Traumatic Brain Injury and Its Association With Orbital Fracture Characteristics and Repair.

Traumatic brain injury (TBI) is common in up to 50% of patients with facial fractures. Orbital fractures account for 25% of all facial fractures. The authors sought to determine the prevalence and risk factors for TBI in patients undergoing orbital fracture repair (OFR) and assess the impact of TBI on surgical timing. A retrospective review of trauma patients who underwent OFR at a single trauma center from 2015 to 2020 was conducted. Excluded were patients <18 years old and those with unreported GCS on presentation. TBI was defined as GCS <15 or any neurological symptom on presentation. TBI was categorized into mild (GCS=14-15), moderate (GCS=9-13), and severe TBI (GCS=3-8). Our primary and secondary outcomes were the prevalence of TBI on presentation and duration from injury to surgery, respectively. Of the 200 patients analyzed, 99 (49.5%) had concomitant TBI on presentation. The most common neurological symptom on presentation was loss of consciousness [n=80 (40%)]. Patients with TBI were significantly more likely to have an orbital roof [n=11 (11.1%), n=4 (4.0%), P=0.048] and lateral wall fractures [n=25 (25.3%), n=14 (13.9%), P=0.031] compared with patients without TBI. Patients with severe TBI were more likely to have delayed OFR-a significantly greater proportion of patients who had severe TBI had OFR after 60 days of injury compared with those without TBI or with mild TBI [5 (39%), 12 (12%), 4 (5%), P=0.032]. Craniofacial surgeons must suspect and screen for TBI in patients presenting with facial trauma, especially those with orbital roof and lateral wall fractures.

Orbital Fracture Characteristics and Outcomes in Baltimore.

Fracture characteristics and postoperative outcomes of patients presenting with orbital fractures in Baltimore remain poorly investigated. The purpose of our study was to determine the fracture patterns, etiologies, and postoperative outcomes of patients treated for orbital fractures at 2 level I trauma centers in Baltimore. A retrospective cohort study was conducted on patients who underwent orbital fracture repair at the R Adams Cowley Shock Trauma Center and the Johns Hopkins Hospital from January 2015 to December 2019. Of 374 patients, 179 (47.9%) had orbital fractures due to violent trauma, 252 (67.4%) had moderate to near-total orbital fractures, 345 (92.2%) had orbital floor involvement, and 338 (90.4%) had concomitant neurological symptoms/signs. Almost half of the patients had at least one postoperative ocular symptom/sign [n = 163/333 (48.9%)]. Patients who had orbital fractures due to violent trauma were more likely to develop postoperative ocular symptoms/signs compared with those who had orbital fractures due to nonviolent trauma [n = 88/154 (57.1%), n = 75/179 (41.9%); P = 0.006]. After controlling for factors pertaining to injury severity, there was no significant difference in patient throughput or incidence of any postoperative ocular symptom/sign after repair between the two centers. Timely management of patients with orbital fractures due to violent trauma is crucial to mitigate the risk of postoperative ocular symptoms/signs.

Characterizing Brain Perfusion in a Swine Model of Raised Intracranial Pressure.

INTRODUCTION: Perfusion of the brain is critical, but this can be compromised due to focal space occupying lesions (SOL). SOLs can raise intracranial pressure (ICP), resulting in reduced cerebral blood flow (CBF). Most gyrencephalic models of brain injury focus on parenchymal injury, with few models of acutely elevated ICP. We hypothesized that we could employ a SOL technique to develop a titratable ICP model and sought to quantitate the resulting decrease in brain perfusion. METHODS: Six swine were anesthetized and instrumented. A Fogarty balloon catheter was inserted intracranially. Blood CO2 partial pressure was maintained between 35 and 45 mmHg. The Fogarty balloon was infused with normal saline at 1 mL/min to ICP targets of 10, 20, 30, and 40 mmHg. CBF (mL/100 g/min) were assessed at each ICP level using computed tomography perfusion (CTP). Data are presented as the mean ± standard deviation with all pressures measured in mmHg. CBF values were compared between baseline and each ICP level using analysis of variance. RESULTS: Baseline ICP was 5 ± 2 and systolic blood pressure was 106 ± 7. Balloon volumes (mL) required to achieve each incremental ICP level were 2.4 ± 0.5, 4.9 ± 1.7, 7.6 ± 1.6, and 9.9 ± 1.7. CBF decreased with each raised ICP level, with CBF being significantly less than baseline at ICP values of 30 (56.1 ± 34.7 versus 20.6 ± 11.0, P < 0.05) and 40 (56.1 ± 34.7 versus 6.5 ± 10.6, P < 0.05). CONCLUSIONS: An intracranial balloon catheter can be used to increase ICP, delivering a proportionate reduction in CBF. This model can be used in the future studies to examine adjuncts that manipulate intracranial pressure and their effect on brain perfusion.

