Rotator cuff tears noncontrast MRI compared to MR arthrography.

OBJECTIVES: To compare the accuracy of indirect magnetic resonance arthrography and noncontrast magnetic resonance imaging for diagnosing rotator cuff tears. MATERIALS AND METHODS: In total, 333 patients who underwent noncontrast magnetic resonance imaging or indirect magnetic resonance arthrography were included retrospectively. Two musculoskeletal radiologists evaluated the images for the presence of supraspinatus-infraspinatus and subscapularis tendon tears. The overall diagnostic performance was calculated using the arthroscopic findings as the reference standard. Statistical differences between the diagnostic performances of the two methods were analyzed. RESULTS: Ninety-six and 237 patients who underwent noncontrast magnetic resonance imaging and indirect magnetic resonance arthrography were assigned into groups A and B, respectively. Sensitivity for diagnosing articular-surface partial-thickness supraspinatus-infraspinatus tendon tear was slightly higher in group B than in group A. Statistical significance was confirmed by multivariate analysis using the generalized estimating equation (p = 0.046). The specificity for diagnosing subscapularis tendon tear (85% vs. 68%, p = 0.012) and grading accuracy (57% vs. 40%, p = 0.005) was higher in group B than in group A; the differences were statistically significant for one out of two readers. Univariate analysis using the generalized estimating equation showed that the accuracy for diagnosing subscapularis tendon tear in group B was higher than in group A (p = 0.042). There were no statistically significant differences between the diagnostic performances of both methods for any other parameters. CONCLUSION: Indirect magnetic resonance arthrography may facilitate more accurate diagnosis and grading of subscapularis tendon tears compared with noncontrast magnetic resonance imaging.

How should anteromedial coronoid facet fracture be managed? A surgical strategy based on O'Driscoll classification and ligament injury.

BACKGROUND: Despite an improved understanding of coronoid anteromedial facet (AMF) fractures, the optimal treatment protocol and technique have not yet been established. The goals of the study were to describe the characteristics of AMF fractures, to suggest a surgical strategy, and to report the outcomes after treatment according to this protocol. METHODS: This was a retrospective study of 19 patients with AMF fractures between 2010 and 2012. Eight patients were excluded because of secondary olecranon fracture, radial head fracture, and elbow dislocation, leaving 11 patients with isolated AMF fracture in the study cohort. There were 7 men and 4 women, with an average age of 42 years (range, 29-62 years). Fracture classification, injury pattern, and accompanying collateral ligament injury were analyzed. O'Driscoll subtype 1 fractures were treated with lateral collateral ligament (LCL) repair; O'Driscoll subtype 2 and subtype 3 fractures were treated with buttress plating and LCL repair. Plain radiographs were used to evaluate union, arthritic change, and joint articulation. Functional outcomes were evaluated with range of motion and the Mayo Elbow Performance Score. RESULTS: Two patients had O'Driscoll anteromedial subtype 1 fracture, 4 patients had subtype 2, and 5 patients had subtype 3. Two patients with subtype 1 fracture had associated posterior dislocation; 9 patients with subtype 2 or subtype 3 had associated varus posteromedial injury. All 11 patients had associated LCL injury, and 6 patients had associated medial collateral ligament injury. The mean range of motion was 128°, and the average Mayo Elbow Performance Score was 89 points. Qualitatively, patient outcomes were scored excellent in 4 patients, good in 6 patients, and fair in 1 patient. CONCLUSION: AMF fractures are almost always accompanied by collateral ligament injuries. Thus, our surgical strategies, which include collateral ligament repair, are able to stabilize and result in favorable clinical outcomes. On the basis of our results, we recommend LCL repair alone for subtype 1 fractures and buttress plating and LCL repair for subtype 2 and subtype 3 fractures.

Knee derangements: comparison of isotropic 3D fast spin-echo, isotropic 3D balanced fast field-echo, and conventional 2D fast spin-echo MR imaging.

