Clinical trial of photodynamic therapy for peripheral-type lung cancers using a new laser device in a pilot study.

INTRODUCTION/AIM: Photodynamic therapy (PDT) involves the use of a tumor-specific photosensitizer and laser irradiation, and is one of the treatment options recommended for early centrally located lung cancers, but not yet for peripheral-type lung cancers. We developed a new laser probe, the composite-type optical fiberscope (COF), which allows accurate laser irradiation of a cancer lesion with simultaneous visualization of the lesion. In this study, we attempted a new endobronchial PDT technique using the new laser probe, and evaluated the effectiveness and feasibility of this novel PDT technique for peripheral lung cancers. METHODS: This phase I study was conducted in 7 patients with peripheral lung cancers (primary tumor ≤20 mm in diameter). We performed endobronchial PDT for these patients using the new laser probe and talaporfin sodium as the photosensitizer. RESULTS: We performed PDT for 3 patients with peripheral lung cancer using a laser dose of 50 J/cm2 at 120 mW, and confirmed the feasibility of using this dose. Then, we escalated the laser dose to 100 J/cm2 in 4 additional patients. A total of 7 patients met our inclusion criteria. Evaluation at 2 weeks and 3 months after the PDT revealed no complication such as pneumonia or pneumothorax. At the evaluation conducted 6 months later, we found CR in 3 cases and SD in the remaining 4 cases. CONCLUSION: PDT was found to be a feasible and non-invasive treatment modality for early peripheral-type lung cancer. In the future, PDT could become a standard treatment option for peripheral-type lung cancer.

Photodynamic therapy for biliary tract organ via a novel ultra-small composite optical fiberscope.

Photodynamic therapy (PDT) is a method used treat tumors via utilizing photodynamic reactions between photosensitive substances with tumor affinity and lasers. For overall bile duct cancers, PDT has been demonstrated to resolve stenosis and improve prognosis; however, when limited to intrahepatic bile duct cancers, modifications to the laser irradiation are necessary as surrounding hepatocytes incorporate a large amount of photosensitive substances. Furthermore, the intrahepatic bile duct is thin, and a guide sheath and thin fiber are necessary to transport laser irradiation probes to the target region. In the present study, a parallel-type ultra-small composite optical fiberscope (COF) with an outer diameter of 1 mm or smaller was developed to target a thin intrahepatic bile duct. PDT was performed using an animal model and talaporfin sodium (Laserphyrin), which is rapidly excreted by hepatocytes and is suitable for use with a long-wavelength laser due to its high tissue penetrating ability. The results demonstrated that Laserphyrin does not cause necrotic changes in the normal biliary tract mucosa. In addition, COF images of sufficient quality were acquired. The present results suggest that COF may be used for the treatment of deep bile duct lesions.

FGF-2 Stimulates the Growth of Tenogenic Progenitor Cells to Facilitate the Generation of Tenomodulin-Positive Tenocytes in a Rat Rotator Cuff Healing Model.

BACKGROUND: Fibroblast growth factor (FGF)-2 has the potential to enhance tendon-to-bone healing after rotator cuff (RC) injury. HYPOTHESIS: FGF-2 stimulates tenogenic differentiation of progenitors to improve the biomechanical strength and histological appearance of repaired RCs in rats. STUDY DESIGN: Controlled laboratory study. METHODS: Adult male Sprague-Dawley rats (N = 156) underwent unilateral surgery to repair the supraspinatus tendon to insertion sites. The FGF-2-treated group (gelatin hydrogel containing 5 µg of FGF-2) and a control group (gelatin hydrogel only) were compared to investigate the effects of FGF-2 at 2, 4, 6, 8, and 12 weeks postoperatively. Biomechanical testing was performed at 6 and 12 weeks. Semiquantitative histological analysis and immunohistochemical analysis for the proliferating cell nuclear antigen (PCNA) were performed, and the expression of tendon-related markers, including Scleraxis (Scx) and Tenomodulin (Tnmd), was monitored by real-time reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization. SRY-box containing gene 9 (Sox9) expression was monitored by RT-PCR and immunohistochemical analysis. At 2 and 4 weeks, immunohistochemical analysis for mesenchymal stem cell (MSC) markers was also performed. RESULTS: The FGF-2-treated group demonstrated a significant improvement in mechanical strength at 6 and 12 weeks and significantly higher histological scores than the control group at ≥4 weeks. The average incidence of PCNA-positive cells was significantly higher at 2 and 4 weeks, and more cells expressing MSC markers were detected at the insertion site in the FGF-2-treated group. The expression level of Scx increased significantly in the FGF-2-treated group from 4 to 8 weeks, while the Tnmd level increased significantly from 4 to 12 weeks postoperatively. The localization of Tnmd overlapped with the locations of reparative tissues accompanying collagen fibers with an aligned orientation. Sox9 expression was significantly upregulated at 4 weeks in the FGF-2-treated group. CONCLUSION: FGF-2 promotes growth of the tenogenic progenitor cells, which participate in tendon-to-bone healing, resulting in biomechanical and histological improvement of the repaired RC. CLINICAL RELEVANCE: These findings provide clues regarding the clinical development of regenerative repair strategies for RC injury.

