KISEP Otology Korean J Otolaryngol 2004;47:827-32 정상측두골전산화단층사진상내이구조물의계측 부산대학교의과대학이비인후과학교실, 1 진단방사선과학교실 2 고의경 1 박성환 1 윤빛나 1 이일우 1 노환중 1 전경명 1 김학진 2 Normative Measurements of the Inner Ear Structures on Temporal Bone CT Images Using PACS Eui Kyung Goh, MD 1, Sung Hwan Park, MD 1, Bit Na Yoon, MD 1, Il Woo Lee, MD 1, Hwan Jung Roh, MD 1, Kyong Myong Chon, MD 1 and Hak Jin Kim, MD 2 1 Department of Otolaryngology-Head and Neck Surgery and 2 Radiology, Pusan National University College of Medicine, Busan, Korea ABSTRACT Background and Objectives:The reports of normative measurements for inner ear structure using computer-based programs are rare. The purpose of this study was to measure the normative data of the Korean inner ear structures and establish the basic data for diagnosis of congenital inner ear anomaly. Subjects and Method:Temporal bone CT of 38 patients 16 men and 22 women without apparent disease of middle and inner ear, fractures or major disorder such as seizure or tumor were retrospectively reviewed. Fifteen dimensions on axial views and 9 dimensions on coronal views were measured in PACS using π-view program. The slice thickness of CT was 0.6 mm. Results:From the axial view, the canal diameter of SSCC was 1.09±0.15 mm, the bony island width was 5.70±0.50 mm, the bony island width of LSCC was 3.99±0.58 mm, the cochlear upper turn width & height were each 5.63±1.07 and 3.03±0.65 mm. The vestibular aqueduct were observed 95.3%. From the coronal view, the cochlear height was 5.14±0.36 mm. The length of IAC was significantly longer in male than female p0.05 and the opening site of IAC was significantly wider in the left than the right p0.05. The upper turn of cochlea in good bone conduction 10 B had larger width and smaller height than those in poor bone conduction 10 db. Conclusion:We established the Korean normative measurements of the inner ear structures, which can be used for further diagnosis of the inner ear anomaly. (Korean J Otolaryngol 2004;47:827-32) KEY WORDS:Temporal bone Labyrinth X ray computed tomography Measurement. - - - - 827
정상내이구조물의계측 A B C D E F G H Fig. 1. Axial inner ear measurements. Canal diameter and bony island width of superior semicircular canal A were measured at maximum size. The ampulla of superior semicircular canal B was identified just before entering the vestibule. Bony island width of lateral semicircular canal C with ring shape was measured at maximum diameter. limb length of posterior semicircular canal D and cochlea was measured. Basal turn of the cochlea E was checked at oval window level and upper turn F separated by imaginary line from basal turn was measured. The upper turn of the cochlea had two parallel turn from apex to bottom. The largest length of IAC from the bony crest to the opening of IAC was measured and the opening width between the angulating points to the posterior cranial fossa was checked G. The width of each vestibular aqueduct H was measured at midpoint. 828 Korean J Otolaryngol 2004;47:827-32
고의경외 A B C D Fig. 2. Coronal inner ear measurements. The bony island width of superior semicircular canal A and lateral semicircular canal B were measured at maximum size. The largest size was checked at cochlear height and vestibule C,D. Table 1. Measurement of the inner ear structures Scan Structure Measuremnt MeanSDmm Axial SSCC Canal diameter 01.090.15 Bony island width 05.700.50 Ampulla diameter 01.170.20 PSCC Canal diameter 01.050.19 Limb length 06.740.74 LSCC Bony island width 03.990.58 Cochlea Basal turn width 07.210.73 Basal turn height 02.020.50 Upper turn width 05.631.07 Upper turn height 03.030.65 IAC Length 11.541.77 Opening width 07.011.41 05.310.36 03.030.44 VA 00.890.16 Coronal SSCC Bony island width 05.590.48 Canal diameter 01.280.21 LSCC Bony island width 03.580.61 Canal diameter 01.010.13 Cochlea Height 05.140.36 IAC Length 11.902.08 Opening width 05.051.26 04.310.37 03.070.35 SSCCsuperior semicircular canal, PSCCposterior semicircular canal, LSCClateral semicircular canal, IACinternal auditory canal, VAvestibular aqueduct 829
