The clinical significance of technetium-99m methylene diphosphonate bone scintigraphy findings in patients with rhabdomyolysis

Hamstring Muscle Cramp Visualized on Bone Single-Photon Emission Computed Tomography/Computed Tomography Hybrid Imaging

ABSTRACT

It is well recognized that bone-seeking radiotracers localize in muscles sustaining an injury from various causes (e.g., strenuous physical activity, trauma, hereditary myopathies, inflammatory myositides, medications, electrical burns, etc.). This report presents the case of an active 50-yr-old man (body mass index = 29) that was recently referred to our nuclear medicine department for bone scintigraphy, for the skeletal staging of a newly diagnosed prostate adenocarcinoma. The scan findings were unremarkable for its oncological indication but revealed extraosseous radiotracer absorption in the medial region of the hamstrings bilaterally. Hybrid scintitomography (single-photon emission computed tomography) with computed tomography indicated that this uptake involved the semitendinosus muscle. On a more meticulous repeat history questioning, he recalled experiencing muscle cramps on both posterior thighs 5 days earlier, during intense work-related physical activity (plumbing) under warm environmental conditions. The combination of strenuous exercise with likely dehydration contributed to bilateral self-limiting heat cramps of the hamstrings, leading to an inconsequential localized minor rhabdomyolysis that was discovered coincidentally a few days later during a bone scan. Although extraskeletal absorption of bone-seeking radiotracers in muscles is widely documented as a result of exertion or injury, this is the first report of radiotracer absorption induced by cramping.

KSNM 60 in General Nuclear Medicine: the Old Dream Comes True

Since the establishment of the Korean Society of Nuclear Medicine (KSNM) in 1961 by Professor Munho Lee, the KSNM has been progressing in various medical fields. Many papers have been published in the Korean Journal of Nuclear Medicine (KJNM), the official journal of KSNM, since 1967 and other domestic/international journals. Here, we tried to highlight the academic activities of KSNM members from the perspective of general nuclear medicine. After the introduction of the ⁹⁹Mo/^99mTc generator, general nuclear medicine has widened the field of clinical application with the advancement of imaging technology and emerging new radiopharmaceuticals; however, there have been many ups and downs. Treatment, as well as diagnosis, was a major concern in Korean nuclear medicine. With the recent advent of single-photon emission computed tomography/computed tomography, we hope that our old dream (diagnosis and treatment under the same principle of nuclear medicine) comes true.

Differential diagnosis of muscle calcification

We report the case of a 36 year old male who demonstrated extensive high attenuation in the muscles of the chest wall and neck on a noncontrast chest CT. The high attenuation in the musculature was due to calcium, sequela from a recent episode of rhabdomyolysis. Although the diagnosis of rhabdomyolysis is made on clinical grounds, the imaging appearance can be confusing given the variability in appearance of rhabdomyolysis depending on the severity and the timeline of disease.