Admission Computed Tomography Research Articles

Hyperdense middle cerebral artery sign as the only radiological manifestation of hyperacute ischemic stroke in computed tomography

ObjectivesThe main aim of the study was to find the effect of hyperdense middle cerebral artery sign (HMCAS), as the only admission computed tomography (CT) manifestation of ischemic stroke involving middle cerebral artery (MCA) region, on the extent of stroke measured by Alberta Stroke Program Early CT score (ASPECTS) in the follow-up CT. The secondary aim was to determine the correlation between length of hyperdense MCA segment on admission CT and ASPECTS in follow-up CT. MethodsThe group analyzed consisted of 118 patients with ischemic MCA region stroke, with no early signs of brain tissue ischemia on admission CT, but infarcts confirmed in follow-up CT, with extent evaluated using ASPECTS. For the subgroups: 66 patients with HMCAS present and 52 with HMCAS absent, median ASPECTS values were compared. In the subgroup with HMCAS present, length of hyperdense segment was measured and correlation with ASPECTS was determined. ResultsThe median ASPECTS 6 (min. 0, max. 9) in the subgroup with HMCAS present was significantly lower, compared to the score 8.5 (min. 0, max. 9) in the subgroup with HMCAS absent. Moderate correlation between the length of hyperdense segment and ASPECTS was found (R=−0.45). ConclusionIn patients with ischemic stroke involving MCA region and no early signs of brain tissue ischemia on the admission CT, HMCAS is associated with significantly lower ASPECTS in the follow-up CT. There is moderate correlation between the length of hyperdense MCA segment and ASPECTS.

Topographic Assessment of Acute Ischemic Changes for Prognostication of Anterior Circulation Stroke.

The location of acute ischemic infarct can affect the clinical outcome of stroke patients. We aimed to develop a prognostic tool based on the topographic distribution of early ischemic changes on admission computed tomography (CT) scans. Using the albumin in acute stroke (ALIAS) trials dataset, patients with anterior circulation stroke were included for analysis. A 3-month modified Rankin scale (mRs) score > 2 defined disability/death; and ≤2 defined favorable outcome. A penalized logistic regression determined independent predictors of disability/death among components of admission CT scan Alberta Stroke Program Early CT score (ASPECTS). Follow-up 24-hour CT/MRI scans were reviewed for intracranial hemorrhage (ICH). A simplified ASPECTS (sASPECTS) was developed including the caudate, lentiform nucleus, insula, and M5 components of ASPECTS-which were independent predictors of disability/death on multivariate analysis. There was no significant difference between ASPECTS and sASPECTS in prediction of disability/death (P = .738). Among patients with sASPECTS ≥ 1, the rate of favorable outcome was higher in those with intravenous (IV) thrombolytic therapy (501/837, 59.9%) versus those without treatment (91/183, 49.7%, P = .013); whereas among patients with sASPECTS of 0, IV thrombolysis was not associated with improved outcome. Also, patients with sASPECTS of 0 were more likely to develop symptomatic ICH (odds ratio = 2.62, 95% confidence interval: 1.49-4.62), compared to those with sASPECTS ≥ 1 (P = .004). Topographic assessment of acute ischemic changes using the sASPECTS (including caudate, lentiform nucleus, insula, and M5) can predict disability/death in anterior circulation stroke as accurately as the ASPECTS; and may help predict response to treatment and risk of developing symptomatic ICH.

Clinical implications of eye deviation on admission CT examination of acute ischaemic stroke patients

To determine the frequency and prognostic value of eye deviation detected on the admission computed tomography (CT) of acute ischaemic stroke patients. The clinical and imaging data from the Albumin in Acute Stroke (ALIAS) Trials 1 and 2 were analysed. Two reviewers evaluated all admission CT images for the presence of eye deviation, and Alberta Stroke Program Early CT Score (ASPECTS). The admission National Institutes of Health Stroke Scale (NIHSS) scores and 3-month modified Rankin scale (mRs) scores were ascertained. Disability or death was defined as mRS score >2, at 3-month follow-up. Of 1,223 patients included in the present series, 352 (28.8%) had rightward and 331 (27.1%) had leftward eye deviation on admission CT. Patients with eye deviation on CT had higher admission NIHSS score and larger middle cerebral artery (MCA) territory infarct volume (based on ASPECTS). The presence of eye deviation on CT was associated with higher rates of haemorrhagic transformation at 24 hours (19.8% versus 13.5%, p=0.004), and higher rates of disability or death at 3-month follow-up (53.1% versus 35.7%, p<0.001). Mediation analysis showed that radiological eye deviation relation with higher rate of disability or death is predominantly due to its association with higher admission NIHSS scores, lower ASPECTS, and to a lesser extent patients' older age. The presence of eye deviation on CT examination of acute ischaemic stroke patients is associated with larger anterior circulation stroke volumes, higher risk of 24-hour haemorrhagic transformation, and 3-month disability or death.

