MR imaging features of hemispherical spondylosclerosis
Joao R. T. Vicentini
Edgar L. Martinez-Salazar
Connie Y. Chang
Miriam A. Bredella
Daniel I. Rosenthal
Received: 31 March 2017 /Revised: 26 May 2017 /Accepted: 7 June 2017 /Published online: 28 June 2017
Objective Hemispherical spondylosclerosis (HS) is a rare
degenerative entity characterized by dome-shaped sclero-
sis of a single vertebral body that may pose a diagnostic
dilemma. The goal of this study was to describe the MR
imaging features of HS.
Materials and methods We identified spine radiographs and
CT examinations of subjects with HS who also had MR im-
aging for correlation. Two musculoskeletal radiologists inde-
pendently assessed sclerosis characteristics, presence of
endplate erosions, marrow signal intensity, and disk degener-
ation (Pfirrmann scale).
Results We identified 11 subjects (six males, five females,
mean 48 ± 10 years) with radiographic/CT findings of HS.
The most commonly affected vertebral body was L4 (6/11;
55%). On MR imaging, variable signal intensity was noted,
being most commonly low on T1 (8/11, 73%) and high on
fat-suppressed T2-weighted (8/11, 73%) images. In two
subjects, diffuse post-contrast enhancement was seen in
the lesion. Moderate disk degeneration and endplate bone
erosions adjacent to sclerosis were present in all subjects.
Erosions of the opposite endplate were present in two sub-
jects (2/11, 18%). CT data from nine subjects showed the
mean attenuation value of HS was 472 ± 96 HU.
Conclusions HS appearance on MR imaging is variable and
may not correlate with the degree of sclerosis seen on
radiographs or CT. Disk degenerative changes and asymmet-
ric endplate erosions are consistent markers of HS.
Keywords Hemispherical spondylosclerosis
Hemispherical spondylosclerosis (HS) is characterized by
a focal dome-shaped sclerotic area at the anterior corner of
a single vertebral body. Radiographic imaging features of
this condition were defined by Dihlmann in 1981 , com-
prising isolated antero-inferior sclerosis of a vertebral
endplate extending towards the body, resulting in round-
shaped sclerosis with well-defined contours. The original
descriptor for this phenomenon was Bhemispherical
spondylosclerosis^ , and has also been reported as
Bpseudoinfection of intervertebral disk^ , Blocalized
vertebral condensation^ , Bdiscogenic vertebral
sclerosis^ , Bidiopathic vertebral sclerosis^ , and
Bidiopathic segmental sclerosis^ .
HS has been attributed to various etiologies. The majority
of subjects described in the literature had no underlying dis-
ease other than disk degeneration [1, 6–8]. Dense, rounded
sclerosis may dominate the imaging picture with minimal disk
space narrowing, leading to an appearance that may suggest
metastatic disease [6, 7]. Familiarity with imaging features of
HS may preclude invasive sampling procedures that potential-
ly increase morbidity .
Imaging features of HS on radiographs have been de-
scribed in prior case reports [1, 5, 6, 10]. However, there is
limited information on the magnetic resonance (MR) imaging
characteristics of HS [11–13]. The purpose of this study was
to describe the MR imaging features of HS identified on
* Martin Torriani
Division of Musculoskeletal Imaging and Intervention, Department
of Radiology, Massachusetts General Hospital and Harvard Medical
School, 55 Fruit Street, YAW 6048, Boston, MA 02114, USA
Skeletal Radiol (2017) 46:1367–1378