A Double-Blind, Placebo-Controlled Study of Ultrasound-Guided Pulsed Radiofrequency Treatment of the Saphenous Nerve for Refractory Osteoarthritis-Associated Knee Pain

BACKGROUND

While the efficacy of pulsed radiofrequency (PRF) for shoulder pain has been demonstrated, its efficacy on the saphenous nerves for knee osteoarthritis (OA)-associated pain has only been reported in observational studies.

OBJECTIVES

The aim of this study was to compare saphenous nerve PRF to placebo for knee OA-associated pain.

STUDY DESIGN

Patients, practitioners, and outcome assessor-blinded randomized placebo-controlled trial.

SETTING

Pain management clinics at 2 hospitals in Japan.

METHODS

Patients were randomly allocated to the PRF (n = 37) or placebo group (n = 33). Patients aged 40-85 years with refractory anteromedial knee pain. PRF in the saphenous nerve under ultrasound guidance. The placebo group underwent the same procedure, but with motor stimulation. The primary endpoint was the average pain intensity measured using the visual analog scale (VAS) at the 12-week post-treatment visit; secondary outcomes included the average VAS at 1 and 4 weeks, and pain intensities at rest, in flexion, at standing, and at walking. Other secondary outcomes were knee pain, symptoms, activities of daily living, knee-related quality of life, mobility, range of motion, and adverse events.

RESULTS

In the PRF group, the mean VAS score was 52.41 ± 26.17 at 12 weeks, while in the sham group, the mean VAS score was 63.06 ± 27.12 (P < 0.05). There were no significant differences between the groups in any of the secondary outcomes.

LIMITATIONS

Patients with comorbidities were excluded from this study. The follow-up time was limited to 12 weeks.

CONCLUSIONS

Ultrasound-guided saphenous nerve PRF proved to be effective for at least 12 weeks in patients with knee OA and showed no adverse events.

Validation of the Japanese version of the Bath CRPS Body Perception Disturbance Scale for CRPS

PURPOSE

Body perception disturbance is a common symptom and may be one of the key targets of treatment intervention in complex regional pain syndrome (CRPS). As a comprehensive assessment tool of body perception in patients with CRPS, the Bath Body Perception Disturbance Scale (BPDS) was developed, and its adequate reliability and validity have been reported. However, there is no available Japanese version. Therefore, this study aimed to develop a Japanese version of BPDS (BPDS-J) and to investigate the validity of this scale in Japanese patients with CRPS.

METHODS

We developed BPDS-J using a forward-backward method. We then assessed 22 patients with CRPS type 1 of the upper limb using BPDS-J, Brief Pain Inventory (BPI), Tampa Scale for Kinesiophobia (TSK), and a two-point discrimination threshold (TPD) on the middle finger. We investigated the internal consistency of BPDS-J and the correlation between BPDS-J and clinical outcomes as a concurrent validity measure.

RESULTS

BPDS-J had good internal consistency (Cronbach's α = 0.73) and was significantly correlated with the TPD ratio (r = 0.65, adjusted p = 0.01) and TSK (r = 0.51, adjusted p = 0.04).

CONCLUSIONS

BPDS-J has good internal consistency and concurrent validity for assessing body perception disturbance in Japanese patients with CRPS. Disturbed body perception may be worth evaluating when managing patients with CRPS using BPDS.

P6241Two-year clinical outcomes of biodegradable polymer versus durable polymer drug-eluting stent implantation in hemodialysis patients after percutaneous coronary intervention

Background

Biodegradable polymer drug-eluting stent (BP-DES) has been developed to improve clinical outcomes after percutaneous coronary intervention (PCI) for patients presenting coronary artery disease (CAD). Although BP-DES showed non-inferior safety and efficacy to durable polymer DES (DP-DES) in several randomized clinical trials, hemodialysis (HD) patients, who have been well known as high risk population for adverse events, were excluded in the most of trials. Therefore, there are limited data comparing the clinical outcomes between BP-DES and DP-DES in HD patients with CAD after PCI.

Purpose

The purpose of this study was to investigate clinical outcomes in HD patients after BP-DES implantation compared with those after DP-DES implantation.

Methods

We retrospectively analyzed 234 HD patients (male 74%, mean age 71±10 years) undergoing PCI for 404 lesions with 472 DESs (71 patients for 138 lesions with 170 BP-DESs [91 Ultimaster and 79 Synergy] and 163 HD patients for 266 lesions with 302 DP-DESs [219 Xience, 53 Promus and 30 Resolute]) from 2011 to 2017. Two-year clinical outcomes were compared between BP-DES group and DP-DES group. The primary outcome measure was the incidence of target lesion revascularization (TLR), while the secondary outcome measures were the occurrence of cardiac death (CD), stent thrombosis (ST), myocardial infraction (MI), target vessel revascularization (TVR), non-TVR and major adverse cardiac event (MACE) defined as a composite of CD, MI, and TVR. Outcome measures were estimated by the Kaplan-Meier method and the differences between BP-DES group and DP-DES group were assessed by the log-rank test. We also conducted Cox's proportional hazard model to identify predictors for TLR occurrence.

Results

Baseline patient and lesion characteristics were similar between the two groups. The two-year incidence of TLR was not significantly different between BP-DES group and DP-DES group (14.1% vs. 22.2%, p=0.391). The two-year incidences of CD (17.3% vs. 17.5%, p=0.381), ST (0% vs. 3.9%, p=0.133), MI (4.2% vs. 5.8%, p=0.965), TVR (21.3% vs. 27.5%, p=0.586), non-TVR (26.1% vs. 31.3%, p=0.439) and MACE (41.1% vs. 42.6%, p=0.526) were also not different between the two groups. After multivariate analysis, diabetes mellitus (hazard ratio 1.97; 95% confidence interval 1.03–3.78, p=0.004) was independently associated with TLR occurrence in HD patients.

Two-year clinical outcomes of HD patient

Conclusions

At two-year follow-up after PCI, BP-DES had comparable safety and efficacy profiles to DP-DES in HD patients presenting CAD.

Acknowledgement/Funding

None

Effect of Flow Induced Orientation of Carbon Nanotubes on the Capillary Extrusion Behavior of Low-Density Polyethylene

The effect of carbon nanotubes (CNTs) on the capillary extrusion behavior of low-density polyethylene (PE) was investigated. From the linear viscoelasticity and the morphology observation, it was found that the CNTs were well dispersed throughout the PE matrix and our system belonged to the semi-dilute regime. The strain hardening, which quantifies the extension of the PE chain, decreased by presence of CNTs in the uniaxial elongational deformation. In contrast, the normal stress difference was almost unaffected by CNTs in the shear deformation. The capillary extrusion behavior revealed that swell ratio decreased with increasing the CNT content although melt fracture was promoted. We summarize that the suppression of swell and promotion of melt fracture are attributable to the orientation of CNTs.

