Magnetic resonance imaging and bone scintigraphy in bone metastasis detection: A comparative study

Abstract

Background/Aim. Bone scintigraphy is well-known method for the detection of neoplastic lesions with a high sensitivity and, at the same time, a lower specificity. On the other hand magnetic resonance imaging (MRI) is previously established noninvasive imaging method regarding its diagnostic specificity. The aim of this study was to determine the possibilities and to correlate two different diagnostic methods - bone scintigraphy and MRI in the detection of bone metastasis in the spine and pelvic bones. Methods. A total of 123 patients who underwent both bone scintigraphy and spine and pelvic MRI on 1.5 T MR imager were enrolled in this study. Scans were subsequently analyzed in total and divided in regions of interest (cervical, upper, middle and lower thoracic, upper and lower lumbar and pelvic region, which includes sacral spinal segment); afterwards the total number of 585 matching regions were compared and statistically analyzed. Results. The statistical analysis demonstrated significant correlation between the findings of both methods in total. Divided by regions of interest, significant degrees of correlation were demonstrated in all of them, except in the cervical spine region where the r-value was in the range of low correlation. Conclusion. Having a high mutual correlation, bone scintigraphy and MRI are to be considered as the complementary diagnostic methods in the detection of bone metastases. Still, increased diagnostic potential of MRI may highlights negative bone scintigraphy findings in the patients with solitary metastatic lesions or diffuse vertebral infiltration. Advances in the bone scintigraphy (single photon emission tomography - SPECT, SPECTcomputed tomography - SPECT-CT) and MRI (whole body MRI, diffusion MRI), make it possible the diagnostic potential of both methods will result in a further improvement in bone metastasis detection.Uvod/Cilj. Scintigrafija skeleta je poznat metod za detekciju neoplastickih lezija i ima visoku senzitivnost i istovremeno nizu specificnost. Magnetno-rezonantno snimanje (MRI) je odranije ustanovljen neinvazivni dijagnosticki metod, znacajan zbog svoje specificnosti. Cilj rada bio je da se odrede mogucnosti i povezanost dva razlicita dijagnosticka modaliteta, scintigrafije skeleta i MRI, u detekciji kostanih metastaza u kicmenom stubu i karlicnim kostima. Metode. Kod ukupno 123 bolesnika nacinjena je scintigrafija skeleta i MRI pregled kicmenog stuba i karlicnih kostiju na uredjaju jacine polja od 1,5 Tesla. Snimci su uporedno analizirani u celosti i po pojedinacno razmatranim regijama od interesa (cervikalna kicma, gornja, srednja i donja torakalna kicma, gornja i donja lumbalna kicma i karlicna regija koja obuhvata i sakralni segment kicme), nakon cega je uporedjeno i statisticki analizirano ukupno 585 nalaza obeju metoda po pojedinacnim navedenim regijama. Rezultati. Statisticka analiza pokazala je znacajan stepen povezanosti izmedju nalaza scintigrafije skeleta i MRI nalaza u celini. Znacajan stepen povezanosti utvrdjen je i prilikom analize pojedinacnih razmatranih regiona, izuzev u regiji cervikalne kicme gde je r-vrednost bila u rangu niskog stepena povezanosti. Zakljucak. Scintigrafija skeleta i MRI mogu se smatrati komplementarnim dijagnostickim modalitetima za detekciju metastaza u kostima s obzirom na to da je utvrdjen visok stepen povezanosti njihovih nalaza u celini. Veci dijagnosticki potencijal MRI moze pruziti dodatne informacije kod negativnog nalaza scintigrafije skeleta kod solitarnih metastatskih lezija ili kod difuzne infiltracije kicmenih prsljenova. Moze se ocekivati da, zahvaljujuci tehnoloskom unapredjenju scintigrafije skeleta (jednofotonska emisijska kompjuterizovana tomografija - SPECT, SPECT-kompjuterizovana tomografija - SPECT-CT) i MRI (MRI celog tela, difuzioni MRI), dijagnosticki potencijal obe metode omoguci dalje poboljsanje detekcije kostanih metastaza.