Oblique Coronal Images Research Articles

Width of High Signal and Extension Posterior to Biceps Tendon as Signs of Superior Labrum Anterior to Posterior Tears on MRI and MR Arthrography

The purpose of our study was to determine the accuracy of two signs for superior labrum anterior to posterior (SLAP) tears: increased width of high signal between the superior labrum and glenoid, and high signal posterior to the biceps tendon. Forty-one patients with SLAP tears and 40 patients without a tear at surgery who had undergone MRI or MR arthrography were retrospectively evaluated. The MR studies were combined and interpreted in a blinded manner. The reviewers measured the width of high signal that extended to the articular surface on oblique coronal images and determined whether the high signal extended posterior to the biceps. A Student's t test was used to determine statistical significance between the means of the signal width. High-signal width was greater in patients with a SLAP tear than in the control group on both MRI and MR arthrography (both p = 0.003). The sensitivity and specificity of at least 2.0 mm on MRI are 39% (11/28) and 89% (24/27) and at least 2.5 mm on MR arthrography are 46% (6/13) and 85% (11/13). The sensitivity and specificity of high signal posterior to the biceps are 54% (15/28) and 74% (20/27) on MRI and 69% (9/13) and 54% (7/13) on MR arthrography. Increased width of high signal has a moderate specificity but a poor positive predictive value for distinguishing a SLAP tear from a normal recess. In addition, labral signal posterior to the biceps tendon is not rare in patients with no SLAP tear.

Coronal oblique turbo STIR imaging of the sacrum and sacroiliac joints at routine MR imaging of the lumbar spine

The objective of the study was to evaluate the clinical impact of coronal oblique imaging of the lumbrosacral junction and the sacrum at initial presentation for MR imaging of the lumbar spine in patients presenting with low back pain or sciatic pain. Two hundred and sixty consecutive patients attending for MRI of the lumbar spine underwent simultaneous coronal oblique turbo short tau inversion recovery (STIR; TR 2500, TE 40, TI 150, echo train length 7, number of scan acquisitions 2) imaging of the sacrum and the sacroiliac joints with a field of view of 30-cm and 3-mm slices (acquisition time 3 min and 20 s). Images were reviewed by two experienced radiologists to determine the cause of back pain, with and without images of the sacrum and sacroiliac joints. The added value of the additional sequence was assessed. Correlation was made with surgery, response to nerve root injection or clinical follow-up at 3 months. Subgroup analysis was performed to determine if patient stratification according to sex or symptoms would be useful. In total, in 19 of 260 patients (7.3%), abnormalities were identified at coronal STIR imaging. In 7 of 260 patients (2.7%), pathology was identified in the sacrum thought to account for back pain, altering the diagnosis made on the standard sequences. These diagnoses were sacroiliitis (n=2), sacral stress fracture (n=1), degenerative sacroiliac joints (n=1), degenerative accessory articulation between the lumbar spine and the sacrum (n=1), Tarlov cyst of nerve root (n=1) and retroverted uterus causing sciatic pain (n=1). Patient stratification according to sex or the presence or absence of sciatic symptoms was not useful in predicting the added benefit of the additional sequence. Routine coronal STIR imaging of the sacrum as part of lumbar spine MRI improves assessment of patients presenting with low back pain or sciatica in only a small number of patients.

