CT imaging of clinically significant abdominopelvic injuries in the damage control surgery patient.

PURPOSE: Damage Control Surgery (DCS) refers to a staged laparotomy performed in patients who have suffered severe blunt or penetrating abdominopelvic trauma with the goal of managing critical injuries while avoiding life threatening metabolic derangements. Within 24 h of the initial laparotomy, computed tomography (CT) is used to assess the full extent of injuries. The purpose of this study was to assess the incidence of clinically significant unknown abdominopelvic injuries which required further dedicated surgical or interventional radiology management and failed surgical repairs identified on CT following initial laparotomy. METHODS: CT findings were correlated with surgical findings from the initial and subsequent staged laparotomy to determine known and unknown injuries. Frequency and percentage analyses was performed. RESULTS: Out of 63 patients who underwent DCS with an open abdomen following initial laparotomy and subsequent CT within 24 h, a total of 13 clinically significant abdominopelvic injuries were identified in 12 patients. Seven clinically significant injuries were identified in seven patients (11.1% of patients) in surgically explored areas. Six clinically significant injuries were identified in six patients (9.5%) in surgically unexplored areas. Four instances of failed initial surgical repair were identified in four patients (6.3%) involving the liver and gastrointestinal tract. Overall, 23.8% of the DCS patient population had an actionable finding on the post laparotomy CT. CONCLUSION: CT demonstrated value for identifying the extent of clinically significant abdominopelvic injuries and evidence of failed initial surgical repair, which informed surgical planning for subsequent laparotomy. The authors advocate for performing CT in post-DCS patients with an open abdomen as soon as possible following correction of metabolic and hemodynamic derangements.

Utility of Torso Imaging for Elderly Patients Sustaining Ground-Level Falls.

INTRODUCTION: Computed tomography (CT) of the torso has become increasingly common for assessment of fall patients in the emergency department. Some data suggest that older adults (≥65) may benefit from torso imaging more than younger patients. We sought to evaluate the usage and utility of CT imaging for elderly patients presenting after ground-level falls (GLFs) from 1 meter or less at our level 1 trauma center. METHODS: Patients ≥18 presenting with GLF in 2015-2019 were included. Data were obtained through chart and trauma registry review. Descriptive statistics were used to summarize the use of CT imaging for patients younger than versus older than 65 y old. Three multivariate logistic regression models with age as a continuous, binary (<65 versus ≥65), or categorical (in multiples of 5) variable were used to investigate whether age is associated with an increased identification of traumatic injury not previously suspected or known based on physical exam (PE) or plain radiograph after GLF. RESULTS: A total of 522 patients <65 and 673 patients ≥65 y old were included. Older patients were significantly more likely to receive screening chest radiograph, screening pelvic radiograph, brain CT, and neck CT (all P < 0.001), but not torso (chest, abdomen, and pelvis) CT (P = 0.144). On multivariate logistic regression, age was not significantly associated with an increased odds of identification of traumatic injury after torso CT (continuous: adjusted odds ratio [aOR] = 1.01, 95% confidence interval [CI] = 0.99-1.03, P = 0.379; binary: aOR = 0.86, 95% CI = 0.46-1.58, P = 0.619; categorical: aOR = 1.03, 95% CI = 0.94-1.14, P = 0.453). A positive PE was the only variable associated with significantly increased odds of having an abnormal torso CT scan in all models. Only two patients ≥65 y old had injuries identified on torso CT in the context of a negative PE and negative screening imaging. CONCLUSIONS: The rate of torso injury identification in patients sustaining GLF is not associated with age, but is strongly associated with positive PE findings. In the subset of elderly GLF patients without positive torso PE findings, more conservative use of CT imaging could decrease health-care utilization costs without compromising patient care.

Hematocrit and lactate trends help predict outcomes in trauma independent of CT and other clinical parameters.

