Clinical indications and utilization of 320-detector row CT in 2500 outpatients

Clinical indications and utilization patterns for 3963 CT scans on 2500 consecutive patents on a 320-detector row CT in an outpatient setting were retrospectively analyzed and compared with previously reported CT studies. The impact of the latest generation CT technology, including whole organ perfusion, on indications and utilization patterns during the study period was also assessed. The top five requested CT scan types were abdomen/pelvis, chest, head, sinuses, and coronary CT angiography. Indication and utilization rates were similar to prior studies for abdomen/pelvis, non-cardiac chest, and head CT scans. Abdominal pain and headaches were the most frequent indications for abdomen/pelvis and head CTs, respectively. The 7.3% cardiac CT scan utilization rate was not comparable to rates of up to 72% in self-referral outpatient settings. Whole organ volume CT imaging was utilized in 100% of coronary CT angiography and 22.7% of head CTs. The 320-row CT had fewer negative head and body CT findings as compared to prior reports. The availability of new technology, such as whole organ dynamic scans, appears to have influenced CT indications, utilization and finding rates with a decrease in negative brain and body results. Comparisons with previous outpatient CT studies were similar for multiple categories with the exception of cardiac CT utilization, which is heavily influenced by self-referral. Further study of outpatient imaging indications and utilization rates from multiple centers may benefit from a standardized categorization to improve understanding of the disparate outpatient imaging environment.     

Coronary CT Calcium Score in Patients With Prior Nongated CT,Is it Necessary?

PurposeTo evaluate the percentage of patients undergoing gated coronary artery calcium score CTs that had a prior nongated chest CT. To assess the accuracy of prior nongated chest CTs in the detection of coronary calcium.BackgroundCardiovascular disease is the most common cause of death worldwide. Quantifying coronary artery calcification on gated calcium score CT has proven to be strongly predictive of adverse coronary artery disease events. However, visual estimation and ordinal scoring on nongated chest CTs is predictive of coronary calcium burden.MethodsConsecutive gated calcium score CTs at a single institution from 10/2014 to 10/2016 were retrospectively evaluated with IRB approval/waiver of informed consent. The presence or absence of coronary calcium and ordinal score on nongated chest CT was compared to Agatston score on gated calcium score CT.ResultsForty-two of 441 patients (9.5%) with a gated calcium score had a prior nongated chest CT, with a mean time difference of 810 days. Of the 42 prior chest CTs, 69% had coronary artery calcium (CAC) and 31% did not, with 100% predictive accuracy for the presence or absence of CAC on subsequent gated calcium score CTs. There was 86% correlation of Agatston score on gated calcium score CT with ordinal score on the prior chest CT. Ordinal score divided into independent groups of severity was related to increased severity of Agatston score on the gated calcium score CT (P< 0.001). A majority of prior chest CT studies with coronary calcium failed to include this information in the final report.ConclusionsA large percentage of gated calcium score CTs were performed despite a prior chest CT. The ordinal score on chest CTs correlated with Agatston score on gated calcium score CTs. The presence of CAC on chest CTs was underreported in a majority of cases.     

Indications for and results of outpatient computed tomography and magnetic resonance imaging in Ontario

OBJECTIVE: Population rates of computed tomography (CT) and magnetic resonance imaging (MRI) continue to increase markedly. However, little is known about the indications for and results of these imaging tests. METHODS: A cross-sectional chart-abstraction study was used to determine the indications for and results of outpatient CT and MRI scans performed on or after January 1, 2005, at randomly selected Ontario hospitals. RESULTS: We studied 11,824 CT and 11,867 MRI scans. Cancer-related indications accounted for over 50% of CT scans of the abdomen-pelvis and chest. Headache was the most frequent indication for CT of the brain. More than one-half of MRI scans of the extremities were for knee pain or suspected meniscal tear. Back pain and radiculopathy were the most frequent indications for MRI of the spine. There was considerable variation between institutions in ordering patterns, with as much as a 70-fold difference between hospitals in the frequency of scans ordered for a specific indication. Less than 2% of CT scans of the brain for headache found abnormalities that could explain the headache, while over 90% of MRI scans of the spine for back pain were abnormal, although the clinical importance of the abnormalities was unclear. Conclusions: These data are a starting point for a discussion about appropriateness. Further information will be obtained by examining individual indications more closely, and linking these data to administrative databases to evaluate the impact of these imaging tests on clinical practice.     