Adhesive capsulitis of the shoulder: evaluation with MR arthrography

The purpose of this study was to determine the usefulness of magnetic resonance (MR) arthrography for diagnosing adhesive capsulitis. Shoulder MR images of 28 patients with (n=14) and without (n=14) adhesive capsulitis were retrospectively analyzed. MR images were assessed for capsule and synovium thickness as well as the width of the axillary recess on oblique coronal fat-suppressed T1-weighted images and T2-weighted images, respectively. On oblique sagittal fat-suppressed T1-weighted images, the width of the rotator interval and the presence of abnormal tissue in the interval were evaluated. Significant differences were found between the two groups in capsule and synovium thickness on both sides of the recess on oblique coronal T2-weighted images (P=0.000), whereas thickness on the humeral aspect showed no significant difference on oblique coronal fat-suppressed T1-weighted images (P=0.109). On oblique coronal T2-weighted images, a cut-off value of 3-mm thickness gave the highest diagnostic accuracy for adhesive capsulitis with sensitivity, specificity, and accuracy of 79% (11/14), 100% (14/14), and 89% (25/28) at the humeral side and 93% (13/14), 86% (12/14), and 89% (25/28) at the glenoid side, respectively. There were significant differences in rotator interval width, presence of abnormal tissue in the rotator interval, and axillary recess width between the two groups (P<0.05). Thickness of capsule and synovium of the axillary recess greater than 3 mm is a practical MR criterion for diagnosing adhesive capsulitis when measured on oblique coronal T2-weighted MR arthrography images without fat suppression. The presence of abnormal tissue in the rotator interval showed high sensitivity but rather low specificity.

Diagnostic Value of Multislice Computed Tomography for Pancreas Divisum

To assess the capabilities of high-resolution oblique coronal reconstruction images obtained by multislice computed tomography (CT) in diagnosing pancreas divisum. This study included 11 patients with and 53 without pancreas divisum confirmed by direct cholangiopancreatography. Two blinded readers retrospectively interpreted oblique coronal reconstruction images with 0.5-mm continuous slices generated from isotropic or nearly isotropic pancreatic phase images with the scrolling mode and assessed the continuity of the ventral pancreatic duct, dorsal pancreatic duct, and main pancreatic duct in the body. The results were correlated with the findings of direct cholangiopancreatography. Other abnormal findings of the pancreatobiliary region on CT were also recorded in patients with pancreas divisum. The sensitivity and specificity of CT for diagnosing pancreas divisum were 100% and 89%, respectively. Computed tomography demonstrated all associated pancreatobiliary diseases. High-resolution oblique coronal reconstruction images allow us to make a diagnosis of pancreas divisum by depicting the continuity of the pancreatic ducts.

Three-Dimensional Demonstration of the Artery of Adamkiewicz With Contrast-Enhanced Magnetic Resonance Angiography

An ascending aortic graft replacement for a Stanford type A aortic dissection was performed on a 58-year-old male. One year later the diameter of the descending aorta reached 60 mm. He was again hospitalized for a second descending aortic replacement. For preoperative assessment a contrast-enhanced magnetic resonance angiography (MRA) was requested in order to determine the level of the artery of Adamkiewicz (AdA) which supplies the anterior spinal artery. A three-dimensional (3D) fast-spoiled gradient-echo (fast-SPGR) technique with fat suppression using a 1.5T superconducting imager (Signa, GE Medical Systems, Milwaukee, WI) was applied with the voxel size being 0.50 × 0.47 × 0.44 mm. Fifteen milliliters of Gd-DTPA (Magnevist, Shering, Berlin, Germany) were injected into the antecubital vein. All the scanned data were transferred to a workstation (ZIO-M900, ZIOsoft, Tokyo, Japan). Multiplanar reconstruction (MPR), maximum intensity projections (MIP), and 3D volume rendering techniques were applied. The oblique coronal MPR image (Fig 1; T10 = tenth thoracic vertebra) illustrates the AdA (arrow) and the posterior branch of the tenth intercostal artery (arrowhead). An axial partial MIP image (Fig 2) illustrates the left tenth intercostal artery (arrow) originating from the false lumen (F) and the right tenth intercostal artery originating from the true lumen (T). A thirty-degree right anterior oblique 3D volume rendering image was obtained (Fig 3 ; the true lumen: red, the false lumen: blue, AdA and anterior spinal artery: purple). This image clearly demonstrated the continuity between the left tenth intercostal artery which originated from the false lumen and the anterior spinal artery. The detection rate of AdA in chronic dissection is 50% by MRA. Selective intercostal and lumbar arteriography was undertaken to depict preoperative anatomy although it was not indicated in the patient with a dissecting aortic aneurysm. MRA may better depict the AdA clearly and provide valuable information for surgical management.Fig 2View Large Image Figure ViewerDownload (PPT)Fig 3View Large Image Figure ViewerDownload (PPT)

Variations in pulmonary venous drainage to the left atrium: implications for radiofrequency ablation.