Background: Hematocrit and lactate have an established role in trauma as indicators of bleeding and cell death, respectively. The wide availability of CT imaging and clinical data poses the question of how these can be used in combination to predict outcomes. Purpose: To assess the utility of hematocrit or lactate trends in predicting intensive care unit (ICU) admission and hospital length of stay (LOS) in patients with torso trauma combined with clinical parameters and injury findings on CT. Materials and Methods: This was a single-center retrospective study of adults with torso trauma in one year. Trends were defined as a unit change per hour. CT findings and clinical parameters were explanatory variables. Outcomes were ICU admission and hospital LOS. Multivariate logistic and negative binomial regression models were used to calculate the odds ratio (OR) and incident rate ratio (IRR). Results: Among 840 patients, 561 (72% males, age 39 ± 18) were included, and 168 patients (30%) were admitted to the ICU. Decreasing hematocrit trend [OR 2.54 (1.41-4.58), p = 0.002] and increasing lactate trend [OR 3.85 (1.35-11.01), p = 0.012] were associated with increased odds of ICU admission. LOS median was 2 (IQR: 1-5) days. Decreasing hematocrit trend [IRR 1.37 (1.13-1.66), p = 0.002] and increasing lactate trend [2.02 (1.43-2.85), p < 0.001] were associated with longer hospital LOS. Conclusion: Hematocrit and lactate trends may be helpful in predicting ICU admission and LOS in torso trauma independent of organ injuries on CT, age, or admission clinical parameters.

Utilization of a two-material decomposition from a single-source, dual-energy CT in acute traumatic vertebral fractures.

Purpose: The purpose of this study is to utilize a two-material decomposition to quantify bone marrow edema on a dual-energy computed tomography (DECT) scanner at the cervical, thoracic, and lumbar spine acute fractures in correlation with short tau inversion recovery (STIR) hyperintensity on magnetic resonance imaging (MRI) in comparison with the normal bone marrow. Materials and methods: This retrospective institutional review board-approved study gathered patients over 18 years old who had acute cervical, thoracic, or lumbar spinal fractures scanned on a DECT scanner. Those who had a spinal MRI done with bone marrow STIR hyperintensity within 3 weeks of the DECT were included. The water (calcium) and fat (calcium) density (mg/cm3) measurements of the region of interest of the bone marrow were obtained at a normal anatomic equivalent site and at the fracture site where STIR hyperintensity was noted on MRI. A statistical analysis was performed using the paired t-test and Wilcoxon signed rank test (p > 0.05). Results: A total of 20 patients met the inclusion criteria (males n = 17 males, females n = 3). A total of 32 fractures were analyzed: 19 cervical and 13 thoracolumbar. There were statistically significant differences in the water (43 ± 24 mg/cm3) and fat (36 ± 31 mg/cm3) density (mg/cm3) at the acute thoracic and lumbar spine fractures in correlation with edema on STIR images (both paired t-test <0.001, both Wilcoxon signed ranked test p < 0.01). There were no significant differences in the water (-10 ± 46 mg/cm3) or fat (+7 ± 50 mg/cm3) density (mg/cm3) at the cervical spine fractures. Conclusion: The DECT two-material decomposition using water (calcium) and fat (calcium) analyses has the ability to quantify a bone marrow edema at the acute fracture site in the thoracic and lumbar spine.

The impact of social risk factors on the presentation, treatment and survival of patients with hepatocellular carcinoma at an urban, academic safety-net hospital.

BACKGROUND: Vulnerable populations have worse hepatocellular carcinoma (HCC) outcomes. We sought to understand if this could be mitigated at a safety-net hospital. METHODS: A retrospective chart review of HCC patients was conducted (2007-2018). Stage at presentation, intervention and systemic therapy were analyzed (Chi-square for categorical variables and Wilcoxon tests for continuous variables) and median survival calculated by Kaplan-Meier method. RESULTS: 388 HCC patients were identified. Sociodemographic factors were similar for stage at presentation, except insurance status (diagnosis at earlier stages for commercial insurance and later stages for safety-net/no insurance). Higher education level and origin of mainland US increased intervention rates for all stages. Early-stage disease patients had no differences in receipt of intervention or therapy. Late-stage disease patients with higher education level had increased intervention rates. Median survival was not impacted by any sociodemographic factor. CONCLUSION: Urban safety-net hospitals with a focus on vulnerable patient populations provide equitable outcomes and can serve as a model to address inequities in HCC management.