Iodine-based Dual-Energy CT of Traumatic Hemorrhagic Contusions: Relationship to In-Hospital Mortality and Short-term Outcome.

BackgroundTraumatic hemorrhagic contusions are associated with iodine leak; however, quantification of leakage and its importance to outcome is unclear.PurposeTo identify iodine-based dual-energy CT variables that correlate with in-hospital mortality and short-term outcomes for contusions at hospital discharge.Materials and MethodsIn this retrospective study, consecutive patients with contusions from May 2016 through January 2017 were analyzed. Two radiologists evaluated CT variables from unenhanced admission head CT and follow-up head dual-energy CT scans obtained after contrast material-enhanced whole-body CT. The outcomes evaluated were in-hospital mortality, Rancho Los Amigos scale (RLAS) score, and disability rating scale (DRS) score. Logistic regression and linear regression were used to develop prediction models for categorical and continuous outcomes, respectively.ResultsThe study included 65 patients (median age, 48 years; interquartile range, 25-65.5 years); 50 were men. Dual-energy CT variables that correlated with mortality, RLAS score, and DRS score were iodine concentration, pseudohematoma volume, iodine quantity in pseudohematoma, and iodine quantity in contusion. The single-energy CT variable that correlated with mortality, RLAS score, and DRS score was hematoma volume at follow-up CT. Multiple logistic regression analysis after inclusion of clinical variables identified two predictors that enabled determination of mortality: postresuscitation Glasgow coma scale (P-GCS) (adjusted odds ratio, 0.42; 95% confidence interval [CI]: 0.2, 0.86; P = 0.01) and iodine quantity in pseudohematoma (adjusted odds ratio, 1.4 per milligram; 95% CI: 1.02 per milligram, 1.9 per milligram; P = 0.03), with a mean area under the receiver operating characteristic curve of 0.96 ± 0.05 (standard error). For RLAS, the predictors were P-GCS (mean coefficient, 0.32 ± 0.06; P < .001) and iodine quantity in contusion (mean coefficient, -0.04 per milligram ± 0.02; P = 0.01). Predictors for DRS were P-GCS (mean coefficient, -1.15 ± 0.27; P < .001), age (mean coefficient, 0.13 per year ± 0.04; P = .002), and iodine quantity in contusion (mean coefficient, 0.19 per milligram ± 0.07; P = .02).ConclusionIodine-based dual-energy CT variables correlate with in-hospital mortality and short-term outcomes for contusions at hospital discharge.© RSNA, 2019Online supplemental material is available for this article.See also the editorial by Talbott and Hess in this issue.

Exploring Intra-arterial Contrast Administration for Intraoperative Imaging Using a Swine Model.

Intraoperative computed tomography (CT) imaging with endovascular delivery of intra-arterial (IA) contrast could potentially provide higher attenuation with lower contrast volumes than intravenous (IV) administration. We aimed to compare IA and IV contrast use for organ-specific CT abdominal imaging. Five anesthetized swine had external jugular and brachial artery access with ascending aortic pigtail placement. An IV protocol was 100 mL at 5 mL/sec over 20 sec vs 50 mL of IA contrast at 5 mL/sec over 10 sec. Region-of-interest markers were applied to anatomical regions to measure attenuation (HU) over time. IA and IV contrast protocols achieved adequate aortic opacification (IA, 455 ± 289 vs IV, 450 ± 114 HU). The IA contrast aortic attenuation curve reached peak attenuation compared with IV contrast (IA, 8 vs 23 sec; P < .001). Time to peak attenuation was similar between IA and IV contrast in the portal vein (IA, 38 vs IV, 42 sec, P = .25). IA administration achieved a superior contrast-to-noise ratio (CNR) in less time compared with IV (R2 = .94; P < .001). IA contrast achieved adequate opacification with less bolus broadening and a superior CNR compared with IV contrast while using a smaller contrast volume for directed organ-directed imaging.

