Examining the Definition of Ventilator-Associated Pneumonia in the Trauma Setting: A Single-Center Analysis.

Background: Ventilator associated pneumonia (VAP) is defined by the American College of Surgeons Trauma Quality Improvement Program (ACS TQIP) using laboratory findings, pathophysiologic signs/symptoms, and imaging criteria. However, many critically ill trauma patients meet the non-specific laboratory and sign/symptom thresholds for VAP, so the TQIP designation of VAP depends heavily upon imaging evidence. We hypothesized that physician opinions widely vary regarding chest radiograph findings significant for VAP. Patients and Methods: The TQIP Spring 2021 Benchmark Report (BR) was used to identify 14 patients with VAP at an academic Level 1 Trauma Center. Critically ill trauma patients (n = 7) who spent at least four days intubated and met TQIP's laboratory and sign/symptom thresholds for VAP but did not appear as VAPs on the BR comprised the control group. For each deidentified patient, four successive chest radiographic images were compiled and arranged chronologically. Cases and controls were randomly arranged in digital format. Blinded physicians (n = 27) were asked to identify patients with VAP based solely on imaging evidence. Results: Radiographic evidence of VAP was highly subjective (Krippendorff α = 0.134). Among physicians of the same job description, inter-rater reliability remained low (α = 0.137 for trauma attending physicians; α = 0.141 for trauma fellows; α = 0.271 for radiologists). When majority judgment was compared to the TQIP BR, there was disagreement between the two tests (Cohen κ = -0.071; sensitivity, 64.3%; specificity, 28.6%). Conclusions: Current definitions of VAP rely on subjective imaging interpretation and ignore the reality that there are numerous explanations for opacities on CXR. The inconsistency of physicians' imaging interpretation and protean physiologic findings for VAP in trauma patients should preclude the current definition of VAP from being used as a quality improvement metric in TQIP.

Illuminating the Use of Trauma Whole-Body CT Scan During the Global Contrast Shortage.

BACKGROUND: Use of whole-body CT scan (WBCT) is widespread in the evaluation of traumatically injured patients and may be associated with improved survival. WBCT protocols include the use of IV contrast unless there is a contraindication. This study tests the hypothesis that using plain WBCT scan during the global contrast shortage would result in greater need for repeat contrast-enhanced CT, but would not impact mortality, missed injuries, or rates of acute kidney injury (AKI). STUDY DESIGN: All trauma encounters at an academic level-I trauma center between March 1, 2022 and June 24, 2022, excluding burns and prehospital cardiac arrests, were reviewed. Imaging practices and outcomes before and during contrast shortage (beginning May 3, 2022) were compared. RESULTS: The study population included 1,109 consecutive patients (72% male), with 890 (80%) blunt and 219 (20%) penetrating traumas. Overall, 53% of patients underwent WBCT and contrast was administered to 73%. The overall rate of AKI was 6% and the rate of renal replacement therapy (RRT) was 1%. Contrast usage in WBCT was 99% before and 40% during the shortage (p < 0.001). There was no difference in the rate of repeat CT scans, missed injuries, AKI, RRT, or mortality. CONCLUSIONS: Trauma imaging practices at our center changed during the global contrast shortage; the use of contrast decreased despite the frequency of trauma WBCT scans remaining the same. The rates of AKI and RRT did not change, suggesting that WBCT with contrast is insufficient to cause AKI. The missed injury rate was equivalent. Our data suggest similar outcomes can be achieved with selective IV contrast use during WBCT.

Thoracic Epidural Analgesia Use in Large Recurrent Desmoid Fibromatosis Resection: A Case Report.

We present a case report of the successful use of thoracic epidural analgesia for the surgical resection of a large recurrent desmoid tumor and forequarter amputation in an adolescent male. Spinal anesthesia has been reported for intra-operative management of desmoid tumor resection, however, there are no reported cases of thoracic epidural analgesia for this tumor. Thoracic epidural should be used with caution in this patient population due to risk of de novo tumor creation but can be useful adjuvant to multi-modal analgesia to decrease post-operative opioid requirement.

Evaluation of penetrating abdominal and pelvic trauma.

