대한방사선의학회지 1996 ; 34( 1) : 21-26 CT- 추간판조영술 : 요추간판탈출증에서의진단적 정확도와시술중유발통증의의미 1 김은호 정태섭 2 김영수 3 노성우 3 정미경 2 목 적 : 요추간판탈출증등에있어서 CT- 추간판조영술 (CT -discography) 의소견과시술중유발 되는통증을분석하여그유용성및진단의정확도를알고자한다. 대상및방법 : 다발성요추간판달출증환자 20명을대상으로 47개의요추간판에서추간판조영술을시행한후 2시간내에 CT를시행하였다. 수술로탈출증유형이확인가능하였던 20 명환자의 28개요추간판에서 CT -'- 이 scogram (28개추간판 /20 명환자 ), MRI(23/ 16 ), CT(21/15) 의소견을비교분석하였다. Di scog raphy시술시초영제투입후유발되는통증을통상느껴온질환통증과비교분석하였다. 결과 : 요추간판탈출증의유형진단에있어수술소견과일치하는정확도가 CT - discogr am Ol I 서 96.4%( 27 추간판 / 28 추간판 ), MRI와 CT 단독판독시 82.6%( 19 추간판 / 23 추간판 ), 71.4%( 15 추간판 / 21 추간판 ) 였다. Discography시생긴유발통증은 12개추간판에서전형적인방사통이, 24개추간판에서는방사통보다요통이더심하게나타났다. 다발성요추간판탈출증환자 10 명에서평소통증과관련된병소추간판의위치를확정하는데 CT - discography로도움을얻을수있었다. 결 론 : 요추간판탈출증진단에있어 CT -discogra phy 는매우높은정확도를나타내는검사방법이 며다발성요추간판질환인경우평소통증과관련된병소추간판위치를정확히진단하는데결정적인 역할을할수있다. 서 를응 '- CT- 추간판조영술 (CT 강 i scography) 은소량의 수용성 조영제를직접척추추간판수핵내에주업한후 CT-scan 을하여얻은영상과조영제주입시유발되는통증을분석 하여척추추간판질환을진단하는방사선학적검사방법이 다 (1). 특히최근까지요추간판탈출증의진단에주로이 용되는척수강조영술, 전산화단층촬영 ( 이하 CT), 자기공 i 병영상 ( 이하 MRI) 에비해서조영제주입후 wide-window 와 narrow - window 로 C T- scan 을함으로써요추간판 탈출증시나타날수있는여러가지누출을정확히반영할 수있고또한조영제주입시유발되는통증으로증상을유 발시키는추간판을찾아낼수있는유일한신경방사선학 검사방법이다. 주로다발성척추추간판탈출증환자에서 증상을유발시키는추간판이불명확할때, 환자증상과단 순영상검사의결과가얼치하지않을때, 및임상치료선택 에중요한역활을하는여러가지형태의조영제누출을확 1 연변의학원진단방사선과중국 2 연세대학교의과대학진단방사선과학교실 3 연세대학교의과대학신경외과 이논문은 1995년 9월 2 0일접수하여 19 95 년 1 2월 9일에채택되었음 - 21 인하는데이용되고있다. 이에본저자들은수술로그유형이확인된요추간판탈출증환자의 CT-discogram 소견과단순 CT, MRI 소견을서로비교분석하였고시술시유발되는통증도분석하여요추간판탈출층의진단에서 CTdiscography의유용성및진단의정확도를알고자하였다. 대상및방법 1994년 3월부터 1995년 2월까지 1년동안연세대학교영동세브란스병원에내원하여사전에 CT 흑은 MRI 에서다발성요추간판질환소견을나타낸환자중 CT- discography를실행했던 20명 (47개추간판 ) 을대상으로 CTdi scogram의소견빛시술중유발되는통증을중심으로분석하였으며이중수술로요추간판탈출증유형이확인된 28예의 CT - discogram(28예 /20명 ), MRI(23/16), CT (2 1/ 15) 소견을서로비교분석하였다. 환자의연령은 22세부터 68세로, 평균연령이 43. 8세였고, 남녀비는 13 : 7 이였다. 환자의자세는측와위를취하고통증이없거나적은쪽을위쪽으로향하게한후후외측으로추간판천자를시행하였다. 천자침위치는 11-2부터 L4-5까지는추간판중심 (center of intervertebral disc) 과대응되는척추중심선
대한방사선의학회지 1996: 34( 1) : 21-26 에서수직되게위쪽으로 8-lO cm 떨어진곳에서시상면과 45도각을주면서투시하에추간판중심을향하여찔렀다. L5 - S1은 L4-5 위치에서횡단변에 15도각을주어장골능을펴하면서찔렀다. 그리고조영제는 Conray를사용하였으며매추간판당 1ml를기준으로환자의통증발생에따라서가감하여주입하였다. 요추간판탈출증의 CT-discogram 소견은수핵, 섬유륜, 후종인대의형태및조영제누출여부에의해 7가지유형 로나누였다 (1-4) (Table 1). 조영제주입시유발되는통증을통상느껴온통증과비교하여그정도를 grade 0 ( 통증이없는경우 ), grade 1( 방사통보다요통이더심한경우 ), grade 2( 전형적인방사통이유발되는경우 ) 의세가 모든환자는 discography 실행 2시간내에 CT scan (General electric 9800, 120 KVp, 100-140 MA, Thickness/gap: 3mm/ 이을하였고 wide -window(w = 1500, L=300) 로는척수강과골구조중에서의조영제확산을 지유형으로나누었다. 