Functional and structural comparisons of the arthroscopic knotless double-row suture bridge and single-row repair for anterosuperior rotator cuff tears.

BACKGROUND: We compared the outcomes of knotless double-row suture bridge and single-row repairs in patients undergoing arthroscopic repair for anterosuperior rotator cuff tears. METHODS: We included 61 full-thickness anterosuperior rotator cuff tears treated by arthroscopic repair, namely, single-row repair (group 1: 25 shoulders; mean patient age, 64 years) and the knotless double-row suture bridge repair (group 2: 36 shoulders; mean patient age, 62 years). Preoperative and postoperative magnetic resonance imaging was performed for all shoulders. Clinical outcomes were evaluated for mean follow-up periods of 81 months (range, 72-96 months) in group 1 and 34 months (range, 24-42 months) in group 2, using the University of California, Los Angeles and Japanese Orthopaedic Association assessments. RESULTS: At the final follow-up, both groups showed improvement in the average University of California, Los Angeles and Japanese Orthopaedic Association scores and range of motion, although no intergroup differences were observed. Both groups showed improved abduction strength, and the average score was higher in group 2 (P = .0112). The lift-off and belly-press test results were improved in both groups. Postoperatively, the incidence of positive lift-off tests tended to be lower (P = .075) and that of positive belly-press tests was lower in group 2, P = .049). The repair failure rate tended to be lower in group 2 (14% [5 of 36]) than in group 1 (32% [8 of 25]; P = .0839). CONCLUSIONS: Arthroscopic knotless double-row suture bridge repair of anterosuperior rotator cuff tears yielded functional outcomes equivalent to those of single-row repair and may be useful for improving subscapularis function, abduction strength, and tendon healing.

Design and Preclinical Validation of the Composite-Type Optical Fiberscope for Minimally Invasive Procedures of Intrauterine Disease.

STUDY OBJECTIVE: Because of the rapid growth of minimally invasive surgical procedures, we developed an ultrathin fiberscopic imaging system for laser surgery that could be an important instrument for clinical use in an office setting. METHODS AND MAIN RESULTS: A new device, consisting of a custom 1.1-mm diameter flexible fiberscope and ytterbium laser-supported ablation system (composite-type optical fiberscope), has been developed to achieve accurate laser irradiation for minimally invasive procedures of intrauterine disease. This system was validated ex vivo with successful laser ablation under observation. This study provides the design, characterization, performance, and preclinical validation of an optimized composite-type optical fiberscope system. The validation of this fiberscope for endometrial ablation was performed in 12 hysterectomy samples. The irradiated spot diameter and depth were (mean ± SD) 2.80 ± 0.28 mm and 1.53 ± 0.58 mm, respectively, in the range of 185 to 400 J. The effects of the laser on endometrial tissue depended strongly on the combined effects of the output power density and duration of irradiation. The new device makes it possible to perform accurate ablation, because our technology concentrated on combining the 2 subsystems into a single prototype capable of simultaneously observing both the endometrial lesion and the laser spot on a monitor. CONCLUSIONS: In conclusion, the feasibility and performance of the composite-type fiberscope system were demonstrated in preclinical studies.

Evaluation of the relationship between T1ρ and T2 values and patella cartilage degeneration in patients of the same age group.

