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Interpreting pathologies in extant and extinct archosaurs using micro-CT.

Anné J, Garwood RJ, Lowe T, Withers PJ, Manning PL - PeerJ (2015)

Bottom Line: Palaeopathology offers unique insight to the healing strategies of extinct organisms, permitting questions concerning bone physiology to be answered in greater depth.Furthermore, we show that the use of comparative species, both through direct analysis and from the literature, provides key information for diagnosing between vertebrate groups in the typical pathological conditions and physiological processes.Micro-CT imaging, combined with comparative observations of extant species, provides more detailed and reliable interpretation of palaeopathologies.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester , Manchester , UK.

ABSTRACT
Palaeopathology offers unique insight to the healing strategies of extinct organisms, permitting questions concerning bone physiology to be answered in greater depth. Unfortunately, most palaeopathological studies are confined to external morphological interpretations due to the destructive nature of traditional methods of study. This limits the degree of reliable diagnosis and interpretation possible. X-ray MicroTomography (micro-CT, XMT) provides a non-destructive means of analysing the internal three-dimensional structure of pathologies in both extant and extinct individuals, at higher resolutions than possible with medical scanners. In this study, we present external and internal descriptions of pathologies in extant and extinct archosaurs using XMT. This work demonstrates that the combination of external/internal diagnosis that X-ray microtomography facilitates is crucial when differentiating between pathological conditions. Furthermore, we show that the use of comparative species, both through direct analysis and from the literature, provides key information for diagnosing between vertebrate groups in the typical pathological conditions and physiological processes. Micro-CT imaging, combined with comparative observations of extant species, provides more detailed and reliable interpretation of palaeopathologies. Micro-CT is an increasingly accessible tool, which will provide key insights for correctly interpreting vertebrate pathologies in the future.

No MeSH data available.


Related in: MedlinePlus

S. serpentarius (NHM S/1869.2.16.1) pedal phalanx; photograph of the specimen in plantar view (A), XMT slices in medial-lateral (B), dorsal-ventral (C) and transverse (D) views, and 3D rendering of the plantar (E) and distal (F) surfaces.A large, circular lesion is seen on the plantar surface (red arrows; A, E), with small necrotic spaces persisting throughout the phalanx (red arrows B, C). Extensive reactive bone growth persists both internally and externally. The outline of the normal bone cortex is barely visible in some areas and indistinguishable in others (red circles; D, F). The extent of the growth makes it difficult to identify any possible indicators of trauma. Both articulation surfaces are relatively untouched. Scale bar is 1 cm.
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fig-1: S. serpentarius (NHM S/1869.2.16.1) pedal phalanx; photograph of the specimen in plantar view (A), XMT slices in medial-lateral (B), dorsal-ventral (C) and transverse (D) views, and 3D rendering of the plantar (E) and distal (F) surfaces.A large, circular lesion is seen on the plantar surface (red arrows; A, E), with small necrotic spaces persisting throughout the phalanx (red arrows B, C). Extensive reactive bone growth persists both internally and externally. The outline of the normal bone cortex is barely visible in some areas and indistinguishable in others (red circles; D, F). The extent of the growth makes it difficult to identify any possible indicators of trauma. Both articulation surfaces are relatively untouched. Scale bar is 1 cm.

Mentions: NHM S/1869.2.16.1: Extensive bone growth persists through the interior of the S. serpentarius phalanx. In many locations, this makes distinguishing normal cancellous struts from pathological growth difficult (Fig. 1). Despite the degree of pathological intrusion, both articular surfaces maintain shape and texture. A large, circular lesion is located on the plantar surface, with signs of necrosis internally. The concentric ring appearance within the necrotic area matches the description for a fibricess; a localised inflammatory process caused by the incomplete elimination of pathogens in archosaurs (Harmon, 1998; Huchzermyer & Cooper, 2000). The most likely cause is osteitis (inflammation of the bone by infection) or osteomyelitis (inflammation of bone marrow by infection; Ritchie, Harrison & Harrison, 1994; Berners, 2002). This diagnosis is based on the lesion on the plantar surface of the bone (Fig. 1E) and internal necrosis (Figs. 1B–1D). In avians, bacterial osteomyelitis is identified based on severe necrosis, with minimal periosteal reaction (Ritchie, Harrison & Harrison, 1994). However, periosteal change can occur in chronic infections, and in fungal osteomyelitis, the periosteal reaction is pronounced (Ritchie, Harrison & Harrison, 1994). Additionally, there seems to be discrepancies between veterinary diagnoses as some characterise osteomyelitis as having a pronounced periosteal reaction (Doneley, 2011).