결 과 관찰하고 narrow-window(w=250-350, L=25-5 이로는 주로척추강과조영이안되는상처반흔을관찰하였다.20 전체 20 명 47 예의추간판에서 CT - discogram 상각유형 의수는 Type 1 (Fig. 1) 3 예, Type 2(Fig. 2) 3 예, Type 3 명의환자중 16 명에서 2 개 (Fig. 3) 1 예, Type 4(Fig. 4) 16 예, Type 5-A(Fig. 5) 8 예, 이상의추간판에서 CT-discography 를시행하여총 47 개의추간판을검사하였다. Type 5 - B(Fig. 6) 1 예, Type 5 - C(Fig. 7) 4 예, Type 6 Table 1. Radiological Classilication 01 the Lumber Disc Pathology on the CT-discogram Type Radiolog cal Findings Normal : Mildy posterior position 01 the round or ovoid shaped nucleus p 비 posus 2. Annulus bulging: Loosening 01 annulus librosus and narrowing 01 the disc space with bulging 01 the nucleus p 비 posus without tear 01 the annulus librosus 3. Annulus tear Radial tear 01 annulus librosus 4. Protrusion: Localized protrusion 01 the nucleus pulposus through the delect 01 the annulus librosus 5. Extrusion: Trans-sectional tear 01 annulus librosus with the extruded nucleus pulposus A. Contained type: Extruded nucleus pulposus through the ruptured annulus librosus without leakage 01 contrast media B. Subligament leak type: Leakage 01 contrast media along the anterior surlace 01 the separated posterior longitudinal ligament C. Epidural leak type :The diffusion 01 contrast media into the extradural space through torn or ruptured posterior longitudinal ligament with the ruptured annulus librosus 6. Sequestered disc Iragment: The separation 01 the herniated Iragment Irom the parent nucleus pulposus 7. Degeneration :The loss 01 boundary between nucleus pulposus and the annulus librosus and the diffusion 01 contrast int the disc through torn annulus librosus Fig. 1. 48-year-old lemale. CT discogram 01 the normal intervertebral disc(type 1) Bright, oval shaped L2-3 nucleus pulposus is seen in the posterior aspect 01 the disc on the narrow window Fig. 2. 34-year-old lemale patient with annulus bulging(type 2) at L4-5 CT-discogram with narrow window 01 L4-5 intervertebral disc shows the anteriorly and posteriorly stretched nucleus pulposus and diffuse bulging 01 annulus librosus 1 2-22
μ김은호외 :CT- 추간판조영술 (Fig. 8) 2 예, T ype 7(Fig. 9) 9예였다. 수술로확진된 28개의추간판중 27개의추간판에있어 CT - discogram과수술소견이일치하여 96.4% 의정확도를보였고 MRI 단독으로판독한경우는 82.6%09개추간판 /23개추간판 ), CT 단독으로판독한경우는 71.4% (157B 추간판 /21 개추간판 ) 의정확도를보였다. 실제실행한각검사방법별추간판탈출유형은 Table2 에요약하였고수 간공이 l 예로서주로경막강의협착은있으나추간공은압박이없거나마약한상태였고, grade 2 인경우돌출방향에따라추간공인경우가 8예, 후외측 3예, 후중심형이 l예로서주로추간공이좁아진상태였다. 다발성요추간판탈출증환자 20명중 10명에서조영제주업시평소느껴온통증과완전히일치하는통증을보여주므로써증상을유발시키는결정적인추간판을찾을수있었다. 술소견과일치하지않았던추간판의유형과빈도는 Table 3 에요약하였다. 조영제주업시생긴유발통증은 grade 0; 11 예, grade 1 고 찰 ; 24 예, grade 2; 1 2 예였다. grade 0 인경우는정상추간판 이 3 개, 심한퇴행성변화가있는추간판이 8 개언반면, grade 1 인경우돌출방향은후중심이 19 예, 후외측 4 예, 추 CT - discogr aphy 시술시조영제를추간판수핵내에주 업하면조영제가수핵내에균일하게분포되면서그형태를 나타내고또한추간판탈출증시돌출된경로를따라흘러 Fig. 3. 36-year-old male patient with annulus tear(type 3) at L4-5. There is no abnormality at the L4-5 intervertebral disc on axial gradient-echo MR images(a). CTdiscogram of the same disc with a narrow window(b) shows an annulus defect with leakage of contrast media(arrow) into the left neural foramen. The pain provoked by the injection of contrast media was identical to the previous radiating pain a b Fig. 4. 