OBJECTIVE: The aim of this study was to investigate the association between the T1ρ and T2 values and the progression of cartilage degeneration in patients of the same age group. MATERIALS AND METHODS: Sagittal T1ρ and T2 mapping and three-dimensional (3D) gradient-echo images were obtained from 78 subjects with medial knee osteoarthritis (OA). The degree of patella cartilage degeneration was classified into four groups using MRI-based grading: apparently normal cartilage, mild OA, moderate OA, and severe OA group. We measured the T1ρ and T2 values (ms) in the regions of interest set on the full-thickness patella cartilage. Then, we analyzed the relationship between the T1ρ and T2 values and the degree of patella cartilage degeneration. RESULTS: There were no significant differences in age among the four groups. Both the T1ρ and T2 values showed a positive correlation with the degree of OA progression (ρ=0.737 and ρ=0.632, respectively). By comparison between the apparently normal cartilage and the mild OA groups, there were significant differences in the T1ρ mapping, but not in the T2 mapping. CONCLUSIONS: Our study confirmed that T1ρ and T2 mapping can quantitatively evaluate the degree of patella cartilage degeneration in patients within the same age group.

Clinical study using novel endoscopic system for measuring size of gastrointestinal lesion.

AIM: To verify the performance of a lesion size measurement system through a clinical study. METHODS: Our proposed system, which consists of a conventional endoscope, an optical device, an optical probe, and a personal computer, generates a grid scale to measure the lesion size from an endoscopic image. The width of the grid scale is constantly adjusted according to the distance between the tip of the endoscope and lesion because the lesion size on an endoscopic image changes according to the distance. The shape of the grid scale was corrected to match the distortion of the endoscopic image. The distance was calculated using the amount of laser light reflected from the lesion through an optical probe inserted into the instrument channel of the endoscope. The endoscopist can thus measure the lesion size without contact by comparing the lesion with the size of the grid scale on the endoscopic image. (1) A basic test was performed to verify the relationship between the measurement error eM and the tilt angle of the endoscope; and (2) The sizes of three colon polyps were measured using our system during endoscopy. These sizes were immediately measured by scale after their removal. RESULTS: There was no error at α = 0°. In addition, the values of eM (mean ± SD) were 0.24 ± 0.11 mm (α = 10°), 0.90 ± 0.58 mm (α = 20°) and 2.31 ± 1.41 mm (α = 30°). According to these results, our system has been confirmed to measure accurately when the tilt angle is less than 20°. The measurement error was approximately 1 mm in the clinical study. Therefore, it was concluded that our proposed measurement system was also effective in clinical examinations. CONCLUSION: By combining simple optical equipment with a conventional endoscope, a quick and accurate system for measuring lesion size was established.

Intracellular accumulation of advanced glycation end products induces apoptosis via endoplasmic reticulum stress in chondrocytes.

Mammalian cells attempt to maintain their homeostasis under endoplasmic reticulum (ER) stress. If the stress cannot be alleviated, cells are led to apoptosis through induction of C/EBP homologous protein (CHOP). ER stress is provoked in osteoarthritis chondrocytes, and intracellular accumulation of advanced glycation end products (AGEs) in chondrocytes is a possible cause. To clarify the role of intracellular AGE accumulation in chondrocytes, the present study investigated the effect of intracellular AGE accumulation on ER stress and apoptosis by in vitro and in vivo analysis. Intracellular AGE accumulation induced by AGE precursors caused apoptosis, induced expression of ER stress markers, and led to co-localization of AGEs with glucose-regulated protein 78, leading to formation of high-molecular-weight complexes in cultured chondrocytes. These reactions were inhibited by an AGE formation inhibitor. CHOP deletion inhibited apoptosis induced by intracellular AGE accumulation. In vivo intracellular AGE accumulation induced by intra-articular injection of AGE precursors caused ER stress and apoptosis in chondrocytes and led to degradation of articular cartilage. Additionally, intracellular AGE accumulation increased the degree of cartilage degradation in an osteoarthritis model. These data indicate that intracellular accumulation of AGEs induces modification of unfolded protein response-related protein by AGEs and apoptosis via ER stress in chondrocytes. Moreover, the in vivo study showed that intracellular AGE accumulation in chondrocytes is involved in the occurrence and progression of osteoarthritis through ER stress. Thus, research on mechanisms of apoptosis via ER stress induced by intracellular AGE accumulation in chondrocytes will lead to a new understanding of osteoarthritis pathology.

A novel ultrasmall composite optical fiberscope.

