Evaluation of distal skin temperature and tissue oxygen saturation determined by near-infrared spectroscopy for predicting ultrasound-guided lateral infraclavicular block success.

BACKGROUND: Changes in tissue oxygen saturation determined by near-infrared spectroscopy (NIRS) may help predict and determine the success of a lateral infraclavicular (LIC) block.We investigated whether evaluation of tissue oxygen saturation determined by NIRS couldbe an indicator of LIC block success. METHODS: Forty patients scheduled for hand or forearm surgery under LIC block were studied. NIRS sensors were placed on the ventral aspect of both mid-forearms, and the contralateral hand was used as the control group. NIRS values were recorded before the block andat regular intervals during the following 30 min. RESULTS: NIRS values were significantly higher in the successfully blocked patients whencompared to the complete failure, partial failure, and contralateral hand groups at the 10thmin. In the successfully blocked patients, NIRS values (mean ± SD [change in %]) increasedby 11.09 ± 4.86 (16.03%), 15.00 ± 4.53 (21.76%), 16.35 ± 5.14 (23.77%), 16.38 ± 4.88(23.85%), 16.67 ± 5.04 (24.29%), and 16.96 ± 5.71 (24.78%), respectively, from baselineto 5, 10, 15, 20, 25, and 30 min. ΔTs values were significantly higher in the successfullyblocked patients than in the complete failure patients and contralateral hand at the 30thmin. However, there was no statistically significant difference when comparing ΔTs values ofsuccessful block and partial failure block patients at the 30th min. CONCLUSIONS: We conclude that measurement of tissue oxygen saturation by NIRS withinthe scope of evaluation of the lateral infraclavicular block is a rapid, effective, and applicabletechnique.

Vascularized Bone Marrow Cellular Depletion or Discontinuity Abrogates Protection of Vascularized Composite Allografts in Nonhuman Primates.

BACKGROUND: Vascularized composite allografts (VCA) have demonstrated good clinical outcomes dependent on chronic immunosuppression. Previous work by our group and others supports that cotransplanted vascularized bone marrow (VBM) as a component of VCA offers immunologic protection to prolong graft survival. We aimed to characterize the requirements and potential mechanisms of VBM-mediated protection of VCA by modifying grafts through various strategies. METHODS: Experimental groups of mismatched cynomolgus macaque recipients received VCA transplants modified by the following approaches: heterotopic separation of the VCA and VBM components; T-cell depletion of either donor or recipient; irradiation of donor VCA; and infusion of donor bone marrow. All groups received standard immunosuppression with tacrolimus and mycophenolate mofetil. RESULTS: Experimental modifications to donor, recipient, or graft all demonstrated short-graft survivals (31 d). Chimerism levels without bone marrow infusion were transient and minimal when detected and were not associated with prolonged survival. Donor bone marrow infusion increased levels of chimerism but resulted in alloantibody production and did not improve graft survival. CONCLUSIONS: VCA graft survival is significantly reduced compared with previously reported VCA with VBM transplants (348 d; P = 0.01) when the hematopoietic niche is removed, altered, or destroyed via irradiation, depletion, or topographical rearrangement. These experimental manipulations resulted in similar outcomes to VCA grafts without cotransplanted VBM (25 d). These data support the presence of a radiosensitive, T-cell population within the VBM compartment not reconstituted by reinfusion of bone marrow cells.

The effect of pre-procedure anxiety on sedative requirements for sedation during upper gastrointestinal endoscopy.

OBJECTIVES: Sedation for upper gastrointestinal endoscopy, commonly used for diagnosis and treatment of gastrointestinal diseases, has been increasing widespread. Sedative agent requirements during sedation or anesthesia can be affected by many factors such as age and sex. In the present study, we aimed to evaluate the effects of pre-procedural anxiety levels on sedative requirements during upper gastrointestinal endoscopy. MATERIAL AND METHODS: 300 patients between the ages of 18-70 years were studied. Baseline anxiety levels were measured before the procedure using Spielberger's State-Trait Anxiety Inventory (STAI) form X1. Propofol was administered to have BIS values between 65-85 during sedation. Doses of propofol, total procedure time, satisfaction of the patients and endoscopists and BIS values were recorded. RESULTS: Pre-procedural anxiety was 44 (40-48 [20-70]). We found significant correlations between pre-procedure anxiety and the usage of propofol (mg, mg/kg, mg/kg/dk) at BIS values between 65-85, [respectively, (p= 0.451, p <0.001), (p= 0.455, p <0.001), (p= 0.428, p <0.001)]. No correlation was found between pre-procedure anxiety and procedural or sedation complications (respectively p= 0.111, p= 0.424 and p= 0.408, p= 0.363). We found significant negative correlations between pre-procedure anxiety and the satisfaction of the patients/endoscopist [respectively, (p= -0.477, p <0.001), (p= -0.495, p <0.001)]. CONCLUSION: Based on the results of this study, we suggest that there is a significant association between the pre-procedural anxiety levels and use of sedative drugs in patients undergoing upper gastrointestinal endoscopy.

