대한척추외과학회지제 15 권제 2 호 Journal of Korean Spine Surg. Vol. 15, No. 2, pp 67~72, 2008 흉요추부골절에서자기공명영상의임상적중요성 노정호 # 정남수 박정욱 신동선 전창훈 아주대학교의과대학정형외과학교실, 성민병원정형외과 # Clinical Importance of MRI in Thoracolumbar Spinal Fracture Jeong-Ho Roh, M.D. #, Nam-Su Chung, M.D., Jeoung-Wook Park, M.D., Dong-Sun Shin, M.D., Chang-Hoon Jeon, M.D. Department of Orthopedic Surgery, Ajou University School of Medicine, Sung-Min Hospital, In-Choen # Abstract Study Design: Retrospective radiologic assessment Objectives: To assess the clinical importance of MRI for the diagnosis of posterior spinal ligament complex injuries in thoracolumbar fractures. Summary of Literature Review: Evaluation of spinal instability is important in thoracolumbar fractures. When simple radiography and CT alone are performed, spinal instability may be missed, especially that involving the posterior spinal ligament complex. Materials and Methods: Eighty-seven patients who were evaluated using simple radiography, computed tomography (CT), and magnetic resonance imaging (MRI) between March 1994 and March 2003 were included in the study. The local kyphotic angle was measured on lateral radiography, and it was then compared to the fracture pattern on MRI. Statistical analysis was performed using ANOVA. Results: There was no correlation between the local kyphotic angle on radiography and fracture involvement on MRI (p=0.106). In 41 patients who were found to have involvement of the anterior column on CT, 25 had anterior column involvement, 4 had middle column involvement, and 12 had posterior column involvement on MRI. In 36 patients who were found to have involvement of the middle column on CT, 17 had involvement of the middle column and 19 had involvement of the posterior column on MRI. The fractures of the ten patients who were found to have posterior column involvement on CT were all seen on MRI. The coincidence of fracture patterns between CT and MRI, which was evaluated using Cohen's Kappa analysis, was 0.434. The sensitivity of CT compared with MRI was 0.741 in the middle column and 0.243 in the posterior column. Conclusions: Many thoracolumbar fractures are missed on both simple radiography and CT. MRI is essential for accurate diagnosis of posterior spinal ligament complex injuries, especially when there is involvement above the middle column, or when canal encroachment is seen on CT. Key Words: Thoracolumbar fracture, Posterior ligament complex, CT, MRI Address reprint requests to Chang-Hoon Jeon, M.D. Department of Orthopaedic Surgery, Ajou University School of Medicine San 5 Wonchun-dong, Youngtong-gu, Suwon, Kyoung-gi, Korea Tel: 82-31-219-5220, Fax: 82-31-219-5229, E-mail: bone@ajou.ac.kr - 67 -
