History,clinical findings,magnetic resonance imaging,and arthroscopic correlation in meniscal lesions

Purpose  

The aim of this prospective study was to compare the accuracy of clinical examination and magnetic resonance imaging (MRI) versus arthroscopic findings and to determine the value of an experienced examiner in clinical decision making.     

Factors affecting meniscal extrusion: correlation with MRI, clinical, and arthroscopic findings

The existence of meniscal extrusion is well known in the natural history of the osteoarthritic knee. However, extruded menisci are also seen in non-pathologic knees. To ascertain the prevalence of meniscal extrusion in non-arthritic patients, the MRIs of 100 knees were prospectively studied. The data were correlated both with clinical and operative arthroscopic findings. The results showed 68.5% of the medial menisci to have some degree of extrusion, averaging at 28% of the meniscal size. While the lateral meniscus were extruded in 18.8% of cases at an average of 15% of the meniscal size. Furthermore, a relationship between the anterior insertion variant of the anterior medial meniscus and meniscal extrusion was found (P=0.001) in this series. The results suggest meniscal extrusion to be much more common in non-arthritic knees than previously estimated. The results also suggest that when the anterior horn of the medial meniscus inserts anteriorly in the tibial plateau, the meniscus tends to be extruded. It must be kept in mind that one of the limitations of this work is that the MRIs are taken in a non-weightbearing position.     

Reactive synovitis of the knee joint: MR imaging appearance with arthroscopic correlation

Objective. To evaluate the use of routine MR imaging sequences in detecting and characterizing secondary reactive synovitis of the knee joint using arthroscopy as the standard of reference. Design and patients. Fifty consecutive patients with a history of knee pain who were referred for MR imaging and subsequently underwent arthroscopy of the knee comprised the study group. MR images were evaluated for the presence and appearance of synovitis reflected in synovial thickening and irregularity. Synovial thickening was graded on MR imaging as follows: 0=normal, 1=thin line of increased signal intensity, 2=increased signal intensity with frond-like or hair-like projections and a granular appearance of joint fluid. Standard knee imaging protocols were used. Results. The sensitivity, specificity, and accuracy of MR imaging in detecting synovitis compared with arthroscopy were 88%, 97%, and 95%, respectively. Grade 1 synovitis was best seen on proton-density-weighted images, demonstrating increased signal intensity of the synovium against the relatively low signal intensity of the joint fluid. Grade 2 synovitis was best seen on proton-density images and T2-weighted spin echo and fast spin echo images with fat saturation, demonstrating a granular and linear hair-like appearance of joint fluid. Axial and sagittal imaging planes were most helpful in the diagnosis of synovitis. Conclusion. Routine MR pulse sequences are useful in identifying the presence and extent of synovial abnormalities. The detection of different stages of synovial pathology should become an important part of the evaluation of the post-traumatic patient as treatment may be altered as a result. Received: 17 March 2000 Revision requested: 5 May 2000 Revision received: 8 June 2000 Accepted: 8 June 2000     

Brain in eclampsia: MR imaging with clinical correlation

Cranial magnetic resonance (MR) imaging was performed on eight consecutive patients with generalized tonic-clonic seizures caused by eclampsia. Each patient underwent serial neurologic examinations until all symptoms resolved. Six of those eight patients underwent follow-up MR imaging. These patients were compared with those in previous case reports of MR imaging abnormalities of the brain in eclampsia. MR imaging typically demonstrates bilateral hyperintense lesions on T2-weighted images and iso- to hypointense lesions on T1-weighted images. MR imaging abnormalities are most commonly located in the distribution of the posterior cerebral circulation and are associated with visual disturbances. Basal ganglia and deep white matter lesions are less common and are associated with mental status changes. Most lesions seen at MR imaging in patients with eclampsia are reversible.     