Type A aortic dissection: Are there CT signs suggestive of valvular involvement?

AimTo identify the predictive signs of aortic valve involvement on the non-electrocardiogram (ECG)-gated admission computed tomography (CT) of patients with Type A aortic dissection (AD) according to the Stanford classification. Materials and methodsWe retrospectively analyzed the non-ECG-gated CT examinations of patients admitted to the emergency department who underwent surgery for Type A AD over a period of 4 years. The diameter of the following structures was calculated as the mean of the smallest and largest diameters (mm) measured in two different planes: aortic annulus, sinus of Valsalva, sinotubular junction, and proximal ascending aorta.These parameters were compared against operative reports in order to determine whether they were predictive of aortic valve involvement. ResultsIn total, 20 patients (13 men and 7 women) of a mean age of 59.5 years (29–80) were included, 55% of patients (11/20) having surgically proven valvular involvement. The mean diameters (inmm) of the aortic annulus, sinus of Valsalva, sinotubular junction and proximal ascending aorta in the group with (and without, respectively) valvular involvement was 27.7 (26.7), 44.3 (38.1), 42.6 (36.6), and 47.8 (45.9). Only the measurement of the mean diameter of the sinuses of Valsalva was significantly predictive (p=0.02) of aortic valve involvement. ConclusionOur findings suggest that measuring the diameter of the sinuses of Valsalva on non-ECG-gated admission CT examinations allows for predicting aortic valve involvement in Type A AD patients.

Predictors of hospital readmission 1year after ischemic stroke.

Predictors of short-term readmission after ischemic stroke have been previously identified, but few studies analyzed predictors of long-term readmission, namely early imaging findings and treatment with intravenous thrombolysis (IVT). To characterize predictors of hospital readmission during the first year after hospitalization for ischemic stroke. The study consists of a retrospective cohort of consecutive ischemic stroke patients admitted in a Portuguese university hospital during 2013, who survived index hospitalization. We collected clinical and imaging information using the electronical clinical record. Information concerning 1-year unplanned hospital readmissions was assessed using the Portuguese electronic Health Data Platform. Descriptive and univariate analyses, Kaplan-Meier survival curve and multivariate survival analysis with Cox regression model were used. We included 480 patients, 50.6% women, median age 79years (interquartile range=68-85). One-year hospital readmissions occurred in 165 patients [34.4%, 95% confidence interval (95% CI) 30.2-38.7]. The main causes for readmission were infectious diseases (43.8%), ischemic stroke or transient ischemic attack recurrence (13.2%) and cardiac diseases (6.4%). In-hospital mortality associated with readmission was 23.0%. The independent predictors of 1-year hospital readmission after ischemic stroke were admission mini-National Institute of Health Stoke Scale [hazards ratio (HR) 1.05, 95% CI 1.02-1.08, p=0.002], and mild or absent early signs of ischemia on admission computed tomography (CT) (HR 0.54, 95% CI 0.32-0.91, p=0.021) and IVT (HR 0.11, 95% CI 0.01-0.80, p=0.029). Hospital readmission during the first year after ischemic stroke occurs in 1/3 of patients and is associated with high in-hospital mortality. Clinical stroke severity, early signs of ischemia on admission CT, and treatment with IVT are independent predictors of 1-year hospital readmission.

Stroke etiologic subtype may influence the rate of hyperdense middle cerebral artery sign disappearance after intravenous thrombolysis.

