Intersection syndrome of the forearm.
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Adult↗
Biomedical subjects
Clyde A Helms
Publications and source records attributed to Clyde A Helms.
Parsonage-Turner syndrome: MR imaging findings and clinical information of 27 patients.
PURPOSE: To review retrospectively the magnetic resonance (MR) imaging findings and clinical information of patients with Parsonage-Turner syndrome (PTS). MATERIALS AND METHODS: The institutional review board did not require its formal approval or informed patient consent at the time of the study. However, the study was HIPAA compliant. The information in a computerized database of 2875 consecutive shoulder MR examinations was retrospectively reviewed. With use of key terms, the database software identified 81 examinations potentially associated with PTS. Both authors together reviewed the 81 imaging reports and the corresponding patients' medical records. In consensus, they made the diagnosis of PTS in 21 patients (two with bilateral involvement) on the basis of MR findings, electromyographic results, and clinical data. They also examined the data of an additional six patients (one with bilateral involvement) obtained from outside facilities. Ultimately, 30 shoulders of 27 patients (18 male, nine female; age range, 12-81 years; mean age, 41 years) were evaluated. The MR findings and clinical information (ie, regarding atrophy, pain, weakness, electromyographic results, neck and spine history, trauma, excessive overhead activity, recent surgery, vaccination, and illness) of all patients with PTS were reviewed. MR findings of diffuse high T2 signal intensity abnormality and fatty atrophy of muscles were evaluated to assess the pattern of nerve involvement. Structural causes (eg, ganglion cyst or other mass) of neurogenic high T2 signal intensity abnormality were excluded at MR imaging. RESULTS: Twenty-nine (97%) of 30 shoulders had suprascapular nerve involvement; in 15 (50%) shoulders, the involvement was limited to this nerve. Fifteen (50%) shoulders had axillary nerve involvement; in only one (3%) shoulder, the involvement was limited to this nerve. One shoulder (3%) had subscapular nerve involvement. Nine (30%) shoulders demonstrated focal muscular atrophy. Eleven (41%) of 27 patients also underwent electromyography; all of these patients demonstrated neuropathies that matched the patterns of neurogenic high T2 signal intensity abnormality seen at MR imaging. CONCLUSION: The suprascapular nerve was almost invariably involved (in 97% of shoulders) in patients with PTS. Axillary nerve involvement also was commonly observed (in 50% of shoulders). Subscapular nerve involvement was uncommon (in 3% of shoulders).
Adolescent↗
MRI appearance of Wrisberg variant of discoid lateral meniscus.
OBJECTIVE: A discoid lateral meniscus is a common normal variant, occurring in approximately 3-5% of the population. A subgroup of the discoid lateral meniscus known as the Wrisberg variant occurs when there is no posterior attachment of the lateral meniscus. Instead, Wrisberg's ligament becomes the only lateral meniscus posterior stabilizer, with a symptomatic hypermobile meniscus. Although it is commonly described in the orthopedics literature, to our knowledge the Wrisberg variant of the discoid lateral meniscus is not mentioned in the radiology literature. This article describes the MRI appearance of this important yet often unrecognized process. CONCLUSION: The Wrisberg variant of the discoid lateral meniscus is a rare condition with a highly suggestive clinical history. The musculoskeletal radiologist should consider this diagnosis whenever a discoid lateral meniscus is identified because making this elusive diagnosis may prove immensely useful for the orthopedic surgeon.
Adolescent↗
Commentary on "Arthrotomography of the temporomandibular joint".
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Arthrography↗
Imaging for evaluation of posterolateral corner injury.
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Diagnostic Imaging↗
Radial meniscal tears: significance, incidence, and MR appearance.
OBJECTIVE: The purpose of this study was to assess the prevalence of radial meniscal tears at arthroscopy and the ability of MRI to detect radial tears preoperatively. In addition, the ability of four radiologic signs to detect radial tears was assessed. Those signs are the truncated triangle, cleft, marching cleft, and ghost meniscus signs. MATERIALS AND METHODS: Arthroscopy of the knee was performed by a single orthopedic surgeon on 196 consecutive patients. The surgeon noted each radial tear he encountered. The MR images that were obtained at our institution were reviewed, whereas those patients who were imaged elsewhere were excluded. The preoperative MRI reports were reviewed to assess the ability to prospectively identify radial meniscal tears. In addition, a retrospective analysis of the MRI studies was performed by two radiologists in which four radiologic signs were applied to detect radial tears. RESULTS: Twenty-nine patients (15%) had radial tears at arthroscopy. Eighteen of the 29 patients had their imaging performed at our institution and were selected for review. There were 19 radial tears found at surgery. Seven (37%) of the 19 tears were identified as radial prospectively. Retrospectively, using the four signs for radial tears, reviewers identified 17 (89%) of 19 radial tears. CONCLUSION: A more accurate preoperative diagnosis may be rendered using the four described signs to detect radial tears, thus allowing informative preoperative counseling and consideration of new therapies that are available for radial meniscal repair.
