Limits...
Healing of the Achilles tendon in rabbits--evaluation by magnetic resonance imaging and histopathology.

Tavares WC, de Castro UB, Paulino E, Vasconcellos Lde S, Madureira AP, Magalhães MA, Mendes DV, Kakehasi AM, Resende V - J Orthop Surg Res (2014)

Bottom Line: The surgical group had an intense contrast enhancement in the contrast sequences, enlargement of the diameter and intra-substantial signal intensity alteration, with hyper-signal focus points and widening of the tendon sheath, which presented irregular contours and intense contrast enhancement.On histology, the Achilles tendon presented diffuse widening of the tendon sheath and wedge-shaped areas with scarring tissue rich in disordered collagen fibres.MRI with perfusion could be a useful technique for evaluating tissue and fibrous scarring in tendons.

View Article: PubMed Central - PubMed

Affiliation: Musculoskeletal Section of Clinics Hospital of Universidade Federal of Minas Gerais (UFMG), Rua Goncalves Dias, 750 Apto, 1803 Funcionarios, Belo Horizonte, CEP 30140091, Minas Gerais, Brazil. wilsoncamp2000@yahoo.com.br.

ABSTRACT

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could provide valuable findings for tendon regeneration. A non-invasive image method that can effectively evaluate the quality of the scar tissue has not yet been employed.

Methods: Thirteen New Zealand rabbits were divided into two groups: group 1--non-treated control (n = 4); group 2--surgical intervention (n = 9). The central portion of the Achilles tendon was resected, and after 30 days, DCE-MRI was performed. Contrast enhancement methods were applied using the region of interest (ROI) technique. In the medium third of the Achilles tendon, the intra-substantial signal intensity and the presence of hyper-intense intra-tendon focus points and of signal heterogeneity were evaluated. Antero-posterior and transversal diameters of the tendon were measured. The Achilles tendon was removed and dissected free from other tissues. Sections from the central part of the tendon were stained for histological analysis.

Results: The difference between the contrast enhancement curves of the control and surgical groups (p < 0.0001) was observed. The surgical group had an intense contrast enhancement in the contrast sequences, enlargement of the diameter and intra-substantial signal intensity alteration, with hyper-signal focus points and widening of the tendon sheath, which presented irregular contours and intense contrast enhancement. On histology, the Achilles tendon presented diffuse widening of the tendon sheath and wedge-shaped areas with scarring tissue rich in disordered collagen fibres. These findings were related to alteration in the intra-substantial signal intensity, with hyper-signal focus points in the DCE-MRI.

Conclusions: MRI with perfusion could be a useful technique for evaluating tissue and fibrous scarring in tendons.

Show MeSH

Related in: MedlinePlus

Transversal sections of the rabbit Achilles tendon (AT) in DCE-MRI and histology. Control group (A-C) and operated group (D-F). Contrast enhancement in MIR in both groups corresponds to the red area on map colour with maximal contrast increase inclination. Scarring area in the operated group (yellow arrow (D)) corresponds to the red area on map colour (white arrow (E)) and pointed area on histology in the posterior region of the tendon (black arrow (F)). Details of the scar tissue (G-I), with less organized collagen in (G) (arrow), hypercellularity on the left side compared to the normal tendon on the right (H) and preserved muscle fibres (arrow) between the scar tissue and normal tendon (I) (haematoxylin-eosin stain).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4269850&req=5

Fig3: Transversal sections of the rabbit Achilles tendon (AT) in DCE-MRI and histology. Control group (A-C) and operated group (D-F). Contrast enhancement in MIR in both groups corresponds to the red area on map colour with maximal contrast increase inclination. Scarring area in the operated group (yellow arrow (D)) corresponds to the red area on map colour (white arrow (E)) and pointed area on histology in the posterior region of the tendon (black arrow (F)). Details of the scar tissue (G-I), with less organized collagen in (G) (arrow), hypercellularity on the left side compared to the normal tendon on the right (H) and preserved muscle fibres (arrow) between the scar tissue and normal tendon (I) (haematoxylin-eosin stain).

Mentions: MRI in the control group revealed an Achilles tendon with homogeneous and hypo-intense aspect and regular and well-defined contours in the T1 and T2 sequences without contrast (Figure 2). There was no significant contrast enhancement in the sequence with perfusion in the control group. The tendon sheath presented a thin enhancement with the contrast (Figure 3A). The surgical group had an intense contrast enhancement in the contrast sequences and a signal intensity alteration with intra-substantial hyper-signal associated to irregular and poorly defined contours at the same sequences. There were an enlargement of the tendon in diameter and alteration in the intra-substantial signal intensity, with hyper-signal focus points and widening of the tendon sheath, which demonstrated irregular contours and intense contrast enhancement (Figures 3D and 4).Figure 2


Healing of the Achilles tendon in rabbits--evaluation by magnetic resonance imaging and histopathology.