대한척추외과학회지 Vol. 15, No. 2, 2008 서 론 척추골절의치료방법을결정하는데가장중요한것은척추의안정성이다. 척추골절에서척추의안정성은척추를구성하는골및인대의손상여부와관계가있으며정확한진단을위해단순방사선사진, 전산화단층촬영, 자기공명영상등의여러가지진단방법들이이용되고있다. 척추골절에서골조직의손상은단순방사선검사나전산화단층촬영으로볼수있으나 1,2,3,4), 인대손상의여부는간접적으로추정할수는있다. 정확한진단을위해서는자기공명영상을시행함으로써후방인대부의손상을확인할수있다. 그러나척추골절환자에서단순방사선사진과전산화단층촬영외에자기공명영상을추가로검사하게되면고비용이발생된다. 자기공명영상이전산화단층촬영의역할을효율적으로대체할수있다면환자에게최선의치료방법을효과적으로제시할수도있다. 척추골절에대한연구에서전산화단층촬영및자기공명영상을모두시행하여두검사방법을비교평가한결과는거의없었다. 본연구에서는척추골절에서단순방사선사진, 전산화단층촬영및자기공명영상을시행하여단순방사선사진, 전산화단층촬영과자기공명영상의정확도를비교하고, 인대손상의정확한진단을위해서자기공명영상의임상적중요성을평가하였다. 연구대상및방법 경우를골절로판단하여 Denis 의삼주설에따라분류하였다. 후방인대복합체의연속성에단절이있거나, 지방억제 T2 강조시상면영상에서후방인대복합체에고신호강도가있는경우후방인대복합체의손상으로판정하였다. 자기공명영상에서침범된정도에따라분류한전주까지손상이있는군, 중주까지손상이있는군, 후주까지손상이있는군들의단순방사선사진상의국소후만각의평균값을 ANOVA test 를이용하여군별로비교하여군간의의미있는차이를분석하여국소후만각과자기공명영상에서의손상과의관계를비교분석하였다. 3. 전산화단층촬영과자기공명영상간의손상의일치도분석 전산화단층촬영상의골절의침범정도를 Denis 의삼주설 5) 에따라전주골절, 중주골절및후주골절로분류하였다. 전산화단층촬영상에서삼주설에따라분류한군과자기공명영상상에서삼주설에따라분류한군들간의손상부위의일치도를비교하기위하여 Cohen s Kappa 분석을시행하였다. 3. 자기공명영상에대한전산화단층촬영의민감도분석 전산화단층촬영과자기공명영상의척추손상진단에대한각각의민감도분석은정확한기준을정하기가불가능하여자기공명영상에대한전산화단층촬영의민감도분석을하였다. 1. 연구대상 본연구는 1994 년 3 월부터 2003 년 3 월까지본원에내원한척추골절환자중초기검사로단순방사선사진, 전산화단층촬영과자기공명영상를시행한 87 명을대상으로연구를시행하였다. 남자 50 명, 여자 37 명이었으며이들의평균연령은 46.2 세였고손상의원인은추락사고 37 례, 넘어짐손상 19 례, 교통사고 26 례, 기타 3 례였다. 골절부위는제 12 흉추 23 례, 제 1 요추 37 례, 제 2 요추 16 례였다. 2. 단순방사선사진상국소후만각과자기공명영상상의손상의비교 수상초기에시행한측면단순방사선사진상골절부위의국소후만각을측정하였다. 자기공명영상에서는 T1 및 T2 강조축단면영상에서피질골의단절이있는 결 과 1. 단순방사선사진상국소후만각과자기공명영상상의손상의정도와의비교 자기공명영상에서전주손상군, 중주손상군및후주손상군에서단순방사선사진에서의국소후만각의평균값은각각 14.48±6.63 도, 15.84±8.86 도, 17.63±8.26 도였다. ANOVA test 를이용하여분석한결과각군사이의통계학적으로의미있는차이를보이지는않았다 (p=0.106)(table 1). 2. 전산화단층촬영과자기공명영상간의손상의정도의일치도분석 전산화단층촬영에서전주에만골절소견이보이는 - 68 -
흉요추골절에서자기공명영상검사의중요성 노정호외 환자 41 례중자기공명영상에서전주에만이환된환자는 25 례, 중주까지는 4 례, 후주까지는 12 례를보였다 (Table 2). 전산화단층촬영에서중주까지골절소견이보이는환자 36 례중자기공명영상에서중주까지만이환된환자는 17 례, 후주까지이환된환자는 19 례에해당됐다 (Table 3). 전산화단층촬영에서후주까지골절소견이보인환자는 10 례였으며모두자기공명영상에서 후주까지이환된소견을보였다 (Table 4). 자기공명영상과전산화단층촬영으로측정한자료의일치성을알아보기위하여 Cohen s Kappa 분석을실시하였다. 