Table 1.
Rhinoceroses.
Figure 1.
Principle of method in synchronized computed tomography (CT)-digital radiography (DR).
Digital radiographic images are calculated and generated from fully rendered, tri-dimensional (3D) CT images. Standard orthogonal (n = 4) and oblique (n = 4) radiographic views (45° apart) are shown here using as example the left front distal limb of Southern white rhinoceros 2. The abbreviations used represent the oblique projections characterized by the point-of-entry to point-of-exit direction of the primary X-ray beam: DMPL [dorsomedial-palmarolateral], PMDL [palmaromedial-dorsolateral], PLDM [palmarolateral-dorsomedial], and DLPM [dorsolateral-palmaromedial].
Figure 2.
Radiographic exposure chart for front and hind feet in both Southern white and Indian rhinoceroses.
On the horizontal axis are the eight radiographic views and the vertical axis shows the exposure values of: milliampere (mA), kilovolt peak (kVp) and time (s) for each projection at a constant source-to-film, or focus-to-film, distance (FFD) of 100 cm. Standard radiographic views were: DP [dorso-palmar (plantar)], DM-PL [dorsomedial-palmaro (plantaro) lateral], ML [medio-lateral], PM-DL [palmaro (plantaro) medial-dorsolateral], PD [palmaro (plantaro)-dorsal], PL-DM [palmaro (plantaro) lateral-dorsomedial]; LM [latero-medial], DL-PM [dorsolateral-palmaro (plantaro) medial].
Figure 3.
Rhinoceroses' species-related radiographic views.
Dorsomedial-palmarolateral (DMPL) 20° oblique view performed at a projection angle of 20° from the dorsal mid-plane (arrow) allows a better visualization of all digits than the traditional DMPL 45° oblique view. Positioning technique is demonstrated on tri-dimensional computed tomographic (3D CT) image of Indian rhinoceros 3 right front foot (right side image) and schematically represented using a cross-sectional CT image (left side image). Semi-transparent 3D CT imaging protocol was employed to show both foot's exterior aspect and the underlying bony structures.
Figure 4.
One-criterion diagnostic value of traditional (45° and multiples of 45° projection angles) radiographic views.
Radiographic diagnostic value per view was calculated by summation of the perceptible radiographic detail assessed with a 5-point rating scale for each autopodial bone of front and, respectively, hind feet in Southern white rhinoceros. Standard radiographic views are schematically represented on the top row. Abbreviations: digits II, III, IV [D II, D III, D IV]; views: dorso-palmar (plantar) [DPa(l)], palmaro (plantaro)-dorsal [Pa(l)D], medio-lateral [ML], latero-medial [LM], and four oblique projections: dorsomedial-palmaro (plantaro) lateral [DM-Pa(l)LO], dorsolateral-palmaro (plantaro) medial [DL-Pa(l)MO], palmaro (plantaro) medial-dorsolateral [Pa(l)M-DLO] and palmaro (plantaro) lateral-dorsomedial [Pa(l)L-DMO].
Figure 5.
One-criterion diagnostic value of traditional (45° and multiples of 45° projection angles) radiographic views.
Radiographic diagnostic value per view was calculated by summation of the perceptible radiographic detail assessed with a 5-point rating scale for each autopodial bone of front and, respectively, hind feet in Indian rhinoceroses. Standard radiographic views are schematically represented on the top row. Abbreviations: digits II, III, IV [D II, D III, D IV]; views: dorso-palmar (plantar) [DPa(l)], palmaro (plantaro)-dorsal [Pa(l)D], medio-lateral [ML], latero-medial [LM], and four oblique projections: dorsomedial-palmaro (plantaro) lateral [DM-Pa(l)LO], dorsolateral-palmaro (plantaro) medial [DL-Pa(l)MO], palmaro (plantaro) medial-dorsolateral [Pa(l)M-DLO] and palmaro (plantaro) lateral-dorsomedial [Pa(l)L-DMO].
