"All-in-one" window/level whole-body computed tomography scan - A faster way to evaluate trauma cases.

PURPOSE: To investigate the accuracy and total assessment time (TAT) of the "All-in-one" (AIO)-window/level setting for whole-body computed tomography (CT) image compared to multiple tissue-specific window/level settings conventionally used for detection of traumatic injuries. METHOD: Contrast-enhanced chest, abdomen, and pelvic CT scans of 50 patients who presented to our emergency department (ED) for major trauma were retrospectively selected. In a simulation of a "wet read" performed at the CT scanner console, 6 readers with different levels of experience had up to 3 min to describe any traumatic finding identified on the CTs. The readers reviewed each patient in two different sessions separated by a washout period to suppress any recall bias from one session to the next. Each scan was reviewed once using the AIO-window/level setting and another time using the conventional bone, lung, and soft tissue window/level display settings, in a randomized order. The CT reports were used as reference standard. RESULTS: Overall, there was no statistically significant difference in the assessment accuracy of the review based on the AIO or the conventional window/level settings (0.89 ± 0.09 vs 0.90 ± 0.08). Using the AIO-window/level settings, TAT was 14.3 s faster when compared with the conventional window/level settings (2.33 ± 0.63 vs 2.57 ± 0.51 min; p < 0.001). CONCLUSIONS: In a time-delimited image review, similar diagnostic accuracy was reached faster using the AIO vs the conventional window/level settings. When providing a "wet read" at the CT console, the ability to identify traumatic injury using a single AIO-window/level may help expedite patient management.

Nivolumab-induced small bowel obstruction and perforation: a rare but life-threatening side effect of immunotherapy.

We present a case of a 58-year-old female with anti-PD-1 immunotherapy-related small bowel perforation. The patient was on long-term therapy with nivolumab for metastatic non-small cell lung cancer. She presented to the emergency department with acute abdominal pain, in which the CT revealed a short segment of dilated distal ileum proximal to a very short segment of bowel with mural thickening and a perforation near the transition point. The patient underwent subsequent laparotomy, which confirmed the CT findings and revealed a short-segment of friable and dilated loop of distal ileum proximal to a stricture and a small perforation at the transition point. Pathological analysis revealed mural thickening at the site of stricture without evidence of malignancy with focal necrosis and perforation at the transition point. Bowel perforation in the setting of anti-PD-1 immunotherapy is rare, but life-threatening complication, and should be considered in oncology patients on immunotherapy presenting with severe abdominal pain.

Nontraumatic Head and Neck Emergencies.

Head and neck imaging is an intimidating subject for many radiologists because of the complex anatomy and potentially serious consequences of delayed or improper diagnosis of the diverse abnormalities involving this region. The purpose of this article is to help radiologists to understand the intricate anatomy of the head and neck and to review the imaging appearances of a variety of nontraumatic head and neck conditions that bring patients to the emergency department, including acute infectious and inflammatory diseases and acute complications of head and neck neoplasms. These conditions are presented in five sections on the basis of their primary location of involvement: the oral cavity and pharynx, neck, sinonasal tract, orbits, and ears. Important anatomic landmarks are reviewed briefly in each related section.Online supplemental material is available for this article.©RSNA, 2019.

Spontaneous Retroperitoneal and Rectus Sheath Hemorrhage-Management, Risk Factors and Outcomes.

BACKGROUND: Spontaneous retroperitoneal and rectus sheath hemorrhage (SRRSH) is associated with high mortality in the literature, but studies on the subject are lacking. The objective of this study was to identify early predictors of the need for angiographic or surgical intervention (ASI) in patients with SRRSH and define risk factors for mortality. METHODS: We conducted a retrospective cohort study at a tertiary academic hospital. All patients with computed tomography-identified SRRSH between 2012 to 2017 were included. Exclusion criteria were age below 18 years, possible mechanical cause of SRRSH, aortic aneurysm rupture or dissection, and traumatic or iatrogenic sources of SRRSH. The primary outcome was the incidence of ASI and/or mortality. RESULTS: Of 100 patients included (median age 70 years, 52% males), 33% were transferred from another hospital, 82% patients were on therapeutic anticoagulation, and 90% had serious comorbidities. Overall mortality was 22%, but SRRSH-related mortality was only 6%. Sixteen patients underwent angiographic intervention (n = 10), surgical intervention (n = 5), or both (n = 1). Flank pain (OR 4.15, 95% CI 1.21-14.16, p = 0.023) and intravenous contrast extravasation (OR 3.89, 95% CI 1.23-12.27, p = 0.020) were independent predictors of ASI. Transfer from another hospital (OR 3.72, 95% CI 1.30-10.70, p = 0.015), age above 70 years (OR 4.24, 95% CI 1.25-14.32, p = 0.020), and systolic blood pressure below 110 mmHg at the time of diagnosis (OR 4.59, 95% CI 1.19-17.68, p = 0.027) were independent predictors of mortality. CONCLUSIONS: SRRSH is associated with high mortality but is typically not the direct cause. Most SRRSHs are self-limited and require no intervention. Pattern identification of ASI is hard.