Tavares WC, de Castro UB, Paulino E, Vasconcellos Lde S, Madureira AP, Magalhães MA, Mendes DV, Kakehasi AM, Resende V - J Orthop Surg Res (2014)

Transversal sections of the rabbit Achilles tendon (AT) in DCE-MRI and histology. Control group (A-C) and operated group (D-F). Contrast enhancement in MIR in both groups corresponds to the red area on map colour with maximal contrast increase inclination. Scarring area in the operated group (yellow arrow (D)) corresponds to the red area on map colour (white arrow (E)) and pointed area on histology in the posterior region of the tendon (black arrow (F)). Details of the scar tissue (G-I), with less organized collagen in (G) (arrow), hypercellularity on the left side compared to the normal tendon on the right (H) and preserved muscle fibres (arrow) between the scar tissue and normal tendon (I) (haematoxylin-eosin stain).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4269850&req=5

Fig3: Transversal sections of the rabbit Achilles tendon (AT) in DCE-MRI and histology. Control group (A-C) and operated group (D-F). Contrast enhancement in MIR in both groups corresponds to the red area on map colour with maximal contrast increase inclination. Scarring area in the operated group (yellow arrow (D)) corresponds to the red area on map colour (white arrow (E)) and pointed area on histology in the posterior region of the tendon (black arrow (F)). Details of the scar tissue (G-I), with less organized collagen in (G) (arrow), hypercellularity on the left side compared to the normal tendon on the right (H) and preserved muscle fibres (arrow) between the scar tissue and normal tendon (I) (haematoxylin-eosin stain).
Mentions: MRI in the control group revealed an Achilles tendon with homogeneous and hypo-intense aspect and regular and well-defined contours in the T1 and T2 sequences without contrast (Figure 2). There was no significant contrast enhancement in the sequence with perfusion in the control group. The tendon sheath presented a thin enhancement with the contrast (Figure 3A). The surgical group had an intense contrast enhancement in the contrast sequences and a signal intensity alteration with intra-substantial hyper-signal associated to irregular and poorly defined contours at the same sequences. There were an enlargement of the tendon in diameter and alteration in the intra-substantial signal intensity, with hyper-signal focus points and widening of the tendon sheath, which demonstrated irregular contours and intense contrast enhancement (Figures 3D and 4).Figure 2

Bottom Line: The surgical group had an intense contrast enhancement in the contrast sequences, enlargement of the diameter and intra-substantial signal intensity alteration, with hyper-signal focus points and widening of the tendon sheath, which presented irregular contours and intense contrast enhancement.On histology, the Achilles tendon presented diffuse widening of the tendon sheath and wedge-shaped areas with scarring tissue rich in disordered collagen fibres.MRI with perfusion could be a useful technique for evaluating tissue and fibrous scarring in tendons.

View Article: PubMed Central - PubMed

Affiliation: Musculoskeletal Section of Clinics Hospital of Universidade Federal of Minas Gerais (UFMG), Rua Goncalves Dias, 750 Apto, 1803 Funcionarios, Belo Horizonte, CEP 30140091, Minas Gerais, Brazil. wilsoncamp2000@yahoo.com.br.

ABSTRACT

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could provide valuable findings for tendon regeneration. A non-invasive image method that can effectively evaluate the quality of the scar tissue has not yet been employed.

Methods: Thirteen New Zealand rabbits were divided into two groups: group 1--non-treated control (n = 4); group 2--surgical intervention (n = 9). The central portion of the Achilles tendon was resected, and after 30 days, DCE-MRI was performed. Contrast enhancement methods were applied using the region of interest (ROI) technique. In the medium third of the Achilles tendon, the intra-substantial signal intensity and the presence of hyper-intense intra-tendon focus points and of signal heterogeneity were evaluated. Antero-posterior and transversal diameters of the tendon were measured. The Achilles tendon was removed and dissected free from other tissues. Sections from the central part of the tendon were stained for histological analysis.

Results: The difference between the contrast enhancement curves of the control and surgical groups (p < 0.0001) was observed. The surgical group had an intense contrast enhancement in the contrast sequences, enlargement of the diameter and intra-substantial signal intensity alteration, with hyper-signal focus points and widening of the tendon sheath, which presented irregular contours and intense contrast enhancement. On histology, the Achilles tendon presented diffuse widening of the tendon sheath and wedge-shaped areas with scarring tissue rich in disordered collagen fibres. These findings were related to alteration in the intra-substantial signal intensity, with hyper-signal focus points in the DCE-MRI.

Conclusions: MRI with perfusion could be a useful technique for evaluating tissue and fibrous scarring in tendons.

Show MeSH
Related in: MedlinePlus