Chen-Jung Chang

Objectives: Differences in image processing protocols may lead to variability in quantitative sacroiliac/sacral (SI/S) ratio measurements in bone scintigraphy. This study aims to compare differences in SI/S ratio values using two image analysis methods (matrix method and line method) on bone scan images. We also studied the interobserver and intraobserver variabilities between experienced and novice observers. Material and Methods: A total of 95 participants (63 with immune rheumatic diseases and 32 healthy controls) underwent Tc-99m methylene diphosphonate bone scintigraphy. SI/S ratios were calculated using two image analysis approaches: (a) the matrix method, which uses rectangular regions of interest in the sacroiliac joints (SIJs) and sacrum, and (b) the line method, which applies a single-pixel horizontal line segment across the SIJs and sacrum. Two senior observers and one junior observer performed the analyses, and interobserver and intraobserver variability were assessed using intraclass correlation coefficients (ICCs). Results: The line method consistently produced higher SI/S ratios than the matrix method across overall, right, and left measurements (all P < 0.05). Similar trends were observed in both patients and healthy subjects. Both interobserver and intraobserver agreements were high (ICC > 0.8), although minor differences were noted in less experienced readers. Conclusion: The line method yielded consistently higher SI/S ratios, indicating greater sensitivity for detecting joint activity. When transitioning between software platforms or reevaluating normal reference values, methodological differences must be acknowledged, and appropriate calibration or database revision should be considered.

In nuclear medicine, simulation-based instruction offers a safer alternative to traditional training, yet no studies have specifically applied virtual reality (VR) to clinical education and training within nuclear medicine departments. This study aimed to investigate whether a VR-based teaching module enhances students’ perceived understanding of myocardial perfusion imaging (MPI) procedures and overall learning satisfaction. Methods: Between July and December 2023, we enrolled a group of 19 internship students, who were asked to complete a survey on their learning expectations regarding MPI. Survey analysis revealed that 73.7% of students were unfamiliar with the MPI procedure and 57.9% indicated that they required over 2 h of learning and hands-on practice to achieve proficiency. To address these needs, the research team produced a 10-min simulation video, covering learning objectives, training duration, evaluation criteria, patient education, procedural steps, and key safety considerations. Using the survey results, we designed a teaching video to capture realistic clinical scenes that involved MPIs. After students completed the simulation-based module, they viewed the teaching video and completed a satisfaction survey to evaluate the effectiveness of our teaching. Results: All students agreed that the video length was appropriate, the quiz questions facilitated understanding, and the interactive design supported understanding. Furthermore, 89.5% of students found the contents clear and easy to understand, with an overall mean satisfaction score of 8.95 (of 10 possible points). Conclusion: The VR teaching program for MPI was successful and serves as an effective preparatory resource for students completing nuclear medicine internships. Visual Abstract

Radiation-induced skin injury (RSI) is a frequent complication of radiotherapy. Severe cases affect the patient’s disease treatment and quality of life. The main purpose of this study is to examine the causative role of egg-yolk oil (EYO) in delayed radiation-induced skin injury, including impaired wound healing. Using polyvinyl pyrrolidone (PVP)-gelatin-chitosan (PGC) composite film as controlled release of egg-yolk oil (EYO) was studied in rats, which were used as a radiation-induced skin injury model. Different composition ratios were tested for their mechanical properties, moisture content, and degradation characteristics. The results showed that the PGC112 (w/w) substrate, which will hence be referred to as PGC, had the better properties. Further, the PGC was mixed with EYO (0.25% and 0.5%) to prepare the films (PGC/0.25EYO and PGC/0.5EYO, respectively). Furthermore, the mechanical and degradation properties and biocompatibility showed better results with PGC/0.5EYO. In animal studies, rats were irradiated with single-dose electron beams of 40 Gy. The animals were divided into five groups to perform wound treatment with various types of wound dressing for 30 days. Histological examination and CD68 immunochemical staining were then conducted, and observations were made. The results showed that PGC/0.5EYO has a significantly healing effects on radiodermatitis and good re-epithelialization.