33-year-old male patient with disc protrusion(type 4) at L5-S1. CT-discogram of L5-S1 with narrow window reveals the diffuse and posterocentrally protruded nucleus pulposus(arrow) through the defect of annulus fibrosus compressing the dural sac Only mild back pain was evoked by the injection of contrast media Fig. 5. CT-discogram of L4-5 with narrow window setting shows the posterocentrally contained type of extruded nucleus pulposus(type 5-A)(arrow) through the tear of the annulus fibrosus with the severely compressed dun;ll sac. Severe back pain was induced by the injection of contrast media 4 5 η
대한방사선의학회지 1996 : 34( 1) : 21-26 6 7 Fig. 6. 27-year-old male patient with subligamentous leak type of extruded nucleus pulposus(type 5-8) at L5-S1 CT-discogram of L5-S1 in wide window setting shows the loss of the normal shape of the nucleus pulposus with multidirectional tearing and the leakage of contrast media into the extradural space Curvilinear contrast filling at the right posterolateral aspect(arrows) suggests a subligamentous leak Fig. 7. 60-year-old male patient with epidural leak type of extruded nucleus p 비 posus(type 5-C) at L4-5. CT-discogram of L4-5 intervertebral disc with a wide window setting exhibits the diffuse infiltration(asterisk) of contrast media throughout the nucleus pulposus due to the degeneration and leakage of contrast media(arrows) into the surrounding epidural space and into the left neural foramen Fig. 8. 23-year-old male with sequestered disc fragment(type 6) at L4-5 Sagittal reformatted CT image reveals the sequestrated particle(arrows) from intradiscal contrast media at L4-5 들면서그형태를잘나타낼수있다. 정상적으로수핵은 원형또는타원형으로약간뒤쪽에위치해있다. 본연구에 서 CT - discogram 상추간판탈출증의여러가지형태를잘 보여주였는데특히외부형태변화가없이경미한열구만 Fig. 9. 60-year-old male patient with degenerative disc(type 7) at L 1-2 CT-discogram of L 1-2 intervertebral disc with a wide window setting shows the IOS5 of border between the nucleus p 비 posus and the annulu5 fibr05us and the diffuse spread of the contrast media in the disc with pool-like appearance 있을경우 (1 예 ) MRI, CT 에비해선명하게잘나타났으며 또한 MR I( 2예 ), CT(3예 ) 에서직접관찰할수없었던후종인대의분리, 혹은파열된정도에따라국한되였거나아래위로확산되는누출을잘보여주는데이는 spin - echo기법의시상면영상에서저신호강도선의소실로후종인대의파열을진단하는 (5) MRI 에비해더정확하고상세한자료를얻을수있으며수술방법선택에서중요한역할을한다 (1). 즉추간판의탈출된부분이수핵과연결되어있고국한된상태인경우화학적수핵용해술 (chemo n ucleolysis) 을할수있고경막외누출, 혈관누출, 분리된추간판분절, 지주막하관통혹은경막내탈출및후종인대파열시는수술치료를요한다. CT - discogram에서재발성돌출 ( protru s ion) 1예를정확히판정하지못하였는데오히려 MRI 에서는잘나타났다. 조영제가균일하게분포되지않은상태에서 CT scan 을하였거나수핵이탈출한통로가섬유유착되어안보인것으로사료된다. 본연구에서 CT - dis cogram과수술소견 - 24-
