Figure 1
Standing skyline radiograph. (a) The subject stands against a flat surface with the back, hip, and heel in a coplanar position. The anterior aspect of the patella is beneath the tip of the corresponding big toe (dashed red line). The X-ray beam is angled 20° toward the patient and centred on a point about 2 cm posterior to the anterior aspect of the patella. (b) The cassette is positioned parallel to the floor on a piece of foam rubber, which adapts itself to the underlying feet. A 25-mm iron ball (white arrowhead) was positioned at the anterior aspect of the right knee in order to correct for magnification [18].
Figure 2
(a) Standing skyline view of the knees. The 25 mm iron ball, used to correct for magnification, is positioned at the anterior aspect of the centre of the patella. (b) Measurements of the medial patellofemoral joint (yellow segment), lateral patellofemoral joint (red segment), and iron ball (black segment) [18].
Figure 3
qMRI. (a) Sagittal view showing segmented bones and cartilage of patella, tibia and femur. (b) Axial image illustrating automated placement of subregional boundaries delimiting left and right facets of the patella and lateral andmedial trochlea. (c) 3D image with the mapping of the mean cartilage thickness; the mean thickness of four different subregions was used for the study: medial trochlea (1), lateral trochlea (2), medial patellar facet (3), and lateral patellar facet (4). The mean cartilage thickness of the medial patellofemoral joint was considered as the sum of 1 + 3; similarly, the mean cartilage thickness of the lateral patellofemoral joint was considered as the sum of 2 + 4 [18].
Figure 4
(a) A large marginal bone erosion of the medial aspect of the head of the of the first metatarsal bone (white arrowhead) is not visible on standard radiographs but (b) It is well visible on tomosynthesis (white arrowhead) and (c) It is confirmed by computed tomography (white arrowhead).
Figure 5
CTA of the hip joint on a patient with a body mass index of 28 kg/m2 and acquisition using 120 kVp and 50 mAs. (a) Axial, (b) Coronal, (c) Sagittal multiplanar reconstruction (MPR) and axial (d) and Coronal (e) and Sagittal (f) Reformats obtained with the routine dose of 140 kVp and 160 mAs. Note that even if the noise is higher in the images obtained with the lowest dose (a, b, c), the depiction of the contrast-cartilage and cartilage-subchondral bone plate interfaces is optimal compared with the high-dose standard protocol (d, e, f). Cartilage defect in the upper pole of the femoral head, visible in the coronal reformatted images (b, e), is well depicted by the low-dose protocol (b) without substantial difference from the high-dose protocol (e).