Magnetic nanoparticles are used to enhance the image contrast of magnetic resonance imaging (MRI). However, the development of magnetic nanoparticles with a low dose/high image contrast and non-toxicity is currently a major challenge. In this study, cobalt-substituted hydroxyapatite nanoparticles deposited on titanium (Ti-CoHA) and cobalt-substituted hydroxyapatite nanoparticles deposited on titanium dioxide nanotubes (TNT-CoHA) were synthesized by the electrochemical deposition method. The particle sizes of Ti-CoHA and TNT-CoHA were 418.6 nm and 127.5 nm, respectively, as observed using FE-SEM. It was shown that CoHA can be obtained with a smaller particle size using a titanium dioxide nanotube (TNT) electrode plate. However, the particle size of TNT-CoHA is smaller than that of Ti-CoHA. The crystal size of the internal cobalt oxide of CoHA was calculated by using an XRD pattern. The results indicate that the crystal size of cobalt oxide in TNT-CoHA is larger than that of the cobalt oxide in Ti-CoHA. The larger crystal size of the cobalt oxide in TNT-CoHA makes the saturation magnetization (Ms) of TNT-CoHA 12.6 times higher than that of Ti-CoHA. The contrast in MRIs is related to the magnetic properties of the particles. Therefore, TNT-CoHA has good image contrast at low concentrations in T₂ images. The relaxivity coefficient of the CoHA was higher for TNT-CoHA (340.3 mM⁻¹s⁻¹) than Ti-CoHA (211.7 mM⁻¹s⁻¹), and both were higher than the commercial iron nanoparticles (103.0 mM⁻¹s⁻¹). We showed that the TNT substrate caused an increase in the size of the cobalt oxide crystal of TNT-CoHA, thus effectively improving the magnetic field strength and MRI image recognition. It was also shown that the relaxivity coefficient rose with the Ms. Evaluation of biocompatibility of CoHA using human osteosarcoma cells (MG63) indicated no toxic effects. On the other hand, CoHA had an excellent antibacterial effect, as shown by E. coli evaluation, and the effect of TNT-CoHA powder was higher than that of Ti-CoHA powder. In summary, TNT-CoHA deposited electrochemically on the TNT substrates can be considered as a potential candidate for the application as an MRI contrast agent. This paper is a comparative study of how different electrode plates affect the magnetic and MRI image contrast of cobalt-substituted hydroxyapatite (CoHA) nanomaterials.

For surface modification and nerve regeneration, chitosan, followed by nerve growth factor (NGF), was immobilized onto the interior surface of poly (lactic acit‐co‐glycolic) conduits, using EDC/NHS/MES system (EDCs) and genipin (GP). Four new conduits were, therefore, obtained and named by immobilizing order‐EDCs/EDCs, GP/EDCs, EDCs/GP, and GP/GP groups. The immobilized methods used were evaluated and compared, respectively. The researchers found that the EDCs‐ and GP‐cross‐linked chitosan displayed higher hydrophilic than pure poly (DL‐lactic acid‐co‐glycolic acid) (PLGA) in water contact angle experiment, which meant the cell compatibility was improved by the modification. Scanning electron microscopic observations revealed that the GP‐cross‐linking of chitosan greatly improved cell compatibility while cultured rat PC12 cells were flatter and more spindle‐shaped than EDCs‐cross‐linked chitosan. The results concerning the GP‐cross‐linked chitosan revealed significant proliferation of the seeded cells relative to pure PLGA films, as determined by counting cells and MTT assay. The NGF was released from the modified conduits in two separate periods—an initial burst in 5 days and then slow release from day 10 to day 40. The GP/EDCs group had the highest NGF value among all groups after the 5th day. Finally, the controlled‐release conduits were used to bridge a 10 mm rat sciatic nerve defect. Six weeks following implantation, morphological analysis revealed the highest numbers of myelinated axons in the midconduit and distal regenerated nerve in GP/EDCs group. Therefore, the results confirm that GP/EDCs groups with good cell compatibility and effective release of NGF can considerably improve peripheral nerve regeneration. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.

