast cancer were added. The index screening mammographic examination was used as input for five AI algorithms to generate continuous scores that were compared with the BCSC clinical risk score. Risk estimates for incident breast cancer 0 to 5 years after the initial mammographic examination were calculated using a time-dependent area under the receiver operating characteristic curve (AUC). Results The subcohort included 13 628 patients, of whom 193 had incident cancer. Incident cancers in eligible patients (additional 4391 of 324 009) were also included. For incident cancers at 0 to 5 years, the time-dependent AUC for BCSC was 0.61 (95% CI: 0.60, 0.62). AI algorithms had higher time-dependent AUCs than did BCSC, ranging from 0.63 to 0.67 (Bonferroni-adjusted P < .0016). Time-dependent AUCs for combined BCSC and AI models were slightly higher than AI alone (AI with BCSC time-dependent AUC range, 0.66-0.68; Bonferroni-adjusted P < .0016). Conclusion When using a negative screening examination, AI algorithms performed better than the BCSC risk model for predicting breast cancer risk at 0 to 5 years. Combined AI and BCSC models further improved prediction. © RSNA, 2023 Supplemental material is available for this article.

Computerized Tomography-Based Screening for Moderate to Severe Hepatic Steatosis in a Multiethnic Population.

Background and Aim Data on prevalence of nonalcoholic fatty liver disease in Hawaii is limited. This study determined the prevalence of moderate to severe hepatic steatosis within a multicultural, multiethnic, and multiracial cohort in Hawaii undergoing computerized tomography (CT) for reasons unrelated to fatty liver disease. Methods The authors performed a retrospective analysis of all patients who were members of an integrated health care system with CT scans including the liver between January 1, 2020, and December 31, 2020. Moderate to severe hepatic steatosis was determined by an average attenuation value < 40 Hounsfield units for non-contrast-enhanced CT and a mean attenuation value < 90 Hounsfield units for contrast-enhanced CT. Patients' electronic medical records were reviewed for existing diagnoses of hepatic steatosis, obesity, and diabetes mellitus type 2 and data to calculate a Fibrosis-4 (FIB-4) index. Results Approximately 26.6% had moderate to severe hepatic steatosis, while only 11.3% of those patients had an active diagnosis of fatty liver disease. Native Hawaiians and Pacific Islanders (33.1%) had the greatest prevalence of hepatic steatosis, followed by White people (28.4%), Asian people (27.7%), and other ethnicities (10.8%). About 61.4% patients with fatty liver had a diagnosis of obesity, while 33.4% had a body mass index < 30.0 kg/m2. Finally, 86.2% patients had enough information in their electronic medical records from which to calculate a FIB-4 score and the mean FIB-4 index was 1.66 ± 3.50. Conclusions Moderate to severe hepatic steatosis is common among patients undergoing CT studies for reasons not related to hepatic steatosis in this multiethnic population most of whom did not have a diagnosis of fatty liver disease.

Harnessing the Electronic Medical Record to Improve the Utilization of Ultrasound Screening for Abdominal Aortic Aneurysms.

PURPOSE: The US Preventive Services Task Force recommends one-time ultrasound screening to detect abdominal aortic aneurysms (AAAs) in male smokers. Despite this recommendation, AAA screening is still underutilized. The aim of this study was to determine the effectiveness of an electronic medical record (EMR) automated ordering program in increasing AAA screening at an integrated health care system. METHODS: This study was a retrospective chart review of patients who underwent ultrasound screening for AAA from January 1, 2016, to December 31, 2021, at a geographically isolated integrated health care system. An automated ordering system was implemented in a stepwise fashion within our EMR beginning in March 2019. The number of ultrasound studies and the incidence of AAA were compared between manual referral and EMR automated ordering periods. RESULTS: A total of 4,176 patients met the inclusion criteria for this study, among whom 148 aneurysms were identified. There was an increase in the average number of monthly screening ultrasound studies performed during the automated ordering period compared with the manual referral period (105 vs 16.3 studies, P < .001). The incidence of AAA was lower in the automated ordering period compared with the manual referral period (3.2% vs 5.3%, P = .013). CONCLUSIONS: An EMR automated ordering program can increase the number of screening ultrasound studies performed for AAA, which may help clinicians identify more high-risk aneurysms requiring urgent repair.