김은호오 1: CT 추간판조영술 Table 2. Type and Frequency 01 Herniated Discs in 20 Operated Cases Type* Annulus tear Protrusi on Extrusion A. Contained B. Subligament leak C. Epidural leak Sequestered disc Iragment Degeneration CT-discogram(n = 20) 9 12 7 4 5 MRI(n=16) 1 9 8 4 gu CT(n=15)?l ns QU 41 끼ζ l 꺼JTotal 28 23 21 *: Type at operative linding Table 3. Type and Frequency 01 Misdiagnosis in Each Modality Compared to Operative Findings in 20 cases Type*\ Study(N/No) Annulus tear Extrusion, subligament leak Extrusion, epidural leak Sequestered disc Iragment Protrusi on (Recurrent) MR(4!16) CT(6/15) CT-discogram(1 /20) 4,, -- η41, *: Type at operative diagnosis N : Frequency 01 misdiagnosis No:Total number 01 each study 을비교했을때 96.4% 의정확도를보여 Bernard(2) 에의한 94% 와비슷했고, MRI 단독으로검사한경우는 82.6%, CT 단독으로검사한경우는 71.4% 의정확도를보였다. 따라서 CT-discogram이 MRI, CT 보다높은정확도를보였는데이는주로조영제를직접수핵내에주입하므로서간접적으로수핵의양상을보여주는 MRI, CT보다더상세한자료를얻을수있기때문이라고생각한다. 추간판의신경분포를보면척수신경근의 ventral root 의분지와 autonomic 분지가결합되어 sinuvertebral 분지를이루고그분지는섬유륜의바깜층, 추체, 경막, 혈관, 후종인대, 후방관절등에분포되어있다 (1, 6, 7). 따라서섬유륜에열구가있으면수핵이바깜섬유륜에노출되면서신경에화학자극이생겨통증을일으킨다고한다 (7). 그런데이신경이때로는반대편에분포되거나아래또는위쪽추간판에분포될수있다. 따라서단순영상소견만으로는다발성요추간판탈출증의경우증상을유발시키는추간판을확정하는데어려움을줄수있다. 이때 discography 를실행하면서유발통증을분석하면정확히증상을유발시키는추간판을찾을수있을뿐만아니라돌출된양상도잘보여줄수있다. 본연구에서전체 20명다발성요추간판탈출증환자중 10명에서증상을유발시키는추간판을확정할수있어 50% 의재현율을보였으나다른논문의 74% 100% (8, 9) 성적과는차이를보였는데이는조영제주업시생기는유발통증이검사기술, 환자의선택, 환자위치, 신경분포의광범성등, 여러요소의영향을받기때문이라고생각된다 (1, 7). 즉천자실행사후방관절에너무접근 하변인위적으로요통을일으킬수있고, 급성환자일수록유발통증이쉽게나타나고, 환자의자세가정확하지않을때도인위적인요통이나타날수있으며, 추체, 후방관절, 혈관등질환시나타나는요통과도감별해야한다. 본연구에서는주로환자에대한선택성이없이후향적으로분석했기에성적이비교적낮은것으로사료된다. CT-discography 실행시유발되는통증은수핵의화학자극을받은신경이조영제주업시압력의증가로다시통증이재생되는물리과정으로해석하고있다 (1 ). 따라서수핵의자극을받지않은정상추간판 (3 예 ), 흑은신경조직의파괴, 기능상실로생각되는심한퇴행성변화가있는추간판의경우는 (8예) 통증이없였는데그병리학적근거는더깊이연구해야할것으로생각한다. 또한유발통증분석시돌출방향이추간공을향하는 (Fig. 3), 즉척수신경근의압박이있는경우 (8 예 ) 전형적인방사통이있었고돌출방향이후중심인경우 (Fig. 4) 즉척수신경근자체의압박이없는경우는 (1 9예 ) 주로요통이발생되었다. 때로는척수신경근이심하게눌렸음에도상응한방사통이없거나반대로미약한신경근압박시에방사통을보이는경우가있었는데이는척추추간판탈출증의방사통이본질적으로화학작용이없는섬유륜에서는상당히심한신경근압박시에발생하는반면화학적자극이주어지는경우수핵이조금이라도신경근에직접접촉할시심한방사통을일으킬수있기때문이다 (7). 또한주입된조영제용량, 시술자가느끼는저항력도추간판상태를반영할수있으며정상추간판에서의평균조영제주업용량은 0.5-0.7ml내외이 - 25 -
대한방사선의학회지 1996:34( 1) :21-26 며조영제주입시저항력이높다. 그러나병적인추간판에 서는주업용량이정상이상으로증가하고조영제주업시 저항력이낮거나, 소실된다고알려져있다 (1). 따라서유 발통증의양상만으로도추간판상태를어느정도간접적으 로추정할수있을것으로생각한다. 결론적으로요추간판탈출증진단에서 CT- discogram 은매우높은정확도 (96.4% ) 를보였으며 discography 중 유발되는통증으로추간판상태를간접적으로추정할수 있었고, 특히다발성요추간판탈출증의경우평소통증과 관련된병소추간판위치를진단하는데결정적인역할을 할수있였다. jij C 그 고 C그 c-r 헌 1. Fabris G, Lavaroni A, Leonardi M. Discography. 1 st ed. Udine Centauro. 1991 : 11-26 2. Bernard TN Jr. Lumbar discography followed by computed tomography: refining the diagnosis of low-back pain. Spine 1990; 15: 690-707 3. Adams MA, Dolan P, Hutton WC. The stages of disc degeneration as revealed by discograms. J Bone Joint Surg(Br) 1986 ; 68-B : 36-41 4. 