The effect of bispectral index monitoring on cognitive performance following sedation for outpatient colonoscopy: a randomized controlled trial.

BACKGROUND: Bispectral index (BIS) monitoring can positively affect cognitive performance through decreasing the use of sedative agents. We aimed to evaluate the effect of BIS monitoring on early cognitive performance among patients undergoing sedation for colonoscopy. DESIGN AND SETTING: Randomized, controlled trial in a university hospital. METHODS: 100 patients were randomized into two groups. In the monitored group (n = 50), the depth of anesthesia was monitored using the BIS, and BIS scores were maintained between 60 and 80. In the usual care group (n = 50), BIS monitoring was not performed. To determine the patients' baseline cognitive performance levels, the mini-mental state examination (MMSE), Trieger dot test (TDT) and clock drawing test (CDT) were used. The patients' post-procedure cognitive performance levels were determined when they were classified as ready for discharge. RESULTS: The total volume (mg) of propofol used [median (range) IQR] in the sedation procedure was lower in the monitored group [100 (50-200) 100-140] than in the usual care group [150 (75-200) 100-200] (P < 0.001). The discharge scores [mean (SD)] using MMSE and CDT were higher in the monitored group [26 (3) and 3 (1), respectively] than in the usual care group [23 (3) and 2 (1), respectively] (P = 0.002 and P = 0.002, respectively). The discharge scores using TDT [mean (SD)] were lower in the monitored group [11 (7)] than in the usual care group [15 (11)] (P = 0.033). CONCLUSION: BIS monitoring among sedated patients was associated with lower propofol use and smaller decline in cognitive performance. CLINICAL TRIAL REGISTRATION: This trial was registered in the Australian New Zealand Clinical Trial Registry (ACTRN12617000134325).

The effect of bispectral index monitoring on cognitive performance following sedation for outpatient colonoscopy: a randomized controlled trial

ABSTRACT BACKGROUND: Bispectral index (BIS) monitoring can positively affect cognitive performance through decreasing the use of sedative agents. We aimed to evaluate the effect of BIS monitoring on early cognitive performance among patients undergoing sedation for colonoscopy. DESIGN AND SETTING: Randomized, controlled trial in a university hospital. METHODS: 100 patients were randomized into two groups. In the monitored group (n = 50), the depth of anesthesia was monitored using the BIS, and BIS scores were maintained between 60 and 80. In the usual care group (n = 50), BIS monitoring was not performed. To determine the patients' baseline cognitive performance levels, the mini-mental state examination (MMSE), Trieger dot test (TDT) and clock drawing test (CDT) were used. The patients' post-procedure cognitive performance levels were determined when they were classified as ready for discharge. RESULTS: The total volume (mg) of propofol used [median (range) IQR] in the sedation procedure was lower in the monitored group [100 (50-200) 100-140] than in the usual care group [150 (75-200) 100-200] (P < 0.001). The discharge scores [mean (SD)] using MMSE and CDT were higher in the monitored group [26 (3) and 3 (1), respectively] than in the usual care group [23 (3) and 2 (1), respectively] (P = 0.002 and P = 0.002, respectively). The discharge scores using TDT [mean (SD)] were lower in the monitored group [11 (7)] than in the usual care group [15 (11)] (P = 0.033). CONCLUSION: BIS monitoring among sedated patients was associated with lower propofol use and smaller decline in cognitive performance. CLINICAL TRIAL REGISTRATION: This trial was registered in the Australian New Zealand Clinical Trial Registry (ACTRN12617000134325).

Hyoscine N-Butylbromide for Preventing Propofol Injection Pain: A Randomized, Placebo-Controlled and Double-Blind Study.