Adult↗
Prominent vascular remnants in the calcaneus simulating a lesion on MRI of the ankle: findings in 67 patients with cadaveric correlation.
OBJECTIVE: Our objective was to prove through cadaveric correlation that a frequently seen focus of MRI signal in the calcaneus is benign. CONCLUSION: A characteristic focus of signal (increased T2, decreased T1) in the calcaneus near the attachment of the cervical and interosseous ligaments is a common, benign finding frequently seen on MRI of the foot and ankle.
Adolescent↗
Glenoid dysplasia: incidence and association with posterior labral tears as evaluated on MRI.
OBJECTIVE: Glenoid dysplasia is known to predispose affected patients to accelerated degenerative joint disease. We have observed that there is often an association between glenoid dysplasia and posterior labral tears. Our goal was to assess glenoid dysplasia as seen on MRI and to assess its association with posterior labral tears. CONCLUSION: In our study population, we found that moderate to severe glenoid dysplasia is not a rare entity as seen on MRI, with an incidence of 14.3%. Furthermore, we found that there is a statistically significant increase in the incidence of posterior labral tears associated with shoulders with moderate or severe glenoid dysplasia compared with those shoulders with no dysplasia or mild dysplasia as evaluated on MRI. Even when the mild cases were included, the incidence of posterior labral tears was significantly increased versus healthy subjects, indicating that even mild cases of glenoid dysplasia may be clinically relevant.
Adolescent↗
MRI of spring ligament tears.
OBJECTIVE: Surgical repair of the spring ligament is becoming recognized as an important management component of adult-acquired flatfoot, yet little literature exists on the MRI appearance of spring ligament abnormalities. In this article, we describe the MRI appearance of surgically proven spring ligament tears. CONCLUSION: MRI findings present in surgically proven spring ligament tears include an abnormal spring ligament caliber, signal intensity, waviness, a full-thickness gap, and posterior tibial tendonopathy. The finding unique to cases with surgically proven tears is a full-thickness gap in the ligament, seen in 79% of the cases in our series. When multiple abnormalities are seen in the spring ligament in conjunction with a full-thickness gap, the diagnosis of a tear can be made with confidence.
Adult↗
MRI appearance of chondral delamination injuries of the knee.
OBJECTIVE: We describe the MRI appearance of five cases of chondral delamination of the knee. CONCLUSION: Chondral delamination injuries of the knee show increased linear signal abnormality at the junction of the articular cartilage and subchondral bone on T2-weighted (fast spin-echo) images of the knee. Identifying and treating these lesions results in an improved prognosis for patients with this injury.
Adolescent↗
Comparison of fast spin-echo versus conventional spin-echo MRI for evaluating meniscal tears.
OBJECTIVE: We compare sensitivities of conventional spin-echo and fast spin-echo sequences in the evaluation of meniscal tears. Furthermore, we reevaluate the results from prior studies comparing these two sequences to understand why there are differing conclusions regarding the efficacy of fast spin-echo sequences as a commensurate replacement for conventional spin-echo sequences. MATERIALS AND METHODS: We used records from a control group of 64 patients (128 menisci) who had undergone arthroscopy to determine the sensitivity of conventional spin-echo sequences for detecting meniscal tears. Two hundred sixteen consecutive patients (432 menisci) were then imaged using conventional spin-echo and fast spin-echo sequences to evaluate for meniscal tears. Both sequences were proton density-weighted with fat suppression. RESULTS: Of the 432 menisci, 170 tears were detected on conventional spin-echo imaging. Only 128 tears were detected on the fast spin-echo sequence. The sensitivities of conventional spin-echo and fast spin-echo imaging were found to be 93% and 80%, respectively. In addition, findings from conventional spin-echo and fast spin-echo sequences were discordant for 72 menisci (17%, p < 0.01). CONCLUSION: The sensitivities of conventional spin-echo and fast spin-echo imaging for detecting meniscal tears have been shown to be greater than 90% and approximately 80%, respectively. However, some authors advocate substituting conventional spin-echo imaging with fast spin-echo imaging. We urge the abandonment of fast spin-echo imaging for evaluating meniscal tears because a loss of greater than 10% in sensitivity is unacceptable.