Disappearance of hyperdense middle cerebral artery sign (HMCAS) on non-contrast brain computed tomography (CT) scan is a reliable sign of arterial recanalization after intravenous (IV) thrombolysis for ischemic stroke. We aimed to assess whether stroke etiologic subtype may influence the rate of HMCAS disappearance and the clinical outcome after IV thrombolysis. We conducted a retrospective analysis of data prospectively collected from 1031 consecutive stroke patients treated with IV thrombolysis. Outcome measures were HMCAS disappearance on follow-up CT scan within 22-36h of IV thrombolysis, neurologic improvement (NIH Stroke Scale [NIHSS] ≤4 points from baseline or NIHSS score of 0) at 7days, and modified rankin scale (mRS) ≤1 at 3months. Of 256 patients with HMCAS on admission CT scan, 125 had a cardioembolic stroke, 67 a stroke due to large-artery atherosclerosis (LAA), 58 a stroke of undetermined etiology, and six a stroke secondary to carotid artery dissection. HMCAS disappearance occurred in 145 (56.6%) patients, neurologic improvement in 122 (55.0%) patients, and mRS ≤1 in 64 (32.8%) patients. Compared with cardioembolic stroke patients, patients with stroke due to LAA had lower odds ratios (OR) for HMCAS disappearance (OR 0.29, 95% CI 0.15-0.58, p<0.001), neurologic improvement (OR 0.42, 95% CI 0.22-0.82, p=0.011), and mRS ≤1 (OR 0.18, 95% CI 0.06-0.52, p=0.002). No significant differences in outcome measures were found between cardioembolic strokes and strokes of undetermined etiology. This study suggests that stroke due to LAA is associated with lower rates of HMCAS disappearance, neurologic improvement, and mRS ≤1 after IV thrombolysis, compared with cardioembolic stroke.

Black Hole Sign: Novel Imaging Marker That Predicts Hematoma Growth in Patients With Intracerebral Hemorrhage.

Early hematoma growth is a devastating neurological complication after intracerebral hemorrhage. We aim to report and evaluate the usefulness of computed tomography (CT) black hole sign in predicting hematoma growth in patients with intracerebral hemorrhage. Patients with intracerebral hemorrhage were screened for the presence of CT black hole sign on admission head CT performed within 6 hours after onset of symptoms. The black hole sign was defined as hypoattenuatting area encapsulated within the hyperattenuating hematoma with a clearly defined border. The sensitivity, specificity, and positive and negative predictive values of CT black hole sign in predicting hematoma expansion were calculated. Logistic regression analyses were used to assess the presence of the black hole sign and early hematoma growth. A total of 206 patients were enrolled. Black hole sign was found in 30 (14.6%) of 206 patients on the baseline CT scan. The black hole sign was more common in patients with hematoma growth (31.9%) than those without hematoma growth (5.8%; P<0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of back hole sign in predicting early hematoma growth were 31.9%, 94.1%, 73.3%, and 73.2%, respectively. The time-to-admission CT scan, baseline hematoma volume, and the presence of black hole sign on admission CT independently predict hematoma growth in multivariate model. The CT black hole sign could be used as a simple and easy-to-use predictor for early hematoma growth in patients with intracerebral hemorrhage.

Colonoscopy after Hinchey I and II left-sided diverticulitis: utility or futility?

BackgroundModern 64- to 128-slice computed tomography (CT) scanners have questioned the need for routine colonoscopy after hospital admission for presumed uncomplicated diverticulitis. MethodsThis is a retrospective review of all patients (>18 years) who underwent planned colonoscopy after admission for Hinchey I or II acute diverticulitis (January 2009 to January 2014). The findings on the final radiologist report were then correlated with the colonoscopy results. ResultsIn total, 110 patients (mean age, 55.2 ± 16; 46.4% female) underwent a subsequent colonoscopy (median, 60 days) after admission for diverticulitis. Overall, 102 patients (92.7%) had CT findings consistent with definitive diverticulitis, 6 patients had a diagnosis suggestive of diverticulitis on CT scan, and 2 patients had masses on their admission CT scans. Within the group with definitive diverticulitis, follow-up colonoscopy identified diverticulosis in 99 (97.0%), whereas the other 3 had normal findings. Of the patients with CT scans suggestive of diverticulitis, follow-up colonoscopy showed 3 with diverticulosis, 2 with malignancies, and 1 with nonspecific inflammation. The reliability of CT scans for diverticulitis compared with colonoscopy was found to have a kappa = .829 (P < .001; 95% confidence interval, .629, 1.21). ConclusionsFollow-up colonoscopy should be performed when a CT scan suggests malignancy, nonspecific inflammatory findings, or the patient is otherwise due for routine screening or surveillance. In this study, there was no benefit of follow-up colonoscopy in patients with CT-confirmed diverticulitis in the absence of other concerning or indeterminate findings.