OBJECTIVE: In this study, the aim was to investigate the effect of hyoscine N-butylbromide (HnBB) pretreatment on pain during propofol injection. SUBJECTS AND METHODS: In this prospective, randomized, placebo-controlled and double-blind trial, 60 patients scheduled to undergo routine outpatient surgery under general anesthesia were randomly allocated to 2 groups, the HnBB (n = 30) and sodium chloride (n = 30) groups. Twenty seconds after the injection of 20 mg HnBB or 0.9 % sodium chloride, a 50-mg dose of propofol was injected in 2-3 s. Ten seconds later, the pain intensity was assessed using a 4-point scale: no pain (0), mild (1), moderate (2), and severe (3) pain. The Student t test was used for the analysis of parametric data and the Pearson χ2 test for categorical data. RESULTS: The occurrence of pain in the HnBB group (43.3%) was significantly lower than the control group (73.3%) (p < 0.018). Of the 30 patients in each group, 10 in the control group and 3 in the HnBB group experienced severe pain (p = 0.001). CONCLUSIONS: Pretreatment with 20 mg HnBB significantly reduced propofol injection pain compared to placebo.

Evaluation of the stability and stratification of propofol and ketamine mixtures for pediatric anesthesia.

BACKGROUND: The combination of propofol and ketamine is commonly used for total intravenous anesthesia. These drugs can be delivered in different syringes or in the same syringe. We hypothesized that the drugs might separate and different concentrations of each drug could be found in different parts of the syringe during the procedure period when they were mixed in 1 syringe. METHODS: Twelve 60-mL polypropylene syringes were prepared by mixing propofol and ketamine as 4 groups on the basis of propofol/ketamine mixture ratios (5:1 and 6.7:1) and propofol solution concentrations. Syringes were placed upright in the vertical position into a rack and kept at room temperature (21.5-22.5°C), in daylight conditions and were not moved for 360 minutes. Samples of the mixture were taken from both the top and the bottom of the syringe. The first 1 mL of the samples was discarded, the following second 1 mL of the samples was filtered using 0.2-µm polytetrafluoroethylene filters and measured twice (n = 6). Samples were taken at the following time intervals: T0, T10, T30, T60, T90, T120, T180, T240, T300, and T360 min. Syringes were checked visually for any color change and separation lines between the drugs. RESULTS: There were no significant differences between the propofol and ketamine concentrations of the top and bottom samples in all 4 groups. In addition, there were no statistically significant changes of propofol and ketamine concentrations of samples over 360 minutes in any of the 4 groups. No visual changes were observed during 6 hours' observation. CONCLUSION: The results of our measurements demonstrated that mixtures of propofol (1% and 2%) and ketamine at 5:1 and 6.7:1 ratios could be used in terms of mixture homogeneity and stability in a polypropylene syringe during a 6-hour period at room temperature.

The validity and reliability of computed tomography orbital volume measurements.

PURPOSE: Orbital volume calculations allow surgeons to design patient-specific implants to correct volume deficits. It is estimated that changes as small as 1 ml in orbital volume can lead to enophthalmos. Awareness of the limitations of orbital volume computed tomography (CT) measurements is critical to differentiate between true volume differences and measurement error. The aim of this study is to analyze the validity and reliability of CT orbital volume measurements. MATERIALS AND METHODS: A total of 12 cadaver orbits were scanned using a standard CT maxillofacial protocol. Each orbit was dissected to isolate the extraocular muscles, fatty tissue, and globe. The empty bony orbital cavity was then filled with sculpting clay. The volumes of the muscle, fat, globe, and clay (i.e., bony orbital cavity) were then individually measured via water displacement. The CT-derived volumes, measured by manual segmentation, were compared to the direct measurements to determine validity. RESULTS AND CONCLUSIONS: The difference between CT orbital volume measurements and physically measured volumes is not negligible. Globe volumes have the highest agreement with 95% of differences between -0.5 and 0.5 ml, bony volumes are more likely to be overestimated with 95% of differences between -1.8 and 2.6 ml, whereas extraocular muscle volumes have poor validity and should be interpreted with caution.

Comparison of the Effects of Different Positive End-Expiratory Pressure Levels on Cerebral Oxygen Saturation With Near Infrared Spectroscopy During Laparoscopic Cholecystectomy.