Injustice Experience Questionnaire, Japanese Version: Cross-Cultural Factor-Structure Comparison and Demographics Associated with Perceived Injustice

OBJECTIVE

The Injustice Experience Questionnaire (IEQ) assesses injury-related perceived injustice. This study aimed to (1) develop a Japanese version (IEQ-J), (2) examine its factor structure, validity, and reliability, and (3) discover which demographic variable(s) positively contributed to prediction of IEQ-J scores.

METHODS

Data from 71 patients (33 male, 38 female; age = 20+) with injury pain were employed to investigate factor structure by exploratory and confirmatory factor analyses. Concurrent validity was examined by Pearson correlation coefficients among the IEQ-J, Brief Pain Inventory (BPI), and Pain Catastrophizing Scale (PCS). Internal consistency was investigated by Cronbach's alpha, and test-retest reliability was indicated with intra-class correlations (ICCs) in 42 of 71 patients within four weeks. Relations between demographic variables and IEQ-J scores were examined by covariance analysis and linear regression models.

RESULTS

IEQ-J factor structure differed from the original two-factor model. A three-factor model with Severity/irreparability, Blame/unfairness, and Perceived lack of empathy was extracted. The three-factor model showed goodness-of-fit with the data and sufficient reliability (Cronbach's alpha of 0.90 for total IEQ-J; ICCs = 0.96). Pearson correlation coefficients among IEQ-J, BPI, and PCS ranged from 0.38 to 0.73. Pain duration over a year (regression coefficient, 11.92, 95%CI; 5.95-17.89) and liability for injury on another (regression coefficient, 12.17, 95%CI; 6.38-17.96) predicted IEQ-J total scores.

CONCLUSIONS

This study evidenced the IEQ-J's sound psychometric properties. The three-factor model was the latter distinctive in the Japanese version. Pain duration over a year and injury liability by another statistically significantly increased IEQ-J scores.

Socioeconomic value of intervention for chronic pain

PURPOSE

The purpose of this study was to examine the cost-effectiveness of pain treatments in two pain centers in Japan.

METHODS

The study population comprised 91 patients receiving various treatments for chronic pain, which were divided into three categories: (1) medication, (2) medication + nerve block, and (3) other modalities (exercise and/or pain education). Pain was assessed using the Pain Disability Assessment Scale (PDAS) score, Hospital Anxiety and Depression Scale (HADS) score, Pain Catastrophizing Scale (PCS) score, and EQ-5D score. First, the reliability of the EQ-5D score first assessed by evaluating the correlation this score with those of the other pain-related evaluation instruments, and then the cost effectiveness of the pain treatments was evaluated. Evaluation of medical costs was based on data provided from the Management Services of the hospital, which in turn were based on national health scheme medical treatment fees. The quality-adjusted life year (QALY) value was calculated from the EQ-5D score, converted to 12 months, and then used for cost-benefit analysis along with medical treatment fees.

RESULTS

According to the recent IASP classification, more patients had chronic neuropathic pain (41) than chronic primary pain (37 patients) or chronic musculoskeletal pain (27 patients). There was a significant correlation between the EQ-5D score and the PDAS, HADS, and PCS scores, which demonstrated the reliability of the EQ-5D score. Significant improvement in the HADS, PCS, and EQ-5D scores was noted after 3 months of pain treatment. Calculation of the cost-effectiveness based on the estimated annual medical treatment cost and QALY revealed a mean value of US $45,879 ± 103,155 per QALY (median US $16,903), indicating adequate socioeconomic utility.

CONCLUSION

Based on our results, the EQ-5D is reliable for evaluating chronic pain in patients. The medico-economic balance was appropriate for all treatments provided in two comprehensive pain centers in Japan.

Dispersive Mixing Performance Evaluation of Special Rotor Segments in an Intermeshing Co-Rotating Twin-Screw Extruder by Using Weighted Probability Distributions

An intermeshing co-rotating twin-screw extruder is widely used for producing polymer composites. In order to satisfy properties of the composites, it is important to understand mixing performance of segments. In this study, we discussed mixing performance of special rotor segments commercially named VCMT (various clearance mixing technology) by using a numerical analysis method. The several tip clearances of VCMT work for achievement of both self-cleaning and effective mixing. We adopted a particle tracking method to obtain the following two evaluation indices; 1) residence time for the evaluation of its uniformity and 2) maximum 1st principal stress for the evaluation of dispersive mixing. And we evaluated mixing performance of VCMT by using probability distributions of each index. Moreover, we proposed weighted probability distributions as theoretically better evaluation. The probability distributions of VCMT were compared with those of two kinds of kneading disk segments (KDs). From the comparison, it was found that the probability of VCMT in large 1st principal stress region is higher than those of KDs. As a conclusion, VCMT has better mixing performance than KDs for the geometries and operating conditions that were investigated.

Pain-Related Brain Activity Evoked by Active and Dynamic Arm Movement: Delayed-Onset Muscle Soreness as a Promising Model for Studying Movement-Related Pain in Humans

OBJECTIVE

To demonstrate delayed-onset muscle soreness (DOMS) is a suitable model for the study of movement-evoked pain, we attempted to identify brain regions specifically involved in pain evoked by active and dynamic movement under DOMS condition.

SUBJECT

Twelve healthy volunteers

METHODS

DOMS was induced in the left upper-arm flexor muscles by an eccentric elbow contraction exercise. Movement-evoked pain in the affected muscles was evaluated just before (day 0) and after (days 1-7 and 30) the exercise using a visual analog scale. Subjects underwent functional magnetic resonance imaging scans while performing repeated elbow flexion on day 2 (DOMS condition) and day 30 (painless condition). We compared brain activity between the DOMS and painless conditions.

RESULTS

Movement-evoked pain reached peak intensity on day 2 and disappeared by day 30 in all subjects. No subject felt pain at rest on either of these days. Contralateral primary motor cortex (M1), parietal operculum and bilateral presupplementary motor area (pre-SMA) showed greater activity during active and dynamic arm movement with DOMS than during the same movement without pain. There was no difference in activation of brain regions known collectively as the "pain matrix," except for the parietal operculum, between the two conditions.