CT in the Emergency Department: A Real-Time Study of Changes in Physician Decision Making.

PURPOSE: To determine how physicians' diagnoses, diagnostic uncertainty, and management decisions are affected by the results of computed tomography (CT) in emergency department settings. MATERIALS AND METHODS: This study was approved by the institutional review board and compliant with HIPAA. Data were collected between July 12, 2012, and January 13, 2014. The requirement to obtain patient consent was waived. In this prospective, four-center study, patients presenting to the emergency department who were referred for CT with abdominal pain, chest pain and/or dyspnea, or headache were identified. Physicians were surveyed before and after CT to determine the leading diagnosis, diagnostic confidence (on a scale of 0% to 100%), alternative "rule out" diagnosis, and management decisions. Primary measures were the proportion of patients for whom the leading diagnosis or admission decision changed and median changes in diagnostic confidence. Secondary measures addressed alternative diagnoses and return-to-care visits (eg, to emergency department) at 1-month follow-up. Regression analysis was used to identify associations between primary measures and site and participant characteristics. RESULTS: Both surveys were completed for 1280 patients by 245 physicians. The leading diagnosis changed in 235 of 460 patients with abdominal pain (51%), 163 of 387 with chest pain and/or dyspnea (42%), and 103 of 433 with headache (24%). Pre-CT diagnostic confidence was inversely associated with the likelihood of a diagnostic change (P < .0001). Median changes in confidence were substantial (increases of 25%, 20%, and 13%, respectively, for patients with abdominal pain, chest pain and/or dyspnea, and headache; P < .0001); median post-CT confidence was high (95% for all three groups). CT helped confirm or exclude at least 95% of alternative diagnoses. Admission decisions changed in 116 of 457 patients with abdominal pain (25%), 72 of 387 with chest pain and/or dyspnea (19%), and 81 of 426 with headache (19%). During follow-up, 70 of 450 patients with abdominal pain (15%), 53 of 387 with chest pain and/or dyspnea (14%), and 49 of 433 with headache (11%) returned for the same indication. In general, changes in leading diagnosis, diagnostic confidence, and admission decisions were not well explained with site or participant characteristics. CONCLUSION: Physicians' diagnoses and admission decisions changed frequently after CT, and diagnostic uncertainty was alleviated.

Blast Injuries: From Improvised Explosive Device Blasts to the Boston Marathon Bombing.

Although most trauma centers have experience with the imaging and management of gunshot wounds, in most regions blast wounds such as the ones encountered in terrorist attacks with the use of improvised explosive devices (IEDs) are infrequently encountered outside the battlefield. As global terrorism becomes a greater concern, it is important that radiologists, particularly those working in urban trauma centers, be aware of the mechanisms of injury and the spectrum of primary, secondary, tertiary, and quaternary blast injury patterns. Primary blast injuries are caused by barotrauma from the initial increased pressure of the explosive detonation and the rarefaction of the atmosphere immediately afterward. Secondary blast injuries are caused by debris carried by the blast wind and most often result in penetrating trauma from small shrapnel. Tertiary blast injuries are caused by the physical displacement of the victim and the wide variety of blunt or penetrating trauma sustained as a result of the patient impacting immovable objects such as surrounding cars, walls, or fences. Quaternary blast injuries include all other injuries, such as burns, crush injuries, and inhalational injuries. Radiography is considered the initial imaging modality for assessment of shrapnel and fractures. Computed tomography is the optimal test to assess penetrating chest, abdominal, and head trauma. The mechanism of blast injuries and the imaging experience of the victims of the Boston Marathon bombing are detailed, as well as musculoskeletal, neurologic, gastrointestinal, and pulmonary injury patterns from blast injuries.

Review of Ingested and Aspirated Foreign Bodies in Children and Their Clinical Significance for Radiologists.