정태섭정은기김영수김태훈권혁우자화전이조영을이용한요 추간판의초기퇴행성변화에대한자기공명영상의연구대한방사선의학회지 1995 ; 32 : 865-870 5 강병철, 김동익, 윤춘식서정호파열형요추추간판탈출증에서자기공명영상의진단적의의대한방사선의학회지 1994 ; 30 : 425-430 6. Kricun ME. Imaging modalities in spinal disorders. 1 st ed Philadelphia : Saunders, 1988; 20-41 7. Yussen PS, Swartz JD. The acute lumbar disc herniation imaging diagnosis. Semin Ultrasound CT MR 1993; 14: 389-398 8. Walsh TR, Weistein JN, Spratt KF, Lehmann TR, Apr 川 C, Sayre H. Lumbar discography in normal subjects: a controlled, prospective study. J Bone Joint Surg(Am) 1990 ; 72-A : 1 081-1088 9. Holt EP. The question of lumbar discograph y. J Bone Joint Surg(Am) 1968 ;50-A :720-725 Journal of the Korea n Rad iological Society 1996 : 34( 1) : 21-26 CT-Discography: Diagnostic Accuracy in Lumbar Disc Herniation and Significance of Induced Pain During Procedure' En-Hao Jin, M.D., Tae-Sub Chung, M.D. 2, Young-Soo Kim, M.D. 3, Sung- Noo Roh, M.D. 3, Mi-Gyoung Jeong, M.D. 2 1 Department of Diagnostic Radiology, Yan Bian Medical CoJlege, China 20epartment of Oiagnostic Radiology, Yonsei University Co Jlege of Medicine, Korea 3 Oepartment of Neurosurgery, Yonsei University College of Medicine, Korea Purpose: To evaluate the usefulness and the accuracy of CT-discography in lumbar disc disease by analyzing the findings of CT-discogram and types of evoked pain during the procedure Materials and Methods: CT-discograms were retrospectively evaluated in 47 intervertebral discs of 20 patients with multilevel involvement of lumbar disc diseases. In 28 herniated discs confirmed at surgery, the findings of CT-discogram (28 disc levels/20 patients), MRI(23/16) and CT(21/15) were comparatively analysed. The type of pain after infusion of contrast media during CT-discography was compared with that prior to the procedure. Resulsts: The accuracy for determining types of the herniated lumbar disc when compared with postoperative results was 96.4%(27 discs/28 discs) in the CT-discogram, 82.6%(19 discs/23 discs) in MRI and 71.4 % (15 discs/21 discs) in the CT scan. Pains encountered during discography were radiating pain in 12 discs and back pain in 24 discs. CT-discography was especially helpful in 10 patients with multilevel involvement of the lumbar disc diseases to evaluate the exact location of diseased disc(s) that provoked the pain. Conclusion: CT-discography is a highly accurate method in diagnosis of the herniated lumbar intervertebral discs and is very useful in determining the precise location related to the development of pain in such cases. Index Words: Spine, intervertebral disks Spine, CT Address reprint requests to: Tae.sub Chung, M.D., Department of Diagnostic Radiology, Yonsei University College of Medicine. Yong D ong Severance Hospital. n 146-92, Dogok-dong, Kangnam-ku, Seoul Tel. 82-2-3450-3514 Fax.82-2-562-5472 - 26 -