Magnetic resonance imaging of the zone of calcified cartilage in the knee joint using 3-dimensional ultrashort echo time cones sequences / 中华医学杂志(英文版)

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. Single-component 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 3.52 ms, with the mean ± SD of 2.09 ± 0.56 ms, and the 95% CI is 1.43 to 2.74 ms 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.

Detection of Repair of the Zone of Calcified Cartilage with Osteoarthritis through Mesenchymal Stem Cells by Ultrashort Echo Time Magnetic Resonance Imaging / 中华医学杂志(英文版)

<p><b>Objective</b>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 of UTE 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.</p><p><b>Data Sources</b>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.</p><p><b>Study Selection</b>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.</p><p><b>Results</b>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.</p><p><b>Conclusions</b>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.</p>

Repair of tissue defects with free composite anterolateral femoral fascia lata perforator tissue flaps / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the clinical effects of repair of complicated tissue defects of several body parts with composite anterolateral femoral fascia lata perforator tissue flaps (fascial flap or fascial skin flap) with the aid of micro-surgery.</p><p><b>METHODS</b>From February 2008 to August 2012, complicated tissue defects in 12 patients were repaired with composite anterolateral femoral fascia lata perforator tissue flaps. Two of the 12 patients suffered from a defect of scalp, skull, and dura mater as a result of resection of a malignant tumor of the scalp; 3 patients showed a defect of skin and tendo calcaneus in the heel and lower leg; 2 patients showed a defect of skin and extensor tendon in the dorsum of hands; the other 5 patients suffered from defects of skin and extensor tendon in the foot and ankle combined with exposure of bone or internal buttress plate. The size of tissue flaps ranged from 12 cm ×6 cm to 19 cm ×18 cm. The donor sites were closed by immediate suturing or skin grafting.</p><p><b>RESULTS</b>All 12 tissue flaps survived. Patients were followed up for 2 to 36 months. The flaps were shown to have good appearance, texture and function. Two patients with the defect of the scalp, skull and dura mater after a resection of the malignant tumor of the scalp did not have recurrence or herniation of brain tissue. The foot-raising function in 3 patients with the defect of skin and tendo calcaneus in the heel and lower leg was recovered, and according to Arner-Lindholm criteria the result was excellent in 2 cases and good in 1 case. The extension function of fingers of 2 patients with defects of skin and extensor tendon in the dorsum of hands was good according to the evaluation criteria of Chinese Medical Association Society of Hand Surgery for tendon repair of hand. The extension function of toes of 5 patients with defects of skin and extensor tendon in the foot and ankle combined with exposure of bone or internal buttress plate was recovered and improved.</p><p><b>CONCLUSIONS</b>Transplantation of composite anterolateral femoral fascia lata perforator tissue flaps with the aid of micro-surgery is an effective method in repairing the tissue defects of skull, dura mater, and the extensor tendon of hands or feet, with restoration of the extension function.</p>