MR accuracy and arthroscopic incidence of meniscal radial tears

OBJECTIVE: A meniscal radial tear is a vertical tear that involves the inner meniscal margin. The tear is most frequent in the middle third of the lateral meniscus and may extend outward in any direction. We report (1) the arthroscopic incidence of radial tears, (2) MR signs that aid in the detection of radial tears and (3) our prospective accuracy in detection of radial tears. DESIGN AND PATIENTS: Three musculoskeletal radiologists prospectively read 200 consecutive MR examinations of the knee that went on to arthroscopy by one orthopedic surgeon. MR images were assessed for location and MR characteristics of radial tears. MR criteria used for diagnosis of a radial tear were those outlined by Tuckman et al.: truncation, abnormal morphology and/or lack of continuity or absence of the meniscus on one or more MR images. An additional criterion used was abnormal increased signal in that area on fat-saturated proton density or T2-weighted coronal and sagittal images. Prospective MR readings were correlated with the arthroscopic findings. RESULTS: Of the 200 consecutive knee arthroscopies, 28 patients had radial tears reported arthroscopically (14% incidence). MR readings prospectively demonstrated 19 of the 28 radial tears (68% sensitivity) when the criteria for diagnosis of a radial tear were truncation or abnormal morphology of the meniscus. With the use of the additional criterion of increased signal in the area of abnormal morphology on fat-saturated T2-weighted or proton density weighted sequences, the prospective sensitivity was 25 of 28 radial tears (89% sensitivity). There were no radial tears described in MR reports that were not demonstrated on arthroscopy (i.e., there were no false positive MR readings of radial tears in these 200 patients). CONCLUSIONS: Radial tears are commonly seen at arthroscopy. There was a 14% incidence in this series of 200 patients who underwent arthroscopy. Prospective detection of radial tears was 68% as compared with arthroscopy when the criteria as outlined by Tuckman et al. were used alone. With the use of the additional criterion of increased signal in the area of abnormal morphology on fat-saturated T2-weighted and proton density weighted sequences, the prospective sensitivity for radial tear detection as compared with arthroscopy was 89% in our series. Fat-saturated proton density and T2-weighted images greatly improve the detection of radial tears as signal intensity changes in radial tears as well as morphologic changes can be utilized for the detection of subtle tears.     

Imaging evaluation of meniscal injury of the knee joint: a comparative MR imaging and arthroscopic study

To evaluate the efficacy of MR imaging in the diagnosis and classification of meniscal tear of the knee joint, we retrospectively characterized the MR features of 78 meniscal tears in 148 patients according to the Mesgarzadeh's criteria. The results showed that the sensitivity and specificity for meniscal tears were 92% and 87%, respectively. Type VI meniscal tear was the most common type, especially in displaced meniscal tear. MR is a reliable diagnostic tool for meniscal tears and associated cruciate ligament injury.     

Phenylketonuria: MR imaging of the brain with clinical correlation

Fifteen patients with biochemically documented phenylketonuria (PKU) were studied with use of magnetic resonance (MR) imaging with spin-echo T2-weighted pulse sequences. The resulting images demonstrated varying degrees of symmetric high signal intensity of the white matter within the posterior cerebral hemispheres. Involvement of the anterior hemispheres was seen only in cases with severe signal intensity changes. There was no involvement of the cerebral cortex, brain stem, or cerebellum. Moreover, no anatomic structural abnormalities were observed. Mild cortical atrophy was observed in eight of the 15 patients. There was no significant correlation between the patients' IQ scores and the level of MR signal intensity changes. Although MR imaging routinely shows relatively distinct abnormalities in patients with PKU, the clinical severity of the disease does not parallel its imaging severity.     

The POLPSA lesion: MR imaging findings with arthroscopic correlation in patients with posterior instability

OBJECTIVE: To evaluate the features of the posterior labrocapsular periosteal sleeve avulsion (POLPSA) lesion on MR imaging in athletes with posterior shoulder instability. DESIGN AND PATIENTS: Six male athletes (age range 19-43 years) with avulsion of the posterior glenoid periosteum were identified on MR imaging. There were four football players, one wrestler, and one competitive weightlifter. The weightlifter had a bilateral condition so that seven shoulders were evaluated. MR imaging was performed with a 1.5 T magnet utilizing conventional and fat-saturated fast spin-echo coronal oblique and sagittal oblique sequences and a 3D-GRE transaxial sequence. Surgical correlation was available in all shoulders. RESULTS: All patients presented with pain and a joint effusion. The size of the periosteal sleeve and redundant joint recess was variable. Fibrous proliferation was noted arthroscopically in four shoulders beneath the sleeve. Although the posterior labrum was detached in all studies, only one labrum had a tear while two showed marked degeneration. CONCLUSION: The POLPSA lesion is an abnormality that can be associated with posterior instability. It differs from a reverse Bankart lesion because the periosteum, although detached, remains intact with the posterior capsule and detached posterior labrum. This lesion may represent an acute form of a Bennett lesion.     