CONCLUSION

Active and dynamic movement with pain selectively evoked activation of M1, pre-SMA, and parietal operculum, as assessed using DOMS. Our results demonstrate that DOMS is a promising experimental model for the study of movement-evoked pain in humans.

Thermal Conductivity of Polypropylene Composites with Combined Boron Nitride Fillers

We prepared polypropylene (PP) filled with boron nitride (BN) particles by melt compounding. The effects of filler content, particle size, and combined filler on the thermal conductivity of PP/BN composites were investigated. The results indicated that the thermal conductivities depend on the content and BN particle size. The good dispersion of BN particles of intermediate size in PP matrices led to a higher thermal conductivity than that of PP matrices containing small and large BN particles in which the agglomeration of BN particles was observed. The incorporation of BN particles of two different sizes could enhance the thermal conductivities of PP composites relative to those of composites containing BN particles of a single size at the same total content. A PP composite containing 50 wt% combined fillers with a mixture of BN particles measuring 45 μm and 10 μm at a weight ratio 1 : 4 showed the highest thermal conductivity in this experiment. Furthermore, several models for predicting the thermal conductivity of the composites were studied.

Effect of Screw Rotation Speed on the Properties of Polycarbonate/Vapor-Grown Carbon Fiber Composites Prepared by Melt Compounding

The effect of screw rotation speed on the mechanical property and thermal conductivity of polycarbonate (PC)/vapor-grown carbon fiber (VGCF) composites prepared by a twin screw extruder was discussed in this paper. Two types of VGCF (VGCF-H, the aspect ratio of 40, and VGCF-S, the aspect ratio of 100) were used. In the tensile test, the breaking pattern of PC composite changed to brittle failures by adding VGCF-H irrespective of screw rotation speed. Young's modulus of PC/VGCF-H slightly increased with the screw rotation speed. On the other hands, the breaking strain of PC/VGCF drastically decreased above 150 min−1. Young's modulus of PC/VGCF-S slightly increased with screw rotation speed until 150 min−1, however, it decreased at 175 min−1. The thermal conductivity of PC/VGCF-H was independent of the screw rotation speed. In contrast, the thermal conductivity of PC/VGCF-S gradually increased with screw rotation speed until 150 min−1 and it also decreased at 175 min−1. From the SEM observation and rheological behavior, the dispersion state of VGCF-H in PC/VGCF-H was independent of the screw rotation speed. On the other hands, the network structures of VGCF-S were observed in PC/VGCF-S and the state of these network structures depended on the screw rotation speed. It was clarified that the mechanical property and thermal conductivity of PC/VGCF were attributable to the dispersion state of VGCF.

Development of Polymer Extrusion Extruder for Evaluating with a Small Amount of Polymeric Material

We developed the extrusion system to evaluate the extrusion behavior such as the shear viscosity, which is one of basic properties, and the processability of mono/multilayer film with a small amount of polymeric material. In order to measure the shear viscosity, the gear pump, the return path and the pressure sensors were introduced into the extruder with intermeshing co-rotating twin screws. The viscosity could be evaluated on-line from the volumetric flow rate of molten polymer and the pressure drop in the return path before film processing. The capacity of gear pump, the shape and size of return path were optimized to evaluate the viscosity of polymeric material, which generally undergoes shear rate of 10 ∼ 1000 s−1 in the film processing. The apparatus for mono and multilayer film processing consisted of two extruders including the multichannel feedblock and T-die with the manifold and land section. The compact feedblock was designed to receive two feedstreams, so that the product can have two layers. We investigated the on-line viscosity measurement methodology and the processability, which is the neck-in phenomenon for monolayer film and the interface stability for multilayer film, using typical polymer material of 30 grams at once. The viscosity evaluated with our system corresponded with the result of commercial rheometer. It was also confirmed that the processability of mono and multilayer film could be evaluated quantitatively with our system.

[Phantom limb pain originates from dysfunction of the primary motor cortex]

Accumulated knowledge indicates that phantom limb pain is a phenomenon of the central nervous system that is related to plastic changes at several levels of the nervous systems. Especially, reports using patients with neuropathic pain clearly indicate the sensorimotor cortex as underlying mechanisms of phantom limb and its pain. Here, we focus the notion that limb amputation or deafferentation results in plasticity of connections between the brain and the body, and that the cortical motor representation of the missing or deafferented limb seemingly disappears. Meanwhile, the sensory representation of the limb does not disappear and thereby patients feel phantom limbs. We propose that dissociation between motor and sensory representations in the primary motor cortex induces pathologic pain and reconcile of sensorimotor integration of the limb would alleviate pain, on the basis of our neurorehabilitation approaches and artificial neuromodulation strategies.

Complex Regional Pain Syndrome (CRPS) Impairs Visuospatial Perception, whereas Post-Herpetic Neuralgia does not: Possible Implications for Supraspinal Mechanism of CRPS

Introduction: Complex regional pain syndrome (CRPS) patients show impaired visuospatial perception in the dark, as compared to normal patients with acute nociceptive pain. The purpose of this study is 2-fold: (i) to ascertain whether this distorted visuospatial perception is related to the chronicity of pain, and (ii) to analyse visuospatial perception of CRPS in comparison with another neuropathic pain condition. Materials and Methods: We evaluated visual subjective body-midline (vSM) representation in 27 patients with post-herpetic neuralgia (PHN) and 22 with CRPS under light and dark conditions. A red laser dot was projected onto a screen and moved horizontally towards the sagittal plane of the objective body-midline (OM). Each participant was asked to direct the dot to a position where it crossed their vSM. The distance between the vSM and OM was analysed to determine how and in which direction the vSM deviated. Results: Under light condition, all vSM judgments approximately matched the OM. However, in the dark, CRPS patients, but not PHN patients, showed a shifted vSM towards the affected side. Conclusion: We demonstrated that chronic pain does not always impair visuospatial percep- tion. The aetiology of PHN is limited to the peripheral nervous system, whereas the distorted visuospatial perception suggests a supraspinal aetiology of CRPS. Key words: Cognitive dysfunction, Higher brain function, Multimodal disturbance, Neuro- pathic pain

Complex regional pain syndrome (CRPS) impairs visuospatial perception,whereas post-herpetic neuralgia does not: possible implications for supraspinal mechanism of CRPS

INTRODUCTION

Complex regional pain syndrome (CRPS) patients show impaired visuospatial perception in the dark, as compared to normal patients with acute nociceptive pain. The purpose of this study is 2-fold: (i) to ascertain whether this distorted visuospatial perception is related to the chronicity of pain, and (ii) to analyse visuospatial perception of CRPS in comparison with another neuropathic pain condition.