Penetrating abdominal trauma comprises a wide variety of injuries that will manifest themselves at imaging depending on the distinct mechanism of injury. The use of computed tomography (CT) for hemodynamically stable victims of penetrating torso trauma continues to increase in clinical practice allowing more patients to undergo initial selective non-surgical management. High diagnostic accuracy in this setting helps patients avoid unnecessary surgical intervention and ultimately reduce morbidity, mortality and associated medical costs. This review will present the evidence and the controversies surrounding the imaging of patients with penetrating abdominopelvic injuries. Available protocols, current MDCT technique controversies, organ-specific injuries, and key MDCT findings requiring intervention in patients with penetrating abdominal and pelvic trauma are presented. In the hemodynamically stable patient, the radiologist will play a key role in the triage of these patients to operative or nonoperative management.

Imaging evaluation of diaphragmatic injuries: Improving interpretation accuracy.

Diaphragmatic Injuries (DIs) remain a challenging diagnosis with potential catastrophic delayed complications. A high degree of suspicion in every case of severe blunt thoracoabdominal trauma or penetrating thoracoabdominal injury is essential. This review will present the evidence and controversies on this topic providing a practical tutorial for radiologists hoping to improve their interpretive accuracy for both blunt and penetrating DIs. The imaging signs of diaphragmatic injuries will be explained with emphasis on multidetector CT. Diagnostic pitfalls, available protocols and other issues will be presented.

Accessory pancreatic lobe in association with a gastric duplication cyst.

Gastric duplication cysts are an extremely rare anomaly with few reported cases in association with accessory pancreatic tissue. Diagnosis can be challenging given a presentation of recurrent pancreatitis and resemblance to pancreatic pseudocysts. We report the case of a 6-year old boy with multiple episodes of pancreatitis who was discovered to have an accessory pancreatic lobe connected to a gastric duplication cyst, successfully treated with surgical excision.

CT pulmonary angiogram quality comparison between early and later pregnancy.

PURPOSE: Pregnancy increases the risk for thromboembolic disease. CT pulmonary angiogram (CTPA) is widely used for the diagnosis of pulmonary embolus (PE); however, a significant number of scans are suboptimal or non-diagnostic in pregnant patients. This phenomenon is attributed to physiology during the gravid state. The aim of this study is to examine whether all stages of pregnancy are similarly at risk for suboptimal scans. METHODS: Pregnant patients who had CTPA scans between February 2008 and November 2014 were included. The attenuation in the major pulmonary arteries was compared among patients and controls. An attenuation of 200 Hounsfield units (HU) was used as a cutoff between adequate and suboptimal studies. Statistical analysis compared attenuation means and number of arteries with adequate versus suboptimal attenuation. RESULTS: Forty patients were included in the study. Nine were at or below 13 weeks of pregnancy and 31 between week 14 and term. A control group of 14 non-pregnant women of similar age were also included. All arteries showed a significantly higher attenuation in early pregnancy and in the control group compared to later in pregnancy, p < 0.05. Fewer suboptimal opacified arteries were found in early pregnancy (11.1%) and controls (5.7%) compared to later in pregnancy (33.3%), p < 0.01. CONCLUSION: Patients in early pregnancy are more likely to have a technically successful CTPA scan compared to later in pregnancy and show similar opacification to non-pregnant women. This suggests a possible paradigm shift from the current approach to suspected PE in pregnant patients.

Occult Lung Cancer Occluding a Pulmonary Vein with Suspected Venous Infarction, Mimicking Pneumonia and a Pulmonary Embolus.

BACKGROUND: Patients with lung cancer present to the emergency department (ED) in a variety of ways. Symptoms are often nonspecific and can lead to a delay in diagnosis. Here, a lung cancer mimicked two illnesses, adding to the diagnostic complexity. This case highlights diagnostic pitfalls as well as advantages and limitations of imaging utilized in the emergency setting. CASE REPORT: We report a case of an occult lung cancer occluding a pulmonary vein, which at first mimicked pneumonia and later a pulmonary embolism (PE) and arterial lung infarction. The patient presented to the ED with cough and a lung opacity on chest radiograph that was treated with antibiotics. However, recurrent visits to the ED with similar complaints were further investigated with computed tomography angiogram (CTA). At first the scan was considered positive for PE. Further inspection revealed that the CTA findings were not typical for PE, but rather a slow flow state likely caused by an occult mass occluding a pulmonary vein with venous infarction. Biopsy revealed a lung adenocarcinoma. In addition to the case presentation, the typical signs of PE on CTA with correlating images and diagnostic pitfalls are discussed. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report raises two themes that can be of interest to emergency physicians. The first is that lung cancer has many guises. Here it mimicked two distinctly different diseases, pneumonia and PE. The second is that, although CTA is highly sensitive and specific for diagnosing PE, it has limitations that may lead to false positive readings. When clinical signs and symptoms fail to correlate with the imaging diagnosis, alternative explanations should be sought.