Characterization of cerebral blood flow during open cardiac massage in swine: Effect of volume status.

Introduction: Patients in cardiac arrest treated with resuscitative thoracotomy and open cardiac massage (OCM) have high rates of mortality with poor neurological outcomes. The aim of this study is to quantitate cerebral perfusion during OCM using computed tomography perfusion (CTP) imaging in a swine model of normo- and hypovolemia. Methods: Anesthetized swine underwent instrumentation with right atrial and aortic pressure catheters. A catheter placed in the ascending aorta was used to administer iodinated contrast and CTP imaging acquired. Cerebral blood flow (CBF; ml/100 g of brain) and time to peak (TTP; s) were measured. Animals were then euthanized by exsanguination (hypovolemic group) or potassium chloride injection (normovolemic group) and subjected to a clamshell thoracotomy, aortic cross clamping, OCM, and repeated CTP. Data pertaining to peak coronary perfusion pressure (pCoPP; mmHg) were collected and % CoPP > 15 mmHg (% CoPP; s) calculated post hoc. Results: Normovolemic animals (n = 5) achieved superior pCoPP compared to the hypovolemic animals (n = 5) pCoPP (39.3 vs. 12.3, p < 0.001) and % CoPP (14.5 ± 1.9 vs. 30.9 ± 6.5, p < 0.001). CTP acquisition was successful and TTP elongated from spontaneous circulation, normovolemia to hypovolemia (5.7 vs. 10.8 vs. 14.8, p = 0.01). CBF during OCM was similar between hypovolemic and normovolemic groups (7.5 ± 8.1 vs. 4.9 ± 6.0, p = 0.73) which was significantly lower than baseline values (51.9 ± 12.1, p < 0.001). Conclusion: OCM in normovolemia generates superior coronary hemodynamics compared to hypovolemia. Despite this, neither generates adequate CBF as measured by CTP, compared to baseline. To improve the rate of neurologically intact survivors, novel resuscitative techniques need to be investigated that specifically target cerebral perfusion as existing techniques are inadequate.

Development of a computed tomography perfusion protocol to support large animal resuscitation research.

BACKGROUND: Adequate cerebral perfusion is crucial for a positive neurological outcome in trauma; however, it is difficult to characterize in the acute setting with noninvasive methods. Intra-arterial computed tomography perfusion may offer a solution. The aim of this study was to develop an intra-arterial computed tomography perfusion protocol for resuscitation research. METHODS: The study examined intra-arterial contrast administration for computed tomography perfusion (CTP) acquisition. It consisted of three phases: intra-arterial contrast dose finding, evaluation of reproducibility, and evaluation during hypotension. Blood pressure and laser Doppler flow data were collected. In phase 1, animals underwent CTPs using several intra-arterial contrast injection protocols. In phase 2, animals underwent two CTPs 7 hours apart using the 2.5 mL/s for 3-second protocol. In phase 3, animals underwent CTPs at several pressures following a computer-controlled bleed including euvolemia and at systolic pressures of 60, 40, and 20 mm Hg. Phase 1 CTPs were evaluated for contrast-to-noise ratio. In phase 2, CTPs were compared within each animal and with laser Doppler flow using linear regression. Phase 3 CTPs were graphed against systolic pressure and fitted with a nonlinear fit. RESULTS: The protocol using 2.5mL/s for 3 seconds was optimal, demonstrating a contrast-to-noise ratio of 40.1 and a superior arterial input function curve compared with the 1 mL/s bolus. Cerebral blood flow demonstrated high concordance between baseline and end of study CTPs (R2 = 0.82, p < 0.001). Cerebral blood flow also compared moderately well against laser Doppler flow during 8 (R2 = 0.53, p = 0.03); however, laser Doppler flow did not perform well during hypovolemia, and the favorable concordance was not maintained (R2 = 0.45, p = 0.06). Cerebral blood flow was graphed against systolic blood pressure and fitted with a nonlinear fit (R2 = 0.95, p = 0.003). CONCLUSION: Computed tomography perfusion using intra-arterial contrast injection may offer a novel alternative to traditional CTP protocols that could prove a useful additional tool in the setting of resuscitation research.