Microstructural Change and Cognitive Alteration in Maxillofacial Trauma and Mild Traumatic Brain Injury: A Diffusion Tensor Imaging Study

The aim of the present study was to establish the incidence of maxillofacial (MF) injury accompanying mild traumatic brain injury (mTBI) and the associated neurocognitive deficits and white matter changes. A prospective review of 41 patients with mTBI and maxillofacial injury (with or without intracranial lesion) due to motor vehicle accidents who had admission computed tomography (CT), neurocognitive evaluation, and quantitative diffusion tensor imaging available was performed during admission and at 6months of follow-up. Descriptive statistics were used for the demographic data, and a paired t test and repeated measure analysis of variance were used to establish the intergroup differences and susceptibility. The included patients were relatively young adults, with a mean age of 27.3 ± 8.8years and 11.3 ± 2.1years of education. Of the 41 patients, 20 (48.8%) had maxillofacial injuries involving the soft tissue and muscles, 18 (43.9%) had facial bone fractures, and 3 (7.3%) had mixed injuries. Of the 41 patients with MF injuries, 28 (68.3%) had intracranial abnormalities found on the admission CT scan. Executive function and attention were significantly altered across the time points, with patients with both MF injury and an intracranial lesion doing poorly at baseline but with improvement 6months later. In contrast, the patients with no visible intracranial lesion but with MF injuries remained impaired, with signs of a slowed recovery. The fractional anisotropy of the genu of the corpus callosum, anterior limb of the internal capsule, and cingulum for patients with MF injuries but without an intracranial lesion showed trends of reduced integrity over time. The presence of MF injury without any intracranial traumatic lesions in patients with mTBI increases the risk of short- and long-term neurocognitive derangement compared with patients with mTBI, MF injury, and intracranial traumatic lesions.

Computed tomography predictors for in-hospital mortality in severe and moderate head injury patients

Background:Traumatic brain injury is single leading cause of death and disability following injury. Clinical information collected at baseline and computed tomography (CT) brain scan findings may predict in-hospital mortality rate. The aim of this study was to evaluate which features on the admission CT scan might add significantly to other baseline clinical information for predicting mortality in patients with head injury.Methods: Baseline CT scans were reviewed for patients with moderate and severe head injuries from head injury registry from October 2007 to October 2009. Baseline demographic and injury status and outcome at discharge or death were recorded. Details from the CT scan using marshals grading was used along with other CT scan findings. CT characteristics like diffuse cerebral edema, mass lesions like extra dural haemotoma, subdural haemotoma, intra parenchymal haemorrhage, traumatic sub arachnoid haemorrhage, intra ventricular haemorrhage, basal cisterns, midline shift were evaluated. All the patients were classified into marshalls divisions. If required repeated scans were evaluated and the worst CT scan has been taken into consideration. Results:211 CT scans were read from patients with moderate severe head injuries. Out of the 24 patients in grade I, 4 died accounting for 16.666%. In grade II out of 47 patients 9 died accounting for 19.148%. In grade III out of 24 patients 5 died accounting for 20.833%. In grade IV out of 30 patients 11 died accounting for 36.666%. In grade V out of 76 patients 20 died accounting for 27.631%. In grade VI out of 10 patients 6 died accounting for 60%. In this study of 211 patients 55 died accounting for 26.06%.Conclusions:Marshall`s CT grading holds good for mortality prediction in moderate and severe head injury patients. Status of basal cisterns and midline shift serves as independent predictors for in-hospital mortality.