Adult↗
MR imaging appearance of 180-360 degrees labral tears of the shoulder.
Glenoid labral tears exceeding 180 degrees are an uncommon entity in which characteristic clinical and MR imaging features can lead to a more accurate preoperative diagnosis. We provide a description of glenoid labral tears that exceed 180 degrees, and their characteristic magnetic resonance imaging features. In the young, heavily muscled male athlete, the identification of multiple sites of labral pathology and isolated, extensive posterior labral injuries are features that should raise suspicion for labral tears that exceed 180 degrees.
Adolescent↗
Lipomas, lipoma variants, and well-differentiated liposarcomas (atypical lipomas): results of MRI evaluations of 126 consecutive fatty masses.
OBJECTIVE: Our objectives were to evaluate the reliability of MRI in distinguishing simple lipomas, lipoma variants, and well-differentiated liposarcomas (atypical lipomas) and to identify various imaging mimics of well-differentiated liposarcoma. MATERIALS AND METHODS: One hundred twenty-six consecutively imaged grossly fatty masses were retrospectively reviewed. MRI examinations, their prospective interpretations, and their corresponding pathology reports were compared to determine the reliability of MRI in distinguishing simple lipomas, lipoma variants, and well-differentiated liposarcomas. RESULTS: The success of MRI in identifying well-differentiated liposarcomas among other fatty masses was as follows: sensitivity, 100%; specificity, 83%; accuracy, 84%; positive predictive value, 38%; and negative predictive value, 100%. MRI was 100% specific in the diagnosis of simple lipoma. Sixty-three percent of lesions considered suspicious for well-differentiated liposarcoma were actually simple lipomas (13%) and benign lipoma variants (50%), including chondroid lipoma (13%), osteolipoma (6%), hibernoma (6%), lipoleiomyoma (6%), angiolipoma (6%), and infarcted lipoma (13%). CONCLUSION: Because of differences in treatment, prognosis, and long-term follow-up, it is important to preoperatively distinguish simple lipomas from well-differentiated liposarcomas. MRI is highly sensitive in the detection of well-differentiated liposarcomas and highly specific in the diagnosis of simple lipomas. However, when an extremity or body wall lesion is considered suspicious for well-differentiated liposarcoma, it is more likely (64%) to represent one of many benign lipoma variants.
Adult↗
Bucket-handle meniscal tears of the knee: sensitivity and specificity of MRI signs.
OBJECTIVE: To determine the sensitivity and specificity of reported MRI signs in the evaluation of bucket-handle tears of the knee. DESIGN AND PATIENTS: A retrospective analysis of 71 knee MR examinations that were read as displaying evidence of a bucket-handle or "bucket-handle type" tear was performed. We evaluated for the presence or absence of the absent bow tie sign, the coronal truncation sign, the double posterior cruciate ligament (PCL) sign, the anterior flipped fragment sign, and a fragment displaced into the intercondylar notch. Sensitivity and specificity were calculated relative to the gold standard of arthroscopy. RESULTS: Forty-three of 71 cases were surgically proven as bucket-handle tears. The absent bow tie sign demonstrated a sensitivity of 88.4%. The presence of at least one of the displaced fragment signs had a sensitivity of 90.7%. A finding of both the absent bow tie sign and one of the displaced fragment signs demonstrated a specificity of 85.7%. The double PCL sign demonstrated a specificity of 100%. The anterior flipped meniscus sign had a specificity of 89.7%. CONCLUSIONS: Bucket-handle tears of the menisci, reported in about 10% of most large series, have been described by several signs with MRI. This report gives the sensitivity and specificity of MRI for bucket-handle tears using each of these signs independently and in combination. MRI is shown to be very accurate for diagnosing bucket-handle tears when two or more of these signs coexist.
Adolescent↗
Accuracy of MR imaging of the knee in adolescents.
