间接法MRI膝关节造影对半月板撕裂的评价

目的　评价间接法MRI膝关节造影对半月板撕裂的诊断价值。方法　回顾性分析 75例常规MRI膝关节扫描和 6 4例间接法MRI膝关节造影病例资料 ,以膝关节镜检查为诊断金标准 ,对比分析常规MRI和间接法MRI膝关节造影对半月板撕裂的诊断。结果　间接法MRI膝关节造影对内侧半月板撕裂的诊断敏感性、特异性、准确性、阳性预测值和阴性预测值分别为 72 %,10 0 %,89.1%,10 0 %和 84.8%;对外侧半月板撕裂分别为 83.8%,90 .9%,87.5 %,89.6 %和 85 .7%。与常规MRI比较 ,间接法MRI膝关节造影对内外侧半月板撕裂的诊断能力都没有统计学差异。结论　尽管间接法MRI膝关节造影对内外侧半月板撕裂诊断价值很高 ,但与常规MRI比较没有统计学差异。     

半月板损伤的MRI诊断与关节镜对照研究

目的：评价MRI对半月板损伤的诊断价值,为临床诊断和治疗半月板损伤提供可靠的影像学依据。方法：对138例拟行关节镜术的膝关节疼痛患者进行术前MRI检查,并于MRI检查后2周内行关节镜术。结果：符合纳入标准的84例患者中,与关节镜结果对照,MRI诊断半月板Ⅰ级损伤、Ⅱ级损伤的符合率分别为100%和91.1%;诊断半月板撕裂的敏感度、特异度、符合率、Kappa值分别为91.5%、90.7%、91.1%和0.82;对半月板撕裂类型诊断的敏感度、特异度、符合率和Kappa值分别为90.9%、85.7%、88.1%和0.76。结论：与关节镜比较,MRI显示半月板Ⅰ、Ⅱ级损伤时的内部信号改变更敏感。MRI诊断半月板撕裂,与关节镜结果具有极好的一致性,并能准确评价半月板撕裂类型。MRI检查可作为评价半月板损伤的首选方法,对半月板损伤临床治疗方案的选择具有重要指导意义。     

Accuracy of MRI patterns in evaluating anterior cruciate ligament tears

 The purpose of this study was to determine the different patterns of anterior cruciate ligament (ACL) tears on MRI and the prevalence and accuracy of these patterns. Images were obtained on high-tesla and low-tesla units and the results compared to determine whether field strength affects the interpretation using the grading system. In 172 patients who underwent knee MRI (109 knees with high-tesla units and 63 knees with low-tesla units) and arthroscopy, there was a total of 91 arthroscopically proven ACL tears. Five patterns of ACL tears were observed and designated as type 1 (diffuse increase in signal on T2-weighted images and enlargement of the ligament, 48%); type 2 (horizontally oriented ACL, 21%); type 3 (nonvisualization of the ACL, 18%); type 4 (discontinuity of the ACL, 11%); and type 5 (vertically oriented ACL, 2%). The positive predictive value (PPV) for type 2, 4, and 5 patterns was 100% for both field strengths; for type 3 PPV was just above 80% for both field strengths. The PPV value for type 1 was 90% for the high-tesla unit and 79% for the low-tesla, unit, which was not statistically significant. Combining the results of both field strengths, the overall sensitivity and specificity were 93% and 89%, respectively. Arthroscopic results were also used to determine the association between meniscal and ACL tears. Only 13% of ACL tears were isolated, the rest being associated with meniscal tears. Forty-five percent of medial meniscal and 50% of lateral meniscal tears were associated with an ACL tear, and 94% of ACLs were torn when both menisci were torn.     