Multisystem inflammatory syndrome in children associated with SARS-CoV-2: extracardiac radiological findings

Objective:Multisystem inflammatory syndrome in children (MIS-C) is seen as a serious delayed complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The aim of this study was to describe the most common imaging features of MIS-C associated with SARS-CoV-2.Methods:A retrospective review was made of the medical records and radiological imaging studies of 47 children (26 male, 21 female) in the age range of 25 months–15 years who were diagnosed with MIS-C between August 2020 and March 2021. Chest radiographs were available for all 47 patients, thorax ultrasound for 6, chest CT for 4, abdominal ultrasound for 42, abdomen CT for 9, neck ultrasound for 4, neck CT for 2, brain CT for 1, and brain MRI for 3.Results:The most common finding on chest radiographs was perihilar–peribronchial thickening (46%). The most common findings on abdominal ultrasonography were mesenteric inflammation (42%), and hepatosplenomegaly (38%, 28%). Lymphadenopathy was determined in four patients who underwent neck ultrasound, one of whom had deep neck infection on CT. One patient had restricted diffusion and T2 hyperintensity involving the corpus callosum splenium on brain MRI, and one patient had epididymitis related with MIS-C.Conclusion:Pulmonary manifestations are uncommon in MIS-C. In the abdominal imaging, mesenteric inflammation, hepatosplenomegaly, periportal edema, ascites and bowel wall thickening are the most common findings.Advances in knowledge:The imaging findings of MIS-C are non-specific and can mimic many other pathologies. Radiologists should be aware that these findings may indicate the correct diagnosis of MIS-C.     

Trends of CT Use in the Adult Emergency Department in a Tertiary Academic Hospital of Korea during 2001-2010

Objective

We wanted to assess the trends of CT examinations that were conducted in an adult emergency department (ED).

Materials and Methods

We searched the medical database to identify adult patients (≥ 18 years) who had visited the ED and the number of CT examinations of the patients during the period from January 2001 to December 2010. We also analyzed the types of CT scans performed in terms of body parts, they were as follows; head CTs, facial bone CTs, neckl CTs, chest CTs, abdominal CTs, and miscellaneous CTs. Further, miscellaneous CTs were subdivided as CT angiography and others.

Results

A total of 113656 CT scans were examined for 409439 adult ED patients during a 10-year period, and the number of CT scans increased by 255% (from 4743 CTs in 2001 to 16856 CTs in 2010), while the adult ED patient volume increased by 34% during the same period. Although the head CTs proportionally occupied the most, the facial bone CTs had the largest rate of increase (3118%), followed by cervical CTs (1173%), chest CTs (455%), miscellaneous CTs (388%; 862% and 84% for CT angiography and others, respectively), abdominal CTs (315%) and head CTs (95%) per 1000 patients during the decade.

Conclusion

CT use in adult ED has increased at a rate that far exceeds the growth of ED patient volume, with facial bone CTs and cervical CTs having the largest increasing rate, followed by chest CTs, miscellaneous CTs, abdominal CTs and head CTs.     

Temporal Trends in Imaging Utilization for Suspected Substance Use Disorder in an Academic Emergency Radiology Department