MR imaging of meniscal bucket-handle tears: a review of signs and their relation to arthroscopic classification

Our objective was to review the MR imaging signs of meniscal bucket-handle tears and assess the relevance of these signs to the arthroscopic classification of displaced meniscal tears. Forty-five menisci in 42 patients who had a diagnosis of bucket-handle tear either on MR imaging or on subsequent arthroscopy (in which Dandy's classification of meniscal tears was used) were retrospectively analyzed for MR imaging findings of double posterior cruciate ligament (PCL), fragment within the intercondylar notch, absent bow tie, flipped meniscus, double-anterior horn, and disproportional posterior horn signs. Arthroscopy, which was considered as the gold standard, revealed 41 bucket-handle tears (either diagnosed or not diagnosed by MR imaging) in 38 patients (33 males, 5 females). There was a stastistically significant male preponderance for the occurrence of meniscal bucket-handle tears. Overall, sensitivity and positive predictive value of MR imaging for the detection of meniscal bucket-handle tears were calculated as 90%. Common MR imaging signs of meniscal bucket-handle tears in arthroscopically proven cases of such tears were the fragment in the notch and absent bow tie signs (98% frequency for each). Double-PCL, flipped meniscus, double-anterior horn, and disproportional posterior horn signs, however, were less common (32, 29, 29, and 27%, respectively). An arthroscopically proven bucket-handle tear was found in all patients who displayed at least three of the six MR imaging signs of meniscal bucket-handle tears. The presence of three or more MR imaging signs of meniscal bucket-handle tears is highly suggestive of this condition. Electronic Publication     

MR imaging of uterine carcinoma: correlation with clinical and pathologic findings

Thirteen patients with clinical stages I and II endometrial carcinoma were examined with magnetic resonance (MR) imaging before surgery. Depth of invasion and stage of disease were assessed, and the results were compared with those from MR images of the surgical specimens and pathologic findings. Staging with MR imaging was accurate in 11 of 13 patients (85%). Our results agree with previous reports that MR imaging is an accurate, noninvasive method of assessing depth of myometrial invasion and cervical involvement. We anticipate that MR imaging will have an increasing role in treatment of patients with endometrial carcinoma.     

A meniscus causing painful snapping of the elbow joint: MR imaging with arthroscopic and histologic correlation

Snapping of the elbow joint can cause pain. We report a case of painful snapping elbow produced by an interposed meniscus in the radiohumeral joint in a 20-year-old man. The MR arthrogram demonstrated a meniscus-like tissue interposed between the radial head and humeral capitellum. The MR-arthrographic findings were well correlated with surgical findings. The location and appearance of the meniscus-like tissue was similar to that of meniscus in the knee joint. Histologic findings of the excised meniscus-like tissue showed a typical presentation of fibrocartilage. A meniscus may exist in the elbow joint and can be a rare cause of painful snapping elbow. MR arthrography is helpful for identifying the snapping tissue in the elbow joint.     

MR imaging findings in autoimmune hepatitis: correlation with clinical staging

PURPOSE: To retrospectively evaluate the morphologic and enhancement features of the liver on magnetic resonance (MR) images obtained in patients with autoimmune hepatitis (AIH) and to determine if there is a correlation between MR imaging findings and severity of clinical disease as measured with the Mayo end-stage liver disease (MELD) score. MATERIALS AND METHODS: This study was compliant with the Health Insurance Portability and Accountability Act and approved by the institutional review board. The need for informed consent was waived. Thirty-two patients (29 female and three male patients; mean age, 44 years; age range, 14-69 years) undergoing treatment for AIH underwent unenhanced and gadolinium-enhanced MR imaging. Two radiologists reviewed all cases independently to determine the presence of patchy or heterogeneous liver enhancement, biliary duct changes, lymphadenopathy, and findings of portal hypertension. Fibrosis was graded as mild, moderate, or severe reticular (corresponding to a grading scale of 1-3) or as confluent. Agreement between radiologists was assessed by using kappa coefficients. Mean MELD scores were compared across fibrosis categories by using the Kruskal-Wallis analysis of variance. RESULTS: Of the 32 patients, two (6%) had no imaging findings of cirrhosis. Thirty patients (94%) had reticular fibrosis with a mean grade of 1.8. Six patients had confluent fibrosis, and all six had associated reticular fibrosis. Mild intrahepatic biliary duct dilatation involving the right and left lobes was observed in four patients (12%). Lymphadenopathy was observed in 12% of patients. None of the patients had hepatocellular carcinoma. There was no significant overall association between fibrosis grade and MELD score (P = .36). CONCLUSION: Although fibrosis is a common feature in AIH and is often moderate to severe, no significant correlation between fibrosis grade and MELD score was found.     