To evaluate and classify the various drainage patterns of the pulmonary veins as depicted with thin-section chest computed tomography (CT). Thin-section (2.5-mm collimation) contrast material-enhanced CT scans of 201 consecutive patients obtained over a 3-month period for diagnosis of pulmonary embolism (n = 197), pulmonary vein stenosis (n = 2), or aortic injury (n = 2) were routinely reviewed in transverse and (if necessary) coronal and coronal-oblique imaging planes. A classification was formulated based on both the number of venous ostia on each side and the drainage patterns of pulmonary veins. The frequency of each pattern was determined, and association with atrial arrhythmia was assessed with the chi(2) and Fisher exact tests. Most patients (n = 142, 71%) had two ostia on the right side for upper and lower lobe veins. Fifty-six patients (28%) had three to five ostia on the right side, which were due to one or two separate middle lobe vein ostia in 52 (26%) patients. Three patients (2%) had a single venous ostium on the right side. Most patients (n = 173, 86%) had two ostia on the left side for upper and lower lobe veins. The remainder (n = 28, 14%) had a single ostium. There was no significant association between any particular venous drainage pattern and atrial arrhythmia; however, patients with a separate ostia for the right middle lobe pulmonary vein(s) tended to have a higher frequency of atrial arrhythmia than those with other patterns (P =.053). A classification system to succinctly describe pulmonary venous drainage patterns was developed. Right-sided venous drainage was more variable than left-sided venous drainage. One-quarter of patients had more than two venous ostia on the right side.

CT Arthrography and Virtual Arthroscopy in the Diagnosis of the Anterior Cruciate Ligament and Meniscal Abnormalities of the Knee Joint

ObjectiveTo determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology.Materials and MethodsThirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images.ResultsThe sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively.ConclusionCT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.

Driven equilibrium (drive) MR imaging of the cranial nerves V–VIII: comparison with the T2-weighted 3D TSE sequence

Purpose: The aim of this study is to evaluate the efficacy of the driven equilibrium radio frequency reset pulse (DRIVE) on image quality and nerve detection when used in adjunction with T2-weighted 3D turbo spin-echo (TSE) sequence. Materials and methods: Forty-five patients with cranial nerve symptoms referable to the cerebellopontine angle (CPA) were examined using a T2-weighted 3D TSE pulse sequence with and without DRIVE. MR imaging was performed on a 1.5-T MRI scanner. In addition to the axial resource images, reformatted oblique sagittal, oblique coronal and maximum intensity projection (MIP) images of the inner ear were evaluated. The nerve identification and image quality were graded for the cranial nerves V–VIII as well as inner ear structures. These structures were chosen because fluid-solid interfaces existed due to the CSF around (the cranial nerves V–VIII) or the endolymph within (the inner ear structures). Statistical analysis was performed using the Wilcoxon test. P<0.05 was considered significant. Results: The addition of the DRIVE pulse shortens the scan time by 25%. T2-weighted 3D TSE sequence with DRIVE performed slightly better than the T2-weighted 3D TSE sequence without DRIVE in identifying the individual nerves. The image quality was also slightly better with DRIVE. Conclusion: The addition of the DRIVE pulse to the T2-weighted 3D TSE sequence is preferable when imaging the cranial nerves surrounded by the CSF, or fluid-filled structures because of shorter scan time and better image quality due to reduced flow artifacts.

