CT Showing Early Ventricular Dilatation after Subarachnoidal Hemorrhage

Johansson, Ingegerd; Bolander, Hans; Kourtopoulos, Harry

doi:10.1177/028418519203300409

Cited by 3 publications

(1 citation statement)

References 23 publications

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“…The number of misinterpreted cranial CTs with early signs of hydrocephalus in this series (six of nine, specifically with dilatation of the posterior temporal horns and/or the infundibular recess of the third ventricle) might offer another potential target for educational intervention. Of note, posterior temporal horn dilation has previously been noted as a prevalent finding in between 66%–84% of SAH cases, even in the absence of visible hemorrhage . Finally, we cannot fully account for unmeasured confounders affecting misinterpretation (years of radiologist experience, clinical workload, fatigue, etc).…”

Section: Discussionmentioning

confidence: 94%

False‐negative Interpretations of Cranial Computed Tomography in Aneurysmal Subarachnoid Hemorrhage

Mark

Sonne

Jun

et al. 2016

Academic Emergency Medicine

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Objectives: Prior studies examining the sensitivity of cranial computed tomography (CT) for the detection of subarachnoid hemorrhage (SAH) have used the final radiology report as the reference standard. However, optimal sensitivity may have been underestimated due to misinterpretation of reportedly normal cranial CTs. This study aims to estimate the incidence of missed CT evidence of SAH among a cohort of patients with aneurysmal SAH (aSAH).Methods: We performed a retrospective chart review of emergency department (ED) encounters within an integrated health delivery system between January 2007 and June 2013 to identify patients diagnosed with aSAH. All initial noncontrast CTs from aSAH cases diagnosed by lumbar puncture (LP) and angiography following a reportedly normal noncontrast cranial CT (CT-negative aSAH) were then reviewed in a blinded, independent fashion by two board-certified neuroradiologists to assess for missed evidence of SAH. Reviewers rated the CT studies as having definite evidence of SAH, probable evidence of SAH, or no evidence of SAH. Control patients who underwent a negative evaluation for aSAH based on cranial CT and LP results were also included at random in the imaging review cohort.Results: A total of 452 cases of aSAH were identified; 18 (4%) were cases of CT-negative aSAH. Of these, seven (39%) underwent cranial CT within 6 hours of headache onset, and two (11%) had their initial CTs formally interpreted by board-certified neuroradiologists. Blinded independent CT review revealed concordant agreement for either definite or probable evidence of SAH in nine of 18 (50%) cases overall and in five of the seven (71%) CTs performed within 6 hours of headache onset. Inter-rater agreement was 83% for definite SAH and 72% for either probable or definite SAH.Conclusions: CT evidence of SAH was frequently present but unrecognized according to the final radiology report in cases of presumed CT-negative aSAH. This finding may help explain some of the discordance between prior studies examining the sensitivity of cranial CT for SAH.ACADEMIC EMERGENCY MEDICINE 2016;23:591-598

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Section: Discussionmentioning

confidence: 94%

False‐negative Interpretations of Cranial Computed Tomography in Aneurysmal Subarachnoid Hemorrhage

Mark

Sonne

Jun

et al. 2016

Academic Emergency Medicine

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Z-score-based semi-quantitative analysis of the volume of the temporal horn of the lateral ventricle on brain CT images

Takahashi

Kinoshita

Ohmura

et al. 2015

Radiol Phys Technol

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The volume of the temporal horn of the lateral ventricle (THLV) on brain computed tomography (CT) images is important for neurologic diagnosis. Our purpose in this study was to develop a z-score-based semi-quantitative analysis for estimation of the THLV volume by using voxel-based morphometry. The THLV volume was estimated by use of a z-score mapping method that consisted of four main steps: anatomic standardization, construction of a normal reference database, calculation of the z score, and calculation of the mean z score in a volume of interest (VOI). A mean z score of the CT value obtained from a VOI around the THLV was used as an index for the THLV volume. CT scans from 50 subjects were evaluated. For evaluation of the accuracy of this method for estimating the THLV volume, the THLV volume was determined manually by neuroradiologists (serving as the reference volume). A mean z score was calculated from the VOI for each THLV of the 50 subjects by use of the proposed method. The accuracy of this method was evaluated by use of the relationship between the mean z score and the reference volume. The quadratic polynomial regression equation demonstrated a statistically significant correlation between the mean z score and the reference volume of the THLV (R (2) = 0.94; P < 0.0001). In 92 of 100 THLVs (92 %), the 95 % prediction interval of the regional mean z score captured the reference volume of the THLV. The z-score-based semi-quantitative analysis has the potential quantitatively to estimate the THLV volume on CT images.

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