scholarly journals Quantitative Radiomics: Impact of Pulse Sequence Parameter Selection on MRI-Based Textural Features of the Brain

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
John Ford ◽  
Nesrin Dogan ◽  
Lori Young ◽  
Fei Yang

Objectives. Radiomic features extracted from diverse MRI modalities have been investigated regarding their predictive and/or prognostic value in a variety of cancers. With the aid of a 3D realistic digital MRI phantom of the brain, the aim of this study was to examine the impact of pulse sequence parameter selection on MRI-based textural parameters of the brain. Methods. MR images of the employed digital phantom were realized with SimuBloch, a simulation package made for fast generation of image sequences based on the Bloch equations. Pulse sequences being investigated consisted of spin echo (SE), gradient echo (GRE), spoiled gradient echo (SP-GRE), inversion recovery spin echo (IR-SE), and inversion recovery gradient echo (IR-GRE). Twenty-nine radiomic textural features related, respectively, to gray-level intensity histograms (GLIH), cooccurrence matrices (GLCOM), zone size matrices (GLZSM), and neighborhood difference matrices (GLNDM) were evaluated for the obtained MR realizations, and differences were identified. Results. It was found that radiomic features vary considerably among images generated by the five different T1-weighted pulse sequences, and the deviations from those measured on the T1 map vary among features, from a few percent to over 100%. Radiomic features extracted from T1-weighted spin-echo images with TR varying from 360 ms to 620 ms and TE = 3.4 ms showed coefficients of variation (CV) up to 45%, while up to 70%, for T2-weighted spin-echo images with TE varying over the range 60–120 ms and TR = 6400 ms. Conclusion. Variability of radiologic textural appearance on MR realizations with respect to the choice of pulse sequence and imaging parameters is feature-dependent and can be substantial. It calls for caution in employing MRI-derived radiomic features especially when pooling imaging data from multiple institutions with intention of correlating with clinical endpoints.

2002 ◽  
Vol 43 (5) ◽  
pp. 464-473
Author(s):  
M. Alemany Ripoll ◽  
R. Raininko

Purpose: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages. Material and Methods: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals. Results: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90–95% at 0.5 T. Blood in the CSF spaces was significantly ( p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive. Conclusion: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.


2016 ◽  
Vol 16 (08) ◽  
pp. 1640020
Author(s):  
SHUO LI ◽  
YANCHUN ZHU ◽  
JIE YANG ◽  
YAOQIN XIE ◽  
SONG GAO

The newly developed open superconducting magnetic resonance imaging (MRI) system, which combines the advantages of the high magnetic fields of superconducting MRI systems and open characteristics of permanent MRI systems, has great potential in clinical and research applications. However, few pulse sequences are applicable to this system. In addition, further testing on this system is needed. Therefore, in this paper, an inversion recovery gradient echo (IR-GE) pulse sequence was developed based on the features of the 0.7 Tesla open superconducting MRI system. An MR Solutions spectrometer was used to control the IR-GE pulse sequence. The developed IR-GE pulse sequence was applied to a pure water phantom using different inversion recovery times (TI). The results of the theoretical analysis and experiments indicate that the developed IR-GE pulse sequence could be effectively applied to the 0.7 Tesla open superconducting MRI system.


2003 ◽  
Vol 48 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Tabassum Laz Haque ◽  
Yukio Miki ◽  
Mitsunori Kanagaki ◽  
Takahiro Takahashi ◽  
Akira Yamamoto ◽  
...  

1999 ◽  
Vol 17 (5) ◽  
pp. 663-668 ◽  
Author(s):  
A.H Karantanas ◽  
N Papanikolaou ◽  
K Vasiou ◽  
E Lavdas

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Morgenstern ◽  
B Mikolich ◽  
D Morgenstern ◽  
J R Mikolich

Abstract Background The Lake Louise Criteria for the diagnosis of myocarditis by cardiac MRI (CMR) was published in 2009 (JACC April 2009; 53(17): 1475–1487) utilizing T2 STIR, “early” gadolinium enhancement (EGE) and late gadolinium enhancement (LGE). In 2012, our CMR unit adopted a chest pain protocol to enhance detection of inflammatory heart disease, using all 3 pulse sequences. In 2017, T1 relaxing mapping and T2 relaxation mapping were added to the chest pain protocol. Purpose This study was designed to assess the impact of pulse sequence changes in the CMR chest pain protocol on the detection rate of myocarditis. Methods An institutional cardiac imaging database was queried for all patients with chest pain who underwent a CMR study from 2009 thru 2018. The number of newly diagnosed cases of myocarditis per year was computed, based on the prevailing CMR diagnostic criteria at that time. The detection rate of new myocarditis cases per year, was calculated by dividing the number of new cases by the total of CMR studies performed for evaluation of chest pain, during each calendar year. Results Of the 4,946 patients in the cardiac imaging database, 2,126 patients underwent CMR imaging for complaints of chest pain. Detection rates of myocarditis by year are shown in Figure 1. Prior to inclusion of T1 STIR pulse sequences, CMR detection of myocarditis was nearly nil. Use of T2 STIR imaging allowed for an increased rate of myocarditis detection. However, addition of T1 mapping and T2 mapping in 2017 resulted in another increase in myocarditis detection rates from baseline. Figure 1. Detection rate of myocarditis. Conclusions Detection rates of myocarditis using CMR were improved by using T2 STIR pulse sequences, per the initial Lake Louise Criteria. Further enhancement of myocarditis detection rates is achieved by addition of T1 and T2 mapping. These CMR impact data provide additional support for the adoption of the recently modified Lake Louise Criteria (JACC Dec 2018; 72(24): 3158–3176).


2010 ◽  
Vol 113 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Ahmed K. Toma ◽  
Andrew Tarnaris ◽  
Joan P. Grieve ◽  
Laurence D. Watkins ◽  
Neil D. Kitchen

Object In this paper, the authors' goal was to compare the artifact induced by implanted (in vivo) adjustable shunt valves in spin echo, diffusion weighted (DW), and gradient echo MR imaging pulse sequences. Methods The MR images obtained in 8 patients with proGAV and 6 patients with Strata II adjustable shunt valves were assessed for artifact areas in different planes as well as the total volume for different pulse sequences. Results Artifacts induced by the Strata II valve were significantly larger than those induced by proGAV valve in spin echo MR imaging pulse sequence (29,761 vs 2450 mm3 on T2-weighted fast spin echo, p = 0.003) and DW images (100,138 vs 38,955 mm3, p = 0.025). Artifacts were more marked on DW MR images than on spin echo pulse sequencse for both valve types. Conclusions Adjustable valve–induced artifacts can conceal brain pathology on MR images. This should influence the choice of valve implantation site and the type of valve used. The effect of artifacts on DW images should be highlighted pending the development of less MR imaging artifact–inducing adjustable shunt valves.


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