Curvature analysis of the mandibular condyle.

To determine whether curvature analysis on high resolution CT images can be used as a tool for evaluation of mandibular condyle morphology. Curvature analysis was performed on reconstructed oblique coronal CT images of 634 normal condyles from 317 patients (144 men and 173 women; age range 4-89 years) with inner or middle ear disease. The condyles were scanned with 1 mm collimation using helical CT. The CT images were analysed manually on a personal computer. The condyle CT images could be categorized into five curvature profile patterns: (1) bi-peak; (2) no peak; (3) tri-peak; (4) bi-peak with an intervening bottom above the base line (bi-peak with a col); and (5) bi-peak with an intervening negative phase. A separate evaluation using computer graphic condyle models indicated that these curvature patterns corresponded to flat (bi-peak), round (no peak), convex (bi-peak with a col), concave (bi-peak with a negative phase) and angled (tri-peak) contours of the condyle's superior surface. The curvature profiles were identical between bilateral condyles in 40% (126/317) of the patients. Gender-related differences in the incidence of the curvature profiles were also found, the bi-peak with a col profile being more frequently observed in women and the bi-peak with a negative phase profile being observed more frequently in men. Curvature analysis on CT images depicts condyle morphology effectively and may be an adjunctive tool for condyle morphometry.

Disk position and the bilaminar zone of the temporomandibular joint in asymptomatic young individuals by magnetic resonance imaging.

The purpose was to study the disk position of the temporomandibular joint (TMJ) in young individuals without any clinical signs or symptoms or history of internal derangement or degenerative joint disease and to study the features of the bilaminar zone of the TMJ in sagittal magnetic resonance (MR) images and the behavior of the bilaminar zone during jaw opening. MR imaging examinations of 80 TMJs of 40 symptom-free healthy subjects (20 women and 20 men) with a mean age of 26.9 years formed the basis of this study. In 33 of the 40 symptom-free subjects (82.5%), there was a normal relationship between disk and condyle at occlusion, whereas 5 individuals had unilateral disk displacement and 2 had bilateral disk displacement. The superior part of the bilaminar zone could be identified in all of the 40 symptom-free subjects. The inferior band of the bilaminar zone was identified bilaterally in 57.5% of individuals and unilaterally in 20%. In 9 subjects, the inferior band of the bilaminar zone could not be identified in any of the TMJs. Disk displacement of the TMJ occurred in approximately 20% of the young individuals in this sample. The use of both sagittal and oblique coronal MR images is of importance for classification of the position of the disk in that the oblique coronal imaging plane rendered significant complementary information to that of the sagittal images. The identification of both the superior and the posterior band of the bilaminar zone must be considered new information. The superior band remained consistently in contact with the fossa at the open-mouth position.

Clinical Utility and Role of Magnetic Resonance Cholangiography in the Evaluation of Choledocholithiasis Prior to Laparoscopic Cholecystectomy

Purpose: To compare the findings of MR cholangiography with those of ultrasound and biochemistry in patients with suspected choledocholithiasis, and to evaluate the clinical utility and role of MR cholangiography prior to laparoscopic cholecystectomy. Materials and Methods: We retrospectively reviewed the radiologic findings and clinical records of 103 consecutive patients in whom choledocholithiasis was suspected and who underwent both ultrasound and MR cholangiography. For MR imaging, a 1.5T unit was used, and axial T1-FLASH, True FISP, and oblique coronal HASTE and RARE images were obtained. Initial biochemical values (AST, ALT, total bilirubin) were correlated with the findings of MR cholangiography. Results: Choledocholithiasis was present in 36 of 103 patients: overall, there were 34 true-positive, 63 truenegative, four false-positive, and two false-negative results. In the detection of choledocholithiasis, MR cholangiography showed the following characteristics: sensitivity, 94%; specificity, 94%; positive predictive value, 89%; negative predictive value, 96%; accuracy, 95%. Calculi in the common bile duct were detected in 3 of 33 patients (9%) in whom ultrasound showed that the caliber of the common bile duct was normal and whose laboratory findings were normal, and in 12 of 43 (28%) of those whose common bile duct was dilatated or whose laboratory values were abnormal. Calculi were present in the common bile duct of 21 of 27 patients (78%) with abnormal laboratory values and abnormal ultrasound findings. Conclusion: Choledocholithiasis was detected in 25% of patients without clinical suspicion and was not present in 25% of patients with strong clinical suspicion. In patients with this condition, MR cholangiography is noninvasive and accurate, and we suggest that in patients with suspected choledocholithiasis, it should be a routine diagnostic procedure prior to laparoscopic cholecystectomy.

