scholarly journals NMR Imaging of the Apparent Diffusion Coefficient (ADC) for the Evaluation of Metabolic Suppression and Recovery after Prolonged Cerebral Ischemia

1994 ◽  
Vol 14 (5) ◽  
pp. 723-731 ◽  
Author(s):  
Konstantin-Alexander Hossmann ◽  
Matthias Fischer ◽  
Kurt Bockhorst ◽  
Mathias Hoehn-Berlage
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Extracellular Volume ◽  
Induced Hypotension ◽  
Tissue Ph ◽  
Close Relationship ◽  
Apparent Diffusion ◽  
Internal Mammary ◽  
Systemic Variables ◽  
Postischemic Recovery

Adult normothermic cats were submitted to 1-h complete cerebrocirculatory arrest by intrathoracic occlusion of the internal mammary, the innominate, and the subclavian arteries in combination with pharmacologically induced hypotension. After ischemia, recirculation was initiated at different blood pressure levels to manipulate the postischemia resuscitation conditions. The resulting spectrum of postischemic recovery was studied by combining nuclear magnetic resonance imaging of the apparent diffusion coefficient (ADC) with pictorial assays of brain tissue pH, ATP, glucose, and lactate. Before ischemia, the mean ADC (average of seven coronal slices of five cats) was 713 ± 40 × 10−6 mm2/s. After 10-min ischemia, ADC declined to 68% of control and after 50 min slightly further to 63% of control. During recirculation after 1-h ischemia, recovery of ADC varied depending on the initial reperfusion pressure and other systemic variables. In two animals ADC only transiently increased followed by a secondary decline below the postischemic level. In three other animals ADC returned to near control within 1 h of recirculation. The comparison of ADC changes with previously reported changes in extracellular volume revealed a close relationship, supporting the notion that ADC is a function of the intra/extracellular water compartmentation. Recovery of ADC correlated closely with tissue pH and metabolic recovery, studied 3 h after the initiation of recirculation. Animals without recovery of ADC exhibited global depletion of ATP and glucose and severe lactacidosis, whereas animals with recovery of ADC showed replenishment of ATP and glucose to near control and a substantial reversal of lactacidosis. Our data demonstrate that imaging of ADC provides reliable information about the metabolic state of the brain and can be used to monitor, with high temporal and regional resolution, the manifestation and reversal of ischemic brain injury.

scholarly journals Erratum

2017 ◽  
Vol 59 (6) ◽  
pp. NP11-NP11
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Myocardial Fibrosis ◽  
Lupus Erythematosus ◽  
Extracellular Volume ◽  
Strongly Correlated ◽  
Systemic Lupus ◽  
Apparent Diffusion

Wu R, An DA, Hu J, et al. The apparent diffusion coefficient is strongly correlated with extracellular volume, a measure of myocardial fibrosis, and subclinical cardiomyopathy in patients with systemic lupus erythematosus. Acta Radiol 2017. DOI: 10.1177/0284185117717763. In the above-referenced article, the corresponding author was wrongly listed as “Lian-Ming Wu” in the initial OnlineFirst version. The online and print versions have been updated to reflect the correct corresponding author, “Jian-Rong Xu.”

The apparent diffusion coefficient is strongly correlated with extracellular volume, a measure of myocardial fibrosis, and subclinical cardiomyopathy in patients with systemic lupus erythematosus

2017 ◽  
Vol 59 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Rui Wu ◽  
Dong-Aolei An ◽  
Jiani Hu ◽  
Meng Jiang ◽  
Qiang Guo ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Myocardial Fibrosis ◽  
Lupus Erythematosus ◽  
Extracellular Volume ◽  
Systemic Lupus ◽  
Suitable Alternative ◽  
Native T1 ◽  
Apparent Diffusion

Background Extracellular volume (ECV) has been histologically validated as a non-invasive quantitative index of myocardial fibrosis that does not require the use of contrast, which is contraindicated in patients with renal insufficiency. Purpose To evaluate the correlation between the contrast-free apparent diffusion coefficient (ADC) and ECV, an index of fibrosis. Material and Methods Twenty-four patients with systemic lupus erythematosus (SLE), who were predominantly women (mean age = 36 ± 12 years) and 12 normal participants (mean age = 38 ± 10 years) underwent cardiac magnetic resonance (CMR) via 3.0 T MR with T1 mapping. Diffusion-weighted imaging (DWI) and late gadolinium-enhanced (LGE) imaging served as the reference standards with which CMR was compared. The mean ADC, native T1, and ECV were calculated for each patient, and the correlations among these parameters were analyzed. Results Both SLE LGE-positive (LGE+) and SLE LGE-negative (LGE–) participants had higher native T1 values, ECV, and ADC than normal controls ( P < 0.05). SLE LGE+ participants exhibited a higher ECV (0.31 ± 0.02) and ADC (2.44 ± 0.32 × 10−3 mm2/s) than SLE LGE– participants ( p < 0.05); however, SLE LGE+ and SLE LGE– participants had similar native T1 values (1227 ± 48.81 ms versus 1174.70 ± 95.80 ms, respectively; P > 0.05). ADC values were positively correlated with increased ECV (R2 = 0.62) and native T1 values (R2 = 0.28) in all participants. Conclusion ADC measurements are a suitable alternative to ECV that may be used to assess and quantify myocardial fibrosis in patients with SLE.

Diffusion tensor imaging reveals microstructural differences between subtypes of trigeminal neuralgia

2020 ◽  
Vol 133 (2) ◽  
pp. 573-579 ◽  
Author(s):  
Matthew S. Willsey ◽  
Kelly L. Collins ◽  
Erin C. Conrad ◽  
Heather A. Chubb ◽  
Parag G. Patil
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Tensor Imaging ◽  
Trigeminal Neuralgia ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Tensor ◽  
Statistical Significance ◽  
Region Of Interest ◽  
Pain Syndrome ◽  
Radial Diffusivity ◽  
Apparent Diffusion

OBJECTIVETrigeminal neuralgia (TN) is an uncommon idiopathic facial pain syndrome. To assist in diagnosis, treatment, and research, TN is often classified as type 1 (TN1) when pain is primarily paroxysmal and episodic or type 2 (TN2) when pain is primarily constant in character. Recently, diffusion tensor imaging (DTI) has revealed microstructural changes in the symptomatic trigeminal root and root entry zone of patients with unilateral TN. In this study, the authors explored the differences in DTI parameters between subcategories of TN, specifically TN1 and TN2, in the pontine segment of the trigeminal tract.METHODSThe authors enrolled 8 patients with unilateral TN1, 7 patients with unilateral TN2, and 23 asymptomatic controls. Patients underwent DTI with parameter measurements in a region of interest within the pontine segment of the trigeminal tract. DTI parameters were compared between groups.RESULTSIn the pontine segment, the radial diffusivity (p = 0.0049) and apparent diffusion coefficient (p = 0.023) values in TN1 patients were increased compared to the values in TN2 patients and controls. The DTI measures in TN2 were not statistically significant from those in controls. When comparing the symptomatic to asymptomatic sides in TN1 patients, radial diffusivity was increased (p = 0.025) and fractional anisotropy was decreased (p = 0.044) in the symptomatic sides. The apparent diffusion coefficient was increased, with a trend toward statistical significance (p = 0.066).CONCLUSIONSNoninvasive DTI analysis of patients with TN may lead to improved diagnosis of TN subtypes (e.g., TN1 and TN2) and improve patient selection for surgical intervention. DTI measurements may also provide insights into prognosis after intervention, as TN1 patients are known to have better surgical outcomes than TN2 patients.

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