Variation in CTA evaluation of ED patients suspected of aortic dissection.

PURPOSE: This study was performed to investigate the variation in CTA imaging for AoD in an ED to determine if limiting the scanned region to the chest can effectively rule-out AoD without delaying care. METHODS: A retrospective chart review was performed for all patients belonging to a geographically isolated health maintenance organization who underwent CTA evaluation for possible acute AoD in the emergency department between 2016 and 2020. We evaluated for the regions included in the CTA, the presence of an acute AoD, and clinical outcomes. For those who were ruled-out of an AoD with a CTA limited to the chest, we investigated clinical follow-up up to 6 months after their initial presentation. RESULTS: Over the study period, there were 1143 CT scans ordered by ED physicians to evaluate for AoD in patients without a history of AoD. Only 23.0% of screening studies were of the chest only. There were 29 acute AoDs diagnosed (14 type A and 15 type B) making for a prevalence of 2.5%. Only one patient with an acute AoD detected on a chest-only CTA required farther imaging, which did not delay clinical care. No patients ruled-out for acute AoD with a chest-only CTA had a return ED visit or repeat CTA within 6 months diagnosing a missed AoD. There were no AoDs limited to the abdominal aorta that would have been missed on a chest-only study. CONCLUSION: In patients in the ED with suspected new acute AoD, a CTA limited to the chest can effectively evaluate the condition without delaying care in this integrated healthcare system with 24/7 CT availability.

Variation in Positivity Rates of Computed Tomography Pulmonary Angiograms for the Evaluation of Acute Pulmonary Embolism Among Emergency Department Physicians.

Computed tomography pulmonary angiography (CTPA) is an imaging study for which there is substantial evidence for its overuse in the evaluation of acute pulmonary embolism (PE). Prior literature has reported low positive PE rates, but the variability in positive rates among the ordering physicians has not been as well studied. The purpose of this study was to evaluate variation in ordering and positive rates among physicians in an emergency department (ED) within an integrated health care system.This study was based in a single ED that is part of a geographically isolated integrated health care system. We reviewed the patient records for all patients who underwent a CTPA for the evaluation for acute PE in the ED between January 1, 2018, and December 31, 2019. For each CTPA examination, we recorded the ordering ED physician, serum d-dimer value (mcg/mL), if any, and the results of the CTPA.Review of CTPAs over the 2-year period revealed 1380 CTPAs ordered by 23 ED physicians with a range of 25-141 studies per physician (mean of 60 + 31 CTPAs). The overall positive rate for PE was 6.9%. Individual ED physician positivity rates showed wide variability ranging from 0% to 18.4% (mean positive rate 7.6 + 4.4%). The results of this study confirm the need for greater adherence to existing guidelines using clinical decision rules and d-dimer testing when appropriate among all ED physicians but especially those who order a greater number of studies and have low rates for positive PE.

Rapidly Destructive Hip Disease Following Intra-Articular Corticosteroid Injection of the Hip.