Wake-up Stroke and Stroke within the Therapeutic Window for Thrombolysis Have Similar Clinical Severity, Imaging Characteristics, and Outcome

Wake-up stroke (WUS) represents 25% of all ischemic strokes. There is conflicting evidence concerning clinical severity, imaging characteristics, and outcome when WUS is compared with stroke of known time of onset. Our aim was to compare WUS patients with patients with ischemic stroke within the therapeutic window (STW) for thrombolysis. This is a retrospective hospital-based study of all consecutive patients hospitalized for acute ischemic stroke during 2013. Patients with STW, WUS, and WUS with computed tomography (CT) at 3 hours or less after awakening (WUS≤3h) were selected for the study. The methods used include a review of clinical records, an independent quantification of early signs of ischemia on admission CT scan, and determination of functional outcome on follow-up. Of 554 patients evaluated, 190 had STW, 113 had WUS (20.4%), and 25 had WUS≤3h. Among all WUS patients, 33.6% did not have any other formal contraindication for thrombolysis besides undetermined time of onset. WUS patients had demographic characteristics, vascular risk factors, and clinical severity similar to STW patients. Mild or absent early signs of ischemia on admission CT in WUS≤3h patients were similar to those in STW patients when adjusted for clinical severity (odds ratio [OR] = .50, 95% confidence interval [CI]=.17-1.47). Favorable prognosis in WUS≤3h was similar to STW when adjusted for age, clinical severity, and thrombolysis (OR = .53, 95% CI=.09-3.14). This study strengthens the evidence that clinical and early imaging characteristics of WUS patients are similar to those of patients with stroke who are eligible for thrombolysis based on the time window criteria, and patients with WUS do not have a worse short outcome.

Lateral Ventricle Volume Asymmetry Predicts Midline Shift in Severe Traumatic Brain Injury.

Midline shift following severe traumatic brain injury (sTBI) detected on computed tomography (CT) scans is an established predictor of poor outcome. We hypothesized that lateral ventricular volume (LVV) asymmetry is an earlier sign of developing asymmetric intracranial pathology than midline shift. This retrospective analysis was performed on data from 84 adults with blunt sTBI requiring a ventriculostomy who presented to a Level I trauma center. Seventy-six patients underwent serial CTs within 3 h and an average of three scans within the first 10 d of sTBI. Left and right LVVs were quantified by computer-assisted manual volumetric measurements. LVV ratios (LVR) were determined on the admission CT to evaluate ventricular asymmetry. The relationship between the admission LVR value and subsequent midline shift development was tested using receiver operating characteristic (ROC) analysis, and odds ratio (OR) and relative risk tests. Sixty patients had no >5 mm midline shift on the initial admission scan. Of these, 15 patients developed it subsequently (16 patients already had >5 mm midline shift on admission scans). For >5 mm midline shift development, admission LVR of >1.67 was shown to have a sensitivity of 73.3% and a specificity of 73.3% (area under the curve=0.782; p<0.0001). LVR of >1.67 as exposure yielded an OR of 7.56 (p<0.01), and a risk ratio of 4.42 (p<0.01) for midline shift development as unfavorable outcome. We propose that LVR captures LVV asymmetry and is not only related to, but also predicts the development of midline shift already at admission CT examination. Lateral ventricles may have a higher "compliance" than midline structures to developing asymmetric brain pathology. LVR analysis is simple, rapidly accomplished and may allow earlier interventions to attenuate midline shift and potentially improve ultimate outcomes.

Blend Sign on Computed Tomography: Novel and Reliable Predictor for Early Hematoma Growth in Patients With Intracerebral Hemorrhage.

Early hematoma growth is not uncommon in patients with intracerebral hemorrhage and is an independent predictor of poor functional outcome. The purpose of our study was to report and validate the use of our newly identified computed tomographic (CT) blend sign in predicting early hematoma growth. Patients with intracerebral hemorrhage who underwent baseline CT scan within 6 hours after onset of symptoms were included. The follow-up CT scan was performed within 24 hours after the baseline CT scan. Significant hematoma growth was defined as an increase in hematoma volume of >33% or an absolute increase of hematoma volume of >12.5 mL. The blend sign on admission nonenhanced CT was defined as blending of hypoattenuating area and hyperattenuating region with a well-defined margin. Univariate and multivariable logistic regression analyses were performed to assess the relationship between the presence of the blend sign on nonenhanced admission CT and early hematoma growth. A total of 172 patients were included in our study. Blend sign was observed in 29 of 172 (16.9%) patients with intracerebral hemorrhage on baseline nonenhanced CT scan. Of the 61 patients with hematoma growth, 24 (39.3%) had blend sign on admission CT scan. Interobserver agreement for identifying blend sign was excellent between the 2 readers (κ=0.957). The multivariate logistic regression analysis demonstrated that the time to baseline CT scan, initial hematoma volume, and presence of blend sign on baseline CT scan to be independent predictors of early hematoma growth. The sensitivity, specificity, positive and negative predictive values of blend sign for predicting hematoma growth were 39.3%, 95.5%, 82.7%, and 74.1%, respectively. The CT blend sign could be easily identified on regular nonenhanced CT and is highly specific for predicting hematoma growth.