Magnetic resonance diagnosis of meniscal tears in patients with acute anterior cruciate ligament tears

OBJECTIVE: To evaluate the accuracy of magnetic resonance imaging in the diagnosis of meniscal tear in patients with acute anterior cruciate ligament tears. METHODS: Magnetic resonance images obtained from 41 patients imaged within 6 weeks of injury who had acute anterior cruciate ligament tears identified at arthroscopy were retrospectively reviewed for meniscal tear. RESULTS: With MR imaging the sensitivity, specificity and accuracy for diagnosing meniscal tears in the presence of acute anterior cruciate ligament tears were 71%, 93%, and 88%; for the lateral meniscal tears were 57%, 100% and 85%; and for the medial meniscal tears were 100%, 88%, 90%. All false negative cases (n = 6) involved the posterior horn of the lateral meniscus. CONCLUSION: In the presence of acute anterior cruciate ligament tears, MRI imaging has relatively low sensitivity for detecting meniscal tears due to missed tears in the lateral meniscus.     

半月板损伤及撕裂的MRI与关节镜或手术对照研究

目的评价不同观察者对膝关节半月板损伤MRI诊断一致性及撕裂形态学MRI诊断分级的准确性。方法由两位有经验的影像科医生回顾性对82例82个疑有半月板损伤的MRI图像,所得两次诊断结果进行Kappa统计量分析。本研究中用关节镜或手术结果作为诊断参考标准,确诊撕裂的内侧半月板有29例,外侧半月板有40例,分别分析内外侧半月板经参考标准确诊的撕裂的两次诊断的诊断价值。结果对内侧半月板Kappa值为0.71,对外侧半月板Kappa值为0.65,两次诊断均有好的诊断一致性。对内侧半月板可修复撕裂两次诊断的灵敏性、特异性、准确性分别为95%、38%、79%;100%、38%、83%。对外侧半月板可修复撕裂两次诊断的灵敏性、特异性、准确性分别为93%、65%、75%;93%、77%、93%。结论MRI两次诊断对内外侧半月板诊断一致性良好,对内外侧半月板可修复撕裂准确性、灵敏度较高,对外侧半月板可修复撕裂特异度较高。     

Magnetic resonance imaging as a tool for evaluation of traumatic knee injuries. Anatomical and pathoanatomical correlations

Traumatic injury to the knee remains a diagnostic and therapeutic challenge. Magnetic resonance imaging (MRI) has been applied to musculoskeletal pathoanatomy and has been shown to be an effective tool for definition and characterization of knee pathology. A systematic approach is taken to establish anatomical and pathoanatomical correlations, as well as the role of MRI in the management of knee injuries. Imaging was performed at the UCLA Medical Center using a permanent magnet system and a combination of solenoidal surface coils and thin-section, high-resolution scanning techniques. Images depict structural anatomical and spatial details of the knee that correlate well with corresponding cadaveric cryosections. To determine pathoanatomical correlations and the efficacy of MRI, 105 patients with preoperative diagnoses of meniscal tears, anterior and posterior cruciate ligament tears, tibial plateau fracture, and patella and quadriceps injuries were imaged. Results indicated that for the medial meniscus MRI demonstrated a 95.7% sensitivity, 81.8% specificity, 90% accuracy, 88.2% positive predictive value (PPV), and 93.1% negative predictive value (NPV). Imaging of the lateral meniscus demonstrated a 75% sensitivity, 95% specificity, 91% accuracy, 80% PPV, and 94% NPV. MRI of the ACL revealed 100% sensitivity, specificity, accuracy, positive and negative predictive values. MRI is a noninvasive tool which uses no ionizing radiation and can accurately define and characterize anatomy and pathoanatomy. This study indicates that MRI in conjunction with clinical evaluation can contribute to treatment decision-making processes and assist in preoperative planning. An algorithm demonstrating the potential clinical use of MRI is presented.     