BACKGROUND: Accurately aiming laser energy at a target from a two-dimensional endoscopic view is difficult during endoscopic laser surgery, particularly when the endoscope and the laser fiber are misaligned. We developed a composite optical fiberscope (COF) that can simultaneously visualize a target area and perform laser irradiation. The identical orientation of the endoscope and the laser fiber allows intuitive aiming at a target, even from a two-dimensional endoscopic view. METHODS: We developed an ultrasmall COF (1.1-mm diameter) with a central cauterizing laser fiber surrounded by imaging and illumination fibers as a tool for various surgical applications. Porcine mesenteric blood vessels were laser irradiated in vivo and the procedure was filmed using ultrahigh-speed (max 1,000,000 frames per second) and thermographic cameras. Blood flow and vessel diameters were measured before and after laser irradiation. RESULTS: The target vessels were highly visible and laser energy was delivered to the center of the view. Images from the ultrahigh-speed camera showed the blocking of the target vessel by the laser irradiation. The irradiated point initially became constricted, then discolored, and then decreased in size. Blood flow was decreased by 81.7% after laser irradiation and the diameter of the vessels at the irradiated point was approximately 46-48% smaller than that of the unirradiated vessels. Medical doctors also confirmed that the blood vessel was blocked after the experiments. CONCLUSIONS: Our new laser surgery device may be useful for many surgical applications because it allows simultaneous diagnosis and treatment as well as intuitive aiming at a target despite its ultrasmall 1.1-mm diameter.

Extra-oral fistula caused by a dental implant.

Dental implantation has become an important procedure for both dental treatment and head and neck reconstructive surgery. However, this useful technique sometimes results in peri-implantitis. We describe a rare complication of peri-implantitis in the maxilla which extended to the soft tissue and caused an extra-oral fistula above the alar region. The patient underwent the placement of dental implants in the maxilla 8 years earlier. Radiography showed osteolysis of the maxilla and implant exposure. After the implants were removed, the patient was fitted with a conventional fixed partial denture. Such unfavorable outcomes are caused by failed endodontic and apicoectomy procedures.

Usefulness of diffusion-weighted imaging for differentiating between desmoid tumors and malignant soft tissue tumors.

PURPOSE: To evaluate the usefulness of diffusion-weighted imaging (DWI) for differentiating between desmoid tumors and malignant soft tissue tumors. MATERIALS AND METHODS: Conventional MRI and DWI were performed for 8 desmoid tumors and 74 malignant soft tissue tumors. DWI was obtained with a single-shot echo-planar imaging sequence using a 1.5 Tesla (T) MR imager. DW images were acquired with motion-probing gradient pulses applied along three directions (x, y, and z axes) with three b-factors (0, 500, and 1000 s/mm²). Two observers blinded to clinical information measured three regions of interest within the solid tumor and selected a minimum apparent diffusion coefficient () in each lesion. The mean ADC of desmoid tumors was calculated and compared with that of malignant soft tissue tumors using the Mann-Whitney U test. RESULTS: The mean ADC of desmoid tumors and malignant soft tissue tumors was 1.36 ± 0.48 × 10⁻³ mm² /s and 0.88 ± 0.20 × 10⁻³ mm² /s (mean ± SD), respectively. The mean ADC of the desmoid tumors was significantly higher than that of malignant soft tissue tumors (P < 0.01). CONCLUSION: DWI is considered to be useful for differentiating between desmoid tumors and malignant soft tissue tumors. In the future, further investigation in a large series is necessary.

The development of a composite-type optical fiberscope system for fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC).

We developed a new laser device using a composite-type optical fiberscope for laser surgery to treat twin-twin transfusion syndrome. The composite-type optical fiberscope (2.2 mm in external diameter) consists of a centrally located single fiber for laser treatment (0.1 mm in diameter) and its surrounding fibers for diagnosis. This fiberscope enables transmission of 40-W Yb fiber laser. The Yb fiber laser can be focused to 10mm focal length using two lenses on the tip of the fiberscope. In this research, we emitted the laser to in vivo porcine mesenteric vessel with blood flow both with an established laser fiber of 0.6-mm diameter (0.6-mm normal fiber) and with our composite-type optical fiberscope to compare the cautery performance of those devices. According to the experimental results, the composite-type optical fiberscope has a cautery efficiency equal to that of a 0.6-mm normal fiber, and it can contract the vein diameter about 35% as compared to the vein diameter before laser irradiation.

The value of diffusion-weighted imaging for monitoring the chemotherapeutic response of osteosarcoma: a comparison between average apparent diffusion coefficient and minimum apparent diffusion coefficient.