PURPOSE: Although positive end-expiratory pressure (PEEP) is commonly used to improve respiratory mechanics and oxygenation during pneumoperitoneum (PP), the effect of PEEP on cerebral homeostasis during carbon dioxide PP remains uncertain. This study investigated the changes in regional cerebral oxygen saturation (rSO2) associated with 0, 5, and 10 cm H2O PEEP during PP while undergoing laparoscopic cholecystectomy under sevoflurane anesthesia. MATERIALS AND METHODS: In total, 105 patients between the ages of 18 to 60 years, scheduled to undergo laparoscopic cholecystectomy under general anesthesia, were studied. The patients were randomized, into 3 groups: group I (n=35) with no external PEEP, group II (n=35) with external PEEP of 5 cm H2O, group III (n=35) with external PEEP of 10 cm H2O. Heart rate, mean blood pressure, oxygen saturation, and rSO2 values were continuously recorded from awake status to tracheal extubation. RESULTS: The measurements of hemodynamic parameters were statistically similar between 3 groups (P>0.05). rSO2 values were statistically similar between 3 groups (P>0.05). CONCLUSIONS: We consider that both 5 and 10 cm H2O PEEP levels can be safely used during PP applied during laparoscopic surgery, without affecting hemodynamics, and without causing a decline in rSO2.

Recellularization via the bile duct supports functional allogenic and xenogenic cell growth on a decellularized rat liver scaffold.

Recent years have seen a proliferation of methods leading to successful organ decellularization. In this experiment we examine the feasibility of a decellularized liver construct to support growth of functional multilineage cells. Bio-chamber systems were used to perfuse adult rat livers with 0.1% SDS for 24 hours yielding decellularized liver scaffolds. Initially, we recellularized liver scaffolds using a human tumor cell line (HepG2, introduced via the bile duct). Subsequent studies were performed using either human tumor cells co-cultured with human umbilical vein endothelial cells (HUVECs, introduced via the portal vein) or rat neonatal cell slurry (introduced via the bile duct). Bio-chambers were used to circulate oxygenated growth medium via the portal vein at 37C for 5-7 days. Human HepG2 cells grew readily on the scaffold (n = 20). HepG2 cells co-cultured with HUVECs demonstrated viable human endothelial lining with concurrent hepatocyte growth (n = 10). In the series of neonatal cell slurry infusion (n = 10), distinct foci of neonatal hepatocytes were observed to repopulate the parenchyma of the scaffold. The presence of cholangiocytes was verified by CK-7 positivity. Quantitative albumin measurement from the grafts showed increasing albumin levels after seven days of perfusion. Graft albumin production was higher than that observed in traditional cell culture. This data shows that rat liver scaffolds support human cell ingrowth. The scaffold likewise supported the engraftment and survival of neonatal rat liver cell slurry. Recellularization of liver scaffolds thus presents a promising model for functional liver engineering.

Anxiety Levels in Patients Undergoing Sedation for Elective Upper Gastrointestinal Endoscopy and Colonoscopy.

BACKGROUND: Anxiety is a common preprocedural problem and during processing especially in interventional medical processes. AIM: Aim of this study was to assess the level of anxiety in patients who will undergo upper gastrointestinal endoscopy and coloscopy. METHODS: Five hundred patients scheduled to undergo sedation for elective upper gastrointestinal endoscopy and colonoscopy were studied. Beck Anxiety Inventory (BAI) was administered to each patient before brought to the endoscopy room. Demographic data of patients were collected. RESULTS: BAI scores and anxiety levels were significantly lower in; males compared to females, patients with no comorbidity compared to patients with comorbidity (both P values < 0.001). BAI scores were significantly lower in patients educational status university and upper compared to patients educational status primary-high school (p=0.026). There were no significant difference between BAI and anxiety levels compared to procedures (Respectively, P=0.144 P=0.054). There were no significant difference between BAI scores and anxiety levels compared to age groups (Respectively, P=0.301 P=0.214). CONCLUSIONS: We think that level of anxiety in patients who will undergo upper gastrointestinal endoscopy and colonoscopy was effected by presence of comorbidities and gender but was not effected by features such as age, procedure type and educational status.

A Rare Cervical Dystonia Mimic in Adults: Congenital Muscular Torticollis (Fibromatosis colli), a Follow-up.

