Emergency Radiology

Correction to: Spectrum of diagnostic errors in cervical spine trauma imaging and their clinical significance The published version of this article unfortunately contained a mistake. Author given and family name Alessandrino Francesco was incorrectly interchanged. The correct presentation is given above. The original article has been corrected.

Core curriculum illustration: supination-external rotation trimalleolar fracture Abstract This is the 37th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and on the use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.erad.org/page/CCIP_TOC.

Core curriculum illustration: pediatric buckle fracture of the distal radius Abstract This is the 38th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at: http://www.erad.org/page/CCIP_TOC

Accessory ossicles of the foot—an imaging conundrum Abstract Various anatomical variations can be found in the foot and ankle, including sesamoid bones and accessory ossicles. These are usually incidental findings and remain asymptomatic; however, they may cause complications resulting in painful syndromes or degenerative changes secondary to overuse or trauma. They can also lead to fractures or simulate fractures. These complications are challenging to diagnose on radiographs. Advanced imaging with US, CT, MRI, or Tc-99m bone scan is useful for definitive diagnosis. This study aims to illustrate how imaging modalities can be used to diagnose complications of common sesamoids and accessory ossicles of the ankle and foot (hallux sesamoids, os trigonum, accessory navicular, os supranaviculare, os peroneum, os intermetatarseum, and os calcaneus secundarius) and demonstrate the imaging differences between fractures and their mimics.

Characterization of all-terrain vehicle–related chest injury patterns in children Abstract Purpose To evaluate chest injury patterns in pediatric patients involved in all-terrain vehicle (ATV) accidents. Methods Retrospective review of patients 0–18 years old admitted to a level I trauma institute following an ATV-related incident from 2004 to 2013 was performed. Chest injury type, accident mechanism, driver/passenger status, and demographic and clinical data were compared between patients with and without chest injury. Results Chest injury was present in 102 (22%) of total 455 patients. The most common chest injuries were pulmonary contusion (61%), pneumothorax (45%), and rib fracture (34%). There were no cardiac, esophageal, or tracheobronchial injuries. Pulmonary lacerations, hemothoraces, and scapular fractures were predominantly not detected on radiography and recognized on CT only (86–92%). Patients with chest injury had longer median hospital stays (3 days vs 2 days, p = 0.0054). There was no significant difference in admission to intensive care after controlling for injury severity scores in patients with chest injury compared to those without (17 vs 9). Eight patients with chest injury died (8%) compared to 2 patients without chest injury (0.6%) (p = 0.0002). Conclusions Chest injuries are common in children following ATV accidents and may be a marker of more severe trauma. Increased public awareness of these potentially devastating injuries and continuing safety efforts are needed.

The cost of callbacks: return visits for diagnostic imaging discrepancies in a pediatric emergency department Abstract Purpose Diagnostic imaging has mirrored the steady growth of healthcare utilization in the USA. This has created greater opportunity for diagnostic errors, which can be costly in terms of morbidity and mortality as well as dollars and cents. The purposes of this study were to describe all return visits to a tertiary care urban pediatric emergency department (PED) resulting from diagnostic imaging discrepancies and to calculate the costs of these return visits. Methods From July 2014 to February 2015, all children who underwent a diagnostic imaging study during an ED visit were assembled. Analysis was performed on all children who were called back and returned to the ED following a discrepant read. Direct and indirect costs to the patient, family, hospital, and society for these return visits were calculated. Results During the study period, 8310 diagnostic imaging studies were performed, with 207 (2.5%) discrepant reads. Among the discrepant reads, 37 (0.4% of total, 17.9% of discrepant) patients had a return visit to the ED for further management. Including ED charges, time and travel costs to the family, and costs of radiation exposure, return visits for radiologic discrepancies over this 8-month period cost a total of $84,686.47, averaging $2288.82 per patient. Conclusions Though the overall diagnostic imaging discrepancy rate among our study population was low, the clinically significant discrepancies requiring return ED visits were potentially high risk, and costly for the patient, family, and healthcare system.

Dismantling the ability of CT and MRI to identify the target mismatch profile in patients with anterior circulation large vessel occlusion beyond six hours from symptom onset Abstract Purpose Patients with large vessel occlusion and target mismatch on imaging may be thrombectomy candidates in the extended time window. However, the ability of imaging modalities including non-contrast CT Alberta Stroke Program Early Computed Tomographic Scoring (CT ASPECTS), CT angiography collateral score (CTA-CS), diffusion-weighted MRI ASPECTS (DWI ASPECTS), DWI lesion volume, and DWI volume with clinical deficit (DWI + NIHSS), to identify mismatch is unknown. Methods We defined target mismatch as core infarct (DWI volume) of < 70 mL, mismatch volume (tissue with TMax > 6 s) of ≥ 15 mL, and mismatch ratio of ≥ 1.8. Using experimental dismantling design, ability to identify this profile was determined for each imaging modality independently (phase 1) and then with knowledge from preceding modalities (phase 2). We used a generalized mixed model assuming binary distribution with PROC GLIMMIX/SAS for analysis. Results We identified 32 patients with anterior circulation occlusions, presenting > 6 h from symptom onset, with National Institute of Health Stroke Scale of ≥ 6, who had CT and MR before thrombectomy. Sensitivities for identifying target mismatch increased modestly from 88% for NCCT to 91% with the addition of CTA-CS, and up to 100% for all MR-based modalities. Significant gains in specificity were observed from successive tests (29, 19, and 16% increase for DWI ASPECTS, DWI volume, and DWI + NIHSS, respectively). Conclusions The combination of NCCT ASPECTS and CTA-CS has high sensitivity for identifying the target mismatch in the extended time window. However, there are gains in specificity with MRI-based imaging, potentially identifying treatment candidates who may have been excluded based on CT imaging alone.