The Public Perception of CT Colonography Versus Colonoscopy via Sentiment Analysis of Social Media.

PURPOSE: The purpose of this study was to understand the public perception of CT colonography (CTC) in comparison with optical colonoscopy as a colorectal cancer screening technique. METHODS: In this observational study, all English-language tweets from January 1, 2015, until September 1, 2021, containing terms related to CTC and terms related to optical colonoscopy were collected. The tweets were given sentiment scores using Twitter-roBERTa-base, a natural language processing model. These scores were then used to classify tweets into positive, neutral, and negative categories. The numbers of negative, positive, and neutral tweets were tabulated. RESULTS: A total of 4,709 tweets from 2,194 users relating to CTC were collected. Of these tweets, 9.81% were negative, 68.52% were neutral, and 21.63% were positive. In comparison, a total of 445,969 tweets from 261,209 users were collected relating to optical colonoscopy. Of these tweets, 31.8% were negative, 51.3% were neutral, and 16.9% were positive. CONCLUSIONS: The public awareness of CTC remains limited in comparison with optical colonoscopy, with Twitter volume relating to CTC being about 1% the volume for optical colonoscopy. There was a higher proportion of negative tweets regarding colonoscopy. The lower proportion of negative tweets regarding CTC may be helpful in encouraging its use as an alternative to optical colonoscopy, with the aim of increasing uptake of colorectal cancer screening.

Quantification of spinal bone marrow fat fraction using three-material decomposition technique on dual-energy CT: A phantom study.

BACKGROUND: Two-material decomposition is insufficient to quantify the fat fraction of spinal bone marrow, which is comprised of a mixture of bone minerals, water, and yellow marrow (fat). PURPOSE: To develop an accurate three-material decomposition-based bone marrow fat fraction ( F F 3 M D $F{F_{3MD}}$ ) quantification technique for dual-energy CT. METHODS: Bone marrow edema phantoms containing trabecular bone minerals, water, and fat were constructed using fat fractions and bone mineral density values matching those expected in healthy and edematous bone, and scanned on a commercial dual-energy CT. Fat quantified by F F 3 M D $F{F_{3MD}}$ were compared to MRI-based fat fraction ( F F M R I $F{F_{MRI}}$ ) and conventional two-material-decomposition-based fat fraction ( F F 2 M D $F{F_{2MD}}$ ) to evaluate its accuracy and dependency on various bone mineral densities. RESULTS: F F 3 M D $F{F_{3MD}}$ demonstrated an excellent correlation with F F M R I $F{F_{MRI}}\;$ (r = 0.97, R2  = 0.96) in the phantom, significantly more accurate than FF2MD when confounding bone minerals are present (50 mg/cm3 : r = 1.02, R2  = 0.95 vs. r = 0.65, R2  = 0.79 (p < 0.01); 100 mg/cm3 : r = 0.81, R2  = 0.47 vs. r = 0.21, R2  = 0.21 (p < 0.05)). CONCLUSIONS: F F 3 M D $F{F_{3MD}}$ accurately quantified bone marrow fat fraction, when compared with F F M R I $F{F_{MRI}}$ , in the specially constructed bone marrow phantom.

Application of creatinine height index in patients with trauma for the evaluation of psoas muscle mass: A clinical validation study.