자기공명영상과전산화단층촬영을이용한결과판독의일치도는 0.434 정도로낮았으며 Kappa 분석결과도유의한차이가있는것으로나타났다. Table 1. Comparison of Fracture Classification by Local Kyphotic Angle and MRI Classification Number Mean of Local Kyphotic Minimum Maximum by MRI of Case Angle ( ) Angle ( ) Angle ( ) Anterior Column Only (Group I) Anterior Column to Middle Column (Group II) Anterior Column to Posterior Column (Group III) 25 14.48±6.63 2 32 21 15.84±8.86 2 37 41 17.63±8.26 2 32 Total 87 15.85±7.96 2 37 (p=0.106) Table 2. Cohen s Kappa Analysis between Each Fracture Pattern Evaluated By Computed Tomography and MRI Number of Case MRI Group I Group II Group III Total (Number) CT GroupII 25 I4 12 41 Group II I0 17 19 36 Group III I0 I0 10 10 Total (Number) 25 21 41 87 (Kappa=0.434) Table 3. Sensitivity analysis of CT which was taken to MRI in group II MRI Injury (-) Injury (+) Total (Number) Injury (-) 25 16 41 CT (Middle Column) Injury (+) 0 46 46 Total (Number) 25 62 87 Table 4. Sensitivity analysis of CT which was taken to MRI in group III. MRI Injury (-) Injury (+) Total (Number) CT (Middle Column) Injury(-) 46 31 77 Injury(+) 40 10 10 Total (Number) 46 41 87-69 -
대한척추외과학회지 Vol. 15, No. 2, 2008 3. 자기공명영상에대한전산화단층촬영의민감도분석 본연구에서전주까지손상이있는경우는전산화단층촬영과자기공명영상이모두일치하였기때문에중주와후주의두경우에대해서만민감도분석을실시하였다. 중주손상군에서전산화단층촬영의민감도는 0.741, 후주손상군에서전산화단층촬영의민감도는 0.243 였다. 고 찰 척추골절에서척추의불안정성에대한정확한진단은적절한치료방법의선택과추후일어날수있는합병증을예방하기위해중요하다 1,5). Denis 는척추를전주, 중주, 후주로분류하였다 5). 각주의손상여부로골절의안정성을결정할수있으며, 각주의손상은골부분일수도있고연부조직의손상일수도있다. 특히후방인대의손상은불안정성골절여부를결정하는데매우중요하다 1,6,7). 단순방사선검사나전산화단층촬영에서골조직의손상은쉽게발견할수있으나 1,2,3,4,8) 연부조직의손상은정확히평가할수없다. 후방인대복합체의손상에대해단순방사선검사에서극간간격의넓어짐이관찰되거나, 국소후만각의변화로간접적으로예측할수있다 4). Kim 등 9) 에의하면극간간격의정도와실제후방인대복합체의손상정도는통계적으로연관성이없는것으로보고되었고, 본연구의결과에서도국소후만각과자기공명영상에서손상정도는의미있는상관관계가없었다 (p=0.106). 자기공명영상은척추골절에서단순방사선검사나전산화단층촬영으로발견하지못한다른부위의척추손상을발견하는데의의가있다고하였고 10), 다중 (Multilevel) 척추손상환자에서전체척추자기공명영상을시행하여야한다는주장도있었다 11). 자기공명영상에서후방인대복합체의손상은인대구조의연속성단절이있거나, 고신호강도가보이면인대손상으로진단할수있다 12,13,14,15). 그러나인대주위의지방조직도또한 T2 강조자기공명영상에서고신호강도로보이므로인대손상의진단에정확성을기하기힘들다. 지방억제 T2 강조자기공명영상의기법이개발되어 16,17,18), 본연구에서도후주의구조물들인후방인대복합체의진단의정확성을위해지방억제 T2 강조자기공명영상을시행하였다. Emery 등 19) 은외상후척추인대손상에서자기공명영상의중요성에대한연구를시행한바있으나, 이연구 에는몇가지단점이있다. 첫째, 전산화단층촬영을동시에시행하여자기공명영상과의비교연구를시행하지않았고둘째, T1 강조영상과 T2 강조영상만으로인대손상을진단하였고, 지방억제 T2 강조자기공명영상을시행하지않았다는단점이있다. Petersilge 등 20) 도자기공명영상으로흉요추골절을검사하였다. 그러나이연구에도몇가지단점들이있다. 이들은후방인대복합체중에서극상인대만을연구하였으며자기공명영상의지방억제방법으로한가지를사용한것이아니고 12 명의환자는 T2 강조 spin-echo sequence, 9 명의환자는 T2 강조 gradient-echo sequence 를사용하였다. Cassar 등 21) 은척추손상환자의선별검사로동반된다른척추의손상여부검사및증상은없으나신경의손상유무를확인하는데있어서자기공명영상이유용하다고주장하였으며, Terk 등 22) 은급성척추손상환자에자기공명영상을시행함으로써초기에연부조직의손상뿐만아니라골조직의손상, 신경의손상, 추간판의손상등여러측면에서의진단이가능하다고주장하였다. 본연구의결과에서는흉요추부손상의진단에있어서후주로갈수록전산화단층촬영이자기공명영상에비해서진단의정확도가떨어졌다. 