MATERIALS AND METHODS

We evaluated visual subjective body-midline (vSM) representation in 27 patients with post-herpetic neuralgia (PHN) and 22 with CRPS under light and dark conditions. A red laser dot was projected onto a screen and moved horizontally towards the sagittal plane of the objective body-midline (OM). Each participant was asked to direct the dot to a position where it crossed their vSM. The distance between the vSM and OM was analysed to determine how and in which direction the vSM deviated.

RESULTS

Under light condition, all vSM judgments approximately matched the OM. However, in the dark, CRPS patients, but not PHN patients, showed a shifted vSM towards the affected side.

CONCLUSION

We demonstrated that chronic pain does not always impair visuospatial perception. The aetiology of PHN is limited to the peripheral nervous system, whereas the distorted visuospatial perception suggests a supraspinal aetiology of CRPS.

Degradation of serine-containing oligopeptides by Peptostreptococcus micros ATCC 33270

BACKGROUND/AIMS

Microorganisms of Peptostreptococcus micros are asaccharolytic, anaerobic gram-positive cocci that are frequently isolated from human oral sites such as periodontal pockets. Preliminary study showed that several amino acids, including serine, enhanced slightly the growth of P. micros. Therefore, we investigated the degradation of serine and serine-containing oligopeptides.

METHODS

Metabolic end products were determined with high-performance liquid chromatography. The related enzymatic activities in cell-free extract were also assayed.

RESULTS

Washed P. micros degraded serine-tripeptides (Ser-Ser-Ser), and produced formate, pyruvate, acetate, and ammonia. They also degraded serinyl-tyrosine (Ser-Tyr) to the same products. Related enzymatic activities, such as serine dehydratase, pyruvate formate-lyase, formate dehydrogenase, pyruvate oxidoreductase, phosphate acetyltransferase, and acetate kinase, were detected in the cell-free extract, indicating that the organisms produced ATP in the serine metabolism.

CONCLUSION

P. micros utilized serine-containing oligopeptides as exogenous metabolic substrates rather than serine itself, and degraded Ser-Ser-Ser and Ser-Tyr to formate, pyruvate, acetate, and ammonia with ATP generation.

Degradation of arginine by Slackia exigua ATCC 700122 and Cryptobacterium curtum ATCC 700683

Slackia exigua ATCC 700122(T) and Cryptobacterium curtum ATCC 700683(T) were our isolates from infected root canal and human periodontal pocket, respectively; they are asaccharolytic anaerobic gram-positive rods, which are predominant in the oral cavity. They utilize arginine, so our aim was to investigate the pathway of arginine degradation. Metabolic end products were determined with high-performance liquid chromatography. The related enzymatic activities in cell-free extract were also assayed. Both S. exigua and C. curtum degraded arginine and produced substantial amounts of citrulline, ornithine and ammonia. Arginine and citrulline supported the growth of both strains. As the related enzymatic activities, arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activities were detected in the cell-free extract of S. exigua and C. curtum. Arginase and urease activities were not detected in either organism. These results suggest that arginine was metabolized by the arginine deiminase pathway. Both S. exigua and C. curtum degrade arginine via the arginine deiminase pathway.

Colonisation on the tongue surface by respiratory pathogens in residents of a nursing home--a pilot study

OBJECTIVE

The morbidity and mortality of the dependent elderly that result from aspiration pneumonia have been recognised as a major geriatric health problem. The tongue has an extremely large surface area and due to its papillary structure can retain considerable quantities of food, and thus can support and harbour a large bacterial population. The purpose of this study was to gain more information on the microflora of the tongue surface and to assess the existence of oral infectious pathogens potentially causing respiratory disease in nursing home residents.

SUBJECTS AND METHODS

The tongue bacterial flora of 69 nursing home residents were examined to identify microorganisms by the culture method.

RESULTS

Thirteen species of microorganisms were detected from the tongue in this study. In 41 of 69 subjects (59%), potential respiratory pathogens, had colonised the tongue surface.

CONCLUSION

The results of the present study revealed that bacteria that commonly cause respiratory infection colonised the tongue of nursing home residents, suggesting that it may function as a reservoir of potential respiratory pathogens to facilitate colonisation on the oropharynx.

Perfusion imaging of meningioma by using continuous arterial spin-labeling: comparison with dynamic susceptibility-weighted contrast-enhanced MR images and histopathologic features

PURPOSE

The goal of the present study was to determine the utility of continuous arterial spin labeling (CASL) for characterization of meningioma by MR perfusion imaging and to compare these results with those obtained from the T2 dynamic susceptibility contrast (T2DSC) method and from histopathologic examination.

METHODS

Twenty-one cases of meningiomas were examined at 1.5T. CASL perfusion imaging was implemented on the basis of multisection single-shot echo-planar imaging with velocity-driven adiabatic spin-inversion preparation. T2DSC perfusion imaging was also performed by using a double-echo spoiled gradient echo sequence in a section containing the tumor. By focusing on the regions of interest, maps of % signal intensity change and cerebral blood flow (CBF) were determined from CASL and cerebral blood volume (CBV). CBF and mean transit time (MTT) were obtained from T2DSC. The microvessel area (MVA) was determined from specimens immunostained with anti-CD31 in 14 cases by measuring the total amount of staining in each histologic section. Linear regression analysis was performed for rCBF values from both perfusion methods and for % signal intensity change and MVA.

RESULTS

There was a significant correlation between CBF values determined from both perfusion methods (r(2) = 0.73; P < .001); however, the slope from T2DSC to CASL was less than unity, likely because of the different vascular weighting used for each method. There was also a significant correlation between CASL-% signal intensity change and MVA determined by histopathology (r(2) = 0.91; P < .00001). Perfusion values were the greatest for angiomatous meningioma and lowest for fibrous meningioma when using either perfusion method.

CONCLUSIONS

CASL and T2DSC perfusion methods are comparable in the characterization of meningiomas. Further, CASL is of use in assessing tumor microcirculation.

Degradation of arginine and other amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods in periodontal pockets

The use of 20 amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods (AAGPRs) in periodontal pockets, i.e. Eubacterium minutum, Filifactor alocis, E. infirmum, E. sulci and E. saphenum, was studied. E. minutum used only arginine and lysine, and produced substantial amounts of butyrate and ammonia as the main metabolic products from arginine, and acetate, butyrate and ammonia from lysine. Fi. alocis used arginine alone and produced butyrate and ammonia. E. infirmum, E. sulci and E. saphenum used lysine alone and produced acetate, butyrate and ammonia. The growth of these bacterial species was supported and enhanced by arginine and/or lysine enriched to culture media, but not by the other amino acids. Arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activity were detected in the cell-free extract of E. minutum, suggesting that arginine was metabolised to citrulline initially, and subsequently to ornithine and carbamoyl phosphate. Ornithine and carbamoyl phosphate were further converted to butyrate, and carbon dioxide and ammonia, respectively. Enzymatic activity of arginine deiminase and ornithine carbamoyltransferase was not detected in Fi. alocis, indicating that Fi. alocis converted arginine to ornithine directly, not via citrulline, and further to butyrate.