Ingested and aspirated foreign bodies are a common occurrence in children and are important causes of morbidity and mortality in the pediatric population. Imaging plays an important role in the diagnosis of ingested and aspirated foreign bodies in children and can be crucial to guiding the clinical management of these patients. Prompt identification and localization of ingested foreign bodies is essential to determining the appropriate treatment, as several types of commonly ingested foreign bodies require urgent removal and others can be managed conservatively. In particular, disk batteries impacted in the esophagus carry a high risk of esophageal injury or perforation; multiple ingested magnets can become attracted to each other across bowel walls and cause bowel perforation and fistula formation; and sharp objects commonly cause complications as they pass through the gastrointestinal tract. Accordingly, these ingested foreign bodies warrant aggressive clinical management and therefore radiologists must be familiar with their imaging appearances and clinical implications. Prompt recognition of secondary radiographic signs of foreign-body aspiration is also crucial, as clinical symptoms can sometimes be nonspecific and most aspirated foreign bodies are radiolucent. Overall, radiography is the most important modality in the evaluation of ingested or aspirated foreign bodies; however, fluoroscopy and computed tomography play an ancillary role in complicated cases. It is essential that every radiologist who interprets imaging examinations of children be aware of the imaging appearances of commonly ingested and aspirated foreign bodies and their clinical significance.

Acetabular fractures: what radiologists should know and how 3D CT can aid classification.

Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article.

Additional Imaging in Alert Trauma Patients with Cervical Spine Tenderness and a Negative Computed Tomographic Scan: Is it Needed?

BACKGROUND: The value of additional imaging in clearing the cervical spine (C-spine) of alert trauma patients with tenderness on clinical exam and a negative computed tomographic (CT) scan is still unclear. METHODS: All adult trauma patients with a Glasgow Coma Scale of 15, C-spine tenderness in the absence of neurologic signs, and a negative C-spine CT were included. The study period extended from September 2011 to June 2012. C-spine CT scans were interpreted in detail and considered negative in the absence of any findings indicating bony, ligamentous, or soft tissue injury around the C-spine. The incidence of C-spine injury was evaluated using early (<24 h) repeat physical examination, MRI, and/or flexion-extension films. RESULTS: Of 2015 patients with a C-spine CT, 383 (19 %) fulfilled the inclusion criteria. The median age was 43 (IQR: 30-53) and 44.7 % were female. Thirty-six patients (9.4 %) underwent MRI (3.7 %), flexion-extension imaging (5.2 %), or both (0.5 %), with no significant injuries identified and subsequent removal of the collar allowed. The remaining patients were clinically cleared within 24 h of presentation. None of the patients developed neurological signs following removal of the collar. On bivariate analysis, no variable except for evaluation by trauma surgery was associated with performance of additional imaging. CONCLUSION: C-spine precautions can be withdrawn without additional imaging in most blunt trauma patients with C-spine tenderness but negative neurologic evaluation and C-spine CT. Focus should be placed on the detailed and comprehensive interpretation of the C-spine CT.

Imaging for appendicitis: should radiation-induced cancer risks affect modality selection?

PURPOSE: To compare life expectancy (LE) losses attributable to three imaging strategies for appendicitis in adults-computed tomography (CT), ultrasonography (US) followed by CT for negative or indeterminate US results, and magnetic resonance (MR) imaging-by using a decision-analytic model. MATERIALS AND METHODS: In this model, for each imaging strategy, LE losses for 20-, 40-, and 65-year-old men and women were computed as a function of five key variables: baseline cohort LE, test performance, surgical mortality, risk of death from delayed diagnosis (missed appendicitis), and LE loss attributable to radiation-induced cancer death. Appendicitis prevalence, test performance, mortality rates from surgery and missed appendicitis, and radiation doses from CT were elicited from the published literature and institutional data. LE loss attributable to radiation exposure was projected by using a separate organ-specific model that accounted for anatomic coverage during a typical abdominopelvic CT examination. One- and two-way sensitivity analyses were performed to evaluate effects of model input variability on results. RESULTS: Outcomes across imaging strategies differed minimally-for example, for 20-year-old men, corresponding LE losses were 5.8 days (MR imaging), 6.8 days (combined US and CT), and 8.2 days (CT). This order was sensitive to differences in test performance but was insensitive to variation in radiation-induced cancer deaths. For example, in the same cohort, MR imaging sensitivity had to be 91% at minimum (if specificity were 100%), and MR imaging specificity had to be 62% at minimum (if sensitivity were 100%) to incur the least LE loss. Conversely, LE loss attributable to radiation exposure would need to decrease by 74-fold for combined US and CT, instead of MR imaging, to incur the least LE loss. CONCLUSION: The specific imaging strategy used to diagnose appendicitis minimally affects outcomes. Paradigm shifts to MR imaging owing to concerns over radiation should be considered only if MR imaging test performance is very high.

High attenuation pericardial fluid on CT following cardiac catheterization.