Value of modern sonography in the assessment of meniscal lesions

The aim of this prospective study was to assess the accuracy of modern ultrasonography in diagnostic imaging of meniscal tears. One hundred and sixty menisci were evaluated in 80 patients (42 females, 38 males, mean age=36.2 years, range=16-70 years). Inclusion criteria for the study were twofold: clinical suspicion of meniscal injury and clinical indication for arthroscopy. Knee examination was performed with the Voluson 730 Expert ultrasound system (General Electric). After sonographic examination, all patients underwent arthroscopic procedures within 1-4 days. The final diagnosis of meniscal tears was taken from surgical reports. The overall sensitivity, specificity, positive predictive value and negative predictive value of sonographic examination in the assessment of meniscal tears amounted to 85.4%, 85.7%, 67.3% and 94.4%, respectively. The statistical parameters were not statistically different in medial and lateral menisci. Age, sex, body mass index (BMI), weight, physical activity, mechanism on injury, and time lapse from injury did not have a statistically significant impact on the usefulness of ultrasonography. The highest sensitivity (>90%) was obtained in medial menisci and in patients with a BMI>25. The highest specificity (>90%) was obtained in lateral menisci, in patients after twisting injuries, in sports injuries, and in recent injuries (time lapse from the injury <1 month). The positive predictive value (PPV) of sonographic examination was higher than 90% only in recent injuries (<1 month), however, the negative predictive value of ultrasound is high, being less than 90% in males with lesions of lateral menisci and in sequelae of sports injuries.     

膝关节半月板撕裂磁共振成像与关节镜对照研究

目的分析磁共振成像（MRI）在膝关节半月板撕裂诊断中的价值。方法分析168例（共计336个半月板）临床疑诊半月板损伤患者,依次在1周内行磁共振（MR）和关节镜检查,对比MR和关节镜检查结果,探讨MRI对膝关节半月板撕裂诊断符合率。结果以关节镜为参考标准,168例（共计336个半月板）中MRI诊断半月板撕裂敏感性96．9％,特异性为87．5％,准确性为92．5％,假阳性率为12．5％,假阴性率3．1％,MRI具有术前诊断价值。结论MRI诊断半月板撕裂具有很高准确性,但仍有一定的假阳性与假阴性。     

Three Tesla MRI for the diagnosis of meniscal and anterior cruciate ligament pathology: a comparison to arthroscopic findings

AIM: To assess the accuracy of 3T magnetic resonance imaging (MRI) in the evaluation of meniscal and anterior cruciate ligament (ACL) injury. MATERIALS AND METHODS: Sixty-one consecutive patients were identified who were referred for evaluation of suspected intra-articular pathology with a 3T MRI and who, subsequently, underwent an arthroscopic procedure of the knee were included for the study. Two musculoskeletal radiologists interpreted the images. The sensitivity, specificity, positive predictive value, and negative predictive value were then calculated for the MRI versus the arthroscopic findings as a reference standard. RESULTS: The sensitivity and specificity for the overall detection of meniscal tears in this study was 84 and 93%, respectively. The results for the medial meniscus separately were 91 and 93% and for the lateral 77 and 93%. The evaluation of ACL integrity was 100% sensitive and specific. The meniscal tear type was correctly identified in 75% of cases and its location in 94%. CONCLUSION: This study demonstrates good results of 3T MRI in the evaluation of the injured knee. Caution should still be given to the interpretation on MRI of a lateral meniscus tear, and it is suggested that the standard diagnostic criteria of high signal reaching the articular surface on two consecutive image sections be adhered to even at these higher field strengths.     

膝关节半月板放射状撕裂的MRI表现

目的 探讨MRI对膝关节半月板放射状撕裂的检出能力.方法 回顾性分析1085例经关节镜证实的膝关节半月板损伤中的半月板放射状撕裂107例(9.9%)患者的MRI资料,同时按住院号顺序采用等足巨抽样方法 ,抽取100例经关节镜证实的非放射状撕裂的半月板损伤患者作为对照组.所有患者均经MR检查,观察裂隙征及裂隙行走征、半月板分离征、半月板消失征及小半月板征4种征象,与关节镜结果 比较.结果 (1)107例半月板放射状撕裂患者中,最常见的发生部位是外侧半月板体部(71例,66.4%)和前体交界部(25例,23.4%).(2)107例半月板放射状撕裂中,MRI诊断放射状撕裂102例.100例半月板非放射状撕裂的半月板损伤中,MRI诊断11例为放射状撕裂,MRI诊断半月板放射状撕裂的敏感度、特异度、阳性预测值、阴性预测值分别为95.3%(102/107)、89.0%(89/100)、90.3%(102/113)、94.7%(89/94).(3)裂隙征和半月板分离征出现频率最高,102例中分别出现59例(57.8%)和43例(42.2%),是诊断放射状撕裂最重要的MRI征象.结论 MRI诊断半月板放射状撕裂的准确率较高,是目前术前无创诊断的最佳方法 .     