Basilar artery occlusion: Prognostic signs of severity on computed tomography

PurposeTo determine the computed tomography (CT) signs that are predictive of the clinical outcome of basilar artery occlusion (BAO). Materials and methodsThe study population consisted in 37 patients (14 women, 23 men, mean age: 63 years), admitted with onset of neurological deficit, starting 1–72h prior to admission, who were diagnosed with BAO on the basis of a CT examination with intravenous contrast agent. The following signs were collected on CT scans performed on admission: clot density on noncontrast images, clot length, and clot location, as well as the presence of acute ischemic lesions. The results were compared against the modified Rankin Scale (mRS) score of patients at 3 months, favorable clinical outcome being defined as a mRS score ≤3. ResultsThe clinical outcome was favorable in 13 (35%) of the 37 patients and unfavorable in 24 (65%). Signs of acute ischemia were visible in 13 of the 24 patients with unfavorable outcome but in none of the 13 patients with favorable outcome (p<0.001). None of the other CT signs analyzed were significantly correlated with clinical prognosis. ConclusionOf all the CT signs analyzed, only the presence of signs of acute ischemia on the admission CT of patients with BAO was associated with poor prognosis.

Early surgical intervention for blunt bowel injury: the Bowel Injury Prediction Score (BIPS).

Computed tomography (CT) scan of the abdomen has been used for 30 years to evaluate the stable blunt trauma patient. However, the early diagnosis of blunt hollow viscus injury (BHVI) remains a challenge. Delayed diagnosis and intervention of BHVI lead to significant morbidity and mortality. This study aimed to identify a combination of radiographic and clinical variables present at admission that could lead to earlier surgical intervention for BHVI. Significant predictors were identified through a retrospective review of all blunt trauma patients admitted to a Level 1 trauma center from 2005 to 2010 with an admission CT of the abdomen/pelvis and diagnosed with any mesenteric injury. The Bowel Injury Prediction Score (BIPS) was calculated based on the following three elements with a point given for each outcome: white blood cell count of 17.0 or greater, abdominal tenderness, and CT scan grade for mesenteric injury of 4 or higher. A total of 18,927 blunt trauma patients were admitted during the study period. Of these, 380 had a mesenteric injury, 110 met inclusion criteria, 60 had a surgical intervention, and 43 had BHVI. Of the 110 study patients, 43 (39%) had an immediate operation, 17 (16%) had a delayed operation (>4 hours), and 50 (46%) had no surgical intervention. The median BIPS for the immediate and delayed group was 2, while for the no-surgery group, the score was 0. Patients with a BIPS of 2 or greater were 19 times more likely to have a BHVI than patients with a BIPS of less than 2 (odds ratio, 19.2; 95% confidence interval, 6.78-54.36; p < 0.001). Three predictors (admission CT scan grade of mesenteric injury, white blood cell count, and abdominal tenderness) were used to create a new bowel injury score, with a score of 2 or greater being strongly associated with BHVI. Prospective validation of these retrospective findings is warranted to fully assess the accuracy of the BIPS. Prognostic study, level III.

Evaluation of Acute Abdominal Pain in the Emergency Setting Using Computed Tomography Without Oral Contrast in Patients With Body Mass Index Greater Than 25.

