The compliance, true positive and false negative rates of the Charing Cross protocol for magnetic resonance imaging screening for cerebellopontine angle lesions

2007 ◽  
Vol 122 (3) ◽  
pp. 255-258
Author(s):  
J D Snelling ◽  
M Krywawych ◽  
A Majithia ◽  
J P Harcourt
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Cerebellopontine Angle ◽  
Compliance Rate ◽  
False Negative ◽  
False Negative Rate ◽  
True Positive Rate ◽  
True Positive ◽  
Resonance Imaging ◽  
Negative Rate

AbstractObjectives:To assess the effectiveness and determine the compliance to a local protocol for requesting magnetic resonance imaging scans to screen for the presence of cerebellopontine angle lesions.Methods:A combined retrospective study of all patients who had magnetic resonance imaging scans requested six months prior to and one year following introduction of the protocol and assessment of the true positive and false negative rate of the protocol by assessment of its sensitivity in cases referred from outside the department.Results:Comparison of the number of scans in each period showed a reduction in annualised rate of 142 to 46. The incidence of positive scans was the same in both periods, increasing the true positive rate from 1.4 to 4.3 per cent. The false negative rate was 1.1 per cent.Conclusions:The Charing Cross protocol has a good compliance rate within the department, has reduced the cost of screening for cerebellopontine angle lesions and has an acceptable true positive and false negative rate.

Diagnostic Accuracy of Magnetic Resonance Imaging and Computed Tomography Scan in Young Athletes With Spondylolysis

2019 ◽  
Vol 58 (6) ◽  
pp. 671-676
Author(s):  
Amy M. West ◽  
Pierre A. d’Hemecourt ◽  
Olivia J. Bono ◽  
Lyle J. Micheli ◽  
Dai Sugimoto
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Ct Scan ◽  
False Negative ◽  
False Negative Rate ◽  
Ct Scans ◽  
Resonance Imaging ◽  
Young Athletes ◽  
Negative Rate

The objective of this study was to determine diagnostic accuracy of magnetic resonance imaging (MRI) and computed tomography (CT) scans in young athletes diagnosed with spondylolysis. A cross-sectional study was used. Twenty-two young athletes (14.7 ± 1.5 years) were diagnosed as spondylolysis based on a single-photon emission CT. Following the diagnosis, participants underwent MRI and CT scan imaging tests on the same day. The sensitivity and false-negative rate of the MRI and CT scans were analyzed. MRI test confirmed 13 (+) and 9 (−) results while CT test showed 17 (+) and 5 (−) results. The sensitivity and false-negative rate of MRI were, respectively, 59.1% (95% confidence interval [CI] = 36.7% to 78.5%) and 40.9% (95% CI = 21.5% to 63.3%). Furthermore, the sensitivity and false-negative rate of CT scan were 77.3% (95% CI = 54.2% to 91.3%) and 22.7% (95% CI = 0.09% to 45.8%). Our results indicated that CT scan is a more accurate imaging modality to diagnose spondylolysis compared with MRI in young athletes.

Magnetic Resonance Imaging of Cerebral Arteriovenous Malformations

Neurosurgery ◽  
1987 ◽  
Vol 21 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Richard Leblanc ◽  
Michel Levesque ◽  
Youssef Comair ◽  
Romeo Ethier
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Arteriovenous Malformations ◽  
False Negative ◽  
Contrast Material ◽  
False Negative Rate ◽  
Ct Scanning ◽  
Venous Drainage ◽  
Brain Structures ◽  
Resonance Imaging