Cardiac Physiology for Radiologists: Review of Relevant Physiology for Interpretation of Cardiac MR Imaging and CT.

Cardiac computed tomography (CT) and magnetic resonance (MR) imaging provide clinicians with important insights into cardiac physiology and pathology. However, not all radiologists understand the language and concepts of cardiac physiology that are used daily by cardiologists. This review article covers basic cardiac physiology as it relates to cardiac CT and MR imaging. Topics include a review of the cardiac cycle and left ventricular pressure-volume loops as they relate to different pathologic states, evaluation of cardiac function, and calculation of key parameters such as left ventricular volumes and the ejection fraction. The hemodynamics of cardiac shunts are covered, with an emphasis on factors important to cardiologists, including the ratio of pulmonary flow to systemic flow. Additionally, valvular physiologic function is reexamined, with a focus on understanding pressure gradients within the heart and also the changes associated with valvular pathologic conditions, including measurement of regurgitant fractions in patients with valvular insufficiency. Understanding these basic concepts will help radiologists tailor the reporting of cardiac studies to clinically relevant information.

Imaging of foreign bodies in prisoners.

Foreign body ingestion or insertion is occasionally encountered by radiologists and is associated with significant morbidity, financial burden, and potential mortality. Incarcerated individuals are a unique group where foreign body ingestion or insertion is more common than the general population. Motivations include reprieve from the confines of prison, sexual stimulation or victimization, or may be secondary to compulsions in patients with psychiatric disorders. These foreign bodies may lead to perforation, obstruction, or infection. Radiologists can help clinicians identify unexpected ingested or inserted objects as well as the sequelae of foreign body ingestion or insertion.

Fractures of the pediatric zygoma: a review of the clinical trends, management strategies, and outcomes associated with zygomatic fractures in children.

Fractures of the pediatric zygoma are uncommon and are often associated with high-impact trauma, as evidenced by the relatively increased prevalence of concomitant injuries observed in these patients. Despite advances in the prevention, diagnosis, and management of pediatric craniofacial injuries, data regarding zygomatic fractures in children remain poorly established. The diagnosis of zygomatic disruption is more difficult in children and requires the maintenance of a high index of suspicion on behalf of the surgeon. Early recognition and implementation of appropriate therapy are critical and depend on the acquisition of a thorough history and physical examination as well as the accurate interpretation of computed tomographic imaging. Options for management depend on fracture severity and can range from observation or closed reduction in nondisplaced or only minimally displaced fractures, to open reduction and internal fixation in fractures that are comminuted or severely displaced. Currently, there is a lack of level I evidence evaluating the long-term consequences associated with pediatric zygomatic fractures and their management. A review of the epidemiology, clinical characteristics, diagnosis, and management of pediatric zygomatic fractures is essential for optimizing function and aesthetic outcomes in children who sustain these injuries.

Penetrating diaphragmatic injury: accuracy of 64-section multidetector CT with trajectography.

PURPOSE: To (a) determine the diagnostic performance of 64-section multidetector computed tomography (CT) trajectography for penetrating diaphragmatic injury (PDI), (b) determine the diagnostic performance of classic signs of diaphragmatic injury at 64-section multidetector CT, and (c) compare the performance of these signs with that of trajectography. MATERIALS AND METHODS: This HIPAA-compliant retrospective study had institutional review board approval, with a waiver of the informed consent requirement. All patients who had experienced penetrating thoracoabdominal trauma, who had undergone preoperative 64-section multidetector CT of the chest and abdomen, and who had surgical confirmation of findings during a 2.5-year period were included in this study (25 male patients, two female patients; mean age, 32.6 years). After a training session, four trauma radiologists unaware of the surgical outcome independently reviewed all CT studies and scored the probability of PDI on a six-point scale. Collar sign, dependent viscera sign, herniation, contiguous injury on both sides of the diaphragm, discontinuous diaphragm sign, and transdiaphragmatic trajectory were evaluated for sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). Accuracies were determined and receiver operating characteristic curves were analyzed. RESULTS: Sensitivities for detection of PDI by using 64-section multidetector CT with postprocessing software ranged from 73% to 100%, specificities ranged from 50% to 92%, NPVs ranged from 71% to 100%, PPVs ranged from 68% to 92%, and accuracies ranged from 70% to 89%. Discontinuous diaphragm, herniation, collar, and dependent viscera signs were highly specific (92%-100%) but nonsensitive (0%-60%). Contiguous injury was generally more sensitive (80%-93% vs 73%-100%) but less specific (50%-67% vs 83%-92%) than transdiaphragmatic trajectory when patients with multiple entry wounds were included in the analysis. Transdiaphragmatic trajectory was a much more sensitive sign of PDI than previously reported (73%-100% vs 36%), with NPVs ranging from 71% to 100% and PPVs ranging from 85% to 92%. CONCLUSION: Sixty-four-section multidetector CT trajectography facilitates the identification of transdiaphragmatic trajectory, which accurately rules in PDI when identified. Contiguous injury remains a highly sensitive sign, even when patients with multiple injuries are considered, and is useful for excluding PDI.