OBJECTIVE: A report in the orthopedics literature states that MR imaging for internal derangement of the knee has a lower accuracy in adolescents than in adults and may even provide spurious information that alters clinical management. This assertion has not been specifically addressed in the radiology literature. The purpose of our study was to determine the accuracy of MR imaging in adolescents with regard to injury of the cruciate ligaments and menisci. MATERIALS AND METHODS: A database search of our institution's records from January 1998 to July 2000 yielded 2140 MR examinations of the knee, all of which had been performed with a standard knee protocol on a 1.5-T magnet. Of these 2140 examinations, 156 included patients younger than 18 years. Fifty-nine of these patients underwent surgery, and the orthopedic surgeons' operative reports were used as the gold standard with which the MR imaging results were compared. Thirty-four boys and 25 girls who ranged in age from 11 to 17 years (mean age, 15 years) were examined. The clinical notes for the remaining 97 patients were evaluated for information about management and clinical improvement. RESULTS: The sensitivity and specificity values for MR imaging of the menisci and cruciate ligaments in adolescents were as follows: medial meniscus, 92% sensitivity and 87% specificity; lateral meniscus, 93% sensitivity and 95% specificity; anterior cruciate ligament, 100% sensitivity and 100% specificity; and posterior cruciate ligament, 0% sensitivity and 100% specificity. CONCLUSION: Our data suggest that MR imaging of the knee in adolescents is sensitive, specific, and accurate.
Adolescent↗
MR imaging of infrapatellar plica injury.
OBJECTIVE: Injury to the infrapatellar plica (ligamentum mucosum) has not been previously described in the radiology literature to our knowledge. This article shows the MR imaging appearance of injury to the infrapatellar plica. CONCLUSION: Injury to the infrapatellar plica is uncommon but should be considered as a potential source of knee pain, especially if no other evidence indicates internal derangement. MR imaging can reveal a typical appearance for infrapatellar plica injury.
Adolescent↗
Enlarged spinoglenoid notch veins causing suprascapular nerve compression.
OBJECTIVE: To report the magnetic resonance (MR) imaging findings of enlarged veins in the spinoglenoid notch as a cause of suprascapular nerve compression. DESIGN AND PATIENTS: Six patients presented to MR imaging for evaluation of chronic shoulder pain. Clinical information and MR imaging studies were reviewed. The spinoglenoid notch vascular structures were compared with measurements made in 10 age-matched controls. RESULTS: Spinoglenoid notch vascular structures measured in 10 asymptomatic age-matched control patients ranged from 1 to 4 mm in diameter with an average of 2.2 mm. The six study patients had vascular structures that ranged from 6 to 10 mm in diameter with an average of 8.4 mm. Atrophy and fatty infiltration of the infraspinatus muscle was noted as an associated finding at MR imaging in all six patients. Surgery was performed in three of the six patients, at which time a venous varix was identified in the spinoglenoid notch in all three patients. CONCLUSION: We describe distended veins in the spinoglenoid notch. These may be readily apparent at MR imaging and should be distinguished from paralabral ganglion cysts compressing the suprascapular nerve in the absence of labral tears, especially if percutaneous aspiration of a ganglion cyst is entertained.
Adult↗
MR imaging of epidural hematoma in the lumbar spine.
OBJECTIVE: To bring attention to the MR imaging appearance of epidural hematoma (EDH) in the lumbar spine as a small mass often associated with disk herniation or an acute event. This paper will show our experience with this entity and describe criteria for its MR imaging appearance. DESIGN AND PATIENTS: Thirteen cases of prospectively diagnosed EDH of the lumbar spine were compared with 12 cases of prospectively diagnosed prominent epidural extrusion. Our criteria were retrospectively evaluated by the two authors for their presence or absence in each case. The chi-square test for nominal data was applied. MR imaging criteria utilized to distinguish EDH from disk herniation at our institution include: (1) signal different from disk, (2) high signal on T1-weighted images, either centrally or peripherally, (3) teardrop- or egg-shaped mass, in the sagittal plane, (4) size greater than half the vertebral body height in a craniocaudal dimension, (5) primarily retrosomatic epidural location, (6) plasticity - the mass is seen to conform closely to the contours of bone (e.g., in the lateral recess), (7) little or no disk space narrowing unless associated with disc herniation. RESULTS: Chi-square analysis demonstrated each criterion to significantly differentiate between EDH and extrusion. Only six of 13 EDH cases went to surgery in spite of their relatively large size. Two of six patients were diagnosed as having epidural clot consistent with hematoma at the time of surgery. The four patients who were not diagnosed at surgery revealed only small disk herniations or fragments of disk. CONCLUSIONS: The occurrence of EDH is more frequent than previously suspected. Spontaneous EDH is frequently associated with disk herniation and acute events such as sneezing or coughing. Most cases of spontaneous EDH will resolve prior to surgery with only the minority becoming chronic in order to be seen at surgery as an encapsulated mass. MR imaging can reliably identify EDH and distinguish between EDH and large disk extrusions.
Adult↗