scholarly journals The apparent diffusion coefficient does not reflect cytotoxic edema on the uninjured side after traumatic brain injury

2014 ◽  
Vol 9 (9) ◽  
pp. 973 ◽  
Author(s):  
Hong Lu ◽  
Xiaoyan Lei
Keyword(s):  
Traumatic Brain Injury ◽  
Diffusion Coefficient ◽  
Brain Injury ◽  
Apparent Diffusion Coefficient ◽  
Cytotoxic Edema ◽  
Uninjured Side ◽  
Apparent Diffusion

Decreased apparent diffusion coefficient in the pituitary and correlation with hypopituitarism in patients with traumatic brain injury

2015 ◽  
Vol 123 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Ping Zheng ◽  
Bin He ◽  
Yijun Guo ◽  
Jingsong Zeng ◽  
Wusong Tong
Keyword(s):  
Traumatic Brain Injury ◽  
Diffusion Coefficient ◽  
Brain Injury ◽  
Apparent Diffusion Coefficient ◽  
Neurological Outcome ◽  
Pituitary Function ◽  
Adc Value ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Adc Values

OBJECT The relationship between microstructural abnormality in patients with traumatic brain injury (TBI) and hormone-secreting status remains unknown. In this study, the authors aimed to identify the role of the apparent diffusion coefficient (ADC) using a diffusion-weighted imaging (DWI) technique and to evaluate the association of such changes with hypopituitarism in patients with TBI. METHODS Diffusion-weighted images were obtained in 164 consecutive patients with TBI within 2 weeks after injury to generate the pituitary ADC as a measure of microstructural change. Patients with TBI were further grouped into those with and those without hypopituitarism based on the secretion status of pituitary hormones at 6 months postinjury. Thirty healthy individuals were enrolled in the study and underwent MRI examinations for comparison. Mean ADC values were compared between this control group, the patients with TBI and hypopituitarism, and the patients with TBI without hypopituitarism; correlational studies were also performed. Neurological outcome was assessed with the Glasgow Outcome Scale (GOS) for all TBI patients 6 months postinjury. RESULTS In the TBI group, 84 patients had hypopituitarism and 80 had normal pituitary function. The pituitary ADC in TBI patients was significantly less than that in controls (1.83 ± 0.16 vs 4.13 ± 0.33, p < 0.01). Furthermore, the mean ADC was much lower in TBI patients with hypopituitarism than in those without pituitary dysfunction (1.32 ± 0.09 vs 2.28 ± 0.17, p < 0.05). There was also a significant difference in ADC values between patients with hyperprolactinemia and those with normal prolactin levels (p < 0.05). Additionally, the receiver operating characteristic curve analysis showed that the pituitary ADC could predict hypopituitarism with a sensitivity of 90.0% and a specificity of 90.1% at the level of 1.720 (ADC value). Finally, the ADC value was positively correlated with neurological outcome at 6 months following TBI (r = 0.602, p < 0.05). CONCLUSIONS Use of DWI demonstrated that the pituitary ADC is correlated with hormone-secreting status in TBI patients. The authors suggest that pituitary ADC may be a useful biomarker to predict pituitary function in patients with TBI.

scholarly journals Magnetic Resonance Diffusion W Imaging in Cerebral Fat Embolism

2004 ◽  
Vol 31 (3) ◽  
pp. 417-421 ◽  
Author(s):  
G.B. Marshall ◽  
V.R. Heale ◽  
L. Herx ◽  
A. Abdeen ◽  
L. Mrkonjic ◽  
...  
Keyword(s):  
Cell Death ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Imaging ◽  
Fat Embolism ◽  
Cytotoxic Edema ◽  
Apparent Diffusion ◽  
Weighted Sequences ◽  
Apparent Diffusion Coefficient Mapping

The use of diffusion weighted imaging with apparent diffusion coefficient mapping in the diagnosis of cerebral fat embolism is shown here to demonstrate infarcts secondary to fat emboli more intensely than T2 weighted sequences 24 hours after the onset of symptoms. Embolic foci are hypointense on apparent diffusion coefficient mapping consistent with cytotoxic edema associated with cell death and restricted water diffusion. This technique increases the sensitivity for detecting cerebral fat embolism and offers a potentially important tool in its diagnosis.

scholarly journals Utility of tubular retractors to minimize surgical brain injury in the removal of deep intraparenchymal lesions: a quantitative analysis of FLAIR hyperintensity and apparent diffusion coefficient maps

2016 ◽  
Vol 124 (4) ◽  
pp. 1053-1060 ◽  
Author(s):  
Evan D. Bander ◽  
Samuel H. Jones ◽  
Ilhami Kovanlikaya ◽  
Theodore H. Schwartz
Keyword(s):  
Diffusion Coefficient ◽  
Brain Injury ◽  
Apparent Diffusion Coefficient ◽  
Brain Lesions ◽  
Restricted Diffusion ◽  
Cellular Damage ◽  
Total Resection ◽  
Tubular Retractor ◽  
Apparent Diffusion ◽  
Apparent Diffusion Coefficient Maps

OBJECT Brain retraction systems are frequently required to achieve surgical exposure of deep-seated brain lesions. Spatula-based systems can be associated with injury to the cortex and deep white matter, particularly adjacent to the sharp edges, which can result in uneven pressure on the parenchyma over the course of a long operation. The use of tubular retractor systems has been proposed as a method to overcome these limitations. There have been no studies assessing the degree of brain injury associated with the use of tubular retractors. METHODS Twenty patients were retrospectively identified at Weill Cornell Medical College who underwent resection of deep-seated brain lesions between 2005 and 2014 with the aid of a METRx tubular retractor system. Using the Brainlab software, pre- and postoperative images were analyzed to assess volume, depth, extent of resection, and change in postoperative MR FLAIR hyperintensity and restricted diffusion on diffusion-weighted imaging (DWI). RESULTS The mean preoperative tumor volume was 16.25 ± 17.6 cm3. Gross-total resection was achieved in 75%, near-total resection in 10%, and subtotal resection in 15% of patients. There was a small but not statistically significant increase in average FLAIR hyperintensity volume by 3.25 ± 10.51 cm3 (p = 0.16). The average postoperative volume of DWI high signal area with restricted diffusion on apparent diffusion coefficient maps was 8.35 ± 3.05 cm3. Assuming that the volume of restricted diffusion on DWI around tumor was 0 preoperatively, this represented a statistically significant increase on DWI (p < 0.001). CONCLUSIONS Although tubular retractors do not appear to significantly increase FLAIR signal in the brain, DWI intensity around the retractors can be identified. These data indicate that although tubular retractors may minimize damage to surrounding tissues, they still cause cytotoxic edema and cellular damage. Objective comparison against other retraction methods, as compared by 3D volumetric analysis or similar methods, will be important in determining the true advantage of tubular retractor systems.

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