Different lag-time of pulse-released nerve growth factor (NGF) from genipin-crosslinked gelatin within polycaprolactone (PCL) conduits was evaluated in large-gap peripheral nerve repair. In this study, 10% (w/v) gelatin was mixed with NGF, crosslinked with 0%, 0.1%, 0.5%, and 1% (w/v) genipin, and then sucked into the wall of PCL conduits. These controlled-release nerve conduits were named NCL (non-crosslink), LCL (low crosslink), MCL (medium crosslink), and HCL (high crosslink), respectively. The NGF releasing character showed four distinctive curves, including initial burst within 5 days, pulse releasing at 5–20 days, pulse releasing at 10–25 days, and steadily releasing. The bioactivity of the released NGF was shown by neurite outgrowth of PC12 cells after culturing in all groups. Finally, the controlled-release conduits were seeded with 9 × 10³ Schwann cells. Conduits were used to bridge a 15-mm rat sciatic nerve defect, and the results were compared with the isografts (control group). Eight weeks after implantation, morphological analysis revealed that LCL, MCL, and HCL groups were similar to autograft treatment in the numbers and area of myelinated axons. The LCL group, although insignificant, showed a trend to have the highest myelinated axon counts of the conduit-treated groups. Thus, comparing the different NGF release characteristics among NCL, MCL, and LCL groups, we concluded that a high concentration of NGF at 5–10 days in LCL groups is needed in bridging a 15-mm peripheral nerve injury.

The gelatin solution crosslinked by genipin (0, 0.1, 0.5, 1.0, and 1.5% w/w) was studied as a nerve growth factor (NGF) carrier (GGp0, GGp0.1, GGp0.5, GGp1.0, and GGp1.5) in a polycaprolactone conduit in large‐gap nerve regeneration. The GGp0 and GGp0.1 displayed the highest activity of PC12 cells and inhibited the reduction of 3‐(4,5‐dimethylthiazol‐2‐yl)2,5‐diphenyl‐tetrazolium bromide (MTT). No cytotoxicity was found in all groups by lactate dehydrogenase (LDH) release. The NGF‐releasing characters were obtained by ELISA tests. A relatively fast release rate appeared during the first 10 days and then a subsequent slower release profile followed. NGF was higher in GGp0.1 than in GGp0 and GGp0.1 after 10 days. The bioactivity of the released NGF remains the same when measuring the neurite outgrowth of PC 12 cells. Finally, the controlled‐release conduits were implanted into 12‐mm long sciatic nerve gaps of rats. In addition, the best site of NGF carrier was determined either by filling carrier into the conduit lumen or by sucking carrier to the conduit wall. Four and 8 weeks after implantation, morphological analysis revealed that GGp0.1 conduits had markedly larger and more number of myelin axons in the midconduit and distal nerve. Further, sucking the carrier into the conduit wall was an efficient and convenient way to prevent the regeneration of axons and vessels from being impaired by the lumen's carrier. The genipin‐crosslinked gelatin is a promising carrier in producing a high release concentration and a long release period of NGF to promote the regeneration over a large‐gap nerve injury. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009

The high outflow permeability of the nerve conduit used to emit the drained waste generated from the traumatized host nerve stump is critical in peripheral nerve regeneration. Our earlier studies have established that asymmetric conduits fulfill the basic requirements for use as nerve guide conduits. In this study, the inflow characteristics of optimal nerve conduits were further examined using in vivo and in vitro trials. Various asymmetric poly(DL‐lactic acid‐co‐glycolic acid) (PLGA) conduits were controlled by modifying precipitation baths using 0, 20, and 95% isopropyl alcohol, with high‐porosity (permeability), medium‐porosity (high outflow and low inflow), and low‐porosity (permeability), respectively. In the in vitro trial, the Schwann cells and fibroblasts were seeded on either side of the asymmetric PLGA films in a newly designed coculture system that simulated the repaired nerve conduit environment. The results of the directional permeable films indicated the statistically significant proliferation of Schwann cells and the inhibition of the division of fibroblasts in lactate dehydrogenase release and inhibition of 3‐(4,5‐dimethylthiazol‐2‐yl)2,5‐diphenyl‐tetrazolium bromide (MTT) reduction, compared with the other films. In the in vivo trial, the PLGA conduits seeded with Schwann cells were implanted into 10 mm right sciatic nerve defects in rats. After 6 weeks, implanted conduits were harvested. Histological examination verified that directional permeable conduits had markedly more A‐type and B‐type myelin fibers in the midconduit and distal nerve. In this work, the directional transport characteristics were established as an extremely important factor to the design and development of optimal nerve guide conduits in peripheral nerve regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007