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Diffusion-weighted magnetic resonance imaging for predicting the clinical outcome of comatose survivors after cardiac arrest: a cohort study.

Choi SP, Park KN, Park HK, Kim JY, Youn CS, Ahn KJ, Yim HW - Crit Care (2010)

Bottom Line: The restricted diffusion abnormalities in the cerebral cortex, caudate nucleus, putamen and thalamus were significantly different between the favourable (n = 13) and unfavourable (n = 26) outcome groups.The cortex and deep grey nuclei pattern was significantly associated with the unfavourable outcome (20 patients with unfavourable vs. 1 patient with favourable outcomes, P < 0.001).In the 22 patients with quantitative ADC analyses, severely reduced ADCs were noted in the unfavourable outcome group.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Emergency Medicine, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.

ABSTRACT

Introduction: The aim of this study was to examine whether the patterns of diffusion-weighted imaging (DWI) abnormalities and quantitative regional apparent diffusion coefficient (ADC) values can predict the clinical outcome of comatose patients following cardiac arrest.

Methods: Thirty-nine patients resuscitated from out-of-hospital cardiac arrest were prospectively investigated. Within five days of resuscitation, axial DWIs were obtained and ADC maps were generated using two 1.5-T magnetic resonance scanners. The neurological outcomes of the patients were assessed using the Glasgow Outcome Scale (GOS) score at three months after the cardiac arrest. The brain injuries were categorised into four patterns: normal, isolated cortical injury, isolated deep grey nuclei injury, and mixed injuries (cortex and deep grey nuclei). Twenty-three subjects with normal DWIs served as controls. The ADC and percent ADC values (the ADC percentage as compared to the control data from the corresponding region) were obtained in various regions of the brains. We analysed the differences between the favourable (GOS score 4 to 5) and unfavourable (GOS score 1 to 3) groups with regard to clinical data, the DWI abnormalities, and the ADC and percent ADC values.

Results: The restricted diffusion abnormalities in the cerebral cortex, caudate nucleus, putamen and thalamus were significantly different between the favourable (n = 13) and unfavourable (n = 26) outcome groups. The cortical pattern of injury was seen in one patient (3%), the deep grey nuclei pattern in three patients (8%), the cortex and deep grey nuclei pattern in 21 patients (54%), and normal DWI findings in 14 patients (36%). The cortex and deep grey nuclei pattern was significantly associated with the unfavourable outcome (20 patients with unfavourable vs. 1 patient with favourable outcomes, P < 0.001). In the 22 patients with quantitative ADC analyses, severely reduced ADCs were noted in the unfavourable outcome group. The optimal cutoffs for the mean ADC and the percent ADC values determined by receiver operating characteristic (ROC) curve analysis in the cortex, caudate nucleus, putamen, and thalamus predicted the unfavourable outcome with sensitivities of 67 to 93% and a specificity of 100%.

Conclusions: The patterns of brain injury in early diffusion-weighted imaging (DWI) (less than or equal to five days after resuscitation) and the quantitative measurement of regional ADC may be useful for predicting the clinical outcome of comatose patients after cardiac arrest.

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This figure shows the axial apparent diffusion coefficient maps indicating the 15 regions of interest. These regions were selected for quantitative measurement of the apparent diffusion coefficient values. (1) precentral cortex, (2) postcentral cortex, (3) frontal cortex, (4) frontal white matter, (5) parietal cortex, (6) parietal white matter, (7) caudate nucleus, (8) putamen, (9) thalamus, (10) temporal cortex, (11) temporal white matter, (12) occipital cortex, (13) occipital white matter, (14) pons, and (15) cerebellum.
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Figure 1: This figure shows the axial apparent diffusion coefficient maps indicating the 15 regions of interest. These regions were selected for quantitative measurement of the apparent diffusion coefficient values. (1) precentral cortex, (2) postcentral cortex, (3) frontal cortex, (4) frontal white matter, (5) parietal cortex, (6) parietal white matter, (7) caudate nucleus, (8) putamen, (9) thalamus, (10) temporal cortex, (11) temporal white matter, (12) occipital cortex, (13) occipital white matter, (14) pons, and (15) cerebellum.

Mentions: The ADC values were only obtained from 22 patients who were examined using the GE Signa Excite due to the use of two kinds of MR scanners. On the workstation, the ADC value of each pixel was constantly displayed on the screen with a movement of a region of interest (ROI) cursor. For each patient, the region of a high signal on the DWI and a low signal on the ADC map was identified. The ROIs were positioned on the areas with a minimum ADC on the ADC maps to produce ADC values for each brain region. If the brain regions were normal, then the ROIs were positioned on the predefined locations (Figure 1). The colour shades were used on the ADC maps to visualise the degree of ADC decrease. Regions of low ADC showed a blue colour; in contrast, regions of high ADC showed a white colour (Figure 2). The colour shades on the ADC maps identified the pixel showing the minimum ADC value in each brain region. The ADC measurements from both sides of the brain were averaged as a patient's ADC value or a control ADC value. ROI sizes varied by region, using 4 mm2 for cortex, 10 mm2 for the caudate nucleus and putamen and 25 to 40 mm2 for the subcortical white matter, thalamus, cerebellum, and pons. The percentage of the patient's ADC, as compared to the average normal control ADC in 15 different brain regions, was computed as a percent ADC value. The person placing the ROIs was blinded to the patient's outcome. To ensure accurate localisation and consistency of the measurements, the ROIs were carefully placed by a single analyst (SPC) who worked in consultation with a neuroradiologist who had 15 years of experience reading MRIs.