BACKGROUND: The creatinine height index (CHI) is an estimate of lean body mass. We hypothesize that a modified CHI estimate using serum creatinine (sCr) levels in patients with normal renal function when performed soon after injury would reflect preinjury protein nutrition status. METHODS: The urine CHI (uCHI) was calculated using the 24-h urine sample. The serum-derived estimated CHI (sCHI) was calculated using the sCr on admission. Correlation between abdominal computed tomography images at specific lumbar vertebral levels and total body fat and muscle content was used for comparison as an independent measurement of nutrition status unlikely to be substantially altered by trauma. RESULTS: A total of 45 patients were enrolled, all with a significant injury burden (median injury severity score [ISS] = 25; interquartile range, 17-35). The calculated sCHI on admission was 71.0% (SD = 26.9%) and likely underestimates the CHI when compared with uCHI (mean = 112.5%, SD = 32.6%). Stratifying by degree of stress demonstrated that in a group of 23 moderately and severely stressed patients, uCHI (mean = 112.7%, SD = 5.7%) and sCHI (mean = 60.8%, SD = 1.9%) were significantly different and without correlation (r = -0.26, P = 0.91). In patients without stress, there was a significant negative correlation between sCHI and psoas muscle area (r = -0.869, P = 0.03), and in patients with severe stress there was a significant positive correlation between uCHI and psoas muscle area (r = 0.733, P = 0.016). CONCLUSION: The CHI calculated from the initial sCr is not an appropriate estimate of uCHI in critically ill trauma patients and is not a valid measure of psoas muscle mass in this setting.

The Impact of Social Determinants of Health on the Time Between Diagnostic Breast Imaging and Biopsy at a Safety Net Hospital.

PURPOSE: Although social determinants of health (SDH) are thought to be associated with health outcomes, there is limited literature on the direct impact of SDH on delays in breast cancer diagnosis via breast imaging. Identifying SDH associated with longer lapses (defined in this study as a time interval between two events) between imaging and biopsy is essential to early-stage detection of breast cancer, which has a significant impact on survival. Previous work demonstrated associations between both housing and food insecurity with longer lapses between diagnostic imaging and biopsy. We aim to expand upon this retrospective analysis with a longer study period, more participants, and improved data cleaning techniques to better understand how SDH may affect the lapse between imaging and biopsy. METHODS: This retrospective study was institutional review board approved and HIPAA compliant. Informed consent was waived. Patients who underwent screening mammography between January 1, 2015, and January 1, 2020, were assessed for timing of recommended biopsy due to a BI-RADS category 4 or 5. SDH were assessed with the unique Tool for Health & Resilience in Vulnerable Environments screening questionnaire developed at Boston Medical Center. Associations between imaging and biopsy timing and eight explanatory SDH variables (food insecurity, housing insecurity, ability to pay for medications, transportation access, ability to pay for utilities, caretaking needs, employment, and desire for more education) were assessed with multivariate Cox proportional hazard modeling, as well as demographic data. RESULTS: There were 2,885 unique patients who underwent 3,142 unique diagnostic imaging studies and were included in the multivariate analysis. Of those 3,142 imaging studies, 196 (6.2%) had not yet been followed by the recommended biopsy by the end of the study period; 2,271 patients (78.7%) had SDH data in at least one domain; and the individual domains ranged from 962 patients (32.1%) with complete data for education to 2,175 patients (75.4%) with complete data for food insecurity. A positive screen for at least one SDH was associated with a longer lapse between diagnostic imaging and biopsy (P = .048). Furthermore, housing insecurity alone was nearly associated with longer lapses between diagnostic imaging and biopsy (P = .059). Those who desired more education were found to have shorter lapses between diagnostic imaging and biopsy (P = .037). CONCLUSIONS: Only a positive screen of the aggregate of all SDH (using a novel tool developed at our safety net hospital) was associated with a statistically significant lengthening of this lapse. Of the eight SDH screened, housing insecurity was the closest to association with longer lapses between diagnostic imaging and biopsy, whereas patients who desired more education were found to have statistically significant shorter lapses; however, this survey domain had the lowest completion rate. CLINICAL RELEVANCE: Identification of which SDH might affect the time from imaging to biopsy can potentially inform targeted programs to intervene. Government and health system interventions addressing SDH, notably housing insecurity, could allow for shorter time to breast cancer diagnosis and treatment.