Pulmonary MR angiography with contrast agent at 4 Tesla: a preliminary result

In this study, pulmonary MR angiography (MRA) using a tailored coil at 4 Tesla in conjunction with an intravenous injection of contrast agent is described. Three-dimensional gradient-echo images were obtained during the intravenous injection of 0.05, 0.1, and 0.2 mmol/kg body weight of gadodiamide to investigate the signal enhancement effect of the contrast agent in pulmonary arteries qualitatively and quantitatively. In the qualitative analysis, the subsegmental branches were visualized on every dose. In the quantitative analysis, the average contrast-to-noise ratios (CNRs) of the main pulmonary arteries increased in a dose-dependent manner. However, the CNRs of segmental arteries did not increase as the dose of contrast agent increased, as observed at 1.5 Tesla MRI. These observations demonstrate the feasibility of delineating the pulmonary vasculature using a contrast agent; however, our results also suggest possible high-field-related disabilities that need to be overcome before high-field (> or =4 Tesla) MRI can be used to full advantage.

Blood volume of gliomas determined by double-echo dynamic perfusion-weighted MR imaging: a preliminary study

BACKGROUND AND PURPOSE

After bolus injection, gadopentetate dimeglumine causes a T2* rate change in permeable tissue that is contaminated by the T1 shortening effect due to the leakage of contrast agent. Therefore, tumor vascularity as reported in previous single-echo perfusion-weighted MR imaging studies has been underestimated. Our aim was to quantitatively and qualitatively evaluate the degree of blood volume of glioblastoma multiformes (GBMs) underestimated by this T1 shortening effect.

METHODS

We used double-echo dynamic MR imaging after a bolus injection of gadopentetate dimeglumine (double-echo perfusion-weighted MR imaging) to simultaneously determine tumor blood volume without (V(T1U)) and with (V(T1C)) T1 shortening correction. MR imaging was performed in five consecutive patients with GBMs. The ratios of V(T1U) and V(T1C) were calculated and compared by means of quantitative analysis. The degree of tumor blood volume as determined by V(T1U) and V(T1C) maps were qualitatively compared using a three-point scale.

RESULTS

All GBMs showed contrast enhancement on postcontrast T1-weighted images. In all subjects, the values of V(T1U) were significantly lower than those of V(T1C) (mean +/- SD, 2.05 +/- 1.01 vs. 3.62 +/- 1.40, respectively [P <.05]), indicating that tumor blood volume obtained by double-echo perfusion-weighted MR imaging was significantly higher than that by single-echo imaging. In the qualitative analysis, tumor blood volume on the V(T1U) map was less conspicuous than that on the V(T1C) map.

CONCLUSION

Careful attention should be paid to the underestimation of tumor blood volume resulting from T1 shortening effects when using single-echo perfusion-weighted MR imaging. Double-echo imaging may be more suitable for the analysis of blood volume in GBMs.

Time course of arterial hyperintensity with fast fluid-attenuated inversion-recovery imaging in acute and subacute middle cerebral arterial infarction

The purpose of this study was to evaluate the time course of arterial hyperintensity (AH) in acute and subacute cerebral infarctions of the middle cerebral artery (MCA) distribution by using fast fluid-attenuated inversion-recovery (FLAIR) imaging. A total of 40 FLAIR MR examinations were performed in 27 patients with MCA infarction within 13 days after ictus. Thirteen patients underwent two MR examinations during this period. Thrombotic or embolic infarctions were included in this study, but lacunar infarctions were excluded. The presence or absence of AH and the location of AH were analyzed. Overall, AH was found in 24 (60%) of 40 FLAIR examinations within 13 days after onset. AH was seen in 17 (100%) examinations less than 24 hours old, four (40%) of 10 examinations 1-4 days old, two (18%) of 11 examinations 5-9 days old, and one (50%) of two examinations 10-13 days old. AH was most frequently found at the sylvian fissure (87%), followed by the sulci (54%), and the horizontal segment of MCA (29%) in the affected MCA distribution. Although AH could be seen even at 13 days after ictus, the presence of AH declined over time. AH represented an early sign of acute embolic or thrombotic infarction. J. Magn. Reson. Imaging 2001;13:987-990.

Structural basis for pulmonary functional imaging

An understanding of fine normal lung morphology is important for effective pulmonary functional imaging. The lung specimens must be inflated. These include (a) unfixed, inflated lung specimen, (b) formaldehyde fixed lung specimen, (c) fixed, inflated dry lung specimen, and (d) histology specimen. Photography, magnified view, radiograph, computed tomography, and histology of these specimens are demonstrated. From a standpoint of diagnostic imaging, the main normal lung structures consist of airways (bronchi and bronchioles), alveoli, pulmonary vessels, secondary pulmonary lobules, and subpleural pulmonary lymphatic channels. This review summarizes fine radiologic normal lung morphology as an aid to effective pulmonary functional imaging.

Quantification of pulmonary perfusion with MR imaging: recent advances

Recent advances in magnetic resonance pulmonary perfusion imaging are reviewed, focusing on magnetic resonance perfusion imaging using gadolinium contrasts agents or spin labeling of blood using naturally flowing spins as the source of intravascular signal. These recent developments in magnetic resonance imaging have made it possible to analyze data quantitatively which holds significant potential for clinical imaging of lung perfusion and opens windows to functional MR imaging of the lung. We believe that fast magnetic resonance functional imaging will play an important role in the assessment of pulmonary function and the pulmonary disease process.

