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Buko EO, Armstrong AR, Laine JC, Tóth F, Johnson CP. Detection of early metaphyseal changes in a piglet model of Legg-Calvé-Perthes disease using quantitative mapping of MRI relaxation times. J Orthop Res 2024. [PMID: 38796746 DOI: 10.1002/jor.25904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/03/2024] [Accepted: 05/07/2024] [Indexed: 05/28/2024]
Abstract
Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder characterized by ischemic injury to the epiphysis of the femoral head, but changes to the metaphysis have also been implicated in its pathogenesis. Quantitative magnetic resonance imaging (MRI) relaxation time mapping techniques are potentially useful to detect injury in LCPD, but studies to date have focused on the epiphysis. The purpose of this study was to assess whether T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation times can detect early metaphyseal changes in an LCPD piglet model. Complete epiphyseal ischemia of one femoral head was surgically induced and confirmed using contrast-enhanced MRI in n = 10 6-week-old piglets; the contralateral side was unoperated. The bilateral hips were imaged 1 week after surgery in vivo at 3T MRI using relaxation time mapping and contrast-enhanced MRI. Relaxation times and thicknesses of the metaphyseal primary and secondary spongiosa were measured and compared between the ischemic and contralateral-control femoral heads using paired t-tests. In the ischemic femoral heads, T2 relaxation times were significantly increased in the primary spongiosa (6.7 ± 9.8 ms, p = 0.029), and T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation times were significantly decreased in the secondary spongiosa (respectively: -13.3 ± 9.3 ms, p = 0.013; -32 ± 23 ms, p < 0.001; -43 ± 41 ms, p = 0.009; and -39 ± 13 ms, p < 0.001). The secondary spongiosa thickness was also significantly decreased in the ischemic femoral heads (p < 0.001). In conclusion, T2, T1ρ, adiabatic T1ρ, and adiabatic T2ρ relaxation time mapping techniques can detect early changes in the metaphysis following ischemic injury to the epiphysis of the femoral head in a piglet model of LCPD.
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Affiliation(s)
- Erick O Buko
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | - Alexandra R Armstrong
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
| | - Jennifer C Laine
- Gillette Children's Specialty Healthcare, St. Paul, Minnesota, USA
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ferenc Tóth
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
| | - Casey P Johnson
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
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Buko EO, Bhave S, Moeller S, Laine JC, Tóth F, Johnson CP. Intravoxel incoherent motion (IVIM) detects femoral head ischemia in a piglet model of Legg-Calvé-Perthes disease. J Orthop Res 2023. [PMID: 37971281 DOI: 10.1002/jor.25733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/11/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023]
Abstract
There is a clinical need for alternatives to gadolinium contrast-enhanced magnetic resonance imaging (MRI) to facilitate early detection and assessment of femoral head ischemia in pediatric patients with Legg-Calvé-Perthes disease (LCPD), a juvenile form of idiopathic osteonecrosis of the femoral head. The purpose of this study was to determine if intravoxel incoherent motion (IVIM), a noncontrast-enhanced MRI method to simultaneously measure tissue perfusion and diffusion, can detect femoral head ischemia using a piglet model of LCPD. Twelve 6-week-old piglets underwent unilateral hip surgery to induce complete femoral head ischemia. The unoperated, contralateral femoral head served as a perfused control. The bilateral hips of the piglets were imaged in vivo at 3T MRI using IVIM and contrast-enhanced MRI 1 week after surgery. Median apparent diffusion coefficient (ADC) and IVIM parameters (diffusion coefficient: Ds ; perfusion coefficient: Df ; perfusion fraction: f; and perfusion flux: f*Df ) were compared between regions of interest comprising the epiphyseal bone marrow of the ischemic and control femoral heads. Contrast-enhanced MRI confirmed complete femoral head ischemia in 11/12 piglets. IVIM perfusion fraction (f) and flux (f*Df) were significantly decreased in the ischemic versus control femoral heads: on average, f decreased 47 ± 27% (Δf = -0.055 ± 0.034; p = 0.0003) and f*Df decreased 50 ± 27% (Δf*Df = -0.59 ± 0.49 × 10-3 mm2 /s; p = 0.0026). In contrast, IVIM diffusion coefficient (Ds ) and ADC were significantly increased in the ischemic versus control femoral heads: on average, Ds increased 78 ± 21% (ΔDs = 0.60 ± 0.14 × 10-3 mm2 /s; p < 0.0001) and ADC increased 60 ± 36% (ΔADC = 0.50 ± 0.23 × 10-3 mm2 /s; p < 0.0001). In conclusion, IVIM is sensitive in detecting bone marrow ischemia in a piglet model of LCPD.