Magnetic resonance imaging of meniscal lesions of the knee

In a prospective study of 25 patients, magnetic resonance imaging (MRI) was employed to detect meniscal tears in the symptomatic knee. All patients underwent arthroscopy and 21 underwent double contrast arthrography. When correlated with these two diagnostic procedures MRI produced no false negative results. There were, however, six false positive MRI findings all of which related to the posterior horn of the medial meniscus. MRI appears to be reliable in detecting meniscal tears but long examination times continue to limit its clinical usefulness.     

Reliability of magnetic resonance imaging in evaluating meniscal and cartilage injuries in anterior cruciate ligament-deficient knees

Purpose

The accuracy of magnetic resonance (MR) imaging in assessing meniscal and cartilage injuries in anterior cruciate ligament (ACL)-deficient knees as compared to arthroscopy was evaluated in the present study.

Methods

The results of all preoperative MR imaging performed within 3 months prior to the ACL reconstruction were compared against intraoperative arthroscopic findings. A total of 206 patients were identified. The location and type of meniscal injuries as well as the location and grade of the cartilage injuries were studied. The negative predictive value, positive predictive value, sensitivity, specificity and accuracy of MR imaging for these 206 cases were calculated and analysed.

Results

In patients with an ACL injury, the highest incidence of concomitant injury was that of medial meniscus tears, 124 (60.2 %), followed by lateral meniscus tears, 105 (51.0 %), and cartilage injuries, 66 (32.0 %). Twenty-three (11.2 %) patients sustained injuries to all of the previously named structures. MR imaging was most accurate in detecting medial meniscus tears (85.9 %). MR imaging for medial meniscus tears also had the highest sensitivity (88.0 %) and positive predictive value (88.7 %), while MR imaging for cartilage injuries had the largest specificity (84.1 %) and negative predictive value (87.1 %). It was least accurate in evaluating lateral meniscus tears (74.3 %). The diagnostic accuracy of medial meniscus imaging is significantly influenced by age and the presence of lateral meniscus tears, while the duration between MR imaging and surgery has greater impact on the likelihood of lateral meniscus and cartilage injuries actually being present during surgery. The majority of meniscus tears missed by MR imaging affected the posterior horn and were complex in nature. Cartilage injuries affecting the medial femoral condyle or medial patella facet were also often missed by MR imaging.

Conclusion

MR imaging remains a reliable tool for assessing meniscus tears and cartilage defects preoperatively. It is most accurate when evaluating medial meniscus tears. However, MR imaging should be used with discretion especially if there is a high index of suspicion of lateral meniscus tears.

Level of evidence

IV.

     

Indirect signs of anterior cruciate ligament injury on SPET: comparison with MRI and arthroscopy

Indirect signs of anterior cruciate ligament (ACL) injury on magnetic resonance imaging (MRI) include bony contusions in the lateral femoral condyle and the posterior portion of the lateral tibial plateau. This study was undertaken to assess the value of single photon emission tomography (SPET) in the diagnosis of ACL injury by examining the uptake pattern in the distal femur and the proximal tibia. Thirty-five patients were examined using SPET, MRI and arthroscopy. Seventeen patients were found to have ACL tears on arthroscopy. The duration of symptoms was 4 days to 10 years (mean 26.4 months). MRI and SPET images were analysed retrospectively without information from arthroscopic examination. Radionuclide uptake in the lateral femoral condyle and the posterior lateral tibial plateau was considered an indirect sign of ACL injury on SPET. We evaluated the diagnostic value of indirect signs of ACL injury obtained on SPET by comparing these findings with arthroscopic and MRI results. Fifteen of 17 patients with ACL injury showed indirect signs on SPET. The sensitivity, specificity, positive predictive value and negative predictive value for indirect signs of ACL injury were 88%, 56%, 65% and 83% on SPET and 59%, 94%, 91% and 71% on MRI, respectively. However, despite the higher sensitivity of indirect signs on SPET than on MRI, the overall diagnostic value of MRI is better than that of SPET. In the clinical setting, indirect signs of ACL injury may be of value in interpreting incidental findings on SPET.     

