Research Review: Research paper from the British Journal of Haematology

This latest report is a study published in the British Journal of Haematology comparing whole-body ultra-low dose CT (WBULDCT) with spinal MRI (SMRI) in the assessment of disease in multiple myeloma.

‘Diagnostic value of whole-body ultra-low dose computed tomography in comparison with spinal magnetic resonance imaging in the assessment of disease in multiple myeloma’¬†focuses on selecting the investigation with the highest diagnostic value in identifying spinal bone marrow involvement in multiple myeloma. It is a retrospective study comprising 35 patients from a single centre with histologically proven myeloma who underwent both WBULDCT and SMRI. 9 of those patients had imaging for staging purposes and 26 for follow-up of disease. All images were analysed by a blinded radiologist with 10 years of experience and were evaluated according to four different patterns of marrow involvement: normal appearing bone, focal myeloma lesions, diffuse bone marrow infiltration and combined.

The results showed that infiltration patterns were concordant in both techniques with the same pattern found for all patients with both techniques. Both found that the same population of patients had no lesions (8 patients). Of the remaining 27 patients, both techniques were positive in 25 patients. The 2 patients for which WBULDCT and SMRI were discordant had 1 patient with positive WBULDCT and negative SMRI and the other with positive SMRI and negative WBULDCT. The concordance according to pattern of disease was 56.1% for the focal pattern and 88.7% for the combined pattern.

The concordance in detection of myelomatous lesions within the axial skeleton was 76.7%. However, there were minor differences between the number of individual lesions identified in each spinal region between the techniques with the concordance in spinal anatomic distribution of lesions being 61.6% in the cervical spine, 71.5% in the thoracic spine, 86.4% in the lumbar spine and 94.4% in the sacral spine.

The authors provided clear advantages of WBULDCT and SMRI over each other in different clinical scenarios. One of the main advantages of WBULDCT is the ability to identify extra-axial and extra-medullary lesions to be identified in the same study. Additionally WBULDCT should be the study of choice in patients in which MRI is contraindicated (metal devices, claustrophobia, etc.). However, SMRI has advantages over WBULDCT in the setting of osteopenia alone (approximately 10% of patients on presentation) or pathological fractures. WBULDCT has low specificity in the evaluation of diffuse bone marrow infiltration and has a reduced ability to differentiate between insufficiency and pathological fractures. A further advantage of SMRI over WBULDCT is the ability to detect spinal cord compression and this technique should be used in any patients where this is suspected.

The results of this study are in agreement with most recent European guidelines suggesting the both SMRI and WBULDCT are recommended for the diagnostic workup of multiple myeloma. As WBULDCT is more readily available, more cost effective, requires a shorter duration of time and its greater capacity to demonstrate extra-medullary and extra-axial lesions, it is a useful first-line tool in diagnosis. However, it is important to consider the addition of SMRI in symptomatic patients with negative or equivocal CT results or in patients where spinal cord compression is suspected.

Download the research paper here >