To evaluate the rate of delayed or missed diagnoses and need for additional computed tomography (CT) imaging in emergency department patients with abdominal pain who are imaged without oral contrast. The institutional review board approved this Health Insurance Portability and Accountability Act-compliant retrospective study; informed consent was waived. All consecutive adult patients with body mass index greater than 25 undergoing a CT abdomen/pelvis with intravenous contrast and without oral contrast with nontraumatic acute abdominal pain during a 16-month period at our academic tertiary care center were included. Medical records were reviewed, imaging findings on admission CT, use of repeat CT examinations within 4 weeks of the original examination, and clinical outcomes were recorded. In patients undergoing repeat imaging, an investigator determined whether repeat imaging was influenced by the lack of oral contrast on the original examination. As the most common cause of bowel-related positive CT scans, an analysis of acute appendicitis was performed. Of the 1992 patients included in this study, 4 patients (0.2%) underwent repeat CT studies directly related to the absence of oral contrast on the original examination. Of the 1992 CT scans, 1193(59.8%) were interpreted as negative, none of which required surgery or direct intervention. In patients with acute appendicitis, there was a sensitivity of CT in this patient population of 100% with a specificity of 99.5%. In patients with body mass index greater than 25 presenting to the ED with acute abdominal pain, CT examinations can be acquired without oral contrast without compromising the clinical efficacy of CT.

Predicting Stroke Outcome Using Clinical- versus Imaging-based Scoring System

Several models to predict outcome in ischemic stroke patients receiving intravenous (i.v.) alteplase can be divided into clinical-based and imaging-based systems. Alberta Stroke Program Early Computed Tomography (CT) Score (ASPECTS) and Dense cerebral artery sign/early infarct signs on admission CT scan, prestroke modified Rankin Scale (mRS) score, Age, Glucose level at baseline, Onset-to-treatment time, and baseline National Institutes of Health Stroke Scale score (DRAGON) are typical imaging- and clinical-based scoring systems, respectively. Therefore, we compared predictability of stroke outcome of clinical (DRAGON)- and imaging (ASPECTS)-based scoring systems. We analyzed patients who were diagnosed with middle cerebral artery territory stroke and treated with i.v. alteplase at Gachon University Gil Hospital over 5 years and compared performance of 2 scoring systems for prediction of good functional outcome (mRS, 0-2) with Pearson correlation and area under the curve-receiver operating characteristic (AUC-ROC). In addition, we analyzed predicting power of several clinical factors and 2 scoring systems by multiple regression analysis. Study population (N = 120) had mean age of 66.2 ± 13.2 years. ASPECTS (r = -.841, P < .0001) and DRAGON (r = .657, P < .0001) were significantly correlated with good functional outcome. In addition, statistical comparisons suggested that ASPECTS (AUC-ROC, .972; 95% confidence interval [CI], .947-.996) is significantly superior to DRAGON (AUC-ROC, .854; 95% CI, .786-.922) in predicting functional outcome (difference between areas, .118 ± .0332; 95% CI, .0559-.180, P = .0002). Multiple regression analysis revealed that ASPECTS was the independent predictor of good prognosis (OR, 6.59 per 1-point increase; 95% CI, 2.35-18.49; P < .0001 and OR, 77.67 for ASPECTS ≥ 8; 95% CI, 14.30-421.79; P < .0001). ASPECTS is superior method for predicting functional outcome in acute ischemic stroke patients receiving i.v. alteplase compared with DRAGON and integration of ASPECTS score into clinical care pathway as decision-making tool can be reasonable.

A new aortic injury score predicts early rupture more accurately than clinical assessment

The optimal timing for repair of a high-grade blunt thoracic aortic injury (BTAI) is uncertain. Delayed repair is common and associated with improved outcomes, but some lesions may rupture during observation. To determine optimal patient selection for appropriate management, we developed a pilot clinical risk score to evaluate aortic stability and predict rupture. Patients presenting in stable condition with Society for Vascular Surgery grade III or IV BTAI diagnosed on computed tomography (CT) were retrospectively reviewed. To determine clinical and radiographic factors associated with aortic rupture, patients progressing to aortic rupture (defined by contrast extravasation on CT or on operative or autopsy findings) were compared with those who had no intervention ≤48 hours of admission. A model targeting 100% sensitivity for rupture was generated and internally validated by bootstrap analysis. Clinical utility was tested by comparison with clinical assessment by surgeons experienced in BTAI management who were provided with CT images and clinical data but were blinded to outcome. The derivation cohort included 18 patients whose aorta ruptured and 31 with stable BTAI. There was no difference in age, gender, injury mechanism, nonchest injury severity, blood pressure, or Glasgow Coma Scale on admission between patient groups. As dichotomous factors, admission lactate >4 mM, posterior mediastinal hematoma >10 mm, and lesion/normal aortic diameter ratio >1.4 on the admission CT were independently associated with aortic rupture. The model had an area under the receiver operator curve of .97, and in the presence of any two factors, was 100% sensitive and 84% specific for predicting aortic rupture. No aortic lesions ruptured in patients with fewer than two factors. In contrast, clinical assessment had lower accuracy (65% vs 90% total accuracy, P < .01). This novel risk score can be applied on admission using clinically relevant factors that incorporate patient physiology, size of the aortic lesion, and extent of the mediastinal hematoma. The model reliably identifies and distinguishes patients with high-grade BTAI who are at risk for early rupture from those with stable lesions. Although preliminary, because it is more accurate than clinical assessment alone, the score may improve patient selection for emergency or delayed intervention.

