Objective：Currently,magnetic resonance imaging （MRI） is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells （MSCs） after in vivo transplantation to treat ost...Objective：Currently,magnetic resonance imaging （MRI） is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells （MSCs） after in vivo transplantation to treat osteoarthritis （OA）.However,it is a challenge to accurately monitor the treatment effects of MSCs in the zone of calcified cartilage （ZCC） with OA.This is especially true in the physiological and biochemical views that are not accurately detected by MRI contrast agents.In contrast,ultrashort time echo （UTE） MRI has been shown to be sensitive to the presence of the ZCC,creating the potential for more effectively observing the repair of the ZCC in OA by MSCs.A special focus is given to the outlook of the use ofUTE MRI to detect repair of the ZCC with OA through MSCs.The limitations of the current techniques for clinical applications and future directions are also discussed.Data Sources：Using the combined keywords：＂osteoarthritis＂,＂mesenchymal stem cells＂,＂calcified cartilage＂,and ＂magnetic resonance imaging＂,the PubMed/MEDLINE literature search was conducted up to June 1,2017.Study Selection：A total of 132 published articles were initially identified citations.Of the 132 articles,48 articles were selected after further detailed review.This study referred to all the important English literature in full.Results：In contrast,UTE MRI has been shown to be sensitive to the presence of the ZCC,creating the potential for more effectively observing the repair of the ZCC in OA by MSCs.Conclusions：The current studies showed that the ZCC could be described in terms of its histomorphology and biochemistry by UTE MRI.We prospected that UTE MRI has been shown the potential for more effectively observing the repair of the ZCC in OA by MSCs in vivo.展开更多
Background: The zone of calcified cartilage (ZCC) plays an important role in the pathogenesis of osteoarthritis (OA) but has never been imaged in vivo with magnetic resonance (MR) imaging techniques. We investigated t...Background: The zone of calcified cartilage (ZCC) plays an important role in the pathogenesis of osteoarthritis (OA) but has never been imaged in vivo with magnetic resonance (MR) imaging techniques. We investigated the feasibility of direct imaging of the ZCC in both cadaveric whole knee specimens and in vivo healthy knees using a 3-dimensional ultrashort echo time cones (3D UTE-Cones) sequence on a clinical 3T scanner. Methods: In all, 12 cadaveric knee joints and 10 in vivo healthy were collected. At a 3T MR scanner with an 8-channel knee coil, a fat-saturated 3D dual-echo UTE-Cones sequence was used to image the ZCC, following with a short rectangular pulse excitation and 3D spiral sampling with conical view ordering. The regions of interests (ROIs) were delineated by a blinded observer. Singlecomponent T2* and T2 values were calculated from fat-saturated 3D dual-echo UTE-Cones and a Carr-Purcell-Meiboom-Gill (T2 CPMG) data using a semi-automated MATLAB code. Results: The single-exponential fitting curve of ZCC was accurately obtained with R2 of 0.989. For keen joint samples, the ZCC has a short T2* ranging from 0.62 to 2.55 ms, with the mean ±standard deviation (SD) of 1.49 ±0.66 ms, and with 95% confidence intervals (CI) of 1.20-1.78 ms. For volunteers, the short T2* ranges from 0.93 to 3.52ms, with the mean±SD of 2.09±0.56 ms, and the 95% CI is 1.43 to 2.74ms in ZCC. Conclusions: The high-resolution 3D UTE-Cones sequence might be used to directly image ZCC in the human knee joint on a clinical 3T scanner with a scan time of more than 10 min. Using this non-invasive technique, the T2* relaxation time of the ZCC can be further detected.展开更多
文摘Objective：Currently,magnetic resonance imaging （MRI） is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells （MSCs） after in vivo transplantation to treat osteoarthritis （OA）.However,it is a challenge to accurately monitor the treatment effects of MSCs in the zone of calcified cartilage （ZCC） with OA.This is especially true in the physiological and biochemical views that are not accurately detected by MRI contrast agents.In contrast,ultrashort time echo （UTE） MRI has been shown to be sensitive to the presence of the ZCC,creating the potential for more effectively observing the repair of the ZCC in OA by MSCs.A special focus is given to the outlook of the use ofUTE MRI to detect repair of the ZCC with OA through MSCs.The limitations of the current techniques for clinical applications and future directions are also discussed.Data Sources：Using the combined keywords：＂osteoarthritis＂,＂mesenchymal stem cells＂,＂calcified cartilage＂,and ＂magnetic resonance imaging＂,the PubMed/MEDLINE literature search was conducted up to June 1,2017.Study Selection：A total of 132 published articles were initially identified citations.Of the 132 articles,48 articles were selected after further detailed review.This study referred to all the important English literature in full.Results：In contrast,UTE MRI has been shown to be sensitive to the presence of the ZCC,creating the potential for more effectively observing the repair of the ZCC in OA by MSCs.Conclusions：The current studies showed that the ZCC could be described in terms of its histomorphology and biochemistry by UTE MRI.We prospected that UTE MRI has been shown the potential for more effectively observing the repair of the ZCC in OA by MSCs in vivo.
文摘Background: The zone of calcified cartilage (ZCC) plays an important role in the pathogenesis of osteoarthritis (OA) but has never been imaged in vivo with magnetic resonance (MR) imaging techniques. We investigated the feasibility of direct imaging of the ZCC in both cadaveric whole knee specimens and in vivo healthy knees using a 3-dimensional ultrashort echo time cones (3D UTE-Cones) sequence on a clinical 3T scanner. Methods: In all, 12 cadaveric knee joints and 10 in vivo healthy were collected. At a 3T MR scanner with an 8-channel knee coil, a fat-saturated 3D dual-echo UTE-Cones sequence was used to image the ZCC, following with a short rectangular pulse excitation and 3D spiral sampling with conical view ordering. The regions of interests (ROIs) were delineated by a blinded observer. Singlecomponent T2* and T2 values were calculated from fat-saturated 3D dual-echo UTE-Cones and a Carr-Purcell-Meiboom-Gill (T2 CPMG) data using a semi-automated MATLAB code. Results: The single-exponential fitting curve of ZCC was accurately obtained with R2 of 0.989. For keen joint samples, the ZCC has a short T2* ranging from 0.62 to 2.55 ms, with the mean ±standard deviation (SD) of 1.49 ±0.66 ms, and with 95% confidence intervals (CI) of 1.20-1.78 ms. For volunteers, the short T2* ranges from 0.93 to 3.52ms, with the mean±SD of 2.09±0.56 ms, and the 95% CI is 1.43 to 2.74ms in ZCC. Conclusions: The high-resolution 3D UTE-Cones sequence might be used to directly image ZCC in the human knee joint on a clinical 3T scanner with a scan time of more than 10 min. Using this non-invasive technique, the T2* relaxation time of the ZCC can be further detected.
