Fortschr Röntgenstr 2018; 190(06): 560
DOI: 10.1055/s-0043-124192
Letter to the Editor
© Georg Thieme Verlag KG Stuttgart · New York

Appropriate Normal Range of Lumbar Disc T1rho of Men and Women with Respect to Physiological Aging

Yì Xiáng J Wáng
Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
› Author Affiliations
Further Information

Publication History

21 October 2017

29 November 2017

Publication Date:
15 May 2018 (online)

Dear Editor,

I read the article by Gübitz et al. [1] with great interest. The data provided by the authors are highly valuable, since even though numerous publications on T2 / T2*/T1rho relaxometry of lumbar intervertebral discs have been published, most of those studies were based on a small sample of selected volunteers or on patients with non-specific low back pain (LBP) who may or may not have disc pathologies associated with LBP. T2 / T2*/T1rho relaxometry data sampled from a general population remain scare [2]. T1rho demonstrates a number of advantages over conventional T2 for disc degeneration evaluation [3] [4], particularly for annulus fibrosis. Knowledge of the normal range of T1rho values in the healthy spine is important for further investigation of disc degeneration and other pathologies [5].

Disc T1rho may be region-specific, age-specific, as well as gender-specific. The fact that disc T1rho is region-specific has been reported and also demonstrated in the study by Gübitz et al. [1]. Disc T1rho is age-specific due to the physiological aging process even in the absence of pathological disc degeneration [6]. It is noteworthy that the study by Gübitz et al. demonstrated that body mass index (BMI) shows a negative correlation with T1rho of the lumbar disc [1]. This may additionally suggest the sensitivity of the T1rho technique for disc pathologies. The study by Gübitz et al. also examined whether disc T1rho might be gender-specific. Gender specificity was not observed.

For a population under the age of fifty, previous studies showed that lumbar disc injury and disc degeneration are more common in men than in women [7] [8]. However, women tend to have accelerated disc degeneration after menopause [9] [10] [11] [12]. It has also been shown that lumbar disc narrowing is more common and more severe in elderly women than in elderly men, and this disparity increases as age advances [13]. With respect to gender specificity of lumbar disc T1rho, it would be interesting for Gübitz et al. to examine pre-menopausal female participants and post-menopausal female participants separately and compare them with their age-matched male counterparts.

Even though the study participants in the study by Gübitz et al. did not have clinical symptoms associated with lumbar disc degeneration, it is still probable that a portion of them had disc degeneration in addition to physiological aging. Providing pooled data of normal subjects by excluding subjects with pathological disc degeneration will help to establish the appropriate normal range of discs at specific regions with respect to physiological aging. In one study composed of healthy volunteers and patients with mild nonspecific LBP, it was shown that on average women had an initially higher T2 value before the age of 50. This trend was reversed in elderly persons, with an intersection at 52.4 years [10]. However, it is still unclear whether menopause is associated with accelerated overall disc aging (as seen by a lowered T2 or T1rho value) or with a higher incidence of disc degeneration, or maybe both. Perhaps a re-analysis of the study by Gübitz et al. can shed some light on this question. A bigger population-based study will offer a more definitive answer.