High-density pericardial fluid may be seen on noncontrast CT performed following cardiac catheterization (CC), raising the possibility of hemopericardium. Our goal was to determine the clinical course and associations of incidentally discovered high-attenuation pericardial fluid on noncontrast CT performed soon after CC. Hospital database search over a 7.5-year period identified 211 patients who underwent CT of the chest and/or abdomen within 60 h before or after CC, 150 having CC first. Pericardial fluid volume and attenuation as well as relevant laboratory and clinical parameters were recorded. Bivariate associations with average pericardial fluid attenuation (HUavg) were assessed. Using the 61 patients with CT before CC as controls, 44 of the patients with CC first had attenuation values greater than the mean + 2SD of 22.6 Hounsfield unit (HU) and 19 had attenuation values greater than the maximum control patient value of 39.8 HU. All patients with incidental finding of high-density pericardial fluid followed a benign course. Bivariate correlations showed time gap between CC and CT (rho = -0.50, p < 0.001), estimated glomerular filtration rate (eGFR) (rho = -0.24, p = 0.004), and female gender (median (IQR) 17.4 (13.6, 29.6) vs. 15.8 (9.9, 23.7), p = 0.02) to be associated with HUavg. In multiple linear regression analysis, only time gap and female gender were independently significantly associated with average attenuation (both p < 0.001). The finding that patients with incidentally discovered high-density pericardial fluid followed an uneventful course suggests a benign etiology such as vicarious excretion, and in patients who are otherwise stable, observation rather than immediate intervention should be considered.

The role of emergency MRI in the setting of acute abdominal pain.

Abdominal pain is one of the most common reasons for patients to present to the emergency department (ED) in the USA, with an estimated seven million visits in 2007-2008, a figure which represents 8 % (±0.2 %) [2] of all ED visits and a 31.8 % increase from 1999-2000. Abdominal pain has a broad differential diagnosis that encompasses multiple organ systems and can provide a significant diagnostic challenge to the ED physician. Although magnetic resonance imaging (MRI) currently plays a limited role in the assessment of abdominal pain presenting to the ED in the nongravid population, its utility in the pregnant and pediatric population has already been proven. A proven diagnostic track record, lack of ionizing radiation and the ability to provide excellent tissue contrast without the use of nephrotoxic iodinated contrast, makes MRI an attractive imaging modality. As physicians and patients become more aware of the potential risks associated with exposure to ionizing radiation, ED MRI utilization is likely to increase. In this article, we discuss the MRI appearance of some of the most common diagnoses, which present as abdominal pain to the ED.

Acute respiratory distress syndrome after spontaneous intracerebral hemorrhage*.

OBJECTIVES: Acute respiratory distress syndrome develops commonly in critically ill patients in response to an injurious stimulus. The prevalence and risk factors for development of acute respiratory distress syndrome after spontaneous intracerebral hemorrhage have not been reported. We sought to determine the prevalence of acute respiratory distress syndrome after intracerebral hemorrhage, characterize risk factors for its development, and assess its impact on patient outcomes. DESIGN: Retrospective cohort study at two academic centers. PATIENTS: We included consecutive patients presenting from June 1, 2000, to November 1, 2010, with intracerebral hemorrhage requiring mechanical ventilation. We excluded patients with age less than 18 years, intracerebral hemorrhage secondary to trauma, tumor, ischemic stroke, or structural lesion; if they required intubation only during surgery; if they were admitted for comfort measures; or for a history of immunodeficiency. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were collected both prospectively as part of an ongoing cohort study and by retrospective chart review. Of 1,665 patients identified by database query, 697 met inclusion criteria. The prevalence of acute respiratory distress syndrome was 27%. In unadjusted analysis, high tidal volume ventilation was associated with an increased risk of acute respiratory distress syndrome (hazard ratio, 1.79 [95% CI, 1.13-2.83]), as were male sex, RBC and plasma transfusion, higher fluid balance, obesity, hypoxemia, acidosis, tobacco use, emergent hematoma evacuation, and vasopressor dependence. In multivariable modeling, high tidal volume ventilation was the strongest risk factor for acute respiratory distress syndrome development (hazard ratio, 1.74 [95% CI, 1.08-2.81]) and for inhospital mortality (hazard ratio, 2.52 [95% CI, 1.46-4.34]). CONCLUSIONS: Development of acute respiratory distress syndrome is common after intubation for intracerebral hemorrhage. Modifiable risk factors, including high tidal volume ventilation, are associated with its development and in-patient mortality.

Journal club: How radiation exposure histories influence physician imaging decisions: a multicenter radiologist survey study.