PurposeTo assess temporal trends and utilization patterns of diagnostic imaging performed for substance use disorder (SUD)-related indications in an academic radiology emergency department (ED).MethodsRetrospective analyses of ED imaging examinations acquired from 2005 to 2015 were performed. Imaging examinations performed for suspected SUD-related indications, based on the order history, were compared with those without a SUD-related indication. Unadjusted analyses comparing demographic and imaging characteristics between SUD-related versus non-SUD-related indications used Wilcoxon and Pearson’s χ² tests. Multivariable logistic regression models, within each imaging modality subgroup and combined, were employed to examine the odds of imaging examinations having an SUD-related indication as a function of demographic and imaging characteristics.ResultsAmong 938,245 examinations, 0.17% had an SUD-related indication. Patients with SUD-related indications were younger (mean 37.2 ± 11.1 versus 53.5 ± 22.4, P < .001) and more commonly male (65% versus 52%, P < .001). The proportions of MR (17%), spine (17%), and extremities (33%) studies performed for SUD-related indications were larger among SUD than non-SUD indications (6%, 8%, 26%, respectively, all P < .001). Regression analysis demonstrated the odds of acquiring an ED imaging examination with an SUD-related indication significantly increased over time (P < .001, adjusted odds ratio [aOR] = 1.06), which was most pronounced among MR (P < .001, aOR = 1.23). For all regression models, younger age, male gender, and body part being imaged were identified as independent predictors of an SUD-related indication for ED imaging.ConclusionImaging performed for an SUD-related indication represented a small but increasing subset of overall ED imaging. Utilization of MR for SUD-related indications significantly outpaced growth of MR without SUD-related indications.     

Trends of CT Use in the Pediatric Emergency Department in a Tertiary Academic Hospital of Korea during 2001-2010

Objective

We wanted to assess the trends of computed tomography (CT) examinations in a pediatric emergency department (ED).

Materials and Methods

We searched the medical database to identify the pediatric patients who had visited the ED, and the number of CTs conducted from January 2001 to December 2010. We analyzed the types of CTs, according to the anatomic region, and the patients who underwent CT examinations for multiple regions. Data were stratified, according to the patient age (< 13 years and 13 ≤ ages < 18 years).

Results

The number of CTs performed per 1000 patients increased by 92% during the 10-year period (per 1000 patients, increased from 50.1 CTs in 2001 to 156.5 CTs in 2006, and then decreased to 96.0 CTs in 2010). Although head CTs were performed most often (74.6% of all CTs), facial bone CTs showed the largest rate of increase (3188%) per 1000 patients, followed by cervical CTs (642%), abdominal CTs (474%), miscellaneous CTs (236%), chest CTs (89%) and head CTs (39%). The number of patients who had CT examinations for multiple regions in the same day showed a similar pattern of increase, to that of overall CT examinations. Increase of CT utilization was more pronounced in adolescents than in pediatric patients younger than 13 years (189% vs. 59%).

Conclusion

The utilization of CTs increases from 2001 to 2006, and has declined since 2006. The increase of CTs is more pronounced in adolescents, and facial bone CTs prevail in increased number of examination followed by cervical CTs, abdominal CTs, miscellaneous CTs, chest CTs, and head CTs.     

Timeliness of Recommended Follow-Up After an Abnormal Finding on Diagnostic Chest CT in Smokers at High Risk of Developing Lung Cancer

PurposeDiagnostic chest CT frequently results in abnormal findings that require follow-up. We assessed the timeliness of follow-up after CT abnormalities were identified in symptomatic smokers at high risk for developing lung cancer.MethodsIn an academic primary care network, we identified current smokers aged 55-79 years who received a diagnostic chest CT to evaluate symptoms during 2012. Medical chart abstraction identified radiologist recommendations and follow-up care. The outcome was the proportion of patients who received timely follow-up (within 30 days of recommendation) after an abnormal chest CT. We assessed for predictors of compliance with recommended follow-up.ResultsOf 3,257 eligible smokers, 446 (14%) had a chest CT during 2012. We excluded 70 patients who already had lung cancer, died, had imaging done elsewhere, or left the practice. Of the remaining 376 patients, 337 (90%) had abnormal chest CT findings, and 184 (55%) had a specific follow-up recommendation. Among those with recommended follow-up, only 102 of 184 (55%) had timely follow-up. Those who had a CT performed to evaluate pulmonary disease and those receiving care in community health centers were more likely to receive timely follow-up. Of 27 patients newly diagnosed with lung cancer, 18 (67%) had their first oncology visit within 30 days of diagnosis.ConclusionsAmong patients undergoing diagnostic chest CTs, most received follow-up for abnormal findings, but it was often delayed. Systems to support patients in obtaining recommended follow-up are needed to ensure that the benefits of lung cancer screening translate into usual clinical practice.     