Radiographer led supplementary anterior cruciate ligament MRI sequences: Technical report

AimsTo compare different supplementary MRI sequences of the ACL to arthroscopy and determine the diagnostic performance of each sequence. To ascertain whether radiographers could identify patients requiring supplementary MRI sequences of anterior cruciate ligament (ACL) tears, without a supervising radiologist.MethodsThe study had ethical approval and two hundred and thirty one consecutive prospective MRI patients with mechanical knee symptoms (77 females, 154 males, of mean age 43.5, range 18–82 years) gave written informed consent. They then had a knee arthroscopy within seven days of the MRI. This was a pragmatic study to see if the six general MRI radiographers, each with over four years experience, could evaluate the ACL on routine orthogonal sequences (sagittal T1, Gradient Echo T2, Coronal STIR and axial fat suppressed dual echo). If they identified no ACL, then two 3D volume sequences (Dual Echo Steady State and Fast Low Angle Shot) and 2D limited sagittal oblique T1 sequences were also performed. Patients requiring extra sequences, missed by the radiographers, were recalled. The MRI sequences were independently evaluated in a blinded fashion by two consultant radiologists and a specialist radiology registrar and compared to the subsequent knee arthroscopy, as the gold standard, to determine the diagnostic performance statistics.ResultsThe cohort was on the knee arthroscopy weighting list and comprised 205 patients with chronic, 20 acute and 6 acute on chronic mechanical knee symptoms. There were no posterior cruciate, medial, or lateral collateral ligament tears at arthroscopy, used as the gold standard. The arthroscopy was normal and the radiographers correctly did not scan the extra sequence in 140 patients (72%) who then had normal arthroscopies. The radiographers did perform additional ACL sequences in 63 patients (27%). Of these, 10 patients had a partial and 12 complete ACL tears. Only two patients (0.9%) were recalled for additional sequences by the radiologist, and one ACL was normal and one had a full thickness tear at arthroscopy. The ACL evaluation for complete tears and a normal ACL on the volume sequences had a sensitivity of 100%, specificity of 97% and accuracy of 97%, excluding partial tears. Volume sequences including partial tears, had specificities and accuracies over 94%, with substantial interobserver agreement (Kappa 0.86, 95% CI 0.71–1.0). The limited oblique T1 sequence had sensitivities and negative predictive value of over 90%, but low specificity and positive predictive values and slight interobserver reliability (Kappa 0.42, 95% CI 0.2–0.6).ConclusionsFirstly, we have shown pragmatically that experienced radiographers identified almost all cases requiring supplementary MRI ACL sequences, without over scanning or needing supervision. Secondly, either volume sequence (DESS or FLASH) could be used as the supplementary sequence, to evaluate the ACL, but a limited oblique T1 sequence of the intercondylar notch cannot be recommended.     

MRI diagnosis of ACL bundle tears: value of oblique axial imaging

Objective

To investigate the diagnostic accuracy of oblique axial intermediate weighting MR imaging in detecting partial thickness anterior cruciate ligament (ACL) bundle tears.

Materials and methods

The study protocol was approved by the institutional ethics committee. Sixty-one subjects (43 male, 18 female; mean age 27.4 years; range 9 to 57 years) with clinically suspected ACL tear or meniscal tear between September 2009 and January 2011 were studied with MRI and arthroscopy. Detection of partial tear for the ACL as a whole and for each ACL bundle by protocol A (standard orthogonal sequences) and protocol B (standard orthogonal sequences plus oblique axial intermediate weighted imaging) was compared in a blinded fashion. Performance characteristics for protocol A and protocol B were compared using sensitivity, specificity, accuracy and ROC curves. A two-tailed p value of <0.05 indicated statistical significance.