BACKGROUND: While recent reports have suggested that hip corticosteroid injections can hasten joint degeneration, there are few published data on the topic. The purpose of the present study was to evaluate for an association between corticosteroid injection and rapidly destructive hip disease (RDHD) and to determine the rate of, and risk factors for, occurrence. METHODS: This study was conducted in 2 parts. First, to assess for a potential association between hip corticosteroid injection and RDHD, a case-control analysis was performed. Patients who developed RDHD between 2013 and 2016 served as cases, whereas those who underwent total hip arthroplasty for diagnoses other than RDHD during the same period served as controls, and the exposure of interest was prior intra-articular hip corticosteroid injection. Second, in a retrospective cohort analysis, we analyzed all patients who received a fluoroscopically guided intra-articular hip corticosteroid injection at our institution from 2013 to 2016. The rate of post-injection RDHD was determined, and logistic regression was used to identify risk factors for occurrence. RESULTS: In the case-control analysis, hip corticosteroid injection was associated with the development of RDHD (adjusted odds ratio, 8.56 [95% confidence interval, 3.29 to 22.3], p < 0.0001). There was evidence of a dose-response curve, with the risk of RDHD increasing with injection dosage as well as with the number of injections received. In the retrospective cohort analysis, the rate of post-injection RDHD was 5.4% (37 of 688). Cases of post-injection RDHD were diagnosed at an average of 5.1 months following injection and were characterized by rapidly progressive joint-space narrowing, osteolysis, and collapse of the femoral head. CONCLUSIONS: This study documents an association between hip corticosteroid injection and RDHD. While the risk of RDHD following a single low-dose (≤40 mg) triamcinolone injection is low, the risk is higher following high-dose (≥80 mg) injection and multiple injections. These findings provide information that can be used to counsel patients about the risks associated with this common procedure. In addition, caution should be taken with intra-articular hip injections utilizing ≥80 mg of corticosteroid and multiple injections. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Recommended D-Dimer Use in Suspected Pulmonary Embolism Is Insufficient to Curb the Long-Term Overutilization of CT Pulmonary Angiography.

PURPOSE: The aim of this study was to determine whether the authors' emergency medicine department has seen a significant change in CT pulmonary angiography (CTPA) utilization or positive rates for pulmonary embolism (PE) over a 10-year period for the 2 years before and 8 years after the implementation of patient population-specific D-dimer recommendations. METHODS: A retrospective chart review was performed among all patients belonging to a geographically isolated health maintenance organization who underwent CTPA for the evaluation of acute PE in the emergency department between 2010 and 2019. The positive rate for acute PE among these studies was calculated and stratified by serum D-dimer value collected within 48 hours previously. RESULTS: A total of 6,013 CT pulmonary angiographic studies were reviewed, of which 40.2% had serum D-dimer ≥ 1.0 µg/mL (positive rate 10.6%), 42.5% did not have serum D-dimer drawn (positive rate 7.3%), and 17.2% had serum D-dimer < 1.0 µg/mL (positive rate 0.6%). There was a significant increase in positivity on CTPA in 2012 with the health group's formal recommendation of a D-dimer cutoff of 1.0 µg/mL. This improvement also corresponded with fewer orders for CTPA after a negative D-dimer result. However, in the following years, CTPA utilization and percentage positivity were found to be reverting to the prerecommendation statistics. CONCLUSIONS: The failure to mandate the use of serum D-dimer with a higher threshold value for patients who are to undergo CTPA for possible PE has resulted in poor lasting compliance despite promising early results. A firmer approach is likely necessary to yield positive long-term outcomes.

The Utility of Brain Magnetic Resonance Imaging/Angiography and Neck Magnetic Resonance Angiography in Patients with Suspected Acute Stroke.

BACKGROUND: In our health maintenance organization, we have seen a trend among our referring physicians to order simultaneous brain magnetic resonance imaging (MRI), head magnetic resonance angiography (MRA), and neck MRA in the evaluation of patients for acute stroke. However, there are little data to demonstrate any improvement in patient care resulting from ordering this triple study. The objective of this study was to analyze the utility of the triple MRI/MRA study for patients who experience stroke-like symptoms. METHODS: We reviewed all triple-study cases between January 1, 2013 and December 31, 2016. We recorded whether or not an acute stroke occurred, the presence or absence of a major stenosis in the intracranial and/or neck arteries, subsequent percutaneous endovascular or open surgical intervention within 90 days, and any follow-up computed tomography angiography or carotid ultrasound studies within 30 days. RESULTS: During the studied period, 591 triple studies were ordered, and 162 patients (27.4%) were found to have moderate or severe stenosis. Of the patients who had an acute stroke, 100 (48.3%) also had a major stenosis. Of 591 patients, only 15 (2.5%) underwent percutaneous endovascular or open surgical intervention within 90 days. Of these, 4 patients had an intervention in less than a week; in all of the cases, the triple study did not need to be ordered simultaneously to achieve the same clinical outcome. CONCLUSION: Brain MRI, head MRA, and neck MRA studies should not be ordered simultaneously as a generalized response to patients presenting with acute stroke-like symptoms.