OBJECTIVE: The objective of this study was to evaluate whether the average apparent diffusion coefficient (ADC) or the minimum ADC is more useful for evaluating the chemotherapeutic response of osteosarcoma. MATERIALS AND METHODS: Twenty-two patients with osteosarcoma were examined in this study. Diffusion-weighted (DW) and magnetic resonance (MR) images were performed for all patients before and after chemotherapy. The pre- and post-chemotherapy values were obtained both in the average and minimum ADC. The pre-chemotherapy values of the average ADC and minimum ADC respectively were compared with the post-chemotherapy values. In addition, the ADC ratios ([ADC(post) - ADC(pre)] / ADC(pre)) were calculated using the average ADC and the minimum ADC. Twenty-two patients with osteosarcomas were divided into two groups, those with a good response to chemotherapy (> or = 90% tumor necrosis, n = 7) and those with a poor response (< 90% tumor necrosis, n = 15). The average ADC ratio and the minimum ADC ratio of the two groups were compared. RESULTS: With both the average ADC and the minimum ADC, post-chemotherapy values were significantly higher than pre-chemotherapy values (P < 0.05). The patients with a good response had a significantly higher minimum ADC ratio than those with a poor response (1.01 + or - 0.22 and 0.55 + or - 0.29 respectively, P < 0.05). However, with regard to the average ADC ratio, no significant difference was observed between the two groups (0.66 + or - 0.18 and 0.46 + or - 0.31 respectively, P = 0.19). CONCLUSION: The minimum ADC is useful for evaluating the chemotherapeutic response of osteosarcoma.

Blood flow measurement system for fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC).

Fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC) applies to the treatment of previable fetuses with severe twin-twin transfusion syndrome (TTTS). The ultimate goal of FLPC is selective blood flow interruption of anastomotic communicating vessels on the placenta fetoscopically. However, there has not been an established method to confirm that the blood flow is blocked, thus, it depends on the operator's experience or intuition to evaluate whether the FLPC was performed successfully or not. For this issue, we have developed a composite-type optical fiberscope (2.2 mm in diameter), which has centrally-located cautery laser fiber and surrounding located fiberglasses for viewing. This fiberscope enables transmission of 50 W Yb fiber laser which can be focused to 10 mm focal length using two lenses on the fiberscope tip. In this study, we combined the fiberscope and a laser blood-flow meter, and irradiated cautery laser to porcine mesenteric vein with measuring blood flow at the same time. From the experimental results, we could quantitatively measure the blood flow before and after laser irradiation, and confirm the blood flow blocking with our system.

Cervical osteomyelitis and epidural abscess treated with a pectoralis major muscle flap.

BACKGROUND: Spinal osteomyelitis and epidural abscess are uncommon but have a potentially disastrous outcome, although the surgical techniques and antimicrobial therapy have advanced. CASE DESCRIPTION: We present a case of cervical osteomyelitis and epidural abscess resulting from pharyngeal squamous cell carcinoma ablation, which were treated with a pectoralis major muscle flap successfully. CONCLUSION: Muscle flap insertion to the cervical contaminated wound enables radical removal of the contaminated tissue, and the muscle flaps for dead-space obliteration and neovasculation were obligatory for successful management of the infected complex wound. Furthermore, the inserted pectoralis major muscle flap can divide vertebrae and epidural canal from these origins of infection. We believe that this technique is simple, can be performed in a one-stage management, has minimal associated morbidity, and thus, is advocated as a desirable treatment option in the treatment of cervical osteomyelitis and epidural abscess.

Complex wounds tend to develop more rapidly in patients receiving hemodialysis because of diabetes mellitus.

The number of patients requiring dialysis because of diabetes mellitus is increasing and such patients often have complex chronic wounds, which are difficult to heal. However, there are few retrospective studies of wounds requiring surgical treatment. We evaluated 14 patients receiving hemodialysis (HD) (8 because of diabetes and 6 because of other diseases) who had extremity wounds and underwent surgical treatment in our unit from 2004 through 2007. We investigated differences in the cause of wounds, and in the interval between the start of HD and wound development. Wounds in patients undergoing HD because of diabetes originated due to ischemia in 2 cases (25%), trauma in 2 cases (25%), and infection in 4 cases (50%). Seven of 8 wounds developed infection with methicillin-resistant Staphylococcus aureus (MRSA). Wounds in patients undergoing HD because of other diseases developed due to ischemia in 2 cases (33%) and trauma in 4 cases (67%). Three of 6 wounds developed infection and MRSA were isolated from 2 wounds. The interval between the start of HD and wound development was significantly shorter in patients with diabetes than in patients without diabetes. All patients with infectious wounds required immediate debridement. We conclude that patients receiving HD because of diabetes are likely to have more severe and rapidly developing wounds due to infections. Thus, they usually require immediate debridement before blood access shunt infection occurs.