Neglected or undiagnosed congenital muscular torticollis in adults is quite rare, although it is the third most common congenital deformity in the newborn (1). When left untreated at an early age, deficits in lateral and rotational range of motion can occur along with irreversible facial and skeletal deformities that develop over time. Subtle cases can go unnoticed until early adulthood, with predominant fibrotic replacement in the sternocleidomastoid (SCM) making physical therapy and chemodenervation mostly ineffective. Surgical intervention, in these cases, can prove effective in alleviating pain, improving function and cosmesis (2). We report an update on a previously reported case, misdiagnosed as cervical dystonia, which had undergone partial myectomy of the anterior belly of the SCM with some relief of symptoms but without total resolution after the correct diagnosis of fibromatosis colli (3).

Vascularized Composite Allotransplantation: Medical Complications.

The objective of this review is to summarize the collective knowledge regarding the risks and complications in vascularized composite tissue allotransplantation (VCA), focusing on upper extremity and facial transplantation. The field of VCA has entered its second decade with an increasing experience in both the impressive good outcomes, as well as defining challenges, risks, and experienced poor results. The limited and selective publishing of negative outcomes in this relatively new field makes it difficult to conclusively evaluate outcomes of graft and patient survival and morbidities. Therefore, published data, conference proceedings, and communications were summarized in an attempt to provide a current outline of complications. These data on the medical complications of VCA should allow for precautions to avoid poor outcomes, data to better provide informed consent to potential recipients, and result in improvements in graft and patient outcomes as VCA finds a place as a therapeutic option for selected patients.

The effects of bispectral index monitoring on hemodynamics and recovery profile in developmentally delayed pediatric patients undergoing dental surgery.

BACKGROUND: General anesthesia is often preferred for dental surgery or rehabilitation in developmentally delayed pediatric patients. Bispectral index monitoring is used to monitor the depth of anesthesia and to ensure early recovery. However, studies on the topic in developmentally delayed pediatric patients are limited. AIM: To evaluate the effects of Bispectral Index Scale (BIS) on hemodynamics and recovery profile in developmentally delayed pediatric patients undergoing dental surgery. METHODS: Forty children between the ages of 6-16 years were studied in this prospective and randomized study. The children were randomized into two groups. In Group 1 (n = 20), general anesthesia was maintained with 1-2 minimum alveolar concentration (MAC) of sevoflurane in oxygen by standard practice. In Group 2 (n = 20), the depth of anesthesia was monitored by BIS. BIS values were continuously recorded from awake status to tracheal extubation. The duration of the surgical procedure, anesthesia, postanesthesia care unit (PACU) stay was noted. To evaluate recovery profile, time to spontaneous ventilation, extubation, open eyes, and PACU discharge were also noted. RESULTS: There were significant differences between recovery times and Non-communicating Children's Pain Checklist - Postoperative Version (NCCPC-PV) scores of two groups. Time to spontaneous ventilation [Difference in means (95% CI); 3.17 (1.79-4.54) P < 0.001], extubation [Difference in means (95% CI); 3.13 (1.66-4.60) P < 0.001], open eyes [Difference in means (95% CI); 3.97 (2.34-5.59) P < 0.001], and PACU stay time [Difference in means (95% CI); 23.55 (18.08-29.01) P < 0.001] were significantly shorter in Group 2. CONCLUSION: In conclusion, results suggest that routine BIS monitoring may be beneficial due to its favorable effects on the recovery profile in developmentally delayed pediatric patients.

[Comparison the effects of prilocaine and the addition of dexketoprofen and dexamethasone to prilocaine for intravenous regional anesthesia]. / Intravenöz rejyonel anestezi tekniginde prilokain, prilokaine eklenen deksketoprofen ve deksametazonun etkinliklerinin karsilastirilmasi