Comparison of virtual bronchoscopy to fiber-optic bronchoscopy for assessment of inhalation injury severity

PurposeCompare virtual bronchoscopy (VB) to fiberoptic bronchoscopy (FOB) for scoring smoke inhalation injury (SII). MethodsSwine underwent computerized tomography (CT) with VB and FOB before (0) and 24 and 48h after SII. VB and FOB images were scored by 5 providers off line. ResultsFOB and VB scores increased over time (p<0.001) with FOB scoring higher than VB at 0 (0.30±0.79 vs. 0.03±0.17), 24h (4.21±1.68 vs. 2.47±1.50), and 48h (4.55±1.83 vs. 1.94±1.29). FOB and VB showed association with PaO2-to-FiO2 ratios (PFR) with areas under receiver operating characteristic curves (ROC): for PFR≤300, VB 0.830, FOB 0.863; for PFR≤200, VB 0.794, FOB 0.825; for PFR≤100, VB 0.747, FOB 0.777 (all p<0.001). FOB showed 80.3% specificity, 77% sensitivity, 88.8% negative-predictive value (NPV), and 62.3% positive-predictive value (PPV) for PFR≤300 and VB showed 67.2% specificity, 85.5% sensitivity, 91.3% NPV, and 53.4% PPV. ConclusionsVB provided similar injury severity scores to FOB, correlated with PFR, and reliably detected airway narrowing. VB performed during admission CT may be a useful screening tool specifically to demonstrate airway narrowing induced by SII.

Abstract W P110: Preexisting Cerebral Small Vessel Disease Increases Cortical Infarct Volume after Distal Middle Cerebral Artery Occlusion

Background: Cerebral small vessel disease (cSVD) predominantly affects the subcortical white matter. However, little is known about its impact on cortical ischemic susceptibility. We sought to assess whether preexisting cSVD is predictive of the cortical infarct volume following middle cerebral artery (MCA) branch occlusion and whether it relates to a worse 90-day outcome. Methods: We analyzed data from 117 consecutive patients with MCA branch occlusion as documented by admission computed tomography (CT)-angiography. To avoid potential confounding, we excluded patients with subcortical infarction. Baseline clinical, laboratory, and outcome data as well as final cortical infarct volumes on follow-up imaging were retrospectively analyzed from a prospectively collected database. Severity of cSVD was assessed on admission CT using the van Swieten scale (VSS), grading the white matter lesions on a 3-point scale from 0 (absent) to 4 (severe). We also dichotomized the degree of cSVD (VSS 0-2 [absent to moderate] vs. 3-4 [severe]) for statistical purposes. Multivariable linear and logistic regression analyses were used to identify independent predictors of the final infarct volume. Results: A final infarct volume of ≤27 mL best predicted a favorable 90-day outcome (mRS≤2) as determined by receiver operating characteristic curves. Severe cSVD (OR 7.434; 95%-CI 1.549-35.676; p=0.012) was independently associated with infarct volume &gt;27 mL. Patients with severe cSVD had significantly larger cortical lesion volumes compared to patients without (Figure1A). Severe cSVD (OR 3.027; 95%-CI 1.013-9.048; p=0.047) and infarct volume &gt;27 mL (OR 9.038; 95%-CI 1.997-40.899; p=0.004) were independent predictors of a poor 90-day outcome (mRS 3-6; Figure 1B). Conclusion: Severe subcortical cSVD contributes to larger cortical infarct volumes and worse functional outcome adding to the notion that the brain is negatively affected beyond cSVD ‘s macroscopic boundaries.