PURPOSE: To compare diagnostic performance, subjective image quality, and artifacts of isotropic three-dimensional (3D) intermediate-weighted (IW) fast spin-echo (SE), isotropic 3D balanced fast field-echo (FFE), and conventional two-dimensional (2D) fast SE 3.0-T MR sequences in evaluation of cartilage, ligaments, menisci, and osseous knee structures in symptomatic patients. MATERIALS AND METHODS: Institutional review board approval and waiver of informed consent were obtained for this HIPAA-compliant study. One hundred MR studies, each with three data sets (3D IW fast SE, 3D balanced FFE, 2D fast SE), were reviewed retrospectively. Two radiologists independently evaluated images for cartilaginous defects, anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial meniscus (MM), lateral meniscus (LM) tears, subchondral bone marrow signal abnormalities, subjective image quality, and image artifacts. Arthroscopic results were the reference standard. Statistical analysis was performed to calculate interobserver agreement and compare diagnostic performance of sequences. RESULTS: Sensitivity and specificity were greater than 85% for all lesions. For cartilaginous defects, sensitivity of 3D IW fast SE was significantly greater than that of 3D balanced FFE (95.5% vs 89.7%). Sensitivity of 3D IW fast SE and 2D fast SE for MM, LM, and ACL tears tended to be greater than that of 3D balanced FFE. IW fast SE had a higher detection rate for subchondral bone marrow signal abnormality than did 3D balanced FFE (34% vs 21%); it also had the best image quality and fewest artifacts, followed by 2D fast SE and 3D balanced FFE. Interobserver agreement was excellent for evaluation of all intraarticular structures (κ = 0.85-1) and good to excellent for detection of subchondral bone marrow signal abnormality (κ = 0.76-0.91). CONCLUSION: The performance of IW fast SE is superior to that of balanced FFE in evaluation of cartilaginous defects, with no significant difference in performance between 2D fast SE, 3D IW fast SE, and 3D balanced FFE in evaluation of meniscal and ligament tears. Subchondral bone marrow signal abnormality is more easily seen on 3D IW fast SE images, with better subjective image quality and fewer artifacts, than on images obtained with other techniques.

MRI findings with arthroscopic correlation for tear of discoid lateral meniscus: comparison between children and adults.

BACKGROUND: Discoid lateral meniscus is more susceptible to tear than normal meniscus. A comparison study for tear types of discoid lateral meniscus between children and adults has not been reported. PURPOSE: To compare tear type of surgically proven discoid lateral meniscus between adults and children, and to analyze diagnostic performance for tear type of discoid lateral meniscus using magnetic resonance imaging (MRI). MATERIAL AND METHODS: Knee MR examinations of 53 children and 84 adults who had discoid lateral menisci identified at arthroscopic surgery were retrospectively evaluated with consensus by two radiologists for tear type including displacement of torn meniscus. MRI findings were compared with surgery as the reference standard. The difference of tear type and displacement of torn meniscus between children and adults in arthroscopic finding was analyzed using the Fisher's exact test or the Chi-squared test with Bonferroni's correction. RESULTS: At arthroscopy, complex tear (children, n = 22; adults, n = 56) and peripheral tear (children, n = 17; adults, n = 8) differed significantly between children and adults (P = 0.006 for complex tear, P = 0.002 for peripheral tear). Displacement of torn meniscus was seen in 28 cases of children and 41 cases of adults, not a statistically significant difference. In children, the positive predictive value (PPV) for horizontal tears was 90%, for peripheral tears 60%, and for complex tears 57%. PPV in adults for horizontal tears was 78%, peripheral tears 25%, and for complex tears 89%. CONCLUSION: Complex tears were more commonly found in adults than children and peripheral tears were more commonly found in children than adults. MRI has a high PPV for diagnosing the type of tear in discoid lateral meniscus for horizontal tears in children and adults and for complex tears in adults.

Qualitative and quantitative assessment of wrist MRI at 3.0T: comparison between isotropic 3D turbo spin echo and isotropic 3D fast field echo and 2D turbo spin echo.