Figure 6.
Two-criteria diagnostic value of traditional (45° and multiples of 45° projection angles) radiographic views.
Whole foot radiographic diagnostic value per view was calculated based on: a) number of bones that could be discerned at a diagnostic value (“Number”, presented as percentage from the total number of foot's bones); b) perceptible radiographic details of each bone estimated with a 5-point radiographic rating scale and summated for all foot's bones (“Detail”). The results are shown for front feet in Southern white and Indian rhinoceroses. The abbreviations used are: dorso-palmar (plantar) [DPa(l)], palmaro (plantaro)-dorsal [Pa(l)D], medio-lateral [ML], latero-medial [LM], and four oblique projections: dorsomedial-palmaro (plantaro) lateral [DM-Pa(l)LO], dorsolateral-palmaro (plantaro) medial [DL-Pa(l)MO], palmaro (plantaro) medial-dorsolateral [Pa(l)M-DLO] and palmaro (plantaro) lateral-dorsomedial [Pa(l)L-DMO].
Figure 7.
Two-criteria diagnostic value of traditional (45° and multiples of 45° projection angles) radiographic views.
Whole foot radiographic diagnostic value per view was calculated based on: a) number of bones that could be discerned at a diagnostic value (“Number”, presented as percentage from the total number of foot's bones); b) perceptible radiographic details of each bone estimated with a 5-point radiographic rating scale and summated for all foot's bones (“Detail”). The results are shown for hind feet in Southern white and Indian rhinoceroses. The abbreviations used are: dorso-palmar (plantar) [DPa(l)], palmaro (plantaro)-dorsal [Pa(l)D], medio-lateral [ML], latero-medial [LM], and four oblique projections: dorsomedial-palmaro (plantaro) lateral [DM-Pa(l)LO], dorsolateral-palmaro (plantaro) medial [DL-Pa(l)MO], palmaro (plantaro) medial-dorsolateral [Pa(l)M-DLO] and palmaro (plantaro) lateral-dorsomedial [Pa(l)L-DMO].
Figure 8.
Left navicular (central tarsal bone, CTB) comparative imaging in two Southern white rhinoceroses.
Tri-dimensional computed tomographic (3D CT) images of CTB allowed comparison of multiple bone pathologies (A) in rhinoceros 1 with normal anatomical aspect (B) in rhinoceros 2. Encountered osteopathologies are: cortical osteogenesis represented by massive, unstructured new bone production and remodelling, with a beak-like formation oriented plantaro-medially (arrow). Additionally (A), the articular surface between CTB and first tarsal bone (TI) is highly irregular, characterized by decreased joint space width and articular bone proliferation that bridges the contiguous bones (ankylosis). The second (TII) and the third (TIII) tarsal bones are within normal limits on both rhinoceroses (A, B).
Figure 9.
Tarsal normal anatomy depicted in Southern white rhinoceros 2 left hind foot by (A) computed tomography (CT) and (B) synchronized digital radiography (Synch DR).
This projection (B) allows the best visualization of calcaneus (highlighted on CT image A) with minimal superimposition of other bony elements. The abbreviations used are: 1-tibia, 2- fibula, 3- talus, 4- calcaneus, 5- navicular, 6-tarsal III, and 7- tarsal IV bones.
Figure 10.
Multi-modality imaging diagnosis of bone pathology in Indian rhinoceros 1.
Fractured bony fragments (circle and star) of the distal phalanx of the left front central digit are imaged ventral to the central small sesamoid (S) by means of: analog radiography (AR), digital radiography (DR), computed tomography (CT), and synchronized CT-DR (Synch CT-DR). Uppermost CT images reveal additional osteopathologies: the second phalanx - dorso-lateral fracture with a displaced fragment (curved arrow); the third phalanx - complete fracture of the medial palmar process (processus palmaris medialis, straight arrow).