Results

Fifteen (24.6%) normal, 15 (24.6%) partial and 31 complete tears were diagnosed by arthroscopy. Sensitivity, specificity and accuracy of protocol A for the diagnosis of partial tear of the ACL was 33%, 87% and 74%, while for protocol B the values were 87%, 87% and 87% respectively. The area under the curve (AUC) for the diagnosis of partial ACL tear and individual bundle tear was higher for protocol B, although this difference did not reach statistical significance (p?>?0.05).

Conclusion

The addition of oblique axial imaging to standard MR imaging improves diagnostic accuracy for detecting partial tears of the ACL as well as individual bundle tears of the ACL.     

膝关节半月板损伤的MRI与关节镜对照研究

目的评价MRI在膝关节半月板撕裂诊断和评级中的价值。方法参照Mesgarzadeh标准对76位患者78个撕裂半月板的MR影像作回顾性分析,3位MRI主治医师在不知道关节镜检查结果的情况下独自阅片,按Mesgarzadeh的分级标准确定半月板撕裂的类型并记录评定结果,包括联合的前交叉韧带撕裂。结果MRI诊断半月板撕裂的敏感性和特异性分别为92%和87%,Ⅵ型是半月板撕裂中最常见的类型,尤其在发生移位的半月板撕裂中最常见。结论MRI是半月板撕裂伤和交叉韧带损伤的可靠诊断工具。     

Magnetic resonance imaging of the knee

Magnetic resonance imaging (MRI) is an accepted non-invasive modality for evaluation of soft tissue pathology without exposure to ionizing radiation. Current applications demonstrate excellent visualization of the anatomy and pathology of various organs. Preliminary studies in the knee reveal fine resolution of anatomy and pathology involving the meniscus. The purpose of this study is to determine a prospective correlation between MRI scans and actual meniscal pathology as documented at the time of arthroscopy. MRI scans were obtained in 155 patients, on 156 knees (one patient with bilateral scans), with 86 patients (87 knees) eventually undergoing diagnostic and operative videoarthroscopy performed by the same surgeon (DWJ). All images were obtained on the same high-resolution 1.5 Tesla GE Signa Magnetic Resonance Scanner with the same radiologist performing all readings (PEB). The knees were studied in the coronal and sagittal plane using a spin echo sequence and 5 mm slice thicknesses. The menisci were described as having Grade 1, 2, or 3 changes, with Grade 3 reserved for complete tears. Using arthroscopy as the diagnostic standard, the accuracy of MRI in diagnosing medial and lateral meniscal tears was 93.1% and 96.6%, respectively with a Grade 3 MRI reading. For tears of the ACL, the accuracy was 96.6% as confirmed at arthroscopy. Five tears of the PCL were also documented by MRI and correlated with clinical evaluation. Other abnormalities seen were articular cartilage and osteochondral defects, bone tumors, tibial plateau fractures, Baker's cysts, and meniscal cysts. The MRI scan is a highly accurate, noninvasive modality for documentation of meniscal pathology as well as cruciate ligament tears in the knee.     

Contribution of thin-slice (1 mm) axial proton density MR images for identification and classification of meniscal tears: correlative study with arthroscopy