BACKGROUND: Isotropic three-dimensional (3D) magnetic resonance imaging (MRI) has been applied to various joints. However, comparison for image quality between isotropic 3D MRI and two-dimensional (2D) turbo spin echo (TSE) sequence of the wrist at a 3T MR system has not been investigated. PURPOSE: To compare the image quality of isotropic 3D MRI including TSE intermediate-weighted (VISTA) sequence and fast field echo (FFE) sequence with 2D TSE intermediate-weighted sequence of the wrist joint at 3.0 T. MATERIAL AND METHODS: MRI was performed in 10 wrists of 10 healthy volunteers with isotropic 3D sequences (VISTA and FFE) and 2D TSE intermediate-weighted sequences at 3.0 T. The signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Contrast ratios (CRs) were calculated between fluid and cartilage, triangular fibrocartilage complex (TFCC), and the scapholunate ligament. Two radiologists independently assessed the visibility of TFCC, carpal ligaments, cartilage, tendons and nerves with a four-point grading scale. Statistical analysis to compare CRs (one way ANOVA with a Tukey test) and grades of visibility (Kruskal-Wallis test) between three sequences and those for inter-observer agreement (kappa analysis) were performed. RESULTS: The SNR of 2D TSE (46.26) was higher than those of VISTA (23.34) and 3D FFE (19.41). CRs were superior in 2D TSE than VISTA (P = 0.02) for fluid-cartilage and in 2D TSE than 3D FFE (P < 0.01) for fluid-TFCC. The visibility was best in 2D TSE (P < 0.01) for TFCC and in VISTA (P = 0.01) for scapholunate ligament. The visibility was better in 2D TSE and 3D FFE (P = 0.04) for cartilage and in VISTA than 3D FFE (P < 0.01) for TFCC. The inter-observer agreement for the visibility of anatomic structures was moderate or substantial. CONCLUSION: Image quality of 2D TSE was superior to isotropic 3D MR imaging for cartilage, and TFCC. 3D FFE has better visibility for cartilage than VISTA and VISTA has superior visibility for TFCC to 3D FFE and the visibility for scapholunate ligament was best on VISTA.

The "bridging sign": a MR finding for combined full-thickness tears of the subscapularis tendon and the supraspinatus tendon.

BACKGROUND: In daily practice, we discovered one of the secondary magnetic resonance (MR) findings of the subscapularis (SSC) tendon tear, the "bridging sign", which has not been previously described. PURPOSE: To describe the "bridging sign" on shoulder MR imaging and its radiological and clinical significance in patients with SSC tendon tear. MATERIAL AND METHODS: Twenty-nine patients who had undergone shoulder arthroscopy and had full-thickness tear of the subscapularis tendon were enrolled. The medical records of the 29 patients were retrospectively reviewed for the duration of shoulder pain, rotator cuff tears, and associated arthroscopic findings: biceps tendon abnormality and superior glenoid labral tear. Then, preoperative shoulder MR images were retrospectively reviewed for the presence or absence of the "bridging sign" and associated MR findings: periarticular fluid and fatty atrophy of the supraspinatus and subscapularis muscles. The type of rotator cuff tear associated with the "bridging sign" was assessed and the sensitivity, specificity, and accuracy of the "bridging sign" for the diagnosis of a certain type of rotator cuff tear were calculated. Associated arthroscopic and MR findings and mean duration of the shoulder pain between the patients with and without the "bridging sign" were compared. RESULTS: The "bridging sign" was seen in 17 of 29 patients and corresponded to a complex of the torn and superomedially retracted subscapularis tendon, coracohumeral ligament, and superior glenohumeral ligament, adhered to the anterior margin of the torn supraspinatus (SSP) tendon on arthroscopy. All patients with the "bridging sign" had combined full-thickness tear (FTT) of the cranial 1/2 portion of the subscapularis tendon and anterior 1/2 portion of the SSP tendon. The sensitivity, specificity, and accuracy of the "bridging sign" for the diagnosis of combined FTTs of the SSC tendon and anterior portion of the SSP tendon were 81.0%, 100%, and 86.2%, respectively. The patients with the "bridging sign" had longer duration of shoulder pain and more frequent associated arthroscopic and MR findings than the patients without the "bridging sign". CONCLUSION: The "bridging sign" is a highly specific finding for combined full-thickness tears of the subscapularis tendon and anterior portion of the supraspinatus tendon, associated with more chronic shoulder pain and more sever rotator cuff tear.