OBJECTIVES: The aim of this study was to compare the anesthetic and analgesic effects of prilocaine alone, prilocaine added dexketoprofen and dexamethasone during intravenous regional anesthesia (IVRA). METHODS: Forty five patients undergoing forearm or hand surgery were randomly assigned to one of three groups to receive (Group P) 3 mg/kg 0.5% prilocaine; (Group PDK) 3 mg/kg 0.5% prilocaine plus 50 mg dexketoprofen; (Group PDM) 3 mg/kg 0.5% prilocaine plus 8 mg dexamethasone in total 40 ml volume for IVRA. The onset and duration of sensory and motor blocks, hemodynamic datas, duration of analgesia and tourniquet, time to first analgesic requirement, visual analog scale (VAS), total analgesic consumption in 24 hours and patient satisfaction score were assessed and recorded. RESULTS: Time to onset of sensory block was found to be longer in Group P (p<0.05), though no significance was found according to sensory block recovery times amoung groups. Time to onset of motor block was found to be longer and recovery time of motor block was found to be shorter in Group P (p<0.05). Time to first analgesic requirement was found to be longer in Group PDK,and was found to be high in Group PDM than Group PDK(p<0.05). The VAS scores was found to be high and patient satisfaction scale was found to be low in Group P (p<0.05). CONCLUSION: The addition of dexketoprofen and dexamethasone to prilocaine during IVRA improves the quality of both anesthesia and analgesia moreover dexketoprofen provides beter postoperative analgesia during the first 24 hour after surgery.

Complications in tissue expander breast reconstruction: a comparison of AlloDerm, DermaMatrix, and FlexHD acellular inferior pole dermal slings.

Acellular dermal matrix (ADM) is frequently used in tissue expander breast reconstruction (TEBR) for coverage of the inferior pole. Several published studies have suggested increased rates of complications with the use of ADM. It is unknown, however, if the type of ADM used for TEBR impacts complication rates. The aim of this study is to compare 3 different types of ADM for TEBR in regard to clinically significant complications, specifically infection. We performed a retrospective analysis of primary breast cancer-related TEBR with or without ADM. Exclusion criteria consisted of prior major breast surgery, inadequate data, or loss to follow-up. Reconstructions were grouped by dermal sling type, AlloDerm, DermaMatrix (DM), FlexHD (FHD), or no ADM. Complications included cellulitis, abscess, seroma, expander leak or puncture, skin necrosis, wound dehiscence, or hematoma. Those requiring admission to hospital or reoperation were considered significant. Of 284 breasts reconstructed, 49 used AlloDerm, 110 used DM, 62 used FHD, and 64 used no ADM. The total complication rate with AlloDerm was 22% [95% confidence interval (CI), 11-34], with DM was 15% (95% CI, 8-21), and with FHD was 18% (95% CI, 8-28) (P=0.47). Infectious complication rates for AlloDerm, DM, and FHD were equal at 10% (P=0.97). The total complication rate of all ADM reconstructions as a grouped cohort was 17% compared to 11% without ADM (P=0.48). The overall incidence of infectious complications with ADM was 10% compared to 2% without ADM (P=0.09). There is no difference in the clinically significant overall complication rate or incidence of infection between AlloDerm, DM, and FHD. Isolating infectious complications, there is a trend toward increased incidence with ADM compared to reconstructions without.

Translational research in pediatric extracorporeal life support systems and cardiopulmonary bypass procedures: 2011 update.

Over the past 6 years at Penn State Hershey, we have established the pediatric cardiovascular research center with a multidisciplinary research team with the goal to improve the outcomes for children undergoing cardiac surgery with cardiopulmonary bypass (CPB) and extracorporeal life support (ECLS). Due to the variety of commercially available pediatric CPB and ECLS devices, both in vitro and in vivo translational research have been conducted to achieve the optimal choice for our patients. By now, every component being used in our clinical settings in Penn State Hershey has been selected based on the results of our translational research. The objective of this review is to summarize our translational research in Penn State Hershey Pediatric Cardiovascular Research Center and to share the latest results with all the interested centers.

Magnetic resonance imaging of chondrocytes labeled with superparamagnetic iron oxide nanoparticles in tissue-engineered cartilage.

The distribution of cells within tissue-engineered constructs is difficult to study through nondestructive means, such as would be required after implantation. However, cell labeling with iron-containing particles may prove to be a useful approach to this problem, because regions containing such labeled cells have been shown to be readily detectable using magnetic resonance imaging (MRI). In this study, we used the Food and Drug Administration-approved superparamagnetic iron oxide (SPIO) contrast agent Feridex in combination with transfection agents to label chondrocytes and visualize them with MRI in two different tissue-engineered cartilage constructs. Correspondence between labeled cell spatial location as determined using MRI and histology was established. The SPIO-labeling process was found not to affect the phenotype or viability of the chondrocytes or the production of major cartilage matrix constituents. We believe that this method of visualizing and tracking chondrocytes may be useful in the further development of tissue engineered cartilage therapeutics.