Coronal CT is Comparable to MR Imaging in Aiding Diagnosis of Dementia in a Memory Clinic in Singapore.

PURPOSE: The present study investigated (a) the agreement between computerized tomography (CT) and 3 T magnetic resonance imaging (MRI) in the visual grading of medial temporal atrophy (MTA); and (b) whether MTA on CT differentiated patients with dementia from no dementia in memory clinics. MATERIALS AND METHODS: Data were obtained from patients who underwent CT scans at the National University Hospital of Singapore, and from a subsample who subsequently underwent 3 T MRI scans in a research study. Agreements and disagreements between CT and MRI were determined. Area under the curve (AUC) analyses determined if CT-graded MTA distinguished patients with dementia from no dementia. RESULTS: Of the 107 patients in the subsample, MTA scores of 71 agreed on both CT and MRI. The true positive rate between CT and MRI for MTA scores ≥2 was 79.7%. The true negative rate for MTA scores between 0 and 1 was 96.4%. CT underestimated MTA severity in 33 of 36 disagreements with the MRI. MTA scores ≥2 on CT distinguished dementia from no dementia in both discovery [n=263; AUC (95% confidence interval)=0.77 (0.72-0.83); sensitivity=0.69; specificity=0.74] and validation [n=264; AUC (95% confidence interval)=0.77 (0.71-0.82); sensitivity=0.72; specificity=0.72] groups. CONCLUSIONS: MTA graded on CT is a viable alternative to MRI to aid in the diagnosis of dementia in memory clinics.

Validation of Serial Alberta Stroke Program Early CT Score as an Outcome Predictor in Thrombolyzed Stroke Patients.

BACKGROUND: The Alberta Stroke Program Early CT Score (ASPECTS) on baseline imaging is an established predictor of functional outcome in anterior circulation acute ischemic stroke (AIS). We studied ASPECTS before intravenous thrombolysis (IVT) and at 24 hours to assess its prognostic value. METHODS: Data for consecutive anterior circulation AIS patients treated with IVT from 2006 to 2013 were extracted from a prospectively managed registry at our tertiary center. Pre-thrombolysis and 24-hour ASPECTS were evaluated by 2 independent neuroradiologists. Outcome measures included symptomatic intracranial hemorrhage (SICH), modified Rankin Scale (mRS) at 90 days, and mortality. Unfavorable functional outcome was defined by mRS >1. Dramatic ASPECTS progression (DAP) was defined as deterioration in ASPECTS by 6 points or more. RESULTS: Of 554 AIS patients thrombolyzed during the study period, 400 suffered from anterior circulation infarction. The median age was 65 years (interquartile range (IQR): 59-70) and the median National Institutes of Health Stroke Scale score was 18 points (IQR: 12-22). Compared with the pre-IVT ASPECTS (area under the curve [AUC] = .64, 95% confidence interval [CI]: .54-.65, P = .001), ASPECTS on the 24-hour CT scan (AUC = .78, 95% CI: .73-.82, P < .001), and change in ASPECTS (AUC = .69, 95% CI: .64-.74, P < .001) were better predictors of unfavorable functional outcome at 3 months. DAP, noted in 34 (14.4%) patients with good baseline ASPECTS (8-10 points), was significantly associated with unfavorable functional outcome (odds ratio [OR]: 9.91, 95% CI: 3.37-29.19, P ≤ .001), mortality (OR: 21.99, 95% CI: 7.98-60.58, P < .001), and SICH (OR: 8.57, 95% CI: 2.87-25.59, P < .001). CONCLUSION: Compared with the pre-thrombolysis score, ASPECTS measured at 24 hours as well as serial change in ASPECTS is a better predictor of 3-month functional outcome.

Prevalence of cognitive impairment in Chinese: epidemiology of dementia in Singapore study.

OBJECTIVE: To study the prevalence of and associated factors for cognitive impairment and dementia in community dwelling Chinese from Singapore. METHODS: This study includes Chinese subjects from the Epidemiology of Dementia in Singapore (EDIS) study, aged ≥60 years, who underwent comprehensive examinations, including cognitive screening with the locally validated Abbreviated Mental Test and Progressive Forgetfulness Questionnaire. Screen positive participants subsequently underwent extensive neuropsychological testing and cerebral MRI. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to internationally accepted criteria. The prevalence of cognitive impairment and dementia were computed per 5 year age categories and gender. To examine the relationship between baseline associated factors and cognitive impairment, we used logistic regression models to compute odd ratios with 95% CI. RESULTS: 1538 Chinese subjects, aged ≥60 years, underwent cognitive screening: 171 (15.2%) were diagnosed with any cognitive impairment, of whom 84 were CIND mild, 80 CIND moderate and seven had dementia. The overall age adjusted prevalence of CIND mild was 7.2%; CIND moderate/dementia was 7.9%. The prevalence increased with age, from 5.9% in those aged 60-64 years to 31.3% in those aged 75-79 years and 44.1% in those aged ≥80 years. Multivariate analysis revealed age, diabetes and hyperlipidaemia to be independently associated with cognitive impairment. CONCLUSIONS: In present study, the overall prevalence of cognitive impairment and dementia in Chinese was 15.2%, which is in the same range as the prevalence reported in Caucasian and other Asian populations.