The effect of high salt intake on the mandibular bone loss in Dahl-Iwai salt-sensitive rat

The purpose of this study was to evaluate the effect of high salt intake on the mandibular bone in Dahl-Iwai salt-sensitive (DS) rats. Twenty-eight 11-week-old male DS rats were divided into four groups (n=7). The control groups received a normal (0.2% NaCl) diet while the experimental groups received a diet supplemented with 8.0% NaCl. The systolic blood pressure was significantly increased in the experimental groups compared to the control groups. The animals were sacrificed under ether anesthesia at the 8th week or the 22nd week of the experiment. The biochemical data in plasma and urine suggested negative calcium balance in the experimental groups compared to the control groups. The bone mineral density was significantly reduced at the 22nd week of high salt loading. The histomorphometric analysis suggested that the reduction of the mandibular bone volume had already started by the 8th week of high salt loading along with the increased bone resorption and the decreased bone formation, and that the improper bone remodeling balance became normalized by the 22nd week of high salt loading. In conclusion, these results indicate that a high salt intake causes not only severe hypertension but also a mandibular bone reduction in the DS rats.

Semi-quantitative approach to estimating GFR by magnetic resonance imaging

OBJECTIVE

The purpose of this study was to compare a semi-quantitative approach to estimating glomerular filtration rate (GFR) by magnetic resonance imaging with radionuclide calculation of GFR, and to investigate whether spin echo or gradient echo is more suitable for estimating GFR.

METHODS AND PATIENTS

Fourteen kidneys of seven patients (GFR ranging from 26 to 57 ml/min) were studied. Spin echo and gradient echo sequences interleaving each other at every excitation were used. After intravenous injection of gadopentetate dimeglumine, serial scans were performed. The signal intensities measured in the regions of interest were converted to time-transverse relaxation rate changes for both spin echo (DeltaR2) and gradient echo (DeltaR2*). The areas under the time-DeltaR2 and time-DeltaR2* curves were calculated as a semi-quantitative index of GFR for both spin echo and gradient echo images, and the results were compared by GFR measured by radionuclide imaging.

RESULTS

The semi-quantitative index of the GFR calculated from spin echo images showed a significant correlation with the GFR measured by radionuclide imaging (r=0.85, P<0.001). On the other hand, the semi-quantitative index of the GFR calculated from gradient echo images showed no such correlation (r=0.46, P=0.10).

CONCLUSION

Spin echo sequences may be more suitable than gradient echo sequences for the evaluation of GFR.

[Study on health awareness of home helper for dependent elderly]

The purpose of this study was to investigate the level of oral health awareness and oral health care activities of home helper for dependent elderly. A questionnaire was mailed to persons who took the profession course of care worker training and education (second and third grade) for home helper and short term course (special subject) at care worker support center foundation (33 branches). Responses were obtained from 220 persons qualified as home helpers. Of 220 home helpers, 104 (47.3%) had worked as a home helper for fewer than six years. One hundred forty two (64.5%) were trained and educated for a home helper as a second grade. The results were as follows: 1. One hundred eleven (50.5%) had used a dental floss and an interdental brush. 2. Two hundred eighteen (99.1%) thought it was necessary to perform oral cleaning of dependent elderly. 3. Two hundred fifteen (97.7%) hoped to perform the oral cleaning of dependent elderly. 4. Two hundred nine (95.0%) considered oral cleaning distasteful. 5. Two hundred three (92.3%) recognized food debris between natural teeth and the denture of dependent elderly who could perform oral cleaning themselves. 6. Two hundred three (92.3%) recognized food debris between natural teeth and the denture of dependent elderly who could not perform oral cleaning themselves. 7. One hundred twenty (54.5%) had been trained in oral cleaning for dependent elderly. 8. Two hundred twelve (96.4%) hoped to receive training in oral cleaning for dependent elderly.

Vascular permeability: quantitative measurement with double-echo dynamic MR imaging--theory and clinical application

Double-echo dynamic magnetic resonance (MR) imaging was used to evaluate both vascularity and permeability of tissues simultaneously. Vascularity was evaluated on the basis of the T2*-shortening effect due to the intravascular fraction of the contrast agent and permeability on the basis of the T1-shortening effect due to the extravascular fraction. Meningioma was characterized on the basis of higher vascularity and neurinoma on the basis of higher permeability. The proposed method enables better tissue characterization.

Vitamin K2 (menatetrenone) induces iNOS in bovine vascular smooth muscle cells: no relationship between nitric oxide production and gamma-carboxylation

It has been recently reported that vitamin K2 (menaquinone-4: menatetrenone, VK2) has an anti-atherogenic effect as well as the ability to produce clotting factors and improve osteoporosis. However, the mechanism by which VK2 acts on atherosclerosis is still unclear. In this paper, we investigated the effects of vitamin K and its side chain on NO production as an anti-atherogenic substance in a cultured vascular system. Treatment of bovine vascular smooth muscle cells (SMC) with VK2 (30 microM) caused a time-dependent (24-72 h) increase in the nitrite (NO2) level in the conditioned medium, but not in bovine vascular endothelial cells. Classical NOS inhibitor (L-nitro arginine) and iNOS-specific inhibitors completely blocked the increased nitrite level induced by VK2 treatment, but D-nitro arginine could not it. Immunostaining and Western blotting analysis showed that VK2 induced iNOS protein in the SMC. VK2 has a naphtoquinone nucleus, which is identical in menadione (VK3), and an unsaturated side chain, which is called geranylgeraniol (GGO). To determine whether the structure of VK2 was related to an increasing nitrite level, we investigated the nitrite level in conditioned medium treated with VK3 or GGO. Neither VK3 nor GGO treatment of SMC increased the nitrite level. In addition, warfarin, an inhibitor of VK2-dependent gamma-carboxylation, did not affect the increased nitrite level induced by VK2 in SMC. In conclusion, VK2 caused NO production through iNOS induction in bovine SMC, that was not related to the structure of VK2, naphtoquinone nucleus or its side chain, independently of gamma-carboxylation.

[Dental treatment and oral health care on Tokashiki Island, Okinawa]

Okinawa Prefecture has been promoting dental treatment and oral health care in places where there are no dentists. The Ministry of Health and Welfare has been cooperating with eight dental colleges, including Tokyo Medical and Dental University, for promotion thereof since 1961. The 155th promotion was held on Tokashiki Island. The caries prevalence rate of the students on Tokashiki Island was relatively high compared with the average caries prevalence rate of the same age group throughout Japan, and most of the caries were thought to be due to too many soft drinks. Resin filling was the most popular treatment during this promotion. Severe periodontal disease was observed in middle-aged persons, but we could only perform initial periodontal treatment because of the limited treatment period. Complete or partial dentures were made or repaired for many elderly. The questionnaire study showed most of the denture wearers on Tokashiki Island were satisfied with their dentures, although many dentures did not fit, and the prescription was improved. The period of this promotion was too short to perform complete dental treatment and to prevent caries and periodontal disease, and primary prevention and higher dental hygiene education should be strengthened in no dentist areas like Tokashiki Island.