Radiologist Reporting and Operational Management for Patients With Suspected COVID-19

PurposeThe aim of this study was to evaluate the adoption and outcomes of locally designed reporting guidelines for patients with possible coronavirus disease 2019 (COVID-19).MethodsA departmental guideline was developed for radiologists that specified reporting terminology and required communication for patients with imaging findings suggestive of COVID-19, on the basis of patient test status and imaging indication. In this retrospective study, radiology reports completed from March 1, 2020, to May 3, 2020, that mentioned COVID-19 were reviewed. Reports were divided into patients with known COVID-19, patients with “suspected” COVID-19 (having an order indication of respiratory or infectious signs or symptoms), and “unsuspected patients” (other order indications, eg, trauma or non–chest pain). The primary outcome was the percentage of COVID-19 reports using recommended terminology; the secondary outcome was percentages of suspected and unsuspected patients diagnosed with COVID-19. Relationships between categorical variables were assessed using the Fisher exact test.ResultsAmong 77,400 total reports, 1,083 suggested COVID-19 on the basis of imaging findings; 774 of COVID-19 reports (71%) used recommended terminology. Of 574 patients without known COVID-19 at the time of interpretation, 345 (60%) were eventually diagnosed with COVID-19, including 61% (315 of 516) of suspected and 52% (30 of 58) of unsuspected patients. Nearly all unsuspected patients (46 of 58) were identified on CT.ConclusionsRadiologists rapidly adopted recommended reporting terminology for patients with suspected COVID-19. The majority of patients for whom radiologists raised concern for COVID-19 were subsequently diagnosed with the disease, including the majority of clinically unsuspected patients. Using unambiguous terminology and timely notification about previously unsuspected patients will become increasingly critical to facilitate COVID-19 testing and contact tracing as states begin to lift restrictions.     

Initial diagnosis of HIV/AIDS in patients presenting to the emergency department: Imaging and clinical findings at a single institution

PurposeTo evaluate the clinical, laboratory, and imaging findings along with treatment and outcomes associated with patients presenting to the emergency department (ED) who were subsequently diagnosed with HIV/AIDS.Methods591 patients with HIV and available imaging studies presenting to our hospital's ED between 2004 and 2019 were identified in the medical record. Following initial review, we identified 19 patients who were diagnosed with HIV within one week after an initial ED visit and also had received CT imaging during the ED visit. Demographic, clinical, treatment, imaging, and outcome data were reviewed and recorded for each patient.ResultsAmong this 19-patient cohort, the most common indication for HIV testing was oral/esophageal candidiasis (n = 8, 42%). 12 patients presented with an AIDS-defining illness upon initial diagnosis; the most common were esophageal candidiasis (4) and Pneumocystis jiroveci pneumonia (PJP) (3). 10 patients (59%) presented with CD4+ counts <200 cells/L. The most common imaging findings were liver abnormalities (n = 9, 47%). Five of the 19 patients were confirmed deceased at the time of this study, with the median time from diagnosis to death of 5.6 months (range 8 days-14 months).ConclusionOur series demonstrates the breadth of potential imaging findings and clinical presentations of late-stage HIV in the emergency setting, including common AIDS-defining illnesses such as PJP and PML. Although the incidence of these conditions is decreasing, maintaining awareness of their clinical and imaging findings, as well as the potential for multi-organ involvement, is essential due to the possibility of rapid decline in these patients.     