Effects of Implementing a Higher Threshold for Recommending Thyroid Biopsies on Malignancy Rates.

INTRODUCTION: We implemented a new thyroid nodule classification system in which a biopsy was recommended for thyroid lesions ≥ 1 cm with at least 2 or more suspicious features. METHODS: Three consecutive years of thyroid biopsies using the new classification system were reviewed for patient demographics, biopsy recommendation based on nodule size and imaging characteristics, and pathology results. The primary outcome was malignancy rates for thyroid biopsies. These results were compared to a 3-year historical data set. RESULTS: Review of thyroid biopsies from 2010 to 2012, prior to the implementation of current recommendations, revealed 996 thyroid biopsies with a malignancy rate of 12.8%. Subsequent to the new classification system in 2017, 483 thyroid biopsies were performed over the next 3 years with a malignancy rate of 21.9%. DISCUSSION: Implementation of the new classification system with a higher threshold for biopsy reduced our yearly biopsy volume by approximately 50% while also increasing our malignancy rate from 12.8% to 21.9%, which is more in line with published rates of malignancy. CONCLUSION: In a community setting performing less than 200 biopsies per year, the use of more stringent requirements for thyroid biopsy are necessary to achieve malignancy rates comparable to the published literature.

One-View Chest Radiograph for Initial Management of Most Ambulatory Patients with Rib Pain.

INTRODUCTION: Rib series are frequently ordered for ambulatory patients who complain of rib pain or have suffered chest trauma. However, the utility of rib series has been questioned in previous studies. The objective of this study was to compare the efficacy of rib series to a single view posteroanterior chest radiograph in the clinical management of most ambulatory patients with rib pain. METHODS: We reviewed all rib series for rib pain performed between January 1, 2016 and December 31, 2016, excluding patients with suspected bony metastasis, chest or rib deformities, and follow-up studies for prior rib series. We recorded any follow-up imaging and/or surgical intervention within 30 ± 7 days, fracture diagnosis, and complications relating to rib fractures. RESULTS: One thousand seven hundred ninety-one rib series were performed during the study period. Of these, 1168 (65.2%) rib series were performed because of trauma as reported in the clinical indication (trauma cohort). Six hundred twenty-three (34.8%) of the rib series were performed for clinical indications which did not specify acute trauma (nontrauma cohort). There were 323 (17.9%) rib series that resulted in a fracture diagnosis and 95 (5.3%) that resulted in a possible fracture diagnosis. There were 50 (2.8%) effusions, 7 (0.4%), pneumothoraces, and 1 (0.1%) hemothorax detected. Two patients, 1 each from the trauma and nontrauma cohorts, underwent subsequent intervention during the follow-up period. In both cases, the findings which led to the subsequent intervention could be seen on the initial posteroanterior chest radiograph. CONCLUSION: Single-view chest radiograph provides sufficient information for the clinical management of ambulatory patients with rib pain.

Inadequate Clinical Indications in Computed Tomography Chest and Abdomen/Pelvis Scans.