Abstract Magnetic resonance imaging (MRI) was performed in 15 patients with small to very large supratentorial arteriovenous malformations (AVMs). Unlike non-contrast infused computed tomographic (CT) scanning, MRI demonstrated the AVM in all cases. The nidus had a characteristic honeycomb appearance, and in all cases feeding arteries and deep or superficial draining veins were demonstrated without intervening bone artifact. The relationship of the AVM to surrounding cortical areas, deep nuclei, important white matter tracts, and the ventricular system was well appreciated. These characteristics make MRI useful for the diagnosis of cerebral AVMs and add to the accuracy of systems that grade operability on the basis of the angiographic demonstration of size, location, depth, arterial supply, and venous drainage. In many cases, based on the MRI appearance of the AVM and its relationship to important brain structures, the lesion can be deemed inoperable or unsuitable for other forms of treatment, making angiography unnecessary. Thus, the superior anatomical and morphological resolution of MRI, the lower false-negative rate, and the independence from x-ray and contrast material make MRI more useful than CT scanning for the diagnosis of AVMs and as an aid in the management of specific cases. (Neurosurgery 21: 15-20, 1987)

Audiological findings in glomus tumours

1997 ◽  
Vol 111 (3) ◽  
pp. 218-222 ◽  
Author(s):  
William W. Qiu ◽  
Shengguang S. Yin ◽  
Fred J. Stucker ◽  
Mardjohan Hardjasudarma
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Auditory System ◽  
Middle Ear ◽  
Otoacoustic Emissions ◽  
Cerebellopontine Angle ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

AbstractGlomus tumours involving the middle ear and the cerebellopontine angle are reported with emphasis on audiological findings. Magnetic resonance imaging (MRI), angiographic and pathological results are presented. Audiological tests, including impedance audiometry, evoked otoacoustic emissions and auditory brainstem responses, are valuable in evaluation of the effect of glomus tumours on the auditory system as well as their pathological extent.

scholarly journals Finding COVID-19 from Chest X-rays using Deep Learning on a Small Dataset

2020 ◽  
Author(s):  
Lawrence Hall ◽  
Dmitry Goldgof ◽  
Rahul Paul ◽  
Gregory M. Goldgof
Keyword(s):  
False Negative ◽  
True Positive Rate ◽  
Small Data ◽  
Good Resolution ◽  
X Rays ◽  
True Positive ◽  
Data Set ◽  
X Ray ◽  
Negative Rate ◽  
Positive Rate

<p>Testing for COVID-19 has been unable to keep up with the demand. Further, the false negative rate is projected to be as high as 30% and test results can take some time to obtain. X-ray machines are widely available and provide images for diagnosis quickly. This paper explores how useful chest X-ray images can be in diagnosing COVID-19 disease. We have obtained 135 chest X-rays of COVID-19 and 320 chest X-rays of viral and bacterial pneumonia. </p><p> A pre-trained deep convolutional neural network, Resnet50 was tuned on 102 COVID-19 cases and 102 other pneumonia cases in a 10-fold cross validation. The results were </p><p> an overall accuracy of 89.2% with a COVID-19 true positive rate of 0.8039 and an AUC of 0.95. Pre-trained Resnet50 and VGG16 plus our own small CNN were tuned or trained on a balanced set of COVID-19 and pneumonia chest X-rays. An ensemble of the three types of CNN classifiers was applied to a test set of 33 unseen COVID-19 and 218 pneumonia cases. The overall accuracy was 91.24% with the true positive rate for COVID-19 of 0.7879 with 6.88% false positives for a true negative rate of 0.9312 and AUC of 0.94. </p><p> This preliminary study has flaws, most critically a lack of information about where in the disease process the COVID-19 cases were and the small data set size. More COVID-19 case images at good resolution will enable a better answer to the question of how useful chest X-rays can be for diagnosing COVID-19.</p>

Cerebellopontine angle lipoma

1993 ◽  
Vol 107 (6) ◽  
pp. 553-555 ◽  
Author(s):  
L. J. O'Keeffe ◽  
R. T. Ramsden ◽  
A. R. Birzgalis
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Acoustic Neuroma ◽  
Cerebellopontine Angle ◽  
Resonance Imaging ◽  
Radiological Features

A case of a cerebellopontine angle lipoma is presented with a typical clinical, audiometric and radiological features of an acoustic neuroma. The correct pre-operative diagnosis was elusive even with the aid of magnetic resonance imaging.

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