The influence of craniofacial form on bite force and EMG activity of masticatory muscles. VIII-1. Bite force of complete denture wearers

Today, Japan as a society is aging. The average life expectancy of Japanese people is approximately 80 years. One result of this is that preservation of masticatory functions in elderly people has become increasingly important from the viewpoint of quality of life. In the future, the use of dentures in facilitating masticatory functions as a substitute for teeth that are lost during the aging process will assume greater significance. Accordingly, appropriate evaluation and judgment of complete dentures for edentate jaws is crucial. This study was designed to elucidate the effects of the craniofacial form in complete denture wearers on the mode of activity of gnathic functions. First, subjects wearing complete dentures in both the upper and lower jaws were instructed to carry out vertical clenching, and bite force direction was determined. These data were then related to the subject's craniofacial morphology. These results suggest that the bite force direction in complete denture wearers is not affected by gender differences, but is closely associated with lateral craniofacial morphology, and that appropriate setting of occlusal plane and the occluded vertical dimension is extremely important in the preparation of complete dentures.

[Phase 1 clinical study of 123I-IBF, a new radioligand for evaluating dopamine D2 receptor with SPECT (I); biodistribution and dosimetry]

A Phase 1 clinical study of 123I-IBF, (S)-5-iodo-7- N-[(1-ethyl-2-pyrrolidinyl)methyl]carboxamido-2,3-dihydrobenzofuran, developed for evaluation of dopamine D2 receptor (D2-R) with SPECT, was performed in 12 healthy male volunteers. No side effects due to 123I-IBF (i.v. 167 MBq) injection were observed. In sequential whole-body images, the radioactivity was distributed mainly in the liver, lungs and brain, and decreased gradually. No significant retention of radioactivity was seen in any organ at 24 hr after injection. The absorbed dose of 123I-IBF, calculated based on the whole-body pharmacokinetics, was equal to or less than those of other brain perfusion imaging agents. No significant problems were observed in terms of the safety, pharmacokinetics or absorbed dose of 123I-IBF.

[Phase 1 clinical study of 123I-IBF, a new radioligand for evaluating Dopamine D2 receptor with SPECT (II); pharmacokinetics study and quantification in the brain]

The pharmacokinetics of (S)-5-iodo-7-N-[(1-ethyl- 2-pyrrolidinyl)methyl]carboxamido-2,3-dihydro-benzofuran (123I-IBF) in the brain were studied in 12 healthy male volunteers as a Phase I clinical study. The striatum-to-frontal cortex count ratio (-1) (St/Fc-1), which is a semi-quantitative index of the binding potential of 123I-IBF reached 1.81 +/- 0.19 and 2.21 +/- 0.39 at 90-120 min and 180-210 min after intravenous injection of 123I-IBF. St/Fc-1 obtained by SPECT at these times correlated well with the distribution volume ratio (-1) (Vd(St)/Vd(Fc)-1) based on three-compartment model analysis using an input function obtained by intermittent arterial sampling. The binding potential (BPR), calculated by the curve-fitting method using the time-activity curve in the reference region, also correlated well with the Vd(St)/ Vd(Fc)-1. The intra-observer and inter-observer reproducibilities of the striatum-to-cerebral cortex count ratios obtained using fixed-shape regions of interest (template ROIs) were superior to those obtained using manual ROIs. These results suggest that 123I-IBF is a promising agent for non-invasive quantification of the dopamine D2 receptor (D2-R) binding potential by SPECT.

Coregistration of FDG PET and MRI of the head and neck using normal distribution of FDG

For better localization of head and neck structures by PET with 2-(18)F-2-deoxy-D-glucose (FDG), direct incorporation of anatomical information from MRI by the coregistration of FDG PET and MRI without external markers is proposed.

METHODS

Seventeen patients with neoplasms and 16 normal subjects who had both FDG PET and MRI were studied. First, the three-dimensional normal distribution of FDG was evaluated, and then the structures of the head and neck regions with normal distribution patterns of FDG were used as internal markers for the coregistration of PET and MRI. The effectiveness of the coregistration was evaluated using focal neoplasms that were identified by both PET and MRI as fiducial internal markers.

RESULTS

The normal structures selected as internal landmarks for coregistration were the tonsils, salivary glands, mucosal layers of the oral cavity and pharynx, spinal cord, inferior portion of the frontal lobe, cerebellum and nasal turbinates. These structures were more easily observed in sagittal or coronal sections than in transaxial sections. All primary neoplasms were delineated by PET, whereas 4 were missed by MRI. Thirteen primary tumors and 7 cervical lymph node metastases coregistered well, with a center-of-mass distance of <2 mm, whereas 10 lymph node metastases were slightly misregistered, with a center-of-mass distance of 7.8+/-6.5 mm (mean+/-s.d.), probably due to differences in neck positions.

CONCLUSION

Normal distribution of FDG uptake in the head and neck regions delineated by multidirectional sections is important for effective coregistration of FDG PET with MRI.

Dive Europa: a search-for-life initiative

Liquid water, underwater volcanoes and possibly life forms have been suggested to be present beneath the estimated 10 km-thick ice shell of Europa the Jovian satellite J2. Europa's possible ocean is estimated to be 100-200km deep. Despite the great depth of the Europa's ocean, hydrostatic pressure at the seafloor would be 130-260 MPa, corresponding to 13-26 km depth of a theoretical Earth's ocean. The hydrostatic pressure is not beyond the edge of existing deep-sea technology. Here we propose exploration of Europa's deep-sea by the use of current technologies, taking a symbolic example of a deep submergence vehicle Shinkai 6500 which dives to a depth of 6.5 km deep (50 km depth of Europa's ocean). Shinkai 6500 is embarkable in the payload bay of the Space Shuttles in terms of size and weight for the transportation to a Low Earth Orbit (LEO). Secondary boost is needed for interplanetary flight from the LEO. On-orbit assembly of the secondary booster is a technological challenge. The International Space Station (ISS) and ISS-related technologies will facilitate the secondary boost. Also, ice shell drilling is a challenge and is needed before the dive into Europa's ocean. These challenges should be overcome during a certain leading time for matured experience in the ISS operation.

