Qualitative Analysis on Magnetic Resonance Imaging for Preoperative Evaluation of Chronic Lateral Ankle Ligament Injury

PURPOSE@#To compare the MRI findings of anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) injuries in chronic lateral ankle instability (CLAI) between surgical treatment groups.@*MATERIALS AND METHODS@#Fifty-two patients with CLAI were divided into the modified Broström procedure (MBP) (n = 31) and lateral ankle ligament reconstruction (LAR) (n = 21) groups. T2-weighted MRI findings between the groups were compared for caliber change, slope, signal intensity, and thickness measurements of the ligaments. Additionally, the talar tilt angles were measured on stress radiographs.@*RESULTS@#The injured ATFL (p = 0.002 vs. p = 0.001) and CFL (p = 0.008 vs. p = 0.039) were more commonly scarce or thin and had decreased slopes in the LAR group. The mean thickness of ATFL (P = 0.002) and CFL (p = 0.002) was 1.1 ± 0.9 mm and 1.3 ± 0.8 mm, respectively, in the LAR group and 2.2 ± 1.3 mm and 2.1 ± 0.9 mm, respectively, in the MBP group. The mean talar tilt angle was greater in the LAR group (13.4 ± 3.9°) than in the MBP group (9.5 ± 3.8°) (p = 0.001).@*CONCLUSION@#A qualitative analysis of the ligaments on MRI is valuable in selecting the surgical method.

Intramuscular Epidermal Cyst of the Buttock: A Case Report

Epidermal cysts are common benign subcutaneous lesions that occur in or on the skin. It is not very difficult to diagnose subcutaneous epidermal cysts using ultrasound imaging because they exhibit typical sonographic features. However, the differential diagnosis can be confused when epidermal cysts are found in unusual sites. The authors report a case involving a 4-year-old girl who presented with an intramuscular epidermal cyst in the gluteus maximus muscle. Magnetic resonance imaging revealed characteristic internal features of the epidermal cyst, despite being in an uncommon site, and was very useful in the preoperative diagnosis.

Benign Fibrous Histiocytoma with Cystic Change of the Femur: a Case Report

Benign fibrous histiocytoma (BFH) is a rare benign primary skeletal tumor that occurs commonly in the long bones, spine and pelvis. BFH constitutes a diagnostic challenge because it shares clinical background, radiological characteristics, and histological features with other fibrous lesions such as non-ossifying fibroma, giant cell tumor. We present a case of BFH with cystic change that occurred in the distal femur. We did not identify any case of BFH with cystic change involving the majority of the lesion that occurred in the metaepiphysis of the long bone.

Charcoal-Induced Granuloma That Mimicked a Nodal Metastasis on Ultrasonography and FDG-PET/CT after Neck Dissection

Charcoal can be used for preoperative localization of metastatic lymph nodes in the neck. Charcoal remains stable without causing foreign body reactions during as hort period. However, foreign body reactions may develop if charcoal is left in situ for more than 6 months. We reported a case of charcoal granuloma mimicking local recurrence on fluorodeoxyglucose-positron emission tomography/computed tomography and ultrasonography in a 47-year-old woman who had cervical lymph node dissection due to metastatic invasive ductal carcinoma of the breast.

Time-Resolved 3D Contrast-Enhanced MRA on 3.0T: a Non-Invasive Follow-Up Technique after Stent-Assisted Coil Embolization of the Intracranial Aneurysm

OBJECTIVE: To evaluate the usefulness of time-resolved contrast enhanced magnetic resonance angiography (4D MRA) after stent-assisted coil embolization by comparing it with time of flight (TOF)-MRA. MATERIALS AND METHODS: TOF-MRA and 4D MRA were obtained by 3T MRI in 26 patients treated with stent-assisted coil embolization (Enterprise:Neuroform = 7:19). The qualities of the MRA were rated on a graded scale of 0 to 4. We classified completeness of endovascular treatment into three categories. The degree of quality of visualization of the stented artery was compared between TOF and 4D MRA by the Wilcoxon signed rank test. We used the Mann-Whitney U test for comparing the quality of the visualization of the stented artery according to the stent type in each MRA method. RESULTS: The quality in terms of the visualization of the stented arteries in 4D MRA was significantly superior to that in 3D TOF-MRA, regardless of type of the stent (p < 0.001). The quality of the arteries which were stented with Neuroform was superior to that of the arteries stented with Enterprise in 3D TOF (p < 0.001) and 4D MRA (p = 0.008), respectively. CONCLUSION: 4D MRA provides a higher quality view of the stented parent arteries when compared with TOF.