Objective To evaluate the diagnostic efficacy of thin-slice (1 mm) axial proton density-weighted (PDW) MRI of the knee for meniscal tear detection and classification. Methods We prospectively assessed pre-operative MR images of 58 patients (41 males, 17 females; age range 18-62 years) with arthroscopically confirmed meniscal tear. First, we evaluated the performance of the sagittal and thin-slice axial MR images for the diagnosis of meniscal tears. Second, we compared the correlation of tear types presumed from sagittal and axial MRI with arthroscopy and tear classification from axial MRI. Tears were classified on the sagittal plane and the axial plane separately. The diagnostic performance and tear classification were compared statistically with arthroscopy results, which is accepted as the standard of reference. Results 8 of 58 patients were removed from the study group because they had complex or degenerative tears. A total of 62 tears were detected with arthroscopy in 50 patients. On the sagittal images, sensitivity and specificity values were 90.62% and 70.37%, respectively, for medial meniscus tears and 72.73% and 77.14%, respectively, for lateral meniscus tears. The corresponding values for axial images were 97.30% and 84.00%, respectively, for medial meniscus tears and 95.65% and 80.50%, respectively, for lateral meniscus tears. There was no significant difference in tear classification between the arthroscopy results and the thin-slice axial PDW MRI results (p>0.05). Conclusion thin-slice axial PDW MRI increases the sensitivity and specificity of meniscal tear detection and especially classification, which is important for surgical procedure decisions.     

MRI对膝关节半月板桶柄样撕裂的诊断价值

目的　评价MRI诊断膝关节半月板桶柄样撕裂的应用价值。方法　经关节镜证实的 2 1例的桶柄样撕裂患者及 11例非桶柄样撕裂患者。采用百胜公司的关节专用磁共振成像系统进行扫描。观察以下 4种MRI征象 ,双前角征 ,双后交叉韧带征 ,髁间碎片征及领结消失征。结果　 3 2例患者中 ,出现双前角征的有 10例 ,双后交叉韧带征 5例 ,髁间碎片征 2 0例 ,领结消失征 2 5例。结论　MRI是诊断半月板桶柄样撕裂的有效手段 ,内侧半月板桶柄样撕裂的敏感性及特异性较外侧高 ,髁间碎片征是诊断内侧半月板桶柄样撕裂最有价值的征象     

Bone injury associated with anterior cruciate ligament and meniscal tears: assessment with bone single photon emission computed tomography

RATIONALE AND OBJECTIVES: Acute injury of the menisci and ligaments about the knee joint is often associated with accompanying bone injury. The role of bone single photon emission computed tomography (SPECT) was assessed in this clinical setting. MATERIALS AND METHODS: Knee SPECT was performed in 94 patients with suspected ACL, meniscal tear, or both and was correlated with arthroscopy (n = 74), magnetic resonance imaging (MRI) (n = 37), or both. Scintigraphic findings were categorized based on their anatomic location and on uptake intensity (0-3 grade scale). RESULTS: Correlation with arthroscopy: Eleven patients had a normal arthroscopy of which in 10, SPECT images detected no abnormality. Sixty-three patients had abnormal arthroscopic findings, whereas all had abnormal SPECT studies. Thirty-eight patients had an anterior cruciate ligament (ACL) tear on arthroscopy. In this type of injury SPECT images detected increased uptake in the posterior aspect of the lateral tibial plateau (LTPp) with a positive predictive value (PPV) of 93% and a negative predictive value (NPV) of 97%. In 55% of the patients, increased uptake was also detected in the region of the middle sulcus of the lateral femoral condyle (LFCm): a "kissing" pattern. Tear of the medial meniscus was diagnosed by arthroscopy in 43 patients. SPECT images detected increased uptake in the medial tibial plateau (MTP) with a PPV of 78% and a NPV of 83%. Correlation with MRI: all seven cortical fractures seen on MRI were detected on SPECT. Twenty-eight patients had MRI findings suggestive of an ACL injury. Accompanying bone bruises were seen in 18 of them (64%). On SPECT images, all 28 patients with an ACL tear had increased uptake in the LTPp. Intensity of uptake in patients with associated bone bruise, however, was significantly higher; mean intensity grade 2.4 +/- 0.7 in case of accompanying bone bruise compared with 1.4 +/- 0.8 in case of an ACL tear without associated bone injury, P< 0.01. CONCLUSION: Results of the study suggest that bone SPECT is valuable in acute knee trauma for assessment of ACL, meniscal tears, or both and for detection of associated bone injury.