Table 1 Inter- and intra-observer reliability (intra class correlation- ICC) of 99mTc-HDP-BTU activity using the localization and semiquantitative BTU grading scheme for the acetabular and femoral zones (Likert scale 0-10)

AS

0.954

0.913–0.976

0.975

0.952–0.987

0.900

0.815–0.947

AI

0.963

0.929–0.981

0.529

0.252–0.726

0.401

0.093–0,639

PS

0.967

0.938–0.983

0.949

0.903–0.973

0.950

0.905–0.974

PI

0.878

0.775–0.935

0.790

0.629–0.886

0.493

0.206–0.703

Z1

0.888

0.794–0.941

0.807

0.656–0.895

0.799

0.643–0.891

Z2

0.882

0.783–0.938

0.692

0.478–0.829

0.703

0.495–0.835

Z3

0.781

0.614–0.881

0.929

0.867–0.963

0.866

0.755–0.928

Z4

0.822

0.680–0.904

0.938

0.883–0.968

0.744

0.557–0.860

Z5

0.884

0.786–0.938

0.975

0.951–0.987

0.829

0.693–0.908

Z6

0.877

0.774–0.935

0.792

0.633–0.887

0.733

0.540–0,853

Z7

0.945

0.895–0.971

0.811

0.663–0.898

0.723

0.524–0.847

Z8

0.955

0.914–0.976

0.923

0.855–0.959

0.864

0.752–0.928

Z9

0.937

0.882–0.967

0.833

0.699–0.910

0.601

0.348–0.773

Z10

0.838

0.708–0.913

0.978

0.958–0.989

0.718

0.517–0.844

Z11

0.878

0.777–0.936

0.955

0.914–0.976

0.681

0.461–0.822

Z12

0.881

0.781–0.937

0.964

0.931–0.981

0.846

0.722–0.918

Z13

0.921

0.852–0.958

0.804

0.651–0.894

0.563

0.296–0.748

Z14

0.889

0.796–0.942

0.876

0.772–0.934

0.819

0.675–0.902

Acetabulum

0.975

0.953–0.987

0.967

0.937–0.983

0.877

0.774–0.935

Femur

0.992

0.984–0.996

0.981

0.963–0.990

0.871

0.764–0.932