MRI Differential Diagnosis of Complete and Partial Tears of the Anterior Cruciate Ligament of the Knee: The Usefulness of Oblique Coronal T2-Weighted Image

Purpose: To assess the usefulness of T2-weighted oblique coronal MR imaging (T2OCI) in the differential diagnosis of complete and partial tears of the anterior cruciate ligament (ACL) of the knee. Materials and Methods: Thirty-three patients with ACL tear (16 complete and 17 partial tears), comfirmed by arthroscopy, were included in this study. Conventional MR imaging and T2OCI were performed, and the findings were retrospectively reviewed by two radiologists in terms of continuity, shape, axis and internal signal intensity of the ligament. Each finding was tested if there were stastistically significant differences in its prevalence between partial and complete tears. The diagnostic accuracy of T2OCI and conventional MR imaging in the detection of partial and complete tears of the ACL were compared. Results: Conventional MR imaging revealed no statistically significant finding for differential diagnosis of complete and partial ACL tears. The reliable and statistically significant (p

Hippocampal sclerosis: correlation of MR imaging findings with surgical outcome.

ObjectiveAtrophy and a high T2 signal of the hippocampus are known to be the principal MR imaging findings of hippocampal sclerosis. The purpose of this study was to determine whether or not individual MRI findings correlate with surgical outcome in patients with this condition.Materials and MethodsPreoperative MR imaging findings in 57 consecutive patients with pathologically-proven hippocampal sclerosis who underwent anterior temporal lobectomy and were followed-up for 24 months or more were retrospectively reviewed, and the results were compared with the postsurgical outcome (Engel classification). The MR images included routine sagittal T1-weighted and axial T2-weighted spin-echo images, and oblique coronal T1-weighted 3D gradient-echo and T2-weighted 2D fast spin-echo images obtained on either a 1.5 T or 1.0 T unit. The images were visually evaluated by two neuroradiologists blinded to the outcome; their focus was the presence or absence of atrophy and a high T2 hippocampal signal.ResultsHippocampal atrophy was seen in 96% of cases (55/57) [100% (53/53) of the good outcome group (Engel class I and II), and 50% (2/4) of the poor outcome group (class III and IV)]. A high T2 hippocampal signal was seen in 61% of cases (35/57) [62% (33/53) of the good outcome group and 50% (2/4) of the poor outcome group]. All 35 patients with a high T2 signal had hippocampal atrophy. 'Normal' hippocampus, as revealed by MR imaging, occurred in 4% of patients (2/57), both of whom showed a poor outcome (Engel class III). The presence or absence of hippocampal atrophy correlated well with surgical outcome (p<0.01). High T2 signal intensity did not, however, significantly correlate with surgical outcome (p>0.05).ConclusionCompared with a high T2 hippocampal signal, hippocampal atrophy is more common and correlates better with surgical outcome. For the prediction of this, it thus appears to be the more useful indicator.

MR arthrography of the labral capsular ligamentous complex in the shoulder: imaging variations and pitfalls.