Diagnostic value of ultrasound and computed tomographic arthrography in diagnosing anterosuperior acetabular labral tears.

PURPOSE: This study investigated the sensitivity, specificity, and accuracy of ultrasound as well as the computed tomography arthrography (CTA) findings and arthroscopic findings for the diagnosis of anterosuperior acetabular tear and correlated tear types using the Lage classification system on ultrasound and CTA compared with the arthroscopic findings. METHODS: We retrospectively reviewed the results of ultrasonographic examinations conducted before injection and after injection of contrast for subsequent CTA in 36 hips (34 patients; 24 men [71%] and 10 women [29%]; mean age, 36 years). All patients had chronic groin pain and a positive impingement test. We analyzed the sensitivity, specificity, and accuracy before injection, after injection, and at CTA and compared these with findings with the arthroscopic findings. Interobserver agreement and intraobserver reproducibility of the presence of a tear and tear type in the anterosuperior quadrant of the acetabular labrum on ultrasonography and CTA were calculated by use of κ coefficients. RESULTS: The sensitivity, specificity, and accuracy for sonographic detection of labral tear before injection/after injection were 58%/79%, 67%/58%, and 61%/72%, respectively, for observer 1 and 75%/92%, 25%/42%, and 58%/75%, respectively, for observer 2. The sensitivity, specificity, and accuracy for CTA detection of labral tears were 96%, 92%, and 94%, respectively, for observer 1 and 88%, 92%, and 89%, respectively, for observer 2. When the sonographic classification was compared with the arthroscopic findings of observer 1 and observer 2, the accuracy before injection/after injection was only 53%/67% and 58%/75%, respectively. The accuracy of morphologic classification of CTA and arthroscopic findings of observer 1 and observer 2 was 83% and 75%, respectively. Interobserver correlation before injection and at CTA was poor (κ = 0.056) and moderate (κ = 0.642), respectively. CONCLUSIONS: Although intra-articular injection during sonographic examination could improve diagnosis of labral tears, sonographic examination as a diagnostic technique is still of limited use. However, CTA shows reliable validity in the diagnosis of acetabular labral tears. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Diagnosis of internal derangement of the knee at 3.0-T MR imaging: 3D isotropic intermediate-weighted versus 2D sequences.

PURPOSE: To compare three-dimensional (3D) isotropic fast spin-echo (SE) intermediate-weighted magnetic resonance (MR) imaging with two-dimensional (2D) fast SE MR imaging-both performed at 3.0 T-for performance in the diagnosis of internal derangements of the knee. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study, and the requirement for informed consent was waived. The authors retrospectively reviewed 87 knee MR images obtained in 85 patients who had undergone both 3D isotropic and 2D MR examinations of the knee at 3.0 T and subsequent arthroscopic surgery. The 2D MR images included intermediate-weighted coronal and sagittal images, intermediate-weighted axial images with fat saturation, and T2-weighted sagittal images. The 3D isotropic MR images were obtained with multiplanar reformation (MPR), a fast SE intermediate-weighted sequence, and a reconstruction voxel size of 0.5 x 0.5 x 0.5 mm. Two radiologists retrospectively and independently evaluated the 2D and 3D data sets, at different sessions, for the presence of medial meniscus (MM), lateral meniscus (LM), anterior cruciate ligament (ACL), and posterior cruciate ligament (PCL) tears. These interpretations were compared with the arthroscopic surgery findings. The statistical differences between the sensitivities, specificities, and accuracies of the two methods were determined at McNemar testing, with surgical findings serving as the reference standard. Interobserver agreement was calculated by using kappa coefficients. RESULTS: For both reviewers, the sensitivity, specificity, and accuracy of both MR techniques were higher than 95% for the diagnosis of ACL and PCL tears, higher than 85% for the diagnosis of MM tears, and higher than 80% for the diagnosis of LM tears. There were no significant differences in sensitivity, specificity, or accuracy between the two methods. Interobserver agreement for evaluation of all lesions was excellent and ranged from 0.81 (LM tears evaluated with 3D and 2D sequences) to 0.93 (ACL tears evaluated with 3D and 2D sequences, PCL tears evaluated with 2D sequence, and MM tears evaluated with 3D sequence). CONCLUSION: The performance of 3D isotropic fast SE intermediate-weighted MR imaging with MPR was not significantly different from that of 2D MR imaging in the diagnosis of cruciate ligament and meniscal tears of the knee.