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Affiliation(s)
- Erick O Buko
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | - Sampada Bhave
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
| | - Steen Moeller
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jennifer C Laine
- Orthopedics Division, Gillette Children's Specialty Healthcare, St. Paul, Minnesota, USA
- Department of Orthopedic Surgery, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ferenc Tóth
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
| | - Casey P Johnson
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, Minnesota, USA
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, USA
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Armstrong AR, Tóth F, Carlson CS, Kim HKW, Johnson CP. Effects of acute femoral head ischemia on the growth plate and metaphysis in a piglet model of Legg-Calvé-Perthes disease. Osteoarthritis Cartilage 2023; 31:766-774. [PMID: 36696941 PMCID: PMC10200741 DOI: 10.1016/j.joca.2023.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/27/2022] [Accepted: 01/17/2023] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To determine the effects of acute (≤7 days) femoral head ischemia on the proximal femoral growth plate and metaphysis in a piglet model of Legg-Calvé-Perthes disease (LCPD). We hypothesized that qualitative and quantitative histological assessment would identify effects of ischemia on endochondral ossification. DESIGN Unilateral femoral head ischemia was surgically induced in piglets, and femurs were collected for histological assessment at 2 (n = 7) or 7 (n = 5) days post-ischemia. Samples were assessed qualitatively, and histomorphometry of the growth plate zones and primary spongiosa was performed. In a subset of samples at 7 days, hypertrophic chondrocytes were quantitatively assessed and immunohistochemistry for TGFβ1 and Indian hedgehog was performed. RESULTS By 2 days post-ischemia, there was significant thinning of the proliferative and hypertrophic zones, by 63 μm (95% CI -103, -22) and -19 μm (95% CI -33, -5), respectively. This thinning persisted at 7 days post-ischemia. Likewise, at 7 days post-ischemia, the primary spongiosa was thinned to absent by an average of 311 μm (95% CI -542, -82) in all ischemic samples. TGFβ1 expression was increased in the hypertrophic zone at 7 days post-ischemia. CONCLUSIONS Alterations to the growth plate zones and metaphysis occurred by 2 days post-ischemia and persisted at 7 days post-ischemia. Our findings suggest that endochondral ossification may be disrupted at an earlier time point than previously reported and that growth disruption may occur in the piglet model as occurs in some children with LCPD.
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Affiliation(s)
- A R Armstrong
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - F Tóth
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - C S Carlson
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - H K W Kim
- Center for Excellence in Hip, Scottish Rite for Children, Dallas, TX, USA; Department of Orthopedic Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
| | - C P Johnson
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA; Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
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Armstrong AR, Zbýň Š, Kajabi AW, Metzger GJ, Ellermann JM, Carlson CS, Tóth F. Naturally occurring osteochondrosis latens lesions identified by quantitative and morphological 10.5 T MRI in pigs. J Orthop Res 2023; 41:663-673. [PMID: 35716161 PMCID: PMC9759621 DOI: 10.1002/jor.25401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 05/31/2022] [Accepted: 06/15/2022] [Indexed: 02/04/2023]
Abstract
Juvenile osteochondritis dissecans (JOCD) is a pediatric orthopedic disorder that involves the articular-epiphyseal cartilage complex and underlying bone. Clinical disease is often characterized by the presence of radiographically apparent osteochondral flaps and fragments. The existence of early JOCD lesions (osteochondrosis latens [OCL] and osteochondrosis manifesta [OCM]) that precede the development of osteochondral flaps and fragments is also well recognized. However, identification of naturally occurring OCL lesions (confined to cartilage) using noninvasive imaging techniques has not yet been accomplished. We hypothesized that 10.5 T magnetic resonance imaging (MRI) can identify naturally occurring OCL lesions at predilection sites in intact joints of juvenile pigs. Unilateral elbows and knees (stifles) were harvested from three pigs aged 4, 8, and 12 weeks, and scanned in a 10.5 T MRI to obtain morphological 3D DESS images, and quantitative T2 and T1ρ relaxation time maps. Areas with increased T2 and T1ρ relaxation times in the articular-epiphyseal cartilage complex were identified in 1/3 distal femora and 3/3 distal humeri and were considered suspicious for OCL or OCM lesions. Histological assessment confirmed the presence of OCL or OCM lesions at each of these sites and failed to identify additional lesions. Histological findings included necrotic vascular profiles associated with areas of chondronecrosis either confined to the epiphyseal cartilage (OCL, 4- and 8-week-old specimens) or resulting in a delay in endochondral ossification (OCM, 12-week-old specimen). Future studies with clinical MR systems (≤7 T) are needed to determine whether these MRI methods are suitable for the in vivo diagnosis of early JOCD lesions in humans.