Interpreting pathologies in extant and extinct archosaurs using micro-CT.

Anné J, Garwood RJ, Lowe T, Withers PJ, Manning PL - PeerJ (2015)

S. serpentarius (NHM S/1869.2.16.1) pedal phalanx; photograph of the specimen in plantar view (A), XMT slices in medial-lateral (B), dorsal-ventral (C) and transverse (D) views, and 3D rendering of the plantar (E) and distal (F) surfaces.A large, circular lesion is seen on the plantar surface (red arrows; A, E), with small necrotic spaces persisting throughout the phalanx (red arrows B, C). Extensive reactive bone growth persists both internally and externally. The outline of the normal bone cortex is barely visible in some areas and indistinguishable in others (red circles; D, F). The extent of the growth makes it difficult to identify any possible indicators of trauma. Both articulation surfaces are relatively untouched. Scale bar is 1 cm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525691&req=5

fig-1: S. serpentarius (NHM S/1869.2.16.1) pedal phalanx; photograph of the specimen in plantar view (A), XMT slices in medial-lateral (B), dorsal-ventral (C) and transverse (D) views, and 3D rendering of the plantar (E) and distal (F) surfaces.A large, circular lesion is seen on the plantar surface (red arrows; A, E), with small necrotic spaces persisting throughout the phalanx (red arrows B, C). Extensive reactive bone growth persists both internally and externally. The outline of the normal bone cortex is barely visible in some areas and indistinguishable in others (red circles; D, F). The extent of the growth makes it difficult to identify any possible indicators of trauma. Both articulation surfaces are relatively untouched. Scale bar is 1 cm.
Mentions: NHM S/1869.2.16.1: Extensive bone growth persists through the interior of the S. serpentarius phalanx. In many locations, this makes distinguishing normal cancellous struts from pathological growth difficult (Fig. 1). Despite the degree of pathological intrusion, both articular surfaces maintain shape and texture. A large, circular lesion is located on the plantar surface, with signs of necrosis internally. The concentric ring appearance within the necrotic area matches the description for a fibricess; a localised inflammatory process caused by the incomplete elimination of pathogens in archosaurs (Harmon, 1998; Huchzermyer & Cooper, 2000). The most likely cause is osteitis (inflammation of the bone by infection) or osteomyelitis (inflammation of bone marrow by infection; Ritchie, Harrison & Harrison, 1994; Berners, 2002). This diagnosis is based on the lesion on the plantar surface of the bone (Fig. 1E) and internal necrosis (Figs. 1B–1D). In avians, bacterial osteomyelitis is identified based on severe necrosis, with minimal periosteal reaction (Ritchie, Harrison & Harrison, 1994). However, periosteal change can occur in chronic infections, and in fungal osteomyelitis, the periosteal reaction is pronounced (Ritchie, Harrison & Harrison, 1994). Additionally, there seems to be discrepancies between veterinary diagnoses as some characterise osteomyelitis as having a pronounced periosteal reaction (Doneley, 2011).

Bottom Line: Palaeopathology offers unique insight to the healing strategies of extinct organisms, permitting questions concerning bone physiology to be answered in greater depth.Furthermore, we show that the use of comparative species, both through direct analysis and from the literature, provides key information for diagnosing between vertebrate groups in the typical pathological conditions and physiological processes.Micro-CT imaging, combined with comparative observations of extant species, provides more detailed and reliable interpretation of palaeopathologies.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester , Manchester , UK.

ABSTRACT
Palaeopathology offers unique insight to the healing strategies of extinct organisms, permitting questions concerning bone physiology to be answered in greater depth. Unfortunately, most palaeopathological studies are confined to external morphological interpretations due to the destructive nature of traditional methods of study. This limits the degree of reliable diagnosis and interpretation possible. X-ray MicroTomography (micro-CT, XMT) provides a non-destructive means of analysing the internal three-dimensional structure of pathologies in both extant and extinct individuals, at higher resolutions than possible with medical scanners. In this study, we present external and internal descriptions of pathologies in extant and extinct archosaurs using XMT. This work demonstrates that the combination of external/internal diagnosis that X-ray microtomography facilitates is crucial when differentiating between pathological conditions. Furthermore, we show that the use of comparative species, both through direct analysis and from the literature, provides key information for diagnosing between vertebrate groups in the typical pathological conditions and physiological processes. Micro-CT imaging, combined with comparative observations of extant species, provides more detailed and reliable interpretation of palaeopathologies. Micro-CT is an increasingly accessible tool, which will provide key insights for correctly interpreting vertebrate pathologies in the future.

No MeSH data available.


Related in: MedlinePlus