정상내이구조물의계측 Table 2. Difference according to sex Scan Structure Measuremnt Male n19 830 MeanSDmm Female n24 Axial SSCC Canal diameter 01.120.17 01.060.12 Bony island width 05.790.44 05.630.54 Ampulla diameter 01.770.23 01.670.19 PSCC Canal diameter 01.080.21 01.020.17 Limb length 06.990.73 06.530.70 LSCC Bony island width 03.900.57 04.060.59 Cochlea Basal turn width 07.360.59 07.090.79 Basal turn height 01.970.32 02.050.61 Upper turn width 05.530.91 05.711.20 Upper turn height 03.120.48 02.960.76 IAC Length 12.001.70* 11.171.77 Opening width 06.791.40 07.201.43 05.340.42 05.280.31 03.150.46 02.940.41 VA 00.890.16 00.880.16 Coronal SSCC Bony island width 05.680.46 05.520.49 Canal diameter 01.270.17 01.290.23 LSCC Bony island width 03.520.56 03.640.66 Canal diameter 01.040.16 00.990.09 Cochlea Height 05.080.41 05.190.32 IAC Length 12.722.14* 11.241.81* Opening width 05.091.54 04.780.92 04.430.36 04.220.35 03.110.34 03.040.36 The data was compared by t-test accoring to sex. the only significant dimension is the length of IAC on coronal viewp0.022 but all other dimensions had no significant difference. SSCC superior semicircular canal, PSCCposterior semicircular canal, LSCClateral semicircular canal, IACinternal auditory canal, VAvestibular aqueduct Table 3. Difference according to bone conduction threshold Scan Structure Measuremnt BC 10 db n32 MeanSDmm BC10 db n11 Axial SSCC Canal diameter 01.110.15 01.010.10 Bony island width 05.660.53 05.810.40 Ampulla diameter 01.710.22 01.710.21 PSCC Canal diameter 01.030.20 01.100.15 Limb length 06.700.82 06.860.45 LSCC Bony island width 03.980.59 04.020.58 Cochlea Basal turn width 07.170.78 07.320.48 Basal turn height 02.040.57 01.960.19 Upper turn width 05.831.07* 05.070.89* Upper turn height 02.900.60 03.400.67 IAC Length 11.801.61 10.762.05 Opening width 07.071.53 06.880.98 05.310.37 05.290.33 03.050.45 02.980.43 VA 00.910.13 00.840.23 Coronal SSCC Bony island width 05.550.50 05.700.41 Canal diameter 01.310.21 01.190.16 LSCC Bony island width 03.620.68 03.490.73 Canal diameter 00.990.11 01.060.16 Cochlea Height 05.120.33 05.210.46 IAC Length 12.081.99 11.372.32 Opening width 04.951.14 05.341.57 04.310.37 04.320.39 03.080.35 03.050.36 BCbone conduction threshold. p0.031, p=0.045 - Korean J Otolaryngol 2004;47:827-32
고의경외 Table 4. Difference according to sides Scan Structure Measuremnt MeanSD mm Lt n=21 Rt n=22 Axial SSCC Canal diameter 01.110.17 01.060.12 Bony island width 05.730.45 05.670.55 Ampulla diameter 01.730.21 01.700.22 PSCC Canal diameter 01.020.20 01.070.17 Limb length 06.900.82 06.580.64 LSCC Bony island width 04.020.45 03.970.69 Cochlea Basal turn width 07.310.70 07.110.73 Basal turn height 01.930.41 02.100.58 Upper turn width 05.670.66 05.601.27 Upper turn height 02.920.45 03.130.79 IAC Length 12.021.79 11.101.65 Opening width 07.081.21 06.961.59 05.320.29 05.300.42 03.020.45 03.050.44 VA 00.880.13 00.900.18 Coronal SSCC Bony island width 05.640.45 05.540.50 Canal diameter 01.280.20 01.290.21 LSCC Bony island width 03.630.44 03.540.75 Canal diameter 00.990.15 01.030.10 Cochlea Height 05.200.39 05.100.33 IAC Length 12.322.35 11.491.73 Opening width 05.471.49* 04.640.85* 04.290.39 04.340.35 03.040.35 03.100.35 p0.027-831
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