scholarly journals Apparent diffusion coefficient of normal adrenal glands

2016 ◽  
Vol 49 (6) ◽  
pp. 363-368 ◽  
Author(s):  
Sara Reis Teixeira ◽  
◽  
Paula Condé Lamparelli Elias ◽  
Andrea Farias de Melo Leite ◽  
Tatiane Mendes Gonçalves de Oliveira ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Adrenal Glands ◽  
Intraclass Correlation ◽  
Apparent Diffusion ◽  
Mri Scans ◽  
Adc Values ◽  
Weighted Magnetic Resonance Imaging ◽  
Adc Map ◽  
The Right

Abstract Objective: To assess the feasibility and reliability of apparent diffusion coefficient (ADC) measurements of normal adrenal glands. Materials and methods: This was a retrospective study involving 32 healthy subjects, divided into two groups: prepubertal (PreP, n = 12), aged from 2 months to 12.5 years (4 males; 8 females); and postpubertal (PostP, n = 20), aged from 11.9 to 61 years (5 males; 15 females). Diffusion-weighted magnetic resonance imaging (DW-MRI) sequences were acquired at a 1.5 T scanner using b values of 0, 20, 500, and 1000 s/mm2. Two radiologists evaluated the images. ADC values were measured pixel-by-pixel on DW-MRI scans, and automatic co-registration with the ADC map was obtained. Results: Mean ADC values for the right adrenal glands were 1.44 × 10-3 mm2/s for the PreP group and 1.23 × 10-3 mm2/s for the PostP group, whereas they were 1.58 × 10-3 mm2/s and 1.32 × 10-3 mm2/s, respectively, for the left glands. ADC values were higher in the PreP group than in the PostP group (p < 0.05). Agreement between readers was almost perfect (intraclass correlation coefficient, 0.84-0.94; p < 0.05). Conclusion: Our results demonstrate the feasibility and reliability of performing DW-MRI measurements of normal adrenal glands. They could also support the feasibility of ADC measurements of small structures.

scholarly journals Apparent Diffusion Coefficient Decreases and Magnetic Resonance Imaging Perfusion Parameters are Associated in Ischemic Tissue of Acute Stroke Patients

2001 ◽  
Vol 21 (5) ◽  
pp. 577-584 ◽  
Author(s):  
Jens Fiehler ◽  
René Knab ◽  
Jürgen R. Reichenbach ◽  
Clemens Fitzek ◽  
Cornelius Weiller ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Resonance Imaging ◽  
Time To Peak ◽  
Ischemic Tissue ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Weighted Magnetic Resonance Imaging

Perfusion-and diffusion-weighted magnetic resonance imaging scans are thought to allow the characterization of tissue at risk of infarction. The authors tested the hypothesis that the apparent diffusion coefficient (ADC) decrease should be associated with the severity of the perfusion deficit in ischemic tissue of acute stroke patients. Perfusion-and diffusion-weighted scans were performed in 11 patients with sudden onset of neurologic deficits within the last 6 hours and T2-weighted magnetic resonance imaging scans were obtained after 6 days. Parameter images of the maximum of the contrast agent concentration, time to peak, relative cerebral blood volume, relative cerebral blood flow, and relative mean transit time were computed from the perfusion-weighted data. A threshold function was used to identify tissue volumes with stepwise ADC decreases. An onionlike distribution of successively decreasing ADC values was found, with the lowest ADC in the center of the ischemic region. Correspondingly, tissue perfusion decreased progressively from the periphery toward the ischemic core. This effect was most pronounced in the time-to-peak maps, with a linear association between ADC decrease and time-to-peak increase. Apparent diffusion coefficient values decreased from the periphery toward the ischemic core, and this distribution of ADC values was strongly associated with the severity of the perfusion deficit.

scholarly journals Magnetic Resonance Imaging Characterization of the Hippocampi in Temporal Lobe Epilepsy: Correlation of Volumetry and Apparent Diffusion Coefficient with Laterality and Duration of Seizures

2021 ◽  
Author(s):  
Apoorva Muralidhar ◽  
Ashok Kumar ◽  
Arjun Prakash ◽  
Umesh Krishnamurthy ◽  
Manjunath S. ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Apparent Diffusion Coefficient ◽  
Temporal Lobe ◽  
Volumetric Analysis ◽  
Resonance Imaging ◽  
Apparent Diffusion ◽  
Adc Values ◽  
The Right

Abstract Background and Purpose It is estimated that hippocampal damage is seen in 50 to 70% of patients with temporal lobe epilepsy (TLE). Although most magnetic resonance imaging (MRI) studies are adequate to detect gross hippocampal atrophy, subtle changes that may characterize early disease in TLE, such as visually nonappreciable volume loss, may often be missed if objective volumetric analysis is not undertaken. Materials and Methods We conducted a hospital-based prospective analytical study in which 40 patients with partial seizures of temporal lobe origin were included and their hippocampal volumes (HVs) were determined by manual volumetric analysis. The findings were recorded and correlated with the side of seizure and its duration. The quantitative assessment was allotted different grades accordingly. Also, the apparent diffusion coefficient (ADC) values of bilateral hippocampi were estimated and their correlation with the side of seizure was determined. Results Most patients in the study were in the age group of 11 to 20 years (37.5%). In total, 57.5% had seizures for a period of 1 to 5 years. While 67.5% (n = 27) had seizure on the right, 32.5% (n = 13) had on the left. The mean HV estimated on the right and left were correlated with the side of seizure and found to be statistically significant (p < 0.001 in those with right-sided seizures and p = 0.02 in those with left-sided seizures). Simultaneously the ADC values estimated were found to correlate with the laterality of seizures with a statistical difference (p < 0.01). Duration of seizures however did not show a positive correlation with the HV. Conclusion MRI with quantitative estimation of HV and ADC values can depict the presence and laterality in TLE with accuracy rates that exceed those achieved by visual inspection alone. Thus, quantitative MRI provides a useful means for translating volumetric analysis into clinical practice.

