RESUMEN
We studied 51 patients with peripheral joint pain to assess the ability of technetium-99m-nanocolloid (99mTc NC) scintigraphy to distinguish patients with active joint disease from those without, irrespective of their underlying aetiology. Patients with peripheral joint pain due to various causes were clinically categorised as either having objective signs of active joint disease or not. Their clinical diagnoses were not made known to the nuclear physician until after scanning. Each patient was given an intravenous injection of 555 MBq of 99mTc NC 1 h prior to taking spot views of the peripheral joints. Seventeen patients with low backache but without peripheral joint pain were imaged in an identical manner to exclude peripheral joint involvement. The latter formed a control group. 99mTc NC scintigraphy demonstrated a sensitivity of 89% for identifying at least one affected joint per patient, a specificity of 87.5%, a negative predictive value (npv) of 87.5%, a positive predictive value (ppv) of 89%, and overall accuracy of 88%. There were three false negative and three false positive cases. The scan was negative in all control subjects. 99mTc NC scintigraphy proved to be sensitive in patients with active joint disease and demonstrated a good correlation with clinical assessment. The value of the high specificity, npv and negative controls together made the test highly discriminatory in excluding patients without active peripheral joint disease.