Early and continuous neurologic improvements after intravenous thrombolysis are strong predictors of favorable long-term outcomes in acute ischemic stroke.

BACKGROUND: Intravenously administered tissue plasminogen activator (IV tPA) remains the only approved therapeutic agent for arterial recanalization in acute ischemic stroke (AIS). Considerable proportion of AIS patients demonstrate changes in their neurologic status within the first 24 hours of intravenous thrombolysis with IV tPA. However, there are little available data on the course of clinical recovery in subacute 2- to 24-hour window and its impact. We evaluated whether neurologic improvement at 2 and 24 hours after IV tPA bolus can predict functional outcomes in AIS patients at 3 months. METHODS: Data for consecutive AIS patients treated with IV tPA within 4.5 hours of symptom onset during 2007-2011 were prospectively entered in our thrombolyzed registry. National Institutes of Health Stroke Scale (NIHSS) scores were recorded before IV tPA bolus, at 2 and 24 hours. Early neurologic improvement (ENI) at 2 hours was defined as a reduction in NIHSS score by 10 or more points from baseline or an absolute score of 4 or less points at 2 hours. Continuous neurologic improvement (CNI) was defined as a reduction of NIHSS score by 8 or more points between 2 and 24 hours or an absolute score of 4 or less points at 24 hours. Favorable functional outcomes at 3 months were determined by modified Rankin Scale (mRS) score of 0-1. RESULTS: Of 2460 AIS patients admitted during the study period, 263 (10.7%) received IV tPA within the time window; median age was 64 years (range 19-92), with 63.9% being men, a median NIHSS score of 17 points (range 5-35), and a median onset-to-treatment time of 145 minutes (range 57-270). Overall, 130 (49.4%) thrombolyzed patients achieved an mRS score of 0-1 at 3 months. The female gender, age, and baseline NIHSS score were found to be significantly associated with CNI on univariate analysis. On multivariate analysis, NIHSS score at onset and female gender (odds ratio [OR]: 2.218, 95% confidence interval [CI]: 1.140-4.285; P=.024) were found to be independent predictors of CNI. Factors associated with favorable outcomes at 3 months on univariate analysis were younger age, female gender, hypertension, NIHSS score at onset, recanalization on transcranial Doppler (TCD) monitoring or repeat computed tomography (CT) angiography, ENI at 2 hours, and CNI. On multivariate analysis, NIHSS score at onset (OR per 1-point increase: .835, 95% CI: .751-.929, P<.001), 2-hour TCD recanalization (OR: 3.048, 95% CI: 1.537-6.046; P=.001), 24-hour CT angiographic recanalization (OR: 4.329, 95% CI: 2.382-9.974; P=.001), ENI at 2 hours (OR: 2.536, 95% CI: 1.321-5.102; P=.004), and CNI (OR: 7.253, 95% CI: 3.682-15.115; P<.001) were independent predictors of favorable outcomes at 3 months. CONCLUSIONS: Women are twice as likely to have CNI from the 2- to 24-hour period after IV tPA. ENI and CNI within the first 24 hours are strong predictors of favorable functional outcomes in thrombolyzed AIS patients.

CT features in surgically proven cases of ovarian torsion-a pictorial review.

Ovarian torsion is a surgical emergency characterized by a partial or complete rotation of the ovarian vascular pedicle, causing obstruction to venous outflow followed by arterial inflow. Clinically, ovarian torsion frequently mimics other causes of acute pelvic pain such as appendicitis, diverticulitis, renal colic etc. Ultrasonography is the first-line imaging modality of choice for evaluation of ovarian torsion. MRI is useful as a problem-solving tool in patients with equivocal or non-diagnostic ultrasonography studies. CT is ordinarily not utilized in a young female with suspected ovarian torsion due to the radiation dose. However, the significant expansion in use of CT imaging in emergency departments for female patients presenting with acute abdominal pain has increased the likelihood that ovarian torsion may be first seen on CT. In addition, a non-specific clinical presentation may lead to an initial imaging with CT rather than ultrasonography. Ultrasound features of the ovarian torsion are well known and sufficiently described across literature as compared with the CT scan findings. In view of the increasing usage of CT as the modality of choice in emergency settings, it is imperative for the radiologist to familiarize with the CT features of ovarian torsion. An early correct diagnosis by the radiologist in clinically unsuspected cases, facilitating a prompt surgery to restore the ovarian blood flow can prevent permanent irreversible damage. There is limited published data available on the CT features of ovarian torsion. This pictorial essay illustrates CT findings with histological correlation of surgically proven ovarian torsion in our institution. These patients were primarily investigated with CT scan for acute pelvic pain ascribed to non-gynaecological causes such as bowel or urinary tract lesions.