Utilization of torso computed tomography for the evaluation of ground level falls: More imaging does not equal better care.

INTRODUCTION: Computed tomography (CT) of the chest (CTC), abdomen, and pelvis (CTAP) is common when assessing trauma patients in the emergency department. However, unnecessary imaging can expose patients to unneeded radiation and increase healthcare costs. Here, we characterize the use of torso CT imaging for the evaluation of ground level falls (GLF) at a single level 1 trauma center. PATIENTS AND METHODS: We conducted a retrospective review of all patients ≥18 years old presenting to a single level 1 trauma center with a GLF (1m or less) in 2015-2019. Data were obtained through chart review. Descriptive statistics were used to summarize patient characteristics. Multivariable logistic regression was used to assess factors leading to patients obtaining torso CT imaging. The utility of CT imaging in identifying injuries that changed management was also evaluated. RESULTS: Of the 1,195 patients captured during the study period, 492 patients had a positive torso physical exam (PE), and 703 had a negative torso PE. Of patients with a negative torso PE, 127 CTC and 142 CTAP were obtained, with only 5.5% CTC identifying traumatic injuries not previously diagnosed on chest radiograph (CXR), and only 0.7% CTAP identifying new injuries not identified on pelvic radiograph (PXR). Multivariable logistic regression demonstrated that only a positive PE was significantly associated with the identification of abnormal imaging findings on torso CT. A negative PE, CXR, and PXR have a negative predictive value of 98%. DISCUSSION: These data suggest that patients with a negative PE, even if intoxicated, intubated, or with a decreased GCS, are highly unlikely to have new, clinically relevant findings on torso CT imaging. CONCLUSION: Using PE, CXR, and PXR as a screening tool in patients sustaining GLF, which if negative close to obviates the need for torso CT, may reduce healthcare costs and radiation exposure without compromising patient care.

Social determinants of health and the prediction of missed breast imaging appointments.

BACKGROUND: Predictive models utilizing social determinants of health (SDH), demographic data, and local weather data were trained to predict missed imaging appointments (MIA) among breast imaging patients at the Boston Medical Center (BMC). Patients were characterized by many different variables, including social needs, demographics, imaging utilization, appointment features, and weather conditions on the date of the appointment. METHODS: This HIPAA compliant retrospective cohort study was IRB approved. Informed consent was waived. After data preprocessing steps, the dataset contained 9,970 patients and 36,606 appointments from 1/1/2015 to 12/31/2019. We identified 57 potentially impactful variables used in the initial prediction model and assessed each patient for MIA. We then developed a parsimonious model via recursive feature elimination, which identified the 25 most predictive variables. We utilized linear and non-linear models including support vector machines (SVM), logistic regression (LR), and random forest (RF) to predict MIA and compared their performance. RESULTS: The highest-performing full model is the nonlinear RF, achieving the highest Area Under the ROC Curve (AUC) of 76% and average F1 score of 85%. Models limited to the most predictive variables were able to attain AUC and F1 scores comparable to models with all variables included. The variables most predictive of missed appointments included timing, prior appointment history, referral department of origin, and socioeconomic factors such as household income and access to caregiving services. CONCLUSIONS: Prediction of MIA with the data available is inherently limited by the complex, multifactorial nature of MIA. However, the algorithms presented achieved acceptable performance and demonstrated that socioeconomic factors were useful predictors of MIA. In contrast with non-modifiable demographic factors, we can address SDH to decrease the incidence of MIA.

American Society of Emergency Radiology (ASER) social media committee workgroup: best practices for the use of social media in emergency radiology.

Social media has become integrated within the profession of medicine, and emergency radiology has inevitably felt the impact of its presence. Emergency radiologists are encouraged to consider the advantages of embracing the digital era and the benefits it may bring to our careers. We aim to present the best practice guidelines for emergency radiologists and radiology departments. This paper is a product of the American Society of Emergency Radiology Social Media (ASER) Committee workgroup and represents the best practices of the society.

Use of MR in Pancreaticobiliary Emergencies.