Using MR arthrography, we examined normal anatomy, anatomic variations, and pitfalls of imaging the labral capsular ligamentous complex in the asymptomatic shoulder. We obtained 108 MR arthrograms of the glenohumeral joint in 95 asymptomatic volunteers with axial (108 shoulders) and oblique coronal (56 shoulders) images. We examined labral shape, patterns of capsular insertion, presence or absence of glenohumeral ligaments, and pitfalls of imaging. Our patients were men (auxiliary policemen) between 19 and 24 years old (mean age, 21 years). The shapes of labra were triangular (anterior part, 64%; posterior part, 47%), round (17%; 33%), flat (2%; 17%), cleaved (11%; 1%), notched (3%; 0%), or absent (2%; 2%). Using the system of Mosely and Overgaard, the anterior capsular insertion was type 1 in 63% of shoulders, type 2 in 20%, and type 3 in 17%; the posterior capsular insertion was type 1 in 60% of shoulders, type 2 in 31%, and type 3 in 9%. The superior and inferior glenohumeral ligaments were present in 99% of shoulders, but the middle glenohumeral ligament was present in only 79%. We also detected many pitfalls of MR imaging in identifying findings such as the undercutting of the labrum by cartilage (32% of shoulders), prominent axillary folds (46%), sublabral holes (7%) or recesses (33%), Buford complexes (2%), and sulci between the biceps tendon and superior labrum (30%). Knowledge of normal anatomy and anatomic variations of the labral complex is important for the examination of the shoulder with MR arthrography.

Tear of the peroneus longus tendon: MR imaging features in nine patients.

To determine the magnetic resonance (MR) imaging features that characterize tear of the peroneus longus tendon at the midfoot. Medical records and MR images in nine patients with a tear of the middle segment of the peroneus longus tendon were retrospectively reviewed. All nine patients had undergone routine ankle MR imaging; three had undergone additional oblique coronal MR imaging. Surgical proof of a tear was available for three patients. Partial tear was present in four patients, and complete tear was present in five. Partial tears were characterized by heterogeneous signal intensity and thickening of the tendon. Complete tears were characterized by discontinuity of the tendon. Additional findings included fluid in the tendon sheath (n = 6), marrow edema of the lateral calcaneal wall (n = 3), enlarged peroneal tubercle (n = 3), and tear of the peroneus brevis tendon (n = 2). The extent of the tear was better assessed with oblique coronal MR images. The characteristic MR imaging appearance of complete or partial tear of the middle portion of the peroneus longus tendon includes foci of increased signal intensity in the distal tendon, morphologic alterations, and/or discontinuity of tendon. Bone marrow edema along the lateral calcaneal wall may be suggestive of the diagnosis. Additional oblique coronal midfoot MR images may help in assessment of the extent of the tear.

Shoulder after rotator cuff repair: MR imaging findings in asymptomatic individuals--initial experience.

To assess the magnetic resonance (MR) imaging appearance of the successfully repaired rotator cuff in an asymptomatic population. Fifteen subjects who had undergone clinically successful rotator cuff repair were included in the study. All underwent functional testing of the affected shoulder and had good to excellent scores on the Constant scale. Standard MR imaging sequences were performed at 1.5 T, including oblique coronal fast spin-echo T2-weighted MR imaging with fat saturation. Three (10%) of 30 supraspinatus and infraspinatus tendons had normal signal intensity, and 16 (53%) had mildly increased signal intensity on fast spin-echo T2-weighted fat-saturated images, compatible with tendonitis or tendinosis. Three partial and four complete tears of the supraspinatus tendon and two partial and two complete tears of the infraspinatus tendon were seen. Other findings included subacromial-subdeltoid effusion (10 subjects), joint effusions (five subjects), and bone marrow edema (six subjects). Postoperative signal intensity changes consistent with tendonitis or tendinosis were common, and clinically "silent" partial and complete rotator cuff tears were seen. Such postoperative MR imaging findings should be interpreted with caution, and meticulous correlation with symptoms and clinical results is recommended.