ACR Appropriateness Criteria® Head Trauma: 2021 Update.

Head trauma (ie, head injury) is a significant public health concern and is a leading cause of morbidity and mortality in children and young adults. Neuroimaging plays an important role in the management of head and brain injury, which can be separated into acute (0-7 days), subacute (<3 months), then chronic (>3 months) phases. Over 75% of acute head trauma is classified as mild, of which over 75% have a normal Glasgow Coma Scale score of 15, therefore clinical practice guidelines universally recommend selective CT scanning in this patient population, which is often based on clinical decision rules. While CT is considered the first-line imaging modality for suspected intracranial injury, MRI is useful when there are persistent neurologic deficits that remain unexplained after CT, especially in the subacute or chronic phase. Regardless of time frame, head trauma with suspected vascular injury or suspected cerebrospinal fluid leak should also be evaluated with CT angiography or thin-section CT imaging of the skull base, respectively. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Major Blunt Trauma.

This review assesses the appropriateness of various imaging studies for adult major blunt trauma or polytrauma in the acute setting. Trauma is the leading cause of mortality for people in the United States <45 years of age, and the fourth leading cause of death overall. Imaging, in particular CT, plays a critical role in the management of these patients, and a number of indications are discussed in this publication, including patients who are hemodynamically stable or unstable; patients with additional injuries to the face, extremities, chest, bowel, or urinary system; and pregnant patients. Excluded from consideration in this review are penetrating traumatic injuries, burns, and injuries to pediatric patients. Patients with suspected injury to the head and spine are also discussed more specifically in other appropriateness criteria documents. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Suspected Upper Extremity Deep Vein Thrombosis.

This publication includes the appropriate imaging modalities to assess suspected deep vein thrombosis in the upper extremities. Ultrasound duplex Doppler is the most appropriate imaging modality to assess upper-extremity deep vein thrombosis. It is a noninvasive test, which can be performed at the bedside and used for serial evaluations. Ultrasound can also directly identify thrombus by visualizing echogenic material in the vein and by lack of compression of the vein walls from manual external pressure. It can indirectly identify thrombus from altered blood-flow patterns. It is most appropriate in the evaluation of veins peripheral to the brachiocephalic vein. CT venography and MR venography are not first-line imaging tests, but are appropriate to assess the central venous structures, or to assess the full range of venous structures from the hand to the right atrium. Catheter venography is appropriate if therapy is required. Radionuclide venography and chest radiography are usually not appropriate to assess upper-extremity deep vein thrombosis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Nonatherosclerotic Peripheral Arterial Disease.

A broad range of nonatherosclerotic diseases affect the peripheral arteries. The appropriate initial diagnostic imaging studies vary, depending upon the clinical presentation and suspicion of disease. Accurate vascular imaging relies upon visualization of the vessel lumen, vessel wall, and surrounding soft-tissue structures, with some modalities also offering the ability to characterize blood flow direction and velocity. Furthermore, nonvascular findings are often paramount in supporting a suspected clinical syndrome or guiding surgical management. The scenarios discussed in this document include the initial evaluation of suspected popliteal entrapment syndrome, external iliac artery endofibrosis, lower-extremity inflammatory vasculitides, dissection or connective tissue disease, noninflammatory vascular disease, and vascular trauma. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Relative importance of geostatistical and transport models in describing heavily tailed breakthrough curves at the Lauswiesen site.