This article presents the MR protocols, imaging features, diagnostic criteria, and complications of commonly encountered emergencies in pancreaticobiliary imaging, which include pancreatic trauma, bile leak, acute cholecystitis, biliary obstruction, and pancreatitis. Various classifications and complications that can arise with these conditions, as well as artifacts that may mimic pathology, are also included. Finally, the emerging utility of abbreviated MR protocols is discussed.

Quantification of bone marrow edema using dual-energy CT at fracture sites in trauma.

PURPOSE: The purpose of our study was to analyze the change in water and fat density within the bone marrow using the GE Revolution dual-energy computed tomography (DECT) platform using two-material decomposition analyses at extremity, spine, and pelvic fracture sites compared to normal bone marrow at equivalent anatomic sites in adult patients who sustained blunt trauma. METHODS: This retrospective study included 26 consecutive adults who sustained blunt torso trauma and an acute fracture of the thoracolumbar vertebral body, pelvis, or upper and lower extremities with a total of 32 fractures evaluated. Two-material decomposition images were analyzed for quantitative analysis. Statistical analysis was performed using the paired t-test and Shapiro-Wilk test for normality. RESULTS: There were statistically significant differences in the water and fat densities in the bone marrow at the site of an extremity, vertebral body, or pelvic fracture when compared to the normal anatomic equivalent (p < 0.01). CONCLUSION: In this preliminary study, DECT basis material images, using water (calcium) and fat (calcium) decomposition illustrated significant differences in water and fat content between fracture sites and normal bone in a variety of anatomical sites.

Dual energy CT angiography for lower extremity trauma: comparison with conventional CT.

PURPOSE: To determine if rapid switching dual-energy CT (rsDECT) provides improvements in vascular attenuation, subjective diagnostic quality, and detection of vascular injuries compared to conventional CT in trauma patients undergoing lower extremity CT angiography. MATERIALS AND METHODS: The IRB approved this HIPAA-compliant retrospective study. Informed consent was waived. Thirty-nine patients with acute lower extremity trauma including gunshot wounds (19 patients), falls (6 patients), motor vehicle accidents (5 patients), stab wounds (4 patients), pedestrian struck (2 patients), and unspecified trauma (3 patients) who underwent IV contrast-enhanced rsDECT angiography of the lower extremities on a rapid-kilovoltage-switching dual-energy CT scanner (Revolution CT, GE Healthcare) from 6/4/2019 to 1/14/2021 were studied. 7 patients were initially positive for vascular injury on conventional CT, while 32 patients were negative. Blended CT reconstructions simulating conventional 120 kVp single-energy CT, and rsDECT reconstructions (50 keV monoenergetic and iodine density maps) were reviewed. Region of interest contrast density measurements were recorded on conventional and 50 keV reconstructions at multiple levels from the distal aorta to the ankles and compared using Wilcoxon signed-rank tests. Vascular contrast density of 150 HU was used as a minimum cutoff for diagnostically adequate opacification. Images were interpreted by consensus for subjective image quality and presence of injury on both conventional and DECT reconstructions by two fellowship-trained abdominal radiologists blinded to clinical data, and compared using the paired McNemar test. RESULTS: Density measurement differences between conventional and rsDECT at every level of the bilateral lower extremities were statistically significant, with the average difference ranging from 304 Hounsfield units (HU) in the distal aorta to 121 HU at the ankles (p < 0.0001). Using a cutoff of 150 HU, 9.5% (93/976) and 3.1% of vascular segments (30/976) were considered non-diagnostic in the conventional and rsDECT groups, respectively, a reduction of 67.7% (p < 0.0001). Subjective image quality between conventional and rsDECT was not statistically significant, but there were 7 vascular segments out of a total of 976 segments across 3 different patients out of a total of 39 patients in which diagnostic quality was upgraded from non-diagnostic on conventional CT to diagnostic on rsDECT, all of which showed suboptimal bolus quality on conventional CT (unmeasurable in 4/7 and ranging from 56-146 HU in the remaining 3). Similarly, rate of injury detection was identical between conventional CT (15/39 patients) and DECT (15/39 patients). CONCLUSIONS: Vascular contrast density is statistically significantly higher with rsDECT compared to conventional CT, and subjective image quality was upgraded from non-diagnostic on conventional CT to diagnostic on rsDECT in 7 vascular segments across 3 patients. CLINICAL RELEVANCE: rsDECT provides greater vascular contrast density than conventional CT, with potential to salvage suboptimal examinations caused by poor contrast opacification.