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Affiliation(s)
- Alexandra R. Armstrong
- Department of Veterinary Clinical Sciences, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Štefan Zbýň
- Center for Magnetic Resonance Research, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Abdul Wahed Kajabi
- Center for Magnetic Resonance Research, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Gregory J. Metzger
- Center for Magnetic Resonance Research, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Jutta M. Ellermann
- Center for Magnetic Resonance Research, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Cathy S. Carlson
- Department of Veterinary Clinical Sciences, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
| | - Ferenc Tóth
- Department of Veterinary Clinical Sciences, University of Minnesota Twin Cities, Minneapolis, Minnesota, USA
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Armstrong AR, Bhave S, Buko EO, Chase KL, Tóth F, Carlson CS, Ellermann JM, Kim HKW, Johnson CP. Quantitative T2 and T1ρ mapping are sensitive to ischemic injury to the epiphyseal cartilage in an in vivo piglet model of Legg-Calvé-Perthes disease. Osteoarthritis Cartilage 2022; 30:1244-1253. [PMID: 35644462 PMCID: PMC9378508 DOI: 10.1016/j.joca.2022.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/27/2022] [Accepted: 05/17/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine if the quantitative MRI techniques T2 and T1ρ mapping are sensitive to ischemic injury to epiphyseal cartilage in vivo in a piglet model of Legg-Calvé-Perthes disease using a clinical 3T MRI scanner. We hypothesized that T2 and T1ρ relaxation times would be increased in the epiphyseal cartilage of operated vs contralateral-control femoral heads 1 week following onset of ischemia. DESIGN Unilateral femoral head ischemia was surgically induced in eight piglets. Piglets were imaged 1 week post-operatively in vivo at 3T MRI using a magnetization-prepared 3D fast spin echo sequence for T2 and T1ρ mapping and a 3D gradient echo sequence for cartilage segmentation. Ischemia was confirmed in all piglets using gadolinium contrast-enhanced MRI. Median T2 and T1ρ relaxation times were measured in the epiphyseal cartilage of the ischemic and control femoral heads and compared using paired t-tests. Histological assessment was performed on a subset of five piglets. RESULTS T2 and T1ρ relaxation times were significantly increased in the epiphyseal cartilage of the operated vs control femoral heads (ΔT2 = 11.9 ± 3.7 ms, 95% CI = [8.8, 15.0] ms, P < 0.0001; ΔT1ρ = 12.8 ± 4.1 ms, 95% CI = [9.4, 16.2] ms, P < 0.0001). Histological assessment identified chondronecrosis in the hypertrophic and deep proliferative zones within ischemic epiphyseal cartilage. CONCLUSIONS T2 and T1ρ mapping are sensitive to ischemic injury to the epiphyseal cartilage in vivo at clinical 3T MRI. These techniques may be clinically useful to assess injury and repair to the epiphyseal cartilage to better stage the extent of ischemic damage in Legg-Calvé-Perthes disease.
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Affiliation(s)
- A R Armstrong
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - S Bhave
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - E O Buko
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA; Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
| | - K L Chase
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - F Tóth
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - C S Carlson
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA.
| | - J M Ellermann
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA; Department of Radiology, University of Minnesota, Minneapolis, MN, USA.
| | - H K W Kim
- Center for Excellence in Hip, Scottish Rite for Children, Dallas, TX, USA; Department of Orthopedic Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
| | - C P Johnson
- Department of Veterinary Clinical Sciences, University of Minnesota, St. Paul, MN, USA; Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
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