Magnetic resonance imaging finding of empty sella in obesity related idiopathic intracranial hypertension is associated with enlarged sella turcica.

INTRODUCTION: Empty sella in MRI is an important finding associated with idiopathic intracranial hypertension (IIH). This study assesses the sensitivity and reproducibility of several morphological measures of the sella and pituitary gland to indentify the measure that best differentiates IIH from controls. Additionally, the study assesses reversal in gland compression following treatment. METHODS: Sagittal 3D-T1W sequence with 1 mm isotropic resolution was obtained from ten newly diagnosed IIH patients and 11 matched healthy controls. Follow-up MRI scans were obtained from eight patients at 1-week post-lumbar puncture and acetazolamide treatment. 1D and 2D measures of absolute and normalized heights and cross-sectional areas of the gland and sella were obtained to identify the measure that best differentiates IIH patients and controls. RESULTS: Overall area-based measurements had higher sensitivity than length with p < 0.0001 for sella area compared with p = 0.004 for normalized gland height. The gland cross-sectional areas were similar in both cohorts (p = 0.557), while the sella area was significantly larger in IIH, 200 ± 24 versus 124 ± 25 mm(2), with the highest sensitivity and specificity, 100% and 90.9%, respectively. Absolute gland area was the most sensitive measure for assessing post treatment changes, with 100% sensitivity and 50 % specificity. Average post-treatment gland area was 18% larger (p = 0.016). Yet, all eight patients remained within the empty sella range based on a normalized gland area threshold of 0.41. CONCLUSIONS: Sellar area is larger in IIH, and it demonstrated highest sensitivity for differentiating IIH from control subjects, while absolute gland area was more sensitive for detecting post treatment changes.

Describing congenital heart disease by using three-part segmental notation.

The segmental classification of congenital heart disease, first conceptualized nearly 50 years ago, is now well established. The Van Praagh classification system, in particular, is commonly used throughout North America to facilitate communication between physicians from various specialties who are involved in diagnosing and managing congenital cardiovascular abnormalities. In the Van Praagh system, a three-part notation consisting of letters separated by commas and encompassed by a set of braces is used to succinctly describe the visceroatrial situs, the orientation of the ventricular loop, and the position and relation of the great vessels. For example, the notation "{S, D, S}" describes the normal anatomic configuration, in which the morphologic right atrium and largest hepatic lobe are on the patient's right side and the morphologic left atrium, stomach, and spleen are on the left side (situs solitus); the ventricular loop is curved rightward (dextro- or d-loop); and the aorta is posterior to and rightward of the main pulmonary artery (situs solitus). Because the Van Praagh notation imposes on its users a systematic approach to anatomic description, it is a helpful device for structuring the interpretation of imaging studies as well as the reporting of results: First, the morphologic right and left atria and ventricles must be identified; next, the visceroatrial situs and ventricular loop orientation may be determined from the positions of the cardiac chambers; and last, the position and relation of the great vessels (normal, inverted, transposed, or malpositioned) can be established. The article provides concise, step-by-step guidance for applying the Van Praagh system in the radiology reading room.

Multidetector row computed tomography in the management of penetrating neck injuries.

Penetrating neck trauma may occur from gun shots, stabbings, and accidental injury. Approximately 50% of gunshot and 10%-20% of stab-wound patients are reported as having severe injuries and the mortality from severe vascular injuries is reported as high as 50%. Penetrating traumatic neck injury is no longer best managed with exploratory surgery or conventional angiography in the stable patient. Computed tomography angiography has proven to be a useful, safe, and reliable means of diagnosis. Experience with interpreting and reconstructing computed tomography images, understanding the clinically important findings, and avoiding pitfalls is critical for successful patient care. Therefore, radiologists and clinicians who treat trauma patients need to familiarize themselves with the computed tomography angiography technique and appearances of vascular injury and know when to recommend further evaluation, such as interventional angiography or open surgery.

