scholarly journals Repeatability and reproducibility of MRI apparent diffusion coefficient applied on four different regions of interest for patients with axial spondyloarthritis and healthy volunteers scanned twice within a week

BJR|Open ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 20200004
Author(s):  
Jakob Møllenbach Møller ◽  
Mikkel Østergaard ◽  
Henrik S Thomsen ◽  
Stine Hangaard ◽  
Inge J Sørensen ◽  
...  

Objectives: The apparent diffusion coefficient (ADC) may be used as a biomarker for diagnosis and/or monitoring treatment response in patients with axial spondyloarthritis (axSpA), but this requires reliable ADC measurements. This study assessed test–retest repeatability and reproducibility of ADC measurements using four different region of interest (ROI) settings. Methods: In this prospective study, the sacroiliac joints (SIJs) of 25 patients with axSpA and 24 age- and sex-matched healthy volunteers were imaged twice at a mean interval of 6.8 days in a 1.5 T scanner using, multishot echoplanar diffusion-weighted sequences. ADCs at four ROI settings were assessed: 5 mm and 10 mm anatomic band-shaped, 15 mm linear, and 40 mm2 circular. Results: Intraclass correlation coefficient (ICC) assessments showed that the interstudy repeatability was good for median ADC (ADCmed) and 95th-percentile ADC (ADC95) measurements in patients with axSpA (0.77–0.83 and 0.75–0.83, respectively), but poor-to-moderate in healthy subjects (0.27–0.55 and 0.13–0.37, respectively). For all ROI settings, intrareader reproducibility was excellent for ADCmed-measurements (ICC:0.85–0.99) and moderate-to-excellent for ADC95 measurements (ICC:0.68–0.96). The 5 mm ROI had the least estimated bias and highest level of agreement on Bland–Altman plots. The interreader reproducibility was moderate (ICC:0.71). The 15 mm linear ROI produced significantly greater ADCmed and ADC95 measurements than all other ROI settings (p < 0.01–0.02), except for the circular ROI ADC95 measurements. Conclusion: ROI settings influence ADC measurements. Interstudy repeatability of SIJ ADC measurements is independent of ROI settings. However, the 5 mm ROI showed the least bias and random error and seems preferable. Advances in knowledge: ADC measurements are affected by ROI settings, and this should be taken into account when assessing ADC maps.

2020 ◽  
Vol 133 (2) ◽  
pp. 573-579 ◽  
Author(s):  
Matthew S. Willsey ◽  
Kelly L. Collins ◽  
Erin C. Conrad ◽  
Heather A. Chubb ◽  
Parag G. Patil

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.


2015 ◽  
Vol 21 (2) ◽  
pp. 123-127 ◽  
Author(s):  
Luísa Nogueira ◽  
Sofia Brandão ◽  
Eduarda Matos ◽  
Rita Gouveia Nunes ◽  
Hugo Alexandre Ferreira ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247301
Author(s):  
Jelena Djokić Kovač ◽  
Marko Daković ◽  
Aleksandra Janković ◽  
Milica Mitrović ◽  
Vladimir Dugalić ◽  
...  

Background The utility of intravoxel incoherent motion (IVIM) related parameters in differentiation of hypovascular liver lesions is still unknown. Purpose The purpose of this study was to evaluate the value of IVIM related parameters in comparison to apparent diffusion coefficient (ADC) for differentiation among intrahepatic mass-forming cholangiocarcinoma (IMC), and hypovascular liver metastases (HLM). Methods Seventy-four prospectively enrolled patients (21 IMC, and 53 HLM) underwent 1.5T magnetic resonance examination with IVIM diffusion-weighted imaging using seven b values (0–800 s/mm2). Two independent readers performed quantitative analysis of IVIM-related parameters and ADC. Interobserver reliability was tested using a intraclass correlation coefficient. ADC, true diffusion coefficient (D), perfusion-related diffusion coefficient (D*), and perfusion fraction (ƒ) were compared among the lesions using Kruskal-Wallis H test. The diagnostic accuracy of each parameter was assessed by receiver operating characteristic (ROC) curve analysis. Results The interobserver agreement was good for ADC (0.802), and excellent for D, D*, and ƒ (0.911, 0.927, and 0.942, respectively). ADC, and D values were significantly different among IMC and HLM (both p < 0.05), while there was no significant difference among these lesions for ƒ and D* (p = 0.101, and p = 0.612, respectively). ROC analysis showed higher diagnostic performance of D in comparison to ADC (AUC = 0.879 vs 0.821). Conclusion IVIM-derived parameters in particular D, in addition to ADC, could help in differentiation between most common hypovascular malignant liver lesions, intrahepatic mass—forming cholangiocarcinoma and hypovascular liver metastases.


Author(s):  
G.B. Marshall ◽  
V.R. Heale ◽  
L. Herx ◽  
A. Abdeen ◽  
L. Mrkonjic ◽  
...  

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.


2020 ◽  
Vol 9 (3) ◽  
pp. 205846012090601 ◽  
Author(s):  
Jakob M Møller ◽  
Mikkel Østergaard ◽  
Henrik S Thomsen ◽  
Inge J Sørensen ◽  
Ole R Madsen ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document