The Impact of Social Determinants of Health on Lung Cancer Screening Utilization.

PURPOSE: The purpose of this study was to understand how social determinants of health might influence lung cancer screening (LCS) adherence. METHODS: All LCS low-dose CT appointments scheduled at an urban, tertiary care academic medical center in the New England region between January 1, 2015, and December 31, 2018, were included. Demographics, insurance type, information on social determinants of health, and appointment status were obtained from the electronic medical records. Multivariate logistic regression was performed to evaluate the associations between the appointment status and the explanatory variables. RESULTS: During the study period, 2,797 patients had 4,747 scheduled LCS appointments. Forty-one percent of patients had at least one missed appointment, and 32.7% of all scheduled appointments were missed. The retention rate of patients after the baseline examination was approximately 50%. Self-reported Black race was independently associated with 1.5 times the odds of missing appointments compared with White race (P = .012). Patients with Medicaid had 6.1 times the odds of missing appointments compared with patients with private insurance and 4.6 times the odds of missing appointments compared with patients with Medicare (P < .0001). Housing insecurity was a risk factor for failing to follow up after the baseline examination, with an odds ratio of 5.3 (P = .0013). CONCLUSIONS: The high rate of missed LCS appointments underscores the need to improve screening compliance. The identification of specific social determinants of health that contribute to disparities in access to LCS could empower policymakers, hospital systems, and providers to use targeted interventions to promote more equitable access.

Fat Fraction Measurements Using a Three-Material Decomposition Dual-Energy CT Technique Accounting for Bone Minerals: Evaluation in a Bone Marrow Phantom Using MRI as Reference.

Conventional two-material dual-energy CT (DECT) decomposition is insufficient to model bone marrow, which contains three materials: bone minerals, red marrow (water), and yellow marrow (fat). We explore an image-domain three-material decomposition DECT technique accounting for bone minerals in a bone-water-fat phantom. Three-material decomposition fat fraction (FF3MD) exhibited stronger correlation than two-material decomposition fat fraction (FF2MD) with MRI-based fat fraction (r = 0.95 vs r = 0.69). With increasing bone minerals, correlation of FF3MD remained stable (r = 0.81-1.02), whereas correlation of FF2MD decreased (r = 0.21-0.65).

Acute cholecystitis: diagnostic value of dual-energy CT-derived iodine map and low-keV virtual monoenergetic images.