Optimization of the Contrast Mixture Ratio for Simultaneous Direct MR and CT Arthrography: an in Vitro Study

OBJECTIVE: This study was designed to determine the optimal mixture ratio of gadolinium and iodinated contrast agent for simultaneous direct MR arthrography and CT arthrography. MATERIALS AND METHODS: An in vitro study was performed utilizing mixtures of gadolinium at six different concentrations (0.625, 1.25, 2.5, 5.0, 10 and 20 mmol/L) and iodinated contrast agent at seven different concentrations (0, 12.5, 25, 37.5, 50, 75 and 92-99.9%). These mixtures were placed in tissue culture plates, and were then imaged with CT and MR (with T1-weighted sequences, proton-density sequences and T2-weighted sequences). CT numbers and signal intensities were measured. Pearson's correlation coefficients were used to assess the correlations between the gadolinium/iodinated contrast agent mixtures and the CT numbers/MR signal intensities. Scatter diagrams were plotted for all gadolinium/iodinated contrast agent combinations and two radiologists in consensus identified the mixtures that yielded the optimal CT numbers and MR signal intensities. RESULTS: The CT numbers showed significant correlation with iodinated contrast concentrations (r = 0.976, p < 0.001), whereas the signal intensities as measured on MR images showed a significant correlation with both gadolinium and iodinated contrast agent concentrations (r = -484 to -0.719, p < 0.001). A review of the CT and MR images, graphs, and scatter diagram of 42 combinations of the contrast agent showed that a concentration of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was the best combination for simultaneous CT and MR imaging. CONCLUSION: A mixture of 1.25 mmol/L gadolinium and 25% iodinated contrast agent was found to be optimal for simultaneous direct MR arthrography and CT arthrography.

Grading Anterior Cruciate Ligament Graft Injury after Ligament Reconstruction Surgery: Diagnostic Efficacy of Oblique Coronal MR Imaging of the Knee

OBJECTIVE: The purpose of this study was to evaluate the diagnostic efficacy of using additional oblique coronal MRI of the knee for grading anterior cruciate ligament (ACL) graft injury after ligament reconstruction surgery. MATERIALS AND METHODS: We retrospectively reviewed 51 consecutive MR knee examinations of 48 patients who underwent both ACL reconstruction and follow-up arthroscopy. The MR examinations included the orthogonal axial, sagittal, coronal images and the oblique coronal T2-weighted images, which were oriented in parallel with the course of the femoral intercondylar roof. Two radiologists independently evaluated the status of the ACL grafts with using the routine knee MRI and then with adding the oblique coronal imaging. The severity of ACL graft injury was graded using a 3-point system from MR images as intact, partial tear or complete tear, and the results were compared with the arthroscopic results. Weighted kappa statistics were used to analyze the diagnostic accuracies of the knee MRI with and without the additional oblique coronal imaging. For each evaluation, the observers reported a confidence level for grading the ACL graft injuries in the two imaging groups. RESULTS: The weighted kappa values according to the routine knee MRI were 0.555 (reader 1) and 0.515 (reader 2). The inclusion of additional oblique coronal imaging increased the weighted kappa values to 0.666 (reader 1) and 0.611 (reader 2). The mean confidence levels by each reader were significantly higher (p < 0.01, paired t-test) with the additional oblique coronal imaging than by using the routine knee MRI alone. CONCLUSION: The additional use of oblique coronal MRI of the knee improves both the diagnostic accuracy and confidence for grading ACL graft injury.

Focal Sparing of the Fatty Liver Caused by a Nontumorous Arterioportal Shunt

We present two cases of focal fatty sparing caused by a nontumorous arterioportal shunt. Two patients underwent ultrasonography (US) as a part of routine medical screening, which revealed a hypoechoic lesion in the diffuse fatty liver. Each lesion appeared to be an arterioportal shunt on triphasic mutidetector computed tomography (CT) and was seen as being slightly hyperdense on noncontrast CT. No tumors were delineated around or within the arterioportal shunt. Both lesions remained unchanged on six-month follow-up US.