특히전산화단층촬영상중주까지이환이되었거나척추체의후방전위가있는경우에자기공명영상상에서 50% 이상에서후주까지이환이되어있는것을볼수있었다. 또한민감도분석의결과들을종합해보면척추손상환자에서전산화단층촬영과자기공명영상두가지방법중선별검사로는자기공명영상이더합당하다는것을보여준다. 전산화단층촬영에대한자기공명영상의위음성률은중주와후주에서모두 0 을보여준다. 이의결과들을종합해보면척추손상환자에서전산화단층촬영과자기공명영상두가지방법중선별검사로는자기공명영상이더적절하였다. 상술한바와같이척추손상환자에서특히전산화단층촬영상중주까지손상이있는환자나또는척추체의후벽의전위가있는경우에는특히정확한침범범위의확인을위하여자기공명영상이중요한역할을한다고사료된다. 요약및결론 흉요추부척추골절에서자기공명영상은단순방사선촬영이나전산화단층촬영에비해서특히중주나후주손상의진단을내리는데정확도가높은검사이었다. 본연구의결과를바탕으로흉요추골절환자에서후방인대복합체의손상이의심될경우에초기검사항목으로 - 70 -
흉요추골절에서자기공명영상검사의중요성 노정호외 자기공명영상을시행하는것이적절하며, 전산화단층촬영상중주까지이환이되어있거나척추체후벽의전위가보이는경우자기공명영상을이용한정확한진단이치료방법의결정에도움이되는것으로생각되었다. 참고문헌 01) Holdsworth FW: Fractures, dislocations, and fracturedislocations of the spine. J Bone Joint Surg Br 1963; 45: 6-20. 02) Brant-Zawadzki M, Miller EM, Federle MP: CT in the evaluation of spine trauma. AJR 1982; 136: 369-375. 03) McAfee PC, Yuan HA, Fredrickson BE, Lubicky JP: The value of computed tomography in thoracolumbar fractures. An analysis of one hundred consecutive cases and a new classification. J Bone Joint Surg Am 1983; 65: 461-473. 04) Daffiner RH, Deeb ZL, Rothfus WE: The posterior vertebral body line: importance in the detection of burst fracture. AJR 1987; 148: 93-96. 05) Denis F: The three column spine and its significance in the classification of acute spinal injuries. Spine 1983; 8: 817-831. 06) Jelsma RK, Kirsch PT, Rice JF, Jelsma LF: The radiographic description of thoracolumbar fractures. Surg Neurol 1982; 18: 230-236. 07) Ferguson RL, Allen BL Jr: A mechanistic classification of thoracolumbar spine fracture. Clin Orthop Relat Res 1984; 189: 77-88. 08) Gehweilier JA, Daffiner RH, Osborne RL Jr: Relevant signs of stable and unstable thoracolumbar vertebral trauma. Skeletal Radiol 1983; 7: 179-183. 09) Dong-Jun Kim, Hwan-Mo Lee, Hak-Sun Kim, Kyung- Soo Suk, Nam-Hyun Kim, Si-Young Park: Reliability of MRI to Detect Posterior Ligament Complex Injury in Thoracolumbar Spinal Fractures. J Kor Soc Spine Surg 2000; 7: 70-76. 10) Qaiyum M, Tyrrell PNM, McCall IW, Cassar-Pullicino VN: MRI detection of unsuspected vertebral injury in acute spinal trauma: incidence and significance. Skeletal Radiol 2001; 30: 299-304. 11) Green RA, Saifuddin A: Whole spine MRI in the assessment of acute vertebral body trauma. Skeletal Radiol 2004; 33: 129-135. Epub 2004 Jan 23. 12) Hackney DB, Asato R, Joseph PM et al: Hemorrhage and edema in acute spinal cord compression: demonstrated by MRI imaging. Radiology 1986; 161: 387-390. 