PURPOSE: To compare conventional and dual-energy CT (DECT) for the diagnosis of acute cholecystitis and gangrene. METHODS: Fifty-seven consecutive adult patients with abdominal pain who underwent IV contrast-enhanced abdominal DECT on a dual-layer (dlDECT) or rapid-switching (rsDECT) scanner from September, 2018 to April, 2021 with cholecystectomy and pathology-confirmed cholecystitis were retrospectively reviewed, and compared with 57 consecutive adult patients without cholecystitis from the same interval scanned with DECT. Images were reviewed independently by two abdominal radiologists with 12 and 16 years of experience in two sessions 4 weeks apart, blinded to clinical data. Initially, only blended reconstructions (simulating conventional single-energy CT images) were reviewed (CT). Subsequently, CT and DECT reconstructions including low-keV virtual monoenergetic images and iodine maps were reviewed. Gallbladder fossa hyperemia, pericholecystic fluid, subjective presence of gangrene, heterogeneous wall enhancement, sloughed membranes, intramural air, abscess, overall impression of the presence of acute cholecystitis, and intramural iodine density were assessed. RESULTS: Gallbladder fossa hyperemia was detected with increased sensitivity on DECT (R1, 61.4%; R2, 75.4%) vs. CT (R1, 22.8%; R2, 15.8%). DECT showed increased sensitivity for gangrene (R1, 24.6%; R2, 38.6%) vs. CT (R1, 5.3%; R2, 14%), heterogeneous wall enhancement (DECT: R1, 33.3%; R2, 63.2% vs. CT: R1, 7%; R2, 31.6%), and cholecystitis (DECT: R1, 86%; R2, 89.5% vs. CT: R1, 77.2%; R2, 70.2%). In addition, DECT was more sensitive for the detection of acute cholecystitis (R1, 86%; R2, 89.5%) vs. CT (R1, 77.2%; R2, 70.2%). Iodine density threshold of 1.2 mg/ml, 0.8 mg/mL, and 0.5 mg/mL showed specificity for gangrenous cholecystitis of 78.26%, 86.96%, and 95.65%, respectively, using the rsDECT platform. CONCLUSION: DECT showed improved sensitivity compared to conventional CT for detection of acute cholecystitis. Iodine density measurements may be helpful to diagnose gangrene.

American Society of Emergency Radiology Multicenter Blunt Splenic Trauma Study: CT and Clinical Findings.

Background Treatment of blunt splenic trauma (BST) continues to evolve with improved imaging for detection of splenic vascular injuries. Purpose To report on treatments for BST from 11 trauma centers, the frequency and clinical impact of splenic vascular injuries, and factors influencing treatment. Materials and Methods Patients were retrospectively identified as having BST between January 2011 and December 2018, and clinical, imaging, and outcome data were recorded. Patient data were summarized descriptively, both overall and stratified by initial treatment received (nonoperative management [NOM], angiography, or surgery). Regression analyses were used to examine the primary outcomes of interest, which were initial treatment received and length of stay (LOS). Results This study evaluated 1373 patients (mean age, 42 years ± 18; 845 men). Initial treatments included NOM in 849 patients, interventional radiology (IR) in 240 patients, and surgery in 284 patients. Rates from CT reporting were 22% (304 of 1373) for active splenic hemorrhage (ASH) and 20% (276 of 1373) for contained vascular injury (CVI). IR management of high-grade injuries increased 15.6%, from 28.6% (eight of 28) to 44.2% (57 of 129) (2011-2012 vs 2017-2018). Patients who were treated invasively had a higher injury severity score (odds ratio [OR], 1.04; 95% CI: 1.02, 1.05; P < .001), lower temperature (OR, 0.97; 95% CI: 0.97, 1.00; P = .03), and a lower hematocrit (OR, 0.96; 95% CI: 0.93, 0.99; P = .003) and were more likely to show ASH (OR, 8.05; 95% CI: 5.35, 12.26; P < .001) or CVI (OR, 2.70; 95% CI: 1.64, 4.44; P < .001) on CT images, have spleen-only injures (OR, 2.35; 95% CI: 1.45, 3.8; P < .001), and have been administered blood product for fewer than 24 hours (OR, 2.35; 95% CI: 1.58, 3.51; P < .001) compared with those chosen for NOM, after adjusting for key demographic and clinical variables. After adjustment, factors associated with a shorter LOS were female sex (OR, 0.84; 95% CI: 0.73, 0.96; P = .009), spleen-only injury (OR, 0.72; 95% CI: 0.6, 0.86; P < .001), higher admission hematocrit (OR, 0.98; 95% CI: 0.6, 0.86; P < .001), and presence of ASH at CT (OR, 0.74; 95% CI: 0.62, 0.88; P < .001). Conclusion Contained vascular injury and active splenic hemorrhage (ASH) were frequently reported, and rates of interventional radiologic management increased during the study period. ASH was associated with a shorter length of stay, and patients with ASH had eight times the odds of undergoing invasive treatment compared with undergoing nonoperative management. © RSNA, 2021 See also the editorial by Patlas in this issue.