Diffusion-weighted magnetic resonance imaging for predicting the clinical outcome of comatose survivors after cardiac arrest: a cohort study.

Choi SP, Park KN, Park HK, Kim JY, Youn CS, Ahn KJ, Yim HW - Crit Care (2010)

This figure shows the axial apparent diffusion coefficient maps indicating the 15 regions of interest. These regions were selected for quantitative measurement of the apparent diffusion coefficient values. (1) precentral cortex, (2) postcentral cortex, (3) frontal cortex, (4) frontal white matter, (5) parietal cortex, (6) parietal white matter, (7) caudate nucleus, (8) putamen, (9) thalamus, (10) temporal cortex, (11) temporal white matter, (12) occipital cortex, (13) occipital white matter, (14) pons, and (15) cerebellum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2875532&req=5

Figure 1: This figure shows the axial apparent diffusion coefficient maps indicating the 15 regions of interest. These regions were selected for quantitative measurement of the apparent diffusion coefficient values. (1) precentral cortex, (2) postcentral cortex, (3) frontal cortex, (4) frontal white matter, (5) parietal cortex, (6) parietal white matter, (7) caudate nucleus, (8) putamen, (9) thalamus, (10) temporal cortex, (11) temporal white matter, (12) occipital cortex, (13) occipital white matter, (14) pons, and (15) cerebellum.
Mentions: The ADC values were only obtained from 22 patients who were examined using the GE Signa Excite due to the use of two kinds of MR scanners. On the workstation, the ADC value of each pixel was constantly displayed on the screen with a movement of a region of interest (ROI) cursor. For each patient, the region of a high signal on the DWI and a low signal on the ADC map was identified. The ROIs were positioned on the areas with a minimum ADC on the ADC maps to produce ADC values for each brain region. If the brain regions were normal, then the ROIs were positioned on the predefined locations (Figure 1). The colour shades were used on the ADC maps to visualise the degree of ADC decrease. Regions of low ADC showed a blue colour; in contrast, regions of high ADC showed a white colour (Figure 2). The colour shades on the ADC maps identified the pixel showing the minimum ADC value in each brain region. The ADC measurements from both sides of the brain were averaged as a patient's ADC value or a control ADC value. ROI sizes varied by region, using 4 mm2 for cortex, 10 mm2 for the caudate nucleus and putamen and 25 to 40 mm2 for the subcortical white matter, thalamus, cerebellum, and pons. The percentage of the patient's ADC, as compared to the average normal control ADC in 15 different brain regions, was computed as a percent ADC value. The person placing the ROIs was blinded to the patient's outcome. To ensure accurate localisation and consistency of the measurements, the ROIs were carefully placed by a single analyst (SPC) who worked in consultation with a neuroradiologist who had 15 years of experience reading MRIs.

Bottom Line: The restricted diffusion abnormalities in the cerebral cortex, caudate nucleus, putamen and thalamus were significantly different between the favourable (n = 13) and unfavourable (n = 26) outcome groups.The cortex and deep grey nuclei pattern was significantly associated with the unfavourable outcome (20 patients with unfavourable vs. 1 patient with favourable outcomes, P < 0.001).In the 22 patients with quantitative ADC analyses, severely reduced ADCs were noted in the unfavourable outcome group.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Emergency Medicine, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.

ABSTRACT

Introduction: The aim of this study was to examine whether the patterns of diffusion-weighted imaging (DWI) abnormalities and quantitative regional apparent diffusion coefficient (ADC) values can predict the clinical outcome of comatose patients following cardiac arrest.

Methods: Thirty-nine patients resuscitated from out-of-hospital cardiac arrest were prospectively investigated. Within five days of resuscitation, axial DWIs were obtained and ADC maps were generated using two 1.5-T magnetic resonance scanners. The neurological outcomes of the patients were assessed using the Glasgow Outcome Scale (GOS) score at three months after the cardiac arrest. The brain injuries were categorised into four patterns: normal, isolated cortical injury, isolated deep grey nuclei injury, and mixed injuries (cortex and deep grey nuclei). Twenty-three subjects with normal DWIs served as controls. The ADC and percent ADC values (the ADC percentage as compared to the control data from the corresponding region) were obtained in various regions of the brains. We analysed the differences between the favourable (GOS score 4 to 5) and unfavourable (GOS score 1 to 3) groups with regard to clinical data, the DWI abnormalities, and the ADC and percent ADC values.

Results: The restricted diffusion abnormalities in the cerebral cortex, caudate nucleus, putamen and thalamus were significantly different between the favourable (n = 13) and unfavourable (n = 26) outcome groups. The cortical pattern of injury was seen in one patient (3%), the deep grey nuclei pattern in three patients (8%), the cortex and deep grey nuclei pattern in 21 patients (54%), and normal DWI findings in 14 patients (36%). The cortex and deep grey nuclei pattern was significantly associated with the unfavourable outcome (20 patients with unfavourable vs. 1 patient with favourable outcomes, P < 0.001). In the 22 patients with quantitative ADC analyses, severely reduced ADCs were noted in the unfavourable outcome group. The optimal cutoffs for the mean ADC and the percent ADC values determined by receiver operating characteristic (ROC) curve analysis in the cortex, caudate nucleus, putamen, and thalamus predicted the unfavourable outcome with sensitivities of 67 to 93% and a specificity of 100%.

Conclusions: The patterns of brain injury in early diffusion-weighted imaging (DWI) (less than or equal to five days after resuscitation) and the quantitative measurement of regional ADC may be useful for predicting the clinical outcome of comatose patients after cardiac arrest.

Show MeSH
Related in: MedlinePlus