Non-invasive estimation of the net influx constant using the standardized uptake value for quantification of FDG uptake of tumours

To reduce the variability of the standardized uptake value (SUV) which is widely used to evaluate 2-[18F]fluoro-2-deoxy-d-glucose (FDG) uptake by neoplasms, net influx constant (Ki) was derived from SUV. The relationship Ki=SUV.kp.V0, where kp is the plasma clearance rate and V0 is the initial distribution volume of FDG, was utilized. A total of 71 plasma input functions were measured up to 60 min after intravenous injection of FDG in 55 patients and were analysed to obtain kp and V0. SUV and V0 were calculated based on either body weight or body surface area. To validate the Ki estimation, another group of eight patients with squamous cell carcinoma of the head and neck was included. Parametric images of the net influx constant were obtained by Patlak graphical analysis of dynamic positron emission tomography (PET) data and measured plasma input function. V0 based on body weight was 0.1627+/-0.0329 (ml/g) and showed a weak negative correlation with body weight (y=0.23356-0.00138x, r=0.591). V0 based on body surface area was 5540+/-871 (ml/m2) and had no significant correlation with body weight. kp at 50 min post injection was 0. 03272+/-0.00243 (1/min), and had no correlation with the plasma glucose concentration. A highly significant positive correlation was noted between true Ki and estimated Ki based on both body weight (y=0.0033+1.0371x, r2=0.897), and body surface area (y=0.0033+1. 0351x, r2=0.926). Ki, a better indicator of FDG uptake by tumour than SUV, is derivable non-invasively. Quantification of FDG uptake by Ki will aid standardization of diagnostic criteria of FDG PET oncology.

Assessment of hepatic portal perfusion using T2 measurements of Gd-DTPA

Recently, perfusion imaging has been of increasing interest in MRI. We applied this method for semiquantitative evaluation of hepatic parenchymal portal blood flow in patients with diffuse liver damage. Twenty patients with diffuse hepatic damage were divided according to the Child's Classification and studied. Gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) was administered into the superior mesenteric artery (SMA), and a dynamic series of T2*-weighted fast low angle shot (FLASH) images was obtained. We evaluated relative regional portal blood volume (rrPBV), mean transit time (MTT), and relative regional portal blood flow (rrPBF). The relationship between the rrPBV, rrPBF, and plasma indocyanine green retention rate test at 15 minutes (ICGR15 was also evaluated in 12 patients. Both rrPBF and rrPBV are significantly decreased in Child B & C patients compared with Child A patients. On the other hand, the MTT is significantly prolonged in Child B & C patients compared with Child A patients. Significant correlations were also noted between rrPBV and ICGR15 and between rrPBF and ICGR15. By means of selective catheterization into the SMA, we were able to estimate rrPBV, rrPBF, and MTT. This method may play a clinical role for assessment of regional portal perfusion in various diseases with diffuse liver damage.

Visualization of the cervical spinal cord with FDG and high-resolution PET

PURPOSE

Our aim was to evaluate the visibility of the cervical spinal cord with [18F]2-fluoro-2-deoxyglucose (FDG) and a high-resolution PET scanner and to quantify the glucose utilization by the cervical cord.

METHOD

Twenty-one normal subjects and three cervical myelopathy patients were studied. The visibility of the cervical spinal cord in sagittal and coronal sections was evaluated. The metabolic rate of glucose (MRGlu) and standardized uptake value (SUV) of FDG in the cord were calculated.

RESULTS

The entire cervical spinal cord was clearly visualized in 57% of the subjects: the upper cord in 81%, the middle cord in 73%, and the lower cord in 57%. The MRGlu of the normal cord was 1.93 +/- 0.37 mg/100 g/min. SUV was constant across all the vertebral levels and negatively correlated with subject age. In the myelopathy patients, the SUV of the entire cervical cord was lower than in the age-matched normal subjects.

CONCLUSION

These preliminary results indicate that the cervical spinal cord can be visualized as a normal structure in routine head and neck PET imaging and that FDG-PET may provide quantitative information about spinal cord disorders.

Fluorine-18-fluorodeoxyglucose PET versus thallium-201 scintigraphy evaluation of thyroid tumors

To determine whether PET could help differentiate malignant from benign thyroid tumors, 18F-fluorodeoxyglucose (FDG) accumulation and 201Tl scintigraphy were examined relative to histological diagnosis.

METHODS

Nodular thyroid lesions in 11 patients were evaluated before surgical resection. Static PET scanning with 370 MBq FDG was done for 20 min (from 40 to 60 min postinjection) in all patients, and standardized uptake values (SUVs) in these lesions were calculated. In addition, eight patients were evaluated with dynamic PET scan up to 60 min postinjection, and the lesions were further evaluated using graphical analysis. Thallium-201 delayed images were visually evaluated in 10 patients.

RESULTS

Four of 11 nodules were well-differentiated papillary carcinoma, another five were benign follicular adenomas, one was a multinodular goiter and another a case of chronic thyroiditis that was proved not to contain a nodule. Time-activity curves of FDG uptake showed different patterns in malignant and benign tumors. In the malignant tumors, FDG uptake increased with time after the tracer injection. By contrast, FDG uptake in benign tumors gradually decreased. With use of a cutoff value of 5.0 mg/ml for SUV and 10 microl x min(-1) x ml(-1) for Kc (K complex value determined using the linear fitting of the time-activity curve of FDG accumulation), all of the four malignant nodules and the six benign nodules were separated correctly. Chronic thyroiditis had high SUV in the malignant range. Of the four patients with thyroid carcinoma, the delayed 201Tl images revealed a slightly higher or equal uptake to background activity. In a patient with chronic thyroiditis, the delayed 201Tl images revealed diffuse accumulation higher than background activity.

CONCLUSION

FDG-PET is superior to 201Tl in differentiating malignant from benign tumors. Both SUVs and Kc values were useful indexes for this discrimination. Although careful evaluation is needed for chronic inflammatory lesions, this technique appears to be useful in evaluating thyroid nodules.

Multiple single sections Turbo FLASH MR arterial portography in the detection of hepatic neoplasms

OBJECTIVE

To determine the sensitivity of multiple single sections Turbo FLASH MR arterial portography (MRAP) in the detection of hepatic neoplasms.

METHODS AND PATIENTS

Twelve patients with hepatic mass underwent MRAP prior to hepatic resection. Findings of MRAP were compared with surgical specimen and intra-operative ultrasonography (US).

RESULTS

A total of 19 separate malignant neoplastic nodules were identified in the resected specimens or intra-operative ultrasonography. The sensitivity was 89.5% (17/19) for MRAP. MRAP depicted all neoplasms more than 1.0 cm in diameter. Two lesions not depicted on MRAP had a diameter of 5 and 9 mm, respectively. One lesion identified by MRAP was confirmed to false positive lesion by intra-operative US.

CONCLUSION

Multiple single sections Turbo FLASH MRAP may be a valuable adjunct for pre-operative detection of malignant hepatic neoplasms.