Screening multidetector computed tomography angiography in the evaluation on blunt neck injuries: an evidence-based approach.

Blunt cerebrovascular injuries (BCVI) can cause ischemic stroke and are associated with high mortality rates. These injuries may have an initial silent course and if recognized in a timely fashion can be treated before neurologic deficit occurs. This has led to the growing implementation of aggressive screening programs to detect and thereby treat BCVI early, before onset of symptoms. Digital subtraction angiography is the diagnostic reference standard for diagnosing BCVI. However, in recent years, there has been a renewed interest in the use of noninvasive techniques, such as multidetector computed tomography angiography (MDCTA) for the evaluation of these patients. The accuracy of MDCTA with respect to digital subtraction angiography is not completely elucidated; however, MDCTA shows a level of accuracy sufficient to serve as an initial screening examination for blunt cerebrovascular injuries.

Characterization of a thromboembolic photochemical model of repeated stroke in mice.

Many stroke research groups utilize the model of middle cerebral artery occlusion induced by insertion of an intraluminal thread, owing to its pragmatism and reliability of cerebral infarct generation. However, 75% of stroke cases result from a thromboembolic event and 10% from occlusive atherothrombosis in situ. Here, we characterize a mouse model of repeated thromboembolic stroke, which closely mimics the intravascular pathophysiology of arterial thrombus generation from an atherosclerotic plaque, and subsequent release of a thrombus into the cerebral circulation as an embolus. Common carotid artery thrombosis (CCAT) was induced photochemically leading to non-occlusive platelet aggregation in C57/BL6 male mice (n=35), and was followed by mechanical assistance to facilitate release of the thrombus (MRT) and thus promote embolism. Six experimental groups, differing by changes in the surgical protocol, were used for the purpose of determining which such procedure yielded the most reliable and consistent brain infarct volumes with the lowest mortality at 3 days after surgery. The group which best satisfied these conditions was a double insult group which consisted of animals that underwent CCAT for 2 min by means of argon laser irradiation (514.5 nm) at an intensity of ca. 130 W/cm(2), with concomitant injection of erythrosin B (EB) (35 mg/kg infused over those same 2 min), followed by MRT 1 min later; the entire procedure was repeated 24h later. This group showed a percent of brain lesion volume of 15+/-4% (mean+/-S.D.) with no associated 3-day mortality. Compared to a single insult group which sustained a percent brain lesion volume of 7+/-3%, there was a statistically significant (p<0.05) increase in the volume of infarction in the double-insult group.

The beneficial effect of mild hypothermia in a rat model of repeated thromboembolic insults.

The post-thrombotic brain has recently been reported to have an enhanced vulnerability to a second embolic insult. Although postischemic hypothermia is neuroprotective in global and focal ischemia models, the effect of mild hypothermia on outcome after thromboembolic insults has not been evaluated. This study therefore determined whether brain hypothermia (33 degrees C) was neuroprotective against repeated thromboembolic insults. Photochemically induced non-occlusive common carotid artery thrombosis (CCAT) leading to platelet embolization to the brain was induced in anesthetized rats ( n=35). Thirty minutes after CCAT, brain temperature was maintained at normothermic (37 degrees C) or hypothermic (33 degrees C) levels for 4 h followed by a slow rewarming period (1.5 h). Three days later, rats underwent a secondary CCAT insult under normothermic conditions and were allowed to survive for an additional 3 days prior to perfusion fixation and quantitative histopathological assessment. Compared to normothermic animals, mild hypothermia after the first embolic insult produced a significant reduction ( P>0.05) in overall infarct volume. Hypothermia reduced total infarct volume from 7.55+/-2.32 mm(3) (mean +/- SEM) in normothermic rats to 2.56+/-0.88 mm(3) in hypothermic animals undergoing repeated insults. Histopathological analysis also demonstrated less evidence for focal hemorrhage in the cooled groups. These data demonstrate that mild hypothermia is protective in a thromboembolic stroke model. In addition, post-thrombotic hypothermia decreases the histopathological vulnerability of the post-thrombotic brain to secondary embolic insults. These findings may be important in the prevention of stroke in patients at risk.