OBJECTIVE: The purpose of this article is to evaluate the influence of patient radiation exposure histories on radiologists' imaging decisions. MATERIALS AND METHODS: We conducted a physician survey study in three academic medical centers. Radiologists were asked to make an imaging recommendation for a hypothetical patient with a history of multiple CT scans. We queried radiologists' decision making, evaluating whether they incorporated cancer risks from previous imaging, reported acceptance (or rejection) of the linear no-threshold model, and understood linear no-threshold model implications in this setting. Consistency between radiologists' decisions and their linear no-threshold model beliefs was evaluated; those acting in accordance with the linear no-threshold model were expected to disregard previously incurred cancer risks. A Fisher exact test was used to verify the generalizability of results across institutions and training levels (residents, fellows, and attending physicians). RESULTS: Fifty-six percent (322/578) of radiologists completed the survey. Most (92% [295/322]) incorporated risks from the patient's exposure history during decision making. Most (61% [196/322]) also reported acceptance of the linear no-threshold model. Fewer (25% [79/322]) rejected the linear no-threshold model; 15% (47/322) could not judge. Among radiologists reporting linear no-threshold model acceptance or rejection, the minority (36% [98/275]) made decisions that were consistent with their linear no-threshold model beliefs. This finding was not statistically different across institutions (p = 0.070) or training levels (p = 0.183). Few radiologists (4% [13/322]) had an accurate understanding of linear no-threshold model implications. CONCLUSION: Most radiologists, when faced with patient exposure histories, make decisions that contradict their self-reported acceptance of the linear no-threshold model and the linear no-threshold model itself. These findings underscore a need for educational initiatives.

Imaging of penile and scrotal emergencies.

Penile and scrotal emergencies are uncommon, but when they do occur, urgent or emergent diagnosis and treatment are necessary. Emergent conditions of the male genitalia are primarily infectious, traumatic, or vascular. Infectious conditions, such as epididymitis and epididymo-orchitis, are well evaluated at ultrasonography (US), and their key findings include heterogeneity and hyperemia. Pyocele and abscess may also be seen at US. Fournier gangrene is best evaluated at computed tomography, which depicts subcutaneous gas. Vascular conditions, such as testicular torsion, infarction, penile Mondor disease, and priapism, are well evaluated at duplex Doppler US. The key imaging finding of testicular torsion and infarction is a lack of blood flow in the testicle or a portion of the testicle. Penile Mondor disease is characterized by a lack of flow to and noncompressibility of the superficial dorsal vein of the penis. Clinical examination and history are usually adequate for diagnosis of priapism, but Doppler US may help confirm the diagnosis. Traumatic injuries of the penis and scrotum are initially imaged with US, which depicts whether the penile corpora and testicular seminiferous tubules are contained by the tunicae albuginea; herniation of contents and discontinuity of the tunica albuginea indicate rupture. In some cases, magnetic resonance imaging may be performed because of its ability to directly depict discontinuity of the tunica albuginea. Radiologists must closely collaborate with emergency physicians, surgeons, and urologists to quickly and efficiently diagnose or rule out emergent conditions of the male genitalia to facilitate prompt and appropriate treatment.

Incidental findings in trauma patients: dedicated communication with the primary care physician ensures adequate follow-up.

BACKGROUND: Frequent use of computed tomography (CT) in trauma patients results in frequent detection of non-trauma-related incidental findings (IFs). Inpatient documentation and disclosure at discharge are infrequent, even when they are potentially serious. We aimed to not only identify the incidence of IFs but also to evaluate the effectiveness of an intervention to trigger follow-up. METHODS: In this before-after study, all trauma patients evaluated by the trauma surgery service who underwent CT were admitted for >24 h, had at least one IF requiring follow-up, and had a primary care physician (PCP) employed in our health care system were identified. The historical control period was from January 2006 to December 2008. The intervention period was from December 2011 to September 2012. Intervention consisted of notifying the PCP via email or postal letter. The outcome of interest-the rate of follow-up-was compared between both groups. RESULTS: During the historical period, 364 (20.5 %) of 1,774 eligible trauma patients had 434 IFs requiring follow-up. During the study period, 197 (26 %) of 692 trauma patients had 212 IFs requiring follow-up. Overall, 91 % of study patients with postdischarge PCP follow-up had documented follow-up of the IF. There was a significant improvement in the rate of follow-up in the study group compared to that of the control group (51 vs. 11 %; p < 0.0001). CONCLUSIONS: Detection of IFs is common in trauma patients. A dedicated effort of communicating the presence of an IF to the patient's PCP triggered a follow-up for 91 % of patients who saw their PCP after hospital discharge.