Augmenting Denver criteria yields increased BCVI detection, with screening showing markedly increased risk for subsequent ischemic stroke Abstract Purpose BCVI may lead to ischemic stroke, disability, and death, while being often initially clinically silent. Screening criteria for BCVI based on clinical findings and trauma mechanism have improved detection, with Denver criteria being most common. Up to 30% of patients do not meet BCVI screening criteria. The aim of this study was to analyze the effect of augmented Denver criteria on detection, and to determine the relative risk for ischemic stroke. Methods Denver screening criteria were augmented by any high-energy trauma of the cervical spine, thorax, abdomen, or pelvis. All acute blunt trauma WBCT including CT angiography (CTA) over a period of 38 months were reviewed retrospectively by two Fellowship-trained radiologists, as well as any cerebral imaging after the initial trauma. Results 1544 WBCT studies included 374 CTA (m/f = 271/103; mean age 41.5 years). Most common mechanisms of injury were MVA (51.5%) and fall from a height (22.3%). We found 72 BCVI in 56 patients (15.0%), with 13 (23.2%) multiple lesions. The ICA was affected in 49 (68.1%) and the vertebral artery in 23 (31.9%) of cases. The most common injury level was C2, with Biffl grades I and II most common in ICA, and II and IV in VA. Interobserver agreement was substantial (Kappa = 0.674). Of 215 patients imaged, 16.1% with BCVI and 1.9% of the remaining cases had cerebral ischemic stroke (p < .0001; OR = 9.77; 95% CI 3.3–28.7). Eleven percent of patients with BCVI would not have met standard screening criteria. Conclusions The increase in detection rate for BCVI justifies more liberal screening protocols.

There has to be an easier way: facet fracture characteristics that reliably differentiate AOSpine F1 and F2 injuries Abstract Purpose To identify morphologic features of isolated cervical spine facet fractures that can reliably differentiate AOSpine F1 and F2 injuries. Materials and methods Retrospective review of cervical spine CTs on all patients who sustained isolated cervical fractures of the facets presenting to our level 1 trauma center from August 2012 through December 2015. CTs were reviewed for facet fracture characteristics and AOSpine facet fracture classification. Association between facet fracture characteristics and AOSpine classification was assessed through multivariable logistic regression models. Results Fifty-six patients with cervical spine fractures isolated to the facets were included in the study. The mean age was 36 (range 9–90) years with 55.4% (n = 31) males. A significant correlation was found between subtype F1 and subtype F2 in laterality (left- or right-sided) (p = 0.004), interfacetal fracture involvement (p < 0.0001), transverse process involvement (p < 0.001), displacement of fracture fragment (p < 0.001), comminution of fracture (p < 0.0001), and vertebral arch disruption (p = 0.001). After multivariable analysis, left side laterality (p = 0.03), transverse process involvement (p = 0.01), and fracture comminution (p = 0.003) were associated with F2 fractures. Conclusion Facet fractures with transverse process involvement or comminution have a higher probability of being an F2 fracture. These characteristics may be helpful when categorizing facet fractures using the AOSpine classification.

Accuracy and timeliness of an abbreviated emergency department MRCP protocol for choledocholithiasis Abstract Purpose To determine the diagnostic accuracy and time savings of an abbreviated magnetic resonance cholangiopancreatography (A-MRCP) protocol for detecting choledocholithiasis in patients visiting the emergency department (ED) for suspected biliary obstruction. Methods and materials This retrospective study evaluated adult patients (ages 18+ years) visiting an academic Level 1 trauma center between January 1, 2016, and December 31, 2017, who were imaged with MRCP for suspected biliary obstruction. Patients were scanned with either a four-sequence A-MRCP protocol or a conventional eight-sequence MRCP (C-MRCP) protocol. Image acquisition and MRI room time were compared. The radiology report was used to determine whether a study was limited by motion or prematurely aborted, as well as for the presence of pertinent biliary findings. Diagnostic accuracy of A-MRCP studies were compared with any available endoscopic retrograde cholangiopancreatography (ERCP) report within 30 days. Results One hundred sixteen patients met inclusion criteria; 85 were scanned with the A-MRCP protocol (45.9% male, mean 57.4 years) and 31 with the C-MRCP protocol (38.7% male, mean 58.3 years). Mean image acquisition time and MRI room time for the A-MRCP protocol were significantly lower compared to those for the C-MRCP protocol (16 and 34 min vs. 42 and 61 min, both p < 0.0001). Choledocholithiasis was seen in 23.5% of A-MRCP cases and 19.4% of C-MRCP cases. Non-biliary findings were common in both cohorts, comprising 56.5% of A-MRCP cases and 41.9% of C-MRCP cases. 44.7% of A-MRCP patients received subsequent (diagnostic or therapeutic) ERCP (mean follow-up time 3 days), in which A-MRCP accurately identified choledocholithiasis in 86.8% of cases, with sensitivity of 85%, specificity of 88.9%, positive predictive value (PPV) of 89.5%, and negative predictive value (NPV) of 84.2%. In comparison, 38.7% of C-MRCP patients underwent ERCP (mean follow-up of 2.3 days) with an accuracy of 91.7%, sensitivity of 80%, specificity of 100%, PPV of 100%, and NPV of 87.5%. Only 4.7% of A-MRCP exams demonstrated motion artifact vs. 12.9% of C-MRCP exams. One study was prematurely aborted due to patient discomfort in the A-MRCP cohort while no studies were terminated in the C-MRCP cohort. Conclusion An abbreviated MRCP protocol to evaluate for choledocholithiasis provides significant time savings and reduced motion artifact over the conventional MRCP protocol while providing similar diagnostic accuracy.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com