We analyze the relative importance of the selection of (1) the geostatistical model depicting the structural heterogeneity of an aquifer, and (2) the basic processes to be included in the conceptual model, to describe the main aspects of solute transport at an experimental site. We focus on the results of a forced-gradient tracer test performed at the "Lauswiesen" experimental site, near Tübingen, Germany. In the experiment, NaBr is injected into a well located 52 m from a pumping well. Multilevel breakthrough curves (BTCs) are measured in the latter. We conceptualize the aquifer as a three-dimensional, doubly stochastic composite medium, where distributions of geomaterials and attributes, e.g., hydraulic conductivity (K) and porosity (phi), can be uncertain. Several alternative transport processes are considered: advection, advection-dispersion and/or mass-transfer between mobile and immobile regions. Flow and transport are tackled within a stochastic Monte Carlo framework to describe key features of the experimental BTCs, such as temporal moments, peak time, and pronounced tailing. We find that, regardless the complexity of the conceptual transport model adopted, an adequate description of heterogeneity is crucial for generating alternative equally likely realizations of the system that are consistent with (a) the statistical description of the heterogeneous system, as inferred from the data, and (b) salient features of the depth-averaged breakthrough curve, including preferential paths, slow release of mass particles, and anomalous spreading. While the available geostatistical characterization of heterogeneity can explain most of the integrated behavior of transport (depth-averaged breakthrough curve), not all multilevel BTCs are described with equal success. This suggests that transport models simply based on integrated measurements may not ensure an accurate representation of many of the important features required in three-dimensional transport models.

Similarity of chest X-ray and thermal imaging of focal pneumonia: a randomised proof of concept study at a large urban teaching hospital.

OBJECTIVE: To assess the diagnostic accuracy of thermal imaging (TI) in the setting of focal consolidative pneumonia with chest X-ray (CXR) as the gold standard. SETTING: A large, 973-bed teaching hospital in Boston, Massachusetts. PARTICIPANTS: 47 patients enrolled, 15 in a training set, 32 in a test set. Age range 10 months to 82 years (median=50 years). MATERIALS AND METHODS: Subjects received CXR with subsequent TI within 4 hours of each other. CXR and TI were assessed in blinded random order. Presence of focal opacity (pneumonia) on CXR, the outcome parameter, was recorded. For TI, presence of area(s) of increased heat (pneumonia) was recorded. Fisher's exact test was used to assess the significance of the correlations of positive findings in the same anatomical region. RESULTS: With TI compared with the CXR (the outcome parameter), sensitivity was 80.0% (95% CIs 29.9% to 98.9%), specificity was 57.7% (95% CI 37.2% to 76.0%). Positive predictive value of TI was 26.7% (95% CI 8.9% to55.2%) and its negative predictive value was 93.8% (95% CI 67.7% to 99.7%). CONCLUSIONS: This feasibility study confirms proof of concept that chest TI is consistent with CXR in suggesting similarly localised focal pneumonia with high sensitivity and negative predictive value. Further investigation of TI as a point-of-care imaging modality is warranted.

ACR Appropriateness Criteria® Imaging of Mesenteric Ischemia.

Mesenteric ischemia is an uncommon condition resulting from decreased blood flow to the small or large bowel in an acute or chronic setting. Acute ischemia is associated with high rates of morbidity and mortality; however, it is difficult to diagnose clinically. Therefore, a high degree of suspicion and prompt imaging evaluation are necessary. Chronic mesenteric ischemia is less common and typically caused by atherosclerotic occlusion or severe stenosis of at least two of the main mesenteric vessels. While several imaging examination options are available for the initial evaluation of both acute and chronic mesenteric ischemia, CTA of the abdomen and pelvis is overall the most appropriate choice for both conditions. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Suspected Lower Extremity Deep Vein Thrombosis.