Magnetic resonance imaging evaluation of muscle usage associated with three exercises for rotator cuff rehabilitation.

Methods of determining muscle usage for exercises involving rotator cuff muscles are limited. Therefore, this investigation used magnetic resonance imaging (MRI) to evaluate the effect of three different exercises used for rehabilitation of the rotator cuff. Five normal volunteer subjects (3 men, 2 women, mean age 31.4 yr) were studied. The exercises were scaption with internal rotation (SIR), military press (MP), and side-lying 45 degrees abduction (SLA). MR imaging was performed immediately before and after exercise using a "fast" spin echo STIR sequence and oblique coronal plane imaging. Changes in signal intensity pre- and post-exercise were measured at comparable section locations for the MR images of the supraspinatus, infraspinatus, teres minor, subscapularis, deltoid, and trapezius. The SLA showed the greatest increase in signal intensity in all the muscles (percent change, P < 0.01) except for the trapezius, which was used more by the MP and SIR. None of the exercises activated the teres minor (percent change, P = not significant). These findings have important implications in efficacy of physical rehabilitation of the rotator cuff and avoidance of subacromial impingement exercise motions.

Posteromedial corner of the knee: MR imaging with gross anatomic correlation

The objective of this study was to illustrate the magnetic resonance (MR) image appearance of the structures of the posteromedial "corner" of the knee with particular emphasis on the anatomy and differentiation between the medial collateral ligament and the posterior oblique ligament. Six cadaveric knee specimens underwent MR imaging, before and following instillation of intra-articular contrast material. The knees were sectioned in the axial, coronal, and coronal oblique planes and the gross morphology of the posteromedial corner and surrounding structures was studied and correlated with the MR images. The human cadaveric specimens were from two female and four male patients (age at death, 72-86 years; average, 78 years). The contrast-enhanced sequences and the coronal oblique images allowed for improved visualization of the structures.

Evaluation of the Size of Rotator Cuff Tear on Oblique Coronal MR Imaging

Evaluation of the Size of Rotator Cuff Tear on Oblique Coronal MR Imaging

Usefulness of 3D CISS Sequence in MR Imaging of Cervical Spine

Purpose : To assess the value of 3D CISS (constructive interference in steady state) MR sequence in imaging the cervical spine. Materials and Methods : MR images of cervical spine were prospectively obtained with both conventional (sagittal TSE and axial 2D FLASH) and CISS sequences in 20 patients suspected of having cervical spinal diseases. MR technique was performed on a 1.5T MR machine. Axial, oblique coronal, and curved coronal images were reformatted with the 3D raw datas of CISS sequence which were obtained in cornal plane. The findings of CISS sequence were compared with those of the conventional sequence in terms of visualization of the neural foramen and nerve roots, detection and differentiation of herniated disc, conspicuity of the intramedullary lesion, contrast between the CSF and spinal cord and between the gray and white matters within the cord. Results : In 17 cases including traumatic root avulsions, 3D CISS sequence demonstrated the intradural nerve roots with excellent contrast especially in coronal plane. Reformatted oblique coronal images of CISS sequence offered better visualization of entire neural foramen beyond the region of interest. CISS sequence was superior to the conventional sequence in demonstration of disease extent and correlation to the clinical symptoms in 4.5 cases of foraminal stenosis and in contrast between the CSF and spinal cord (n=15). CISS sequence was almost equal to the conventional sequence in detection of herniated disc (n=15). CISS was inferior to the conventional sequence in differentiation of herniated disc (n=7), delineation of intramedullary lesion (n=4) and in contrast between the gray and white matter within the cord in all patients. Conclusion : The 3D CISS sequence gives better information than the conventional sequence especially in the evaluation of the nerve roots and neural foramens but worse contrast of intramedullary lesion. It may well be used as a supplementary sequence in assessment of foraminal stenosis and nerve root injury.