Low signal intensities of MRI T1 mapping predict refractory diplopia in Graves’ ophthalmopathy

Abstract

ObjectiveIn Graves’ ophthalmopathy (GO), fibrosis in extraocular muscles (EOMs) may be related to intravenous glucocorticoid (ivGC)‐resistant diplopia. Signal intensity (SI) of magnetic resonance imaging (MRI) T1 mapping can quantify properties of EOM components, including fibrosis. We investigated EOM features of GO patients with diplopia using T1 mapping SI and the predictive value of T1 mapping SI in the response of diplopia to ivGCs.DesignWe performed a cross‐sectional study that included 13 active GO patients, 34 inactive GO patients with history of diplopia, including 20 with a history of diplopia disappearance, 14 GO patients with refractory diplopia and 35 control subjects. In nine active GO patients, the relationship between T1 mapping SI at pretreatment and at diplopia outcome after ivGC treatment was prospectively investigated.MethodsT1 mapping SI of left and right inferior rectus and medial rectus muscles was measured in all participants.ResultsT1 mapping SI in inactive GO patients with refractory diplopia was significantly lower than that of other groups in all evaluated EOMs. Diagnostic accuracy for refractory diplopia by T1 mapping SI in GO patients with a history of diplopia disappearance was excellent (AUC 0.89) compared with other assessments. Furthermore, among nine active GO patients, pretreatment T1 mapping SI in four patients with ivGC‐resistant diplopia tended to be low compared with the other five patients with improved diplopia.ConclusionsLow intensity T1 mapping in EOMs is likely to be associated with refractory diplopia and may be useful in predicting the response of diplopia to ivGCs.

Elbow valgus stability of the transverse bundle of the ulnar collateral ligament

“…Second, it has been reported that the mechanical properties of Thiel cadaver are not similar to life-like, depending on the measurement part [ 42 ]. But, in a previous study, it was revealed that the changes in JS associated with increased elbow valgus stress are similar to those in human volunteers [ 41 ]. Third, this study is that the dominant hand of the donors was unknown, and whether donors had been involved in overhead sports during their lifetime was also unknown.…”

“…This study referred to a previous study [ 41 ] that measured the JS. Thiel-embalmed cadavers were placed in the supine position, with the shoulder abducted and in 90° of external rotation, with the elbow flexed to 30° and the forearm supinated in a Telos Stress Device (Telos) (Aimedic MMT, Tokyo, Japan).…”

“…and the Telos was performed by another operator (K.M.). This study also referred to a previous study [ 41 ] for the measurement protocol. The Telos was first set to starting limb position, and three images of the medial elbow were taken.…”

“…Thiel embalming has been reported as a fixation method that can maintain flexibility in a life-like condition [ 37 , 38 ], facilitating reliable ultrasound imaging [ 39 , 40 ] and life-like mechanical properties [ 37 , 39 , 40 ]. In addition, Thiel-embalmed cadavers reportedly show JS changes similar to those seen in living human volunteers when elbow valgus stress is applied [ 41 ]. Specimens with deformation of the elbow joint or a history or elbow surgery were excluded.…”

“…2B ). Sufficient the intraclass correlation coefficient (ICC) has been confirmed for the US measurement [ 41 ]. US measurement was performed by 1 operator (M.E.)…”