Suspected lower extremity deep venous thrombosis is a common clinical scenario which providers seek a reliable test to guide management. The importance of confidently making this diagnosis lies in the 50% to 60% risk of pulmonary embolism with untreated deep vein thrombosis and subsequent mortality of 25% to 30%, balanced with the risks of anticoagulation. The ACR Appropriateness Criteria Expert Panel on Vascular Imaging reviews the current literature regarding lower extremity deep venous thrombosis and compared various imaging modalities including ultrasound, MR venography, CT venography, and catheter venography. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Sudden Onset of Cold, Painful Leg.

Acute limb ischemia (ALI) requires urgent diagnosis and treatment to prevent limb loss. Invasive digital subtraction arteriography (DSA) is the gold standard for diagnosing ALI. DSA is the only diagnostic modality that permits simultaneous treatment of acute arterial occlusion. Noninvasive imaging with MRA or CT angiography may also be appropriate before treatment, especially when the diagnosis of ALI is in doubt or where DSA is unavailable. Other imaging and noninvasive physiologic tests may prove important for longer term management but are less recommended in the acute setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Penetrating Neck Injury.

In patients with penetrating neck injuries with clinical soft injury signs, and patients with hard signs of injury who do not require immediate surgery, CT angiography of the neck is the preferred imaging procedure to evaluate extent of injury. Other modalities, such as radiography and fluoroscopy, catheter-based angiography, ultrasound, and MR angiography have their place in the evaluation of the patient, depending on the specific clinical situation and question at hand. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Imaging of head trauma.

Imaging is an indispensable part of the initial assessment and subsequent management of patients with head trauma. Initially, it is important for diagnosing the extent of injury and the prompt recognition of treatable injuries to reduce mortality. Subsequently, imaging is useful in following the sequelae of trauma. In this chapter, we review indications for neuroimaging and typical computed tomography (CT) and magnetic resonance imaging (MRI) protocols used in the evaluation of a patient with head trauma. We review the role of CT), the imaging modality of choice in the acute setting, and the role of MRI in the evaluation of patients with head trauma. We describe an organized and consistent approach to the interpretation of imaging of these patients. Important topics in head trauma, including fundamental concepts related to skull fractures, intracranial hemorrhage, parenchymal injury, penetrating trauma, cerebrovascular injuries, and secondary effects of trauma, are reviewed. The chapter concludes with advanced neuroimaging techniques for the evaluation of traumatic brain injury, including use of diffusion tensor imaging (DTI), functional MRI (fMRI), and MR spectroscopy (MRS), techniques which are still under development.

Assessment of Pediatric Neurotrauma Imaging Appropriateness at a Level I Pediatric Trauma Center.

PURPOSE: The aim of this study was to assess the prevalence of appropriate neuroimaging on the basis of the ACR Appropriateness Criteria among pediatric patients presenting after head trauma to a level I emergency department. METHODS: A retrospective emergency department record review was performed for patients <18 years of age undergoing head CT or MRI for the indication "head trauma" between January 2013 and December 2014. Clinical history and symptoms were compared with the ACR Appropriateness Criteria; the indication was deemed appropriate for ratings of ≥7. Patients were analyzed by age, gender, presentation, imaging obtained, follow-up, treatment, and outcomes. RESULTS: Among 207 patients, 120 (58%) were imaged with CT and 107 (52%) with MRI; 20 patients underwent both CT and MRI. One hundred eighty-seven patients (90.3%) were appropriately imaged, with 90.0% of CT studies (108 of 120) deemed appropriate and 91.6% of MRI studies (98 of 107) deemed appropriate. Younger patients were more likely to be inappropriately imaged with CT or MRI than older patients (P = .02 and P < .01, respectively). Patients undergoing CT were older (mean age 9.9 ± 5.8 years) and more likely to be male (85.2%) than those undergoing MRI (5.6 ± 5.6 years and 55.1%, respectively) (P < .01 and P < .001, respectively). The diagnostic yield of positive imaging findings for intracranial trauma was significantly lower in the MRI group (P < .01), and patients undergoing MRI were significantly more likely to return to baseline with conservative management (P < .01). CONCLUSIONS: Most pediatric patients undergoing neuroimaging for head trauma did so appropriately per ACR guidelines and had symptom resolution with conservative management. The minority not imaged appropriately represent a target for quality improvement efforts.