MR imaging of meniscal cysts: incidence, location, and clinical significance.

OBJECTIVE: The purpose of this study was to determine the incidence of medial versus lateral meniscal cysts as seen on MR imaging. MATERIALS AND METHODS: A total of 2572 knee MR imaging reports were retrospectively reviewed for the presence of meniscal tears and cysts. Two musculoskeletal radiologists reviewed all images with reported cysts. The type and location of meniscal tear and the presence and location of meniscal cysts were recorded. RESULTS: A total of 1402 meniscal tears were reported in 2572 MR examinations (922 [66%] of 1402 in the medial compartment; 480 [34%] of 1402 in the lateral compartment). Meniscal cysts were present in 109 (4%) of 2572 knees. Of the 109 cysts, 72 (66%) were in the medial compartment, and 37 (34%) were in the lateral compartment. Meniscal cysts were found in association with 72 (7.8%) of the 922 medial meniscal tears and 37 (7.7%) of the 480 lateral meniscal tears. Meniscal cysts showed direct contact with an adjacent meniscal tear in 107 (98%) of 109 cases, with the tear showing a horizontal component in 96 (90%) of 107 cases. CONCLUSION: Meniscal cysts occur almost twice as often in the medial compartment as in the lateral compartment. Medial and lateral tears occur with the same frequency. These findings, when viewed in the context of the historical literature on meniscal cysts, suggest that MR imaging detects a greater number of medial meniscal cysts than physical examination or arthroscopy, and that MR imaging can have an important impact on surgical treatment of patients.     

MR imaging of a meniscal ossicle

We report the MR appearance of a meniscal ossicle, which is an unusual etiology for knee pain. The role of MR in differentiating a meniscal ossicle from a loose body is presented. The MR images also demonstrated associated tibial cartilage thinning and a possible meniscal tear. These MR findings led to arthroscopic treatment rather than conservative management. A review of the literature on meniscal ossicles is also presented.     

MR imaging of meniscal tears: comparison of intermediate-weighted FRFSE imaging with intermediate-weighted FSE imaging

Purpose

We compared intermediate-weighted fast spin-echo (IW-FSE) images with intermediate-weighted fast-recovery FSE (IW-FRFSE) images in the diagnosis of meniscal tears.

Materials and methods

First, 64 patients were recruited, and the arthroscopic findings (n?=?40) and image analysis (n?=?19) identified 59 torn menisci with 36 patients. Both the diagnostic performance and image quality in assessing meniscal tears was evaluated for IW-FSE and IW-FRFSE images using a four-point scale. Signal-to-noise ratio (SNR) calculation was performed for both sets of images.

Results

IW-FRFSE image specificity (100?%) for diagnosing the posterior horn of the medial meniscus (MM) tear with reader 1 was significantly higher than that of IW-FSE images (90?%). Mean ratings of the contrast between the lesion and normal signal intensity within the meniscus were significantly higher for the IW-FRFSE image ratings than the IW-FSE images in most meniscal tears. Mean SNRs were significantly higher for IW-FSE images than for IW-FRFSE images (P?<?0.05).

Conclusions

IW-FRFSE imaging can be used as an alternative to the IW-FSE imaging to evaluate meniscal tears.     

Renal allografts: evaluation by MR imaging

The value of magnetic resonance (MR) imaging in assessing renal transplants was prospectively studied in 45 patients with 46 allografts. Four allografts were imaged at two different times, and separate diagnoses were given for both examinations. Therefore, this study was based on 50 proved diagnoses: nine normally functioning allografts, four allografts with acute tubular necrosis (ATN), 29 with acute rejection, one with chronic rejection, five with cyclosporin nephrotoxicity, and two with local inflammation secondary to adjacent abscess. Twenty-seven of the allografts had concomitant fluid collections. Normal renal structures with preservation of corticomedullary contrast (CMC) on T1-weighted images were demonstrated in all the normally functioning allografts. Decreased or absent CMC on T1-weighted images, reflecting a long T1 relaxation time for cortex, was found to be the most consistent sign of acute renal allograft rejection (27/29). No abnormalities on on MR images were observed in allografts compromised by cyclosporin nephrotoxicity. Hydronephrosis of the renal allograft was easily diagnosed with MR. Perirenal abscess (three cases) and perirenal hematomas (five cases), because of their higher MR signal intensity on T1-weighted images (TR = 0.5 sec, TE = 28 msec), could be differentiated from clinically insignificant postoperative fluid seromas (seven cases), lymphoceles (11 cases), and urinoma (one case).