13) Goldberg AL, Rothfus WE, Vital JM, et al: The impact of magnetic resonance on the diagnostic evaluation of acute cervicothoracic spinal trauma. Skeletal Radiol 1988; 17: 89-95. 14) Grenier N, Gresselle JF, Vital JM, et al: Normal and disrupted lumbar longitudinal ligaments: correlative MR and anatomic study. Radiology 1989; 171: 197-205. 15) Kliewer MA, Gray L, Paver J, et al: Acute spinal ligament disruption: MR imaging with anatomic correlation. J Magn Reson Imaging 1993; 3: 855-861. 16) Atlas SW, Regenbogen V, Rogers LF, Kim KS: The radiologic characterization of burst fractures of the spine. AJR 1986; 147: 575-582. 17) Henkelman RM, Hardy PA, Bishop JE, Poon CS, Plewes DB: Why fat is bright in RARE and fast spin-echo imaging. J Magn Reson Imaging 1992; 2: 533-540. 18) Georgy BA, Hesselink JR: MR imaging of the spine: recent advances in pulse sequences and special techniques. AJR 1994; 162: 923-934. 19) Emery SE, Pathria MN, Wilber G, Massary T, Bohlman HH: Magnetic resonance imaging of post traumatic spinal injury. J Spinal Disord 1989; 2: 229-233. 20) Persilge CA, Pathria MN, Emery SE, Masaryk TJ: Thoracolumbar burst fractures: evaluation with MR imaging. Radiology 1995; 194: 49-54. 21) Cassar-Pullicino VN: Spinal injury: optimizing the imaging options. Eur J Radiol 2002; 42: 85-91. 22) Terk MR, Hume-Neal M, Fraipoint M, Ahmadi J, Colletti PM: Injury of the posterior ligament complex in patients with acute spinal trauma: Evaluation by MR imaging. AJR 1997; 168: 1481-1486. - 71 -
대한척추외과학회지 Vol. 15, No. 2, 2008 국문초록 연구계획 : 후향적실험군-대조군연구연구목적 : 흉요추골절에서후방인대복합체의손상에대한자기공명영상의중요성에대해서알아보고자하였다. 대상및방법 : 1994년 3월부터 2003년3월까지본원에내원한흉요추골절환자중초기검사로전산화단층촬영과자기공명영상모두를시행한 87명의환자를대상으로초기방사선측면사진상국소후만각의정도를측정하여자기공명영상상에서의골절의상관관계를비교하였다 (ANOVA test). 전산화단층촬영과자기공명영상의이환의일치도정도를알아보기위해 Cohen s Kappa 분석을시행하였으며, 자기공명영상에대한전산화단층촬영의민감도분석을시행하였다. 결과 : 단순방사선사진에서의국소후만각과척추골절의삼주설에의한골절의침범정도와는연관성은없었다 (p=0.106). 전산화단층촬영에서전주에만골절소견이보이는환자 41례중자기공명영상에서전주에만이환된환자는 25례, 중주까지는 4례, 후주까지는 12례를보였다. 전산화단층촬영에서중주까지골절소견이보이는환자 36 례중자기공명영상에서중주까지만이환된환자는 17례, 후주까지이환된환자는 19례에해당됐다. 전산화단층촬영에서후주까지골절소견이보인환자는 10례였으며이들은모두자기공명영상에서후주까지이환된소견을보였다. Cohen s Kappa 분석을실시하여자기공명영상과전산화단층촬영의결과의일치도는 0.434 였으며, 자기공명영상에대한전산화단층촬영의민감도분석에서중주손상군에서 0.741, 후주손상군에서 0.243였다. 결론 : 흉요추골절환자에서후방인대복합체의손상에대한진단은단순방사선사진과전산화단층촬영만시행시진단의정확성이떨어진다. 전산화단층촬영상중주이상을침범한경우와골편의척추강내로의전위가있을시는자기공명영상을시행하여후방인대복합체의손상에대해정확한진단이필요하다. 색인단어 : 흉요추부골절, 후방인대복합체, 전산화단층촬영, 자기공명영상 통신저자 : 전창훈경기도수원시팔달구원천동산 5 아주대학교의과대학정형외과학교실 Tel: 82-31-219-5220 Fax: 82-31-219-5229 E-mail: bone@ajou.ac.kr - 72 -