CONTEXT: As the use of computed tomography (CT) scans, which are expensive and result in considerable radiation exposure to the patient, continues to increase, communication between physicians and radiologists remains vital to explain the clinical context for the examination. However, the clinical information provided to the radiologist is often lacking. OBJECTIVE: To determine whether the clinical information provided in CT scan requests meets minimum criteria for requesting the examination. METHODS: We reviewed the clinical indications for 400 CT chest scans and 400 CT abdomen/pelvis scans performed from January 1, 2016, through March 8, 2016. We determined whether each CT study indication was complete on the basis of whether the clinical information included an adequate clinical history with 1) a primary symptom, 2) the location of the symptom, and 3) the duration of the symptom as well as a suspected etiology. RESULTS: Of the CT chest indications, 56 (14.0%) of the clinical histories were considered complete and 17 (4.3%) had none of the components. A principal etiology was included in 195 (48.8%) of the indications. Of the CT abdomen/pelvis indications, 94 (23.5%) of the clinical histories were complete and 13 (3.3%) had none of the components. A principal etiology was included in 173 (43.3%) of the indications. Only 23 (5.8%) of the CT chest studies and 35 (8.8%) of the CT abdomen/pelvis studies had information considered sufficient for the radiologist. CONCLUSION: The percentage of complete clinical indications for both CT chest and abdomen/pelvis scans was much lower than 50%, suggesting that more emphasis should be placed on providing complete clinical indications.

Appropriate Interval for Imaging Follow-up of Small Simple Pancreatic Cysts.

CONTEXT: The frequency at which patients should undergo follow-up imaging of small pancreatic cysts is problematic because different medical societies have different follow-up guidelines. OBJECTIVE: To determine whether short-term follow-up of small pancreatic cysts is necessary to detect pancreatic cancer or cystic neoplasia. DESIGN: We retrospectively reviewed all abdominal magnetic resonance imaging (MRI) studies obtained in a geographically isolated health maintenance organization between January 1, 2012, and December 31, 2014, looking for pancreatic cysts. For each patient with one or more simple cysts, we recorded the size of the largest cyst. For patients with cysts, all their other computed tomography and MRI studies were reviewed to determine any change in size or morphology. The electronic medical record of every patient who underwent MRI was reviewed to determine development of pancreatic cancer. MAIN OUTCOME MEASURES: Change in cyst size on images. RESULTS: Of 1946 patients, 342 were found to have at least 1 pancreatic cyst. A total of 228 patients had additional imaging from which to determine rates of change. The mean rate (standard deviation) of change for these cysts was 0.1 ± 2.0 mm/y. None of those cysts measuring 2 cm or smaller on MRI grew more than 5 mm in 2 years. CONCLUSION: Our data validate the clinical efficacy of obtaining follow-up imaging no sooner than 24 months after the initial detection of a simple pancreatic cyst 2 cm or smaller. Patients with cysts are more likely to have pancreatic cancer, but earlier follow-up imaging would not change their diagnosis of pancreatic cancer.

Risk of Venous Thromboembolism after a Single Normal Proximal Lower Extremity Venous Ultrasound.

CONTEXT: The optimal lower extremity venous ultrasound (US) protocol to diagnose deep venous thrombosis of the popliteal and more proximal veins is unclear. OBJECTIVE: To determine the three-month rate of symptomatic venous thromboembolism (VTE) and clinical outcomes of inpatients and ambulatory patients with normal findings on single venous ultrasound of the popliteal and more proximal veins (single proximal US). DESIGN: Single proximal US results and clinical data of all inpatient and ambulatory patients with suspected acute deep venous thrombosis were retrospectively reviewed during a 12-month period between January and December 2014. Three-month follow-up data were reviewed for all these patients, who received all their care from a single geographically isolated health maintenance organization. MAIN OUTCOME MEASURES: Three-month rate of symptomatic VTE and clinical outcomes after an initially normal single proximal US result. RESULTS: Of 1295 patients, 111 (8.6%) were found to have acute deep venous thrombosis on the initial proximal US. Of the remaining 1184 patients with initially normal results on proximal US who were sampled at 3-month follow-up, 1075 patients (90.8%) had no venous thromboembolic event. Among the others, 11 (0.9%) had a subsequent imaging-confirmed venous thromboembolic event, 53 (4.5%) died (none owing to venous thromboembolism), and 45 (3.8%) did not complete follow-up. CONCLUSION: Symptomatic VTE after an initially normal single proximal US result occurred in less than 1% of this cohort. Therefore, serial proximal US is unnecessary for most of our patients, and its elimination will save time and out-of-pocket expenses.