Three-dimensional isotropic shoulder MR arthrography: comparison with two-dimensional MR arthrography for the diagnosis of labral lesions at 3.0 T.

PURPOSE: To compare the diagnostic accuracy of three-dimensional (3D) isotropic magnetic resonance (MR) arthrography with two-dimensional (2D) MR arthrography for the diagnosis of labral lesions of the shoulder performed by using a 3.0-T imager. MATERIALS AND METHODS: Institutional review board approval was given for this retrospective study and informed consent was waived. From March 2006 to January 2007, 100 patients underwent 3D isotropic and 2D MR shoulder arthrographic imaging by using a 3.0-T imager and subsequent arthroscopic surgery. The 3D isotropic sequences were performed by using fast gradient-echo imaging with fat suppression (voxel size, 0.6 x 0.6 x 0.6 mm; imaging time, 5 minutes 32 seconds) and were evaluated for the presence of superior, anterior, and posterior labral lesions by using 3D isotropic and 2D MR arthrography. The statistical differences between the sensitivity and specificity for both methods were analyzed by using the McNemar test, with arthroscopic findings regarded as reference standard. RESULTS: Surgical findings confirmed 53 superior labral anterior posterior (SLAP) lesions, 17 anterior labral lesions, and five posterior labral lesions. Respective sensitivity and specificity were 85% and 96% for SLAP lesions, 100% and 98% for anterior labral lesions, and 80% and 99% for posterior labral lesions by using 2D MR arthrography and 83% and 96% for SLAP lesions, 100% and 96% for anterior labral lesions, and 80% and 99% for posterior labral lesions by using 3D isotropic MR arthrography. There was no significant difference in sensitivities and specificities of both methods; however, the power of this study was limited and larger comparison is needed. CONCLUSION: Isotropic 3D shoulder MR arthrography combined with a multiplanar reconstruction technique can help in the diagnosis of shoulder labral lesions as does 2D MR arthrography, but with shorter imaging times.

Initial experience with imaging-guided intramuscular botulinum toxin injection in patients with idiopathic cervical dystonia.

OBJECTIVE: The objective of our study was to present our initial experiences of imaging-guided intramuscular botulinum toxin (BTX) injection in patients with idiopathic cervical dystonia. CONCLUSION: Imaging-guided BTX injection is a useful treatment technique in patients with idiopathic cervical dystonia when target muscles are located deeply or an injection must be delivered to a focal muscle area.

Comparison of indirect isotropic MR arthrography and conventional MR arthrography of labral lesions and rotator cuff tears: a prospective study.