scholarly journals MRI findings, including diffusion-weighted imaging and apparent diffusion coefficient value, in two cats with nasopharyngeal polyps and one cat with lymphoma

2018 ◽  
Vol 4 (2) ◽  
pp. 205511691881225 ◽  
Author(s):  
Toshiyuki Tanaka ◽  
Hideo Akiyoshi ◽  
Keiichiro Mie ◽  
Hidetaka Nishida
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Weighted Imaging ◽  
Mri Findings ◽  
Adc Value ◽  
Mri Examination ◽  
Diffusion Weighted ◽  
Apparent Diffusion ◽  
Adc Values ◽  
Adc Map

Objectives Most nasopharyngeal masses in cats are lymphomas or polyps. To our knowledge, there is no report of MRI findings, including diffusion-weighted imaging (DWI) or apparent diffusion coefficient (ADC) values, of nasopharyngeal lymphomas and nasopharyngeal polyps in cats. This study aimed to evaluate the MRI findings of nasopharyngeal lymphomas and nasopharyngeal polyps, including DWI and ADC values. Methods MRI examination was performed on two cats with a histologically confirmed nasopharyngeal polyp and one cat with lymphoma. The magnetic resonance scanning protocol included T2-weighted imaging (T2WI), T1-weighted imaging (T1WI) and DWI. An ADC map was created based on DWI. ADC values were then calculated. Results MRI of the nasopharyngeal polyps revealed well-defined masses with strong rim enhancement, mass-associated stalk-like structures and asymmetric tympanic bulla lesions. The polyps appeared hyperintense on T2WI, hypo- to isointense on T1WI, and of mixed intensity or hypointense on DWI. On the ADC map, the masses appeared hyperintense. The ADC values of the polyps were 2.07 × 10−3 mm2/s and 2.28 × 10−3 mm2/s. MRI examination of the nasopharyngeal lymphoma revealed a strongly enhancing heterogeneous lesion. The mass appeared mildly hyperintense on T2WI, isointense on T1WI and hyperintense on DWI. On the ADC map, the mass appeared hypointense. The ADC value of the mass was 0.46 ×10−3 mm2/s. The ADC values of the nasopharyngeal polyps were higher than the ADC value of the nasopharyngeal lymphoma. Conclusions and relevance Measurement of ADC values may be useful for differentiating between nasopharyngeal polyps and nasopharyngeal lymphomas.

scholarly journals Apparent diffusion coefficient cannot discriminate metastatic and non-metastatic lymph nodes in rectal cancer: a meta-analysis

2021 ◽  
Author(s):  
Alexey Surov ◽  
Hans-Jonas Meyer ◽  
Maciej Pech ◽  
Maciej Powerski ◽  
Jasan Omari ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Lymph Nodes ◽  
Meta Analysis ◽  
Adc Value ◽  
Metastatic Lymph Nodes ◽  
Metastatic Lymph ◽  
Apparent Diffusion ◽  
Adc Values

Abstract Background Our aim was to provide data regarding use of diffusion-weighted imaging (DWI) for distinguishing metastatic and non-metastatic lymph nodes (LN) in rectal cancer. Methods MEDLINE library, EMBASE, and SCOPUS database were screened for associations between DWI and metastatic and non-metastatic LN in rectal cancer up to February 2021. Overall, 9 studies were included into the analysis. Number, mean value, and standard deviation of DWI parameters including apparent diffusion coefficient (ADC) values of metastatic and non-metastatic LN were extracted from the literature. The methodological quality of the studies was investigated according to the QUADAS-2 assessment. The meta-analysis was undertaken by using RevMan 5.3 software. DerSimonian, and Laird random-effects models with inverse-variance weights were used to account the heterogeneity between the studies. Mean DWI values including 95% confidence intervals were calculated for metastatic and non-metastatic LN. Results ADC values were reported for 1376 LN, 623 (45.3%) metastatic LN, and 754 (54.7%) non-metastatic LN. The calculated mean ADC value (× 10−3 mm2/s) of metastatic LN was 1.05, 95%CI (0.94, 1.15). The calculated mean ADC value of the non-metastatic LN was 1.17, 95%CI (1.01, 1.33). The calculated sensitivity and specificity were 0.81, 95%CI (0.74, 0.89) and 0.67, 95%CI (0.54, 0.79). Conclusion No reliable ADC threshold can be recommended for distinguishing of metastatic and non-metastatic LN in rectal cancer.

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