In:
Investigative Radiology, Ovid Technologies (Wolters Kluwer Health), Vol. 57, No. 5 ( 2022-5), p. 301-307
Abstract:
Multi spin echo (MSE) sequences are often used for obtaining T2-relaxometry data as they provide defined echo times (TEs). Due to their time-consuming acquisition, they are frequently replaced by turbo spin echo (TSE) sequences that in turn bear the risk of systematic errors when analyzing small structures or lesions. With this study, we aim to test whether T2-relaxometry data derived from either dual-echo TSE or 12-echo MSE sequences are equivalent for quantifying peripheral nerve lesions. Hereditary transthyretin (ATTRv) amyloidosis was chosen as a surrogate disease, as it allows the inclusion of both asymptomatic carriers of the underlying variant transthyretin gene (var TTR ) and symptomatic ATTRv amyloidosis patients. Materials and Methods Overall, 50 participants with genetically confirmed var TTR (20 clinically symptomatic ATTRv amyloidosis; 4 females, 16 males; mean age, 61.8 years; range, 33–76 years; and 30 asymptomatic var TTR -carriers; 18 females, 12 males; mean age, 43.1 years; range, 21–62 years), and 30 healthy volunteers (13 females, 17 males, mean age 41.3 years, range 22–73) were prospectively included and underwent magnetic resonance neurography at 3 T. T2-relaxometry was performed by acquiring an axial 2-dimensional dual-echo TSE sequence with spectral fat saturation (TE 1 /TE 2 , 12/73 milliseconds; TR, 5210 milliseconds; acquisition time, 7 minutes, 30 seconds), and an axial 2-dimensional MSE sequence with spectral fat saturation and with 12 different TE (TE 1 , 10 milliseconds to TE 12 , 120 milliseconds; ΔTE, 10 milliseconds; TR, 3000 milliseconds; acquisition time, 11 minutes, 23 seconds) at the right mid to lower thigh. Sciatic nerve regions of interest were manually drawn in ImageJ on 10 central slices per participant and sequence, and the apparent T2-relaxation time (T2app) and proton spin density (ρ) were calculated individually from TSE and MSE relaxometry data. Results Linear regression showed that T2app values obtained from the dual-echo TSE (T2app TSE ), and those calculated from the 12-echo MSE (T2app MSE ) were mathematically connected by a factor of 1.3 throughout all groups (controls: 1.26 ± 0.02; var TTR- carriers: 1.25 ± 0.02; symptomatic ATTRv amyloidosis: 1.28 ± 0.02), whereas a factor of 0.5 was identified between respective ρ values (controls: 0.47 ± 0.01; var TTR- carriers: 0.47 ± 0.01; symptomatic ATTRv amyloidosis: 0.50 ± 0.02). T2app calculated from both TSE and MSE, distinguished between symptomatic ATTRv (T2app TSE 66.38 ± 2.6; T2 appMSE 84.6 ± 3.3) and controls (T2app TSE 58.1 ± 1.0, P = 0.0028; T2app MSE 72.8 ± 0.7, P 〈 0.0001), whereas differences between var TTR- carriers (T2app TSE 61.8 ± 1.5; T2app MSE 76.7 ± 1.3) and ATTRv amyloidosis were observed only for T2app MSE ( P = 0.0082). The ρ value differentiated well between healthy controls (ρ TSE 365.1 ± 7.2; ρ MSE 170.4 ± 3.8) versus var TTR- carriers (ρ TSE 415.7 ± 9.8, P = 0.0027; ρ MSE 193.7 ± 5.3, P = 0.0398) and versus symptomatic ATTRv amyloidosis (ρ TSE 487.8 ± 17.9; ρ MSE 244.7 ± 13.1, P 〈 0.0001, respectively), but also between var TTR -carriers and ATTRv amyloidosis (ρ TSE P = 0.0001; ρ MSE P 〈 0.0001). Conclusions Dual-echo TSE and 12-echo MSE sequences provide equally robust and reliable T2-relaxometry data when calculating T2app and ρ. Due to their shorter acquisition time and higher resolution, TSE sequences may be preferred in future magnetic resonance imaging protocols. As a secondary result, ρ can be confirmed as a sensitive biomarker to detect early nerve lesions as it differentiated best among healthy controls, asymptomatic var TTR -carriers, and symptomatic ATTRv amyloidosis, whereas T2app might be beneficial in already manifest ATTRv amyloidosis.
Type of Medium:
Online Resource
ISSN:
1536-0210
,
0020-9996
DOI:
10.1097/RLI.0000000000000837
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2022
detail.hit.zdb_id:
2041543-6
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