OBJECTIVE: The purpose of our study was to prospectively compare the diagnostic accuracy of 3D isotropic indirect MR arthrography with conventional sequences of indirect MR arthrography for the diagnosis of labral and rotator cuff lesions on a 3-T MR unit. SUBJECTS AND METHODS: Thirty-six consecutive patients who were scheduled for shoulder arthroscopic surgery at our institution underwent indirect MR arthrography. Both conventional sequences and an additional 3D isotropic sequence were obtained 1 day before arthroscopic surgery. Two musculoskeletal radiologists prospectively evaluated the images in consensus for the presence of superior and anterior labral lesions and subscapularis and supraspinatus-infraspinatus tendon tears using the conventional sequences and the 3D isotropic sequence. We analyzed the statistical difference between the sensitivities and specificities of both methods using arthroscopic findings as the reference standard. RESULTS: Surgical findings confirmed the presence of 23 superior labral lesions, eight anterior labral lesions, 21 subscapularis tears, and 24 supraspinatus-infraspinatus tears. The sensitivity and specificity of the conventional sequences were 74% and 54% for superior labral lesions, 88% and 96% for anterior labral lesions, 67% and 85% for subscapularis tendon tears, and 96% and 75% for supraspinatus-infraspinatus tendon tears. The sensitivity and specificity of the 3D isotropic sequence were 70% and 85% for superior labral lesions, 100% and 100% for anterior labral lesions, 67% and 85% for subscapularis tendon tears, and 96% and 67% for supraspinatus-infraspinatus tendon tears. No statistically significant difference was seen in sensitivities and specificities for both methods. CONCLUSION: Three-dimensional isotropic MR arthrography sequences with multiplanar reconstruction can provide a similar capability for the diagnosis of labral and rotator cuff lesions as conventional MR arthrography sequences but in a shorter imaging time.

Slot-scan digital radiography of the lower extremities: a comparison to computed radiography with respect to image quality and radiation dose.

OBJECTIVE: To compare the slot-scan digital radiography (SSDR) of the lower extremity region and the computed radiography (CR) method with respect to the image quality and radiation exposure. MATERIALS AND METHODS: We enrolled 54 patients who underwent both the SSDR and CR of the lower extremities. The study evaluated and statistically compared the image quality of four features (outer cortex, inner cortex, trabeculae and intermuscular fat) at six different levels (pelvis, hip, femur, knee, tibia and ankle) between each method. The image quality was evaluated using a visibility scale, and the entrance skin dose was measured using a dosimeter at three different levels of a phantom (hip, knee, and ankle). RESULTS: The mean image visibility scale values for the SSDR method were significantly higher than for the CR method. The entrance skin dose for the SSDR method was 278 microGy at each level, compared to the entrance skin doses of the CR method, which were 3,410 microGy for the hip, 1,152 microGy for the knee, and 580 microGy for the ankle. CONCLUSION: Both the image quality and patient entrance skin dose data suggest that the SSDR method is superior to the CR method for the lower extremity musculoskeletal examination.

Comparison study of indirect MR arthrography and direct MR arthrography of the shoulder.

OBJECTIVE: To compare the diagnostic value of indirect magnetic resonance arthrography (I-MRA) with that of direct MR arthrography (D-MRA) for labral tears, rotator cuff tears, and long head of biceps tendon (LHBT) tears using a 3-T MR unit. MATERIALS AND METHODS: Institutional review board approval was given; written informed consent was obtained from all patients. From November 2005 to June 2006, 19 patients (eight men and 11 women; mean age, 51 years) who had undergone both I-MRA and D-MRA underwent arthroscopic surgery. Both methods were performed in fat-saturated axial, coronal oblique, and sagittal oblique T1-weighted sequences, as well as axial and coronal oblique T2-weighted sequences. Two radiologists independently and retrospectively evaluated two sets of MRA for the diagnosis of superior and anterior labral tears, subscapularis tendon (SSC), and supraspinatus-infraspinatus tendon (SSP-ISP) tears, and LHBT tears. With the arthroscopic finding as a gold standard, we analyzed statistical differences of sensitivities and specificities between two sets of MRA and inter-observer agreement was evaluated using the kappa value. RESULTS: The sensitivity and specificity of I-MRA and D-MRA for reader 1 were 79/80% and 71/80%, respectively, for superior labral tears; 100/100% and 100/100%, respectively, for anterior labral tears; 64/75% and 64/100%, respectively, for SSC tears; 100/86% and 100/100%, respectively, for SSP-ISP tears; and 67/100% and 78/100%, respectively, for LHBT tears. Those of I-MRA and D-MRA for reader 2 were 86/80% and 71/100%, respectively, for superior labral tears; 100/83% and 100/100%, respectively, for anterior labral tears; 64/88% and 82/100%, respectively, for SSC tears; 92/86% and 100/100%, respectively, for SSP-ISP tears; and 78/90% and 89/100%, respectively, for LHBT tears. No significant differences were found between the methods. Inter-observer agreements were higher than moderate (kappa > 0.41) with both methods. CONCLUSIONS: Based on a relatively small number of patients, no significant difference was detected between I-MRI and D-MRI with regard rotator cuff, labral, and LHBT tears.

