Objectives: To assess the median nerve in carpal tunnel with motion ofthe wrists and hands.Methods: Seventy wrists of 50 patients with proved carpal tunnelsyndrome were enrolled (group A). The 30 asymptomatic wrists (groupB) and 50 wrists of 25 volunteers (group C) were scanned for com-parison. Axial high resolution ultrasonography (HRUS) scanning ofwrists through the pre-tunnel, proximal tunnel and distal tunnel withwrists in neutral and extension, and fingers in rest and flexion wasperformed. The shape, cross-sectional area (CSA) and flattening ratio(FR) of median nerve were assessed. The sliding distance of mediannerve with motion of wrists and hands were recorded.Results: With wrists in neutral position and fingers in rest, the meanCSA of the median nerve were significantly enlarged in group A. Themean FR of the median nerve at proximal tunnel level was significantlyincreased in group A. With wrists in extension position and fingersflexion, the mean distance of median nerve sliding was significantlydecreased in group A and group B.Conclusions: The HRUS might be useful for the evaluation of carpaltunnel syndrome. The decrease in mobility of the median nerve in thecarpal tunnel might be a predisposing factor of carpal tunnel syndrome.

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High resolution ultrasonography of carpal tunnel: A dynamicevaluation of asymptomatic volunteersLan HH-C, Wang P-Y, Keng C-Y, Su Y-G, Lee T, Lee S-K, TaichungVeterans General Hospital, Taiwan; Yuanshan and Suao VeteransHospital, Taiwan

Objectives: To assess the median nerve in carpal tunnel with motion ofwrists and hands in asymptomatic volunteers.Methods: Fifty asymptomatic wrists of 25 volunteers were scannedwith high resolution ultrasonography (HRUS). Axial scanning of wriststhrough pre-tunnel, proximal tunnel and distal tunnel with wrists inneutral and extension positions, and with fingers in rest and flexion wasperformed. The shape, cross-sectional area (CSA) and flattening ratio(FR) of median nerve were assessed. The sliding distance of mediannerve with wrists and hands were recorded.Results: With wrists in neutral position and fingers in rest, the meanCSA of the median nerve at pre-tunnel, proximal tunnel and distaltunnel levels were 8.7 � 1.2 mm2, 8.0 � 1.1 mm2 and 7.4� 1.4 mm2,respectively. The mean FR of median nerve at proximal tunnel levelwas 2.8 � 0.3 mm. With wrists in extension position and the fingers inflexion, the median nerve slipped laterally. The mean sliding distancewas 2.8 � 1.1 mm. In eight wrists, the nerves slipped laterodorsally andbecome round. In seven wrists, the nerves slipped a shorter distanceand were compressed by the tendons in the tunnel.Conclusions: The HRUS might be useful for evaluation of morphologyand mobility changes of median nerve in the carpal tunnel.

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High-resolution sonography of the wrist and hand: Pictorialreview of ultrasonic anatomy and pathologyChoi YS, Adler RS, Sofka CM, Choi KH, Park SW, An JK, Kim SH,Woo JJ, Kim H-S, Han CY, Eulji Hospital, Eulji University Schoolof Medicine, Korea; Hospital For Special Surgery, Weill MedicalCollege of Cornell University, United States of America

The purpose of this essay is to demonstrate the ultrasonic anatomy andpathology of the wrist and hand. The development of high-resolutiontransducer has allowed the assessment of superficial structures. Itbecomes possible to evaluate tendon, ligament, pulley, soft tissuetumor, triangular fibrocartilage complex, compressive neuropathy andarthritis in the wrist and hand. We believe high-resolution ultrasonog-raphy may be helpful to establish the accurate diagnosis in the normal

and diseased wrist and hand, and will be considered as one of thefirst-line imaging modalities, performing after plain radiography.

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Interscapular area muscle thickness measurement byultrasonographyTsai W-C, Yang S-HC, Chen H-C, Chang Gung Memorial Hospital,Taiwan; Buddist Tzu Chi General Hospital, Taiwan

Objectives: To measure the interscapular area thickness near themedial border of scapula including skin, fat and muscle (trapezius,rhomboid and serratus posterior muscles) thickness and to determinethe correlation between the total thickness with the anthropometricindices.Methods: High-resolution (12 MHz) linear assay ultrasound was usedto measure the skin, fat and muscle thickness near the medial border ofscapula of 21 male volunteers (aged 18 to 34 years old).Results: The thickness of skin, fat, trapezius muscle, rhomboid muscleand serratus posterior muscle are 1.80 plusmn; .33, 4.00 plusmn; .40,5.04 plusmn; .08, 5.81 plusmn; .29 and 3.74 plusmn; .45 mm, respec-tively. Total thickness of the interscapular area was 20.39 plusmn; 4.39mm. No difference was found between dominant and nondominantsides. Correlations between the total thickness and the anthropometricindices including body weight, body mass index, chest circumference,waist circumference and hip circumference were statistically significant(p � 0.05).Conclusions: Ultrasonography is a useful tool to measure musclethickness. The results could provide a reference to the physician whileperforming needle electromyography examination, acupuncture or lo-cal injection therapy to the interscapular area.

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Diagnostic value of high-resolution ultrasonography for imagingof the knee, elbow and wrist joints in rheumatoid arthritisXiao Y, Zhang G, Zuo X, Xiangya Hospital of Central SouthUniversity, China; Department of Internal Medicine, XiangyaHospital, Central South University, China; Department of InternalMedicine, Xiangya hospital, Central South University, China

Objectives: In order to value high resolution ultrasound (HRUS)including two-dimensional ultrasound (2D), color Doppler (CDFI),power Doppler (PDI), and spectrum Doppler (SD), n early diagnosis ofrheumatoid arthritis (RA).Methods: Two hundred forty joints, including knee, elbow and wrist ofthe patients with RA and 120 joints of control persons were checked byGE LogiQ-9 unit with 10.0 MHz transducer. The joints were firstscanned in 2D. Then the blood flow signals were observed with CDFI,PDI and SD.Results: By 2D hydrarthrodial effusion was found in 191 joint spaces(79.50%), and synovial thickening in 174 joints (72.50%) in RApatients. PDI and CDFI identified vascularization as blood signal withspot, cudgel or streak and pannus formation in 165 joints (68.75%). Theflow profile of the arteries measured with SD showed low resistanceindex.Conclusions: HRUS can clearly depict hydrarthrodial effusion, syno-vial thickening and vascularization in RA patients and is a sensitivemethod for early diagnosis of RA.

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Preliminary experience of musculoskeletal ultrasound in atertiary rheumatology centerCheng YK, Kong KO, Tan Tock Seng Hospital, Singapore

Abstracts P253