Repeated sinus CT imaging after recent head imaging

ObjectivesExcessive use of sinus CT is a significant problem in medical imaging, resulting in unnecessary costs and radiation exposure. This study assesses frequency of sinus CT performed after recent head imaging has already adequately evaluated the sinuses.MethodsA retrospective search of the PACS database of an academic medical center was performed to identify cases of sinus CT imaging in 2017. Cases were excluded if sinus CT was performed related to trauma, tumor, operative evaluation, or acute infection other than sinusitis (orbital cellulitis, intracranial abscess). Studies with separate imaging covering the sinuses ordered at the same time as sinus CT or performed previously within 4 weeks were identified and clinical information was recorded.ResultsOf 735 sinus CTs performed, 19 (5%) had same-day head imaging and 30 (8%) had previous head imaging within 4 weeks, adding up to a cumulative 13% of cases with recent head imaging. The average patient age was 42, with 13 pediatric cases. Of ordering providers, residents ordered the highest percentage of sinus CTs with same-day head imaging (84%) and previous imaging within 4 weeks (63%). The sinuses were described in all head CT radiology reports, while 10 of 12 brain MRI reports did not mention the sinuses.ConclusionIn one year, 13% of patients receiving sinus CTs at our institution had recent head imaging. A focused education effort for ordering providers to avoid repeating sinus imaging, and for radiology to comment on sinuses on head imaging, may reduce unnecessary sinus CTs.     

Prediction of Patient Management in COVID-19 Using Deep Learning-Based Fully Automated Extraction of Cardiothoracic CT Metrics and Laboratory Findings

ObjectiveTo extract pulmonary and cardiovascular metrics from chest CTs of patients with coronavirus disease 2019 (COVID-19) using a fully automated deep learning-based approach and assess their potential to predict patient management.Materials and MethodsAll initial chest CTs of patients who tested positive for severe acute respiratory syndrome coronavirus 2 at our emergency department between March 25 and April 25, 2020, were identified (n = 120). Three patient management groups were defined: group 1 (outpatient), group 2 (general ward), and group 3 (intensive care unit [ICU]). Multiple pulmonary and cardiovascular metrics were extracted from the chest CT images using deep learning. Additionally, six laboratory findings indicating inflammation and cellular damage were considered. Differences in CT metrics, laboratory findings, and demographics between the patient management groups were assessed. The potential of these parameters to predict patients'' needs for intensive care (yes/no) was analyzed using logistic regression and receiver operating characteristic curves. Internal and external validity were assessed using 109 independent chest CT scans.ResultsWhile demographic parameters alone (sex and age) were not sufficient to predict ICU management status, both CT metrics alone (including both pulmonary and cardiovascular metrics; area under the curve [AUC] = 0.88; 95% confidence interval [CI] = 0.79–0.97) and laboratory findings alone (C-reactive protein, lactate dehydrogenase, white blood cell count, and albumin; AUC = 0.86; 95% CI = 0.77–0.94) were good classifiers. Excellent performance was achieved by a combination of demographic parameters, CT metrics, and laboratory findings (AUC = 0.91; 95% CI = 0.85–0.98). Application of a model that combined both pulmonary CT metrics and demographic parameters on a dataset from another hospital indicated its external validity (AUC = 0.77; 95% CI = 0.66–0.88).ConclusionChest CT of patients with COVID-19 contains valuable information that can be accessed using automated image analysis. These metrics are useful for the prediction of patient management.     

Comparison of deep learning,radiomics and subjective assessment of chest CT findings in SARS-CoV-2 pneumonia

PurposeComparison of deep learning algorithm, radiomics and subjective assessment of chest CT for predicting outcome (death or recovery) and intensive care unit (ICU) admission in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.MethodsThe multicenter, ethical committee-approved, retrospective study included non-contrast-enhanced chest CT of 221 SARS-CoV-2 positive patients from Italy (n = 196 patients; mean age 64 ± 16 years) and Denmark (n = 25; mean age 69 ± 13 years). A thoracic radiologist graded presence, type and extent of pulmonary opacities and severity of motion artifacts in each lung lobe on all chest CTs. Thin-section CT images were processed with CT Pneumonia Analysis Prototype (Siemens Healthineers) which yielded segmentation masks from a deep learning (DL) algorithm to derive features of lung abnormalities such as opacity scores, mean HU, as well as volume and percentage of all-attenuation and high-attenuation (opacities >−200 HU) opacities. Separately, whole lung radiomics were obtained for all CT exams. Analysis of variance and multiple logistic regression were performed for data analysis.ResultsModerate to severe respiratory motion artifacts affected nearly one-quarter of chest CTs in patients. Subjective severity assessment, DL-based features and radiomics predicted patient outcome (AUC 0.76 vs AUC 0.88 vs AUC 0.83) and need for ICU admission (AUC 0.77 vs AUC 0.0.80 vs 0.82). Excluding chest CT with motion artifacts, the performance of DL-based and radiomics features improve for predicting ICU admission.ConclusionDL-based and radiomics features of pulmonary opacities from chest CT were superior to subjective assessment for differentiating patients with favorable and adverse outcomes.     

Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as "triple rule out" scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.     

Assessment of chest pain in the emergency room: What is the role of multidetector CT?

Chest pain is one of the most frequent complaints for patients seen in the emergency department. The current article describes the clinical stratification of patients who present to the emergency department with chest pain and discusses imaging options and analysis for these patients. It reviews conventional imaging approaches to assessing chest pain including chest radiography and stress testing. The main discussion focuses on the potential utility use of cross-sectional imaging, particularly multidetector CT, in the evaluation of chest pain in the emergency department.     

Yield of head CT for acute findings in patients presenting to the emergency department

ObjectivesThe aim of our study was to evaluate the yield of head CT in the ED in different age groups and different referral indications.Patients and methodsRecords of one large academic tertiary care ED were retrospectively reviewed for consecutive adult patients who underwent a head CT between January 1st 2017 and February 10th 2017. CT referral forms and interpretations were obtained and evaluated for demographics, referral indications, and findings.Scans were divided into three groups: acute findings, chronic findings, and normal. The cohort was divided into three age groups. Associations between referral indications and acute findings were calculated.ResultsOverall, 1536 of adult patients with ED head CT were included. Acute findings were found in 239/1536 (15.5%) of the CTs. The frequency of acute findings increased with age (p = 0.027). The most common acute findings were brain hemorrhage (32.6%), infarct (27.6%), and mass (23%). The top three referral indications were focal neurologic deficit (28%), trauma (24.7%), and headache (17.5%).The rates of positive acute findings for different referral indications were seizure 27%, confusion 20%, syncope 19%, focal neurologic deficit 16%, head injury 15%, headache 12%, and dizziness 8%.ConclusionThis study shows the yield of ED head CT for acute findings for different age groups and for different referral indications. The frequency of acute findings increased with age. Suspected seizure had the highest association with an acute finding, whereas dizziness had the lowest association.     

Coronavirus Disease 2019 (COVID-19) CT Findings: A Systematic Review and Meta-analysis

PurposeTo date, considerable knowledge gaps remain regarding the chest CT imaging features of coronavirus disease 2019 (COVID-19). We performed a systematic review and meta-analysis of results from published studies to date to provide a summary of evidence on detection of COVID-19 by chest CT and the expected CT imaging manifestations.MethodsStudies were identified by searching PubMed database for articles published between December 2019 and February 2020. Pooled CT positive rate of COVID-19 and pooled incidence of CT imaging findings were estimated using a random-effect model.ResultsA total of 13 studies met inclusion criteria. The pooled positive rate of the CT imaging was 89.76% and 90.35% when only including thin-section chest CT. Typical CT signs were ground glass opacities (83.31%), ground glass opacities with mixed consolidation (58.42%), adjacent pleura thickening (52.46%), interlobular septal thickening (48.46%), and air bronchograms (46.46%). Other CT signs included crazy paving pattern (14.81%), pleural effusion (5.88%), bronchiectasis (5.42%), pericardial effusion (4.55%), and lymphadenopathy (3.38%). The most anatomic distributions were bilateral lung infection (78.2%) and peripheral distribution (76.95%). The incidences were highest in the right lower lobe (87.21%), left lower lobe (81.41%), and bilateral lower lobes (65.22%). The right upper lobe (65.22%), right middle lobe (54.95%), and left upper lobe (69.43%) were also commonly involved. The incidence of bilateral upper lobes was 60.87%. A considerable proportion of patients had three or more lobes involved (70.81%).ConclusionsThe detection of COVID-19 chest CT imaging is very high among symptomatic individuals at high risk, especially using thin-section chest CT. The most common CT features in patients affected by COVID-19 included ground glass opacities and consolidation involving the bilateral lungs in a peripheral distribution.