Evaluation of Small Adrenal Incidental Nodules: Is Imaging Follow-Up Necessary?

INTRODUCTION: Low incidence of adrenal cortical carcinoma in the general adult population has prompted a reevaluation of current protocol for the assessment of adrenal incidentalomas. OBJECTIVE: To determine whether follow-up imaging for small (≤ 4 cm) incidental adrenal nodules is necessary for patients without known cancer. METHODS: We performed a retrospective analysis of all patients found to have an incidental adrenal nodule on abdominal computed tomography (CT) scan during a 27-month period. The electronic medical record was reviewed to determine clinical outcomes in all patients with a minimum of 3 years of follow-up (mean follow-up = 6.7 years). Patients with a known primary cancer were excluded from the analysis unless they had a prior CT scan that documented an incidental adrenal nodule. Unenhanced CT attenuation was measured for all nodules, if available. RESULTS: A total of 392 patients with an incidental adrenal nodule had a mean (standard deviation [SD]) clinical follow-up of 6.7 (2.7) years. There were 200 men and 192 women with a mean (SD) age of 66.0 (13.2) years. None of these patients developed primary adrenocortical carcinoma during the follow-up period.Two hundred forty of these patients also had a minimum 3 years of imaging follow-up (mean [SD], 6.4 [2.4] years; range, 3.1-13.6 years). There were 173 left-sided and 91 right-sided nodules on index CT scan. There was no significant difference in the mean (SD) rate of growth between left- and right-sided nodules (0.1 [0.8] mm/year vs 0.1 [0.8] mm/year, p = 0.58). Mean unenhanced CT attenuation of adrenal nodules did not affect the likelihood of adrenal malignancy during follow-up. CONCLUSION: Patients with small incidental adrenal nodules do not require additional imaging to exclude the possibility of adrenocortical carcinoma.

Carotid MRI Detection of Intraplaque Hemorrhage at 3T and 1.5T.

BACKGROUND AND PURPOSE: Carotid intraplaque hemorrhage leads to plaque progression and ischemic events. Detection can be accomplished with 3T T1w sequences, but may be limited by false-positive lipid/necrosis. The purpose of this study was threefold: (1) to determine if magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) detects intraplaque hemorrhage versus lipid/necrosis; (2) if 3T MPRAGE image quality is retained at 1.5T; and (3) to determine observer agreement. METHODS: MPRAGE positive areas were compared to hemorrhage and lipid/necrosis areas from 100 carotid endarterectomy slides in 12 subjects using multivariable linear regression. Image quality was determined between 3T and 1.5T in 716 carotid arteries using t-tests and multivariable linear regression. Kappa analysis was used to determine agreement. RESULTS: Intraplaque hemorrhage, not lipid/necrosis, was a significant predictor of MPRAGE positive area before and after adjusting for confounders (slope = .52 vs. .51, P < .001). Image quality at 3T was slightly lower than 1.5T (mean 3.87 vs. 4.34, P < .0001). 3T image quality remained slightly decreased before and after adjusting for confounders (slope = -.46 vs. -.41, P < .001). Kappa values for inter-/intraobserver agreement were .807/.919 at 3T and .803/.871 at 1.5T. CONCLUSIONS: Carotid MPRAGE detects intraplaque hemorrhage, not lipid/necrosis. 3T image quality was retained at 1.5T with very good observer agreement.

Journal Club: Head CT scans in the emergency department for syncope and dizziness.