Transforaminal Epidural Steroid Injection for Lumbosacral Radiculopathy: Preganglionic versus Conventional Approach

OBJECTIVE: The present study was undertaken to evaluate the effectiveness of transforaminal epidural steroid injection (TFESI) with using a preganglionic approach for treating lumbar radiculopathy when the nerve root compression was located at the level of the supra-adjacent intervertebral disc. MATERIALS AND METHODS: The medical records of the patients who received conventional TFESI at our department from June 2003 to May 2004 were retrospectively reviewed. TFESI was performed in a total of 13 cases at the level of the exiting nerve root, in which the nerve root compression was at the level of the supra-adjacent intervertebral disc (the conventional TFESI group). Since June 2004, we have performed TFESI with using a preganglionic approach at the level of the supra-adjacent intervertebral disc (for example, at the neural foramen of L4-5 for the L5 nerve root) if the nerve root compression was at the level of the supra-adjacent intervertebral disc. Using the inclusion criteria described above, 20 of these patients were also consecutively enrolled in our study (the preganglionic TFESI group). The treatment outcome was assessed using a 5-point patient satisfaction scale and by using a VAS (visual assessment scale). A successful outcome required a patient satisfaction scale score of 3 (very good) or 4 (excellent), and a reduction on the VAS score of > 50% two weeks after performing TFESI. Logistic regression analysis was also performed. RESULTS: Of the 13 patients in the conventional TFESI group, nine showed satisfactory improvement two weeks after TFESI (69.2%). However, in the preganglionic TFESI group, 18 of the 20 patients (90%) showed satisfactory improvement. The difference between the two approaches in terms of TFESI effectiveness was of borderline significance (p = 0.056; odds ratio: 10.483). CONCLUSION: We conclude that preganglionic TFESI has the better therapeutic effect on radiculopathy caused by nerve root compression at the level of the supra-adjacent disc than does conventional TFESI, and the diffence between the two treatments had borderline statistical significance.

Value of Preoperative Cervical Discography

PURPOSE: The aim of this study was to describe the method and the value of cervical discography as correlated with the MR findings. MATERIALS AND METHODS: Twenty-one discs in 11 consecutive patients who underwent cervical discography were analyzed. MR and CT discography (CTD) were performed in all patients. Discography was performed after swallowing barium for visualizing the pharynx and the esophagus to prevent penetration. We also analyzed the preceding causes of the subjects' cervical pain. The results of the pain provocation test were classified into concordant pain, discordant pain and a negative test. MRI was analyzed according to the T2-signal intensity (SI) of the disc, disc height, annular bulging and disc herniation. The CTD was analyzed for degeneration or radial tear of the disc, epidural leakage of the contrast agent and pooling of the contrast agent at the periphery of the disc. The pain provocation tests were correlated with the MR and CTD findings. We used the chi-square test to analyze the results. RESULTS: Concordant pain was observed in 14 cases, discordant pain in 3 cases and there were negative tests in 4 cases. There were no complications related to the procedure. Four patients had undergone anterior cervical fusion and four patients had pain that developed after traffic injuries. The decreased T2-SI and annular bulging on MRI, disc degeneration and peripheral pooling of the contrast agent on CT were significantly correlated with pain provocation. CONCLUSION: When the diagnosis of disc disease is difficult with performing MRI, cervical discography with using swallowed barium solution to reduce the penetration of the esophagus or hypopharynx may play be helpful. The decreased T2-SI and annular bulging on MRI correlated significantly with a positive result on the pain provocation test.

Pelvic Fistulas Complicating Pelvic Surgery or Diseases: Spectrum of Imaging Findings

Pelvic fistulas may result from obstetric complications, inflammatory bowel disease, pelvic malignancy, pelvic radiation therapy, pelvic surgery, or other traumatic causes, and their symptoms may be distressing. In our experience, various types of pelvic fistulas are identified after pelvic disease or pelvic surgery. Because of its close proximity, the majority of such fistulas occur in the pelvic cavity and include the vesicovaginal, vesicouterine, vesicoenteric, ureterovaginal, ureteroenteric and enterovaginal type. The purpose of this article is to illustrate the spectrum of imaging features of pelvic fistulas.