Pelvic bone complications after radiation therapy of uterine cervical cancer: evaluation with MRI.

OBJECTIVE: The purpose of this study was to assess the prevalence and distribution of radiation-induced insufficiency fractures and to investigate other bony complications of the female pelvis associated with radiation therapy using MR images. MATERIALS AND METHODS: Two radiologists retrospectively evaluated pelvic MR images of 510 patients (mean age, 54.7 years) who underwent pelvic irradiation for uterine cervical cancer for the presence and location of insufficiency fractures by consensus. We calculated the cumulative prevalence of pelvic insufficiency fractures on the basis of their results. In addition, we identified other associated bony complications of the female pelvis by reviewing the MR images. RESULTS: Insufficiency fractures were diagnosed in 100 patients; the 5-year cumulative prevalence was 45.2%. An insufficiency fracture was diagnosed a median of 16.9 months after radiation therapy. The fracture sites were the sacrum body and alae, medial side of the iliac bone, the roof of the acetabulum, superior rami of the pubic bone, femoral heads, and L5 vertebra. Sixty-one patients (61%) developed multiple fractures, and among them, 40 (40%) had bilateral symmetric lesions of the sacral alae. Other complications associated with the radiation therapy, as determined by evaluation of the MR images, were osteolysis and avascular necrosis of the femoral head. CONCLUSION: Radiation-induced pelvic insufficiency fractures are a frequent complication of radiation therapy for uterine cervical cancer. Osteolysis and avascular necrosis of the femoral head were also diagnosed using MRI after radiation therapy.

Leakage of polymethylmethacrylate in percutaneous vertebroplasty: comparison of osteoporotic vertebral compression fractures with and without an intravertebral vacuum cleft.

OBJECTIVE: We compared polymethylmethacrylate (PMMA) leakage from vertebral bodies in osteoporotic compression fractures with and without intravertebral vacuum clefts (IVCs) on computed tomography (CT) after vertebroplasty. METHODS: Percutaneous vertebroplasty was performed in 59 patients, comprising 36 compression fractures with IVCs in 33 patients and 49 fractures without IVCs in 26 patients. All patients underwent postprocedural CT of treated and adjacent vertebral bodies. CT findings and clinical complications were assessed retrospectively with regard to the presence of PMMA leakage. When present, leakage types were classified as intradiscal, epidural, foraminal, and perivertebral venous. The frequencies and types of leakages were compared in both groups using chi and Fisher exact tests, respectively. RESULTS: The PMMA leakage occurred in 20 (55.5%) of 36 fractures with IVCs and in 25 (51.0%) of 49 fractures without IVCs, without significant difference (P=0.679). No patients experienced clinical complications. The leakage types that frequently occurred were intradiscal (13/20, 65.0%), perivertebral venous (5/20, 25%), epidural (1/20, 5%), and foraminal (1/20, 5%) in compression fractures with IVCs; and epidural (11/25, 44.0%), intradiscal (6/25, 24%), and perivertebral venous (8/25, 32%) in those without. A significant difference was found between the most frequent types in both groups (P=0.006, P=0.003, respectively). CONCLUSIONS: On CT after vertebroplasty, the incidences of PMMA leakage in osteoporotic compression fractures with and without IVCs were similar; however, leakage type frequencies differed.