OBJECTIVE: The purpose of this study was to determine the yield of acutely abnormal findings on head CT scans in patients presenting to the emergency department with dizziness, near-syncope, or syncope and to determine the clinical factors that potentially predicted acutely abnormal head CT findings and hospital admission. MATERIALS AND METHODS: We retrospectively reviewed the electronic medical records of all patients presenting to an HMO emergency department between July 1, 2012, and December 31, 2012, who underwent head CT for a primary complaint of dizziness, syncope, or near-syncope. The primary outcomes were head CT scans with acutely abnormal findings and hospital admission. Binary logistic regression was used to assess the association between clinical variables and acute head CT findings and between clinical variables and hospital admission. RESULTS: Of the 253 patients who presented with dizziness, 7.1% had head CT scans with acutely abnormal findings, and 18.6% were admitted. Of the 236 patients who presented with syncope or near-syncope, 6.4% had head CT scans with acutely abnormal findings, and 39.8% were admitted. The following three clinical factors were found to be significantly correlated with acutely abnormal head CT findings: a focal neurologic deficit (p = 0.003), age greater than 60 years (p = 0.011), and acute head trauma (p = 0.026). CONCLUSION: Our results suggest that most patients presenting with syncope or dizziness to the emergency department may not benefit from head CT unless they are older, have a focal neurologic deficit, or have a history of recent head trauma.

Improving appropriate use of pulmonary computed tomography angiography by increasing the serum D-dimer threshold and assessing clinical probability.

OBJECTIVE: To determine whether the implementation of an increased D-dimer threshold value and clinical probability assessment increases the prevalence of pulmonary embolism (PE) in patients undergoing pulmonary computed tomography angiography (PCTA) in an Emergency Department setting. METHODS: A retrospective review of all patients undergoing PCTA during 2 separate 12-month intervals, 1 before the implementation of an increased D-dimer threshold and recommendation for formal clinical probability assessment and the other after regional implementation. The primary outcome measure was the prevalence of acute PE in each of the samples. RESULTS: After the implementation of the increased D-dimer threshold and recommendation for formal clinical probability assessment, the prevalence of PE detected by PCTA increased from 4.7% to 11.7% (p < 0.001). Among all PCTAs performed after the new guidelines were promulgated, 8.6% were still performed on patients who had serum D-dimer values lower than the threshold of 1.0 µg/mL. Despite the recommendation for formal clinical probability assessment before ordering a PCTA, only 4% of patients had a formal clinical probability assessment recorded in their electronic medical record. CONCLUSION: The implementation of an increased D-dimer threshold value increased the prevalence of PE in patients undergoing PCTA in an Emergency Department setting, but more consistent application of clinical probability assessment remains an elusive target.

Four-year cumulative radiation exposure in patients undergoing computed tomography angiography for suspected pulmonary embolism.

Purpose. The objective of this study was to determine the estimated effective radiation dose of pulmonary CT angiography (CTA) for suspected pulmonary embolism (PE) contributing to total medical radiation exposure over a 4-year period. Materials and Methods. This investigation retrospectively reviewed 300 patients who presented to the emergency department and received a pulmonary CTA scan for suspected PE. We evaluated these patients' electronic medical record to determine their estimated radiation exposure to CT scans during the following four years. Using DLP to E conversion coefficients, we calculated the cumulative effective radiation dose each subject received. Results. A total of 900 CT scans were reviewed in this study. Pulmonary CTA delivered an average effective radiation dose of 10.7 ± 2.5 mSv and accounted for approximately 65% of subjects' 4-year cumulative medical radiation dose. Only 6.3% of subjects had a positive acute PE according to their radiology report. Conclusion. Pulmonary CTA accounted for the majority of subjects' medically related effective radiation dose over a 4-year period. With only a minority of subjects having positive findings for acute PE, increased efforts should be made to clinically assess pretest probability before the consideration of imaging.