Characterization of chondroblastic osteosarcoma: gadolinium-enhanced versus diffusion-weighted MR imaging.

PURPOSE: To detect differences in magnetic resonance imaging (MRI) between chondroblastic osteosarcoma and the other types of osteosarcomas or chondrosarcomas using gadolinium-enhanced versus diffusion-weighted sequences. MATERIALS AND METHODS: Contrast-enhanced MRI and diffusion-weighted imaging (DWI) were performed in five chondroblastic osteosarcoma (CO) cases, 17 other types of osteosarcomas (OS), and 18 chondrosarcomas (CS). DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5 T MR imager. The apparent diffusion coefficients (ADCs) of the minimum and maximum values were also obtained. The contrast-enhancement pattern was evaluated and minimum-maximum ADC value of CO was compared with other types of OS and CS. RESULTS: Both CO and CS showed a similar enhancement pattern; both showed septonodular and peripheral rim enhancement. The minimum ADC value of CO (1.24 +/- 0.10 x 10(-3)mm(2)/sec) was significantly higher than that of other types of OS (0.84 +/- 0.15 x 10(-3)mm(2)/sec) and was significantly lower than that of CS (1.64 +/- 0.20 x 10(-3)mm(2)/sec). In addition, the maximum ADC value of CO (2.28 +/- 0.20 x 10(-3)mm(2)/sec) was significantly higher than that of other types of OS (1.33 +/- 0.26 x 10(-3)mm(2)/sec). CONCLUSION: DWI appears to be more useful for differentiating between chondroblastic osteosarcoma and chondrosarcoma or other types of osteosarcoma than Gd-enhanced MRI.

Alcaligenes xylosoxidans cholecystitis and meningitis acquired during bathing procedures in a burn unit: a case report.

The information in this article was presented at the 37th Annual Meeting of the Japan Society of Burn, Nagoya, Japan, June 7-8, 2008. Alcaligenes xylosoxidans, a nonfermentative, Gram-negative rod often found in aqueous environments, has been isolated from respirators, incubators, and disinfectant solutions in the hospital environment. It is known to cause disease in immunocompromised (eg, burn) patients and represents a cross-contamination risk related to wound care. In the authors' burn unit, two patients, admitted with deep dermal burns during a 1-month time period, acquired serious A. xylosoxidans infections. The first involved A. xylosoxidans-associated cholecystitis in an adult with 32% total body surface area (TBSA) burns and the second involved A. xylosoxidans meningitis in an adult with 30% TBSA burns. Both patients received hydrotherapy (bathing) in the same bathing tub, one patient after the other. Culture from environmental sources isolated A. xylosoxidans from the bathing mattress. Bacterial analysis of the isolates, including antimicrobial susceptibility testing and pulsed-field gel electrophoresis, suggested the patients had been infected by the same strain - ie, cross-contaminated - probably during treatment of their burns. The isolated strains were resistant not only to broad-spectrum penicillins and cephalosporins, but also to imipenem, to which past A. xylosoxidans strains have been susceptible. These findings underscore the need for strict infection control to prevent cross-contamination and disease outbreak.

Ability of diffusion-weighted imaging for the differential diagnosis between chronic expanding hematomas and malignant soft tissue tumors.

PURPOSE: To evaluate the potential of diffusion-weighted imaging (DWI) in distinguishing chronic expanding hematomas (CEHs) from malignant soft tissue tumors. MATERIALS AND METHODS: We performed conventional MRI and DWI of six CEHs and 31 malignant soft tissue tumors from 37 patients seen between May 2000 and November 2006. DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5T MR imager. The mean apparent diffusion coefficient (ADC) value was also calculated. We evaluated MRI findings of CEHs and compared ADC value of CEHs with malignant soft tissue tumors. RESULTS: On conventional MRI, two of six CEHs were difficult to differentiate from malignant soft tissue tumors based on imaging findings. The mean ADC value of CEHs and malignant soft tissue tumors was 1.55+/-0.121x10(-3) mm2/sec and 0.92+/-0.139x10(-3) mm2/sec (mean+/-SD), respectively. The mean ADC value of CEHs was significantly higher than that of malignant soft tissue tumors (P<0.01). There was no overlap in the minimum ADC values among CEHs and malignant soft tissue tumors. CONCLUSION: DWI is useful for differentiating between CEHs and malignant soft tissue tumors.