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Biomedical subjects

C A Helms

Publications and source records attributed to C A Helms.

At least 19 recordsLinked to original sources
PubMed1992

Suprascapular nerve entrapment: evaluation with MR imaging.

Entrapment of the suprascapular nerve is frequently overlooked in the differential diagnosis of shoulder pain. The diagnosis is typically not considered until patients develop severe weakness secondary to atrophy of the spinatus (spinous) musculature that the nerve supplies. Twenty-seven masses were identified adjacent to the suprascapular nerve on magnetic resonance (MR) images of the shoulder; there were 21 ganglion cysts, two synovial sarcomas, one Ewing sarcoma, one chondrosarcoma, one metastatic renal cell carcinoma, and one hematoma associated with a fracture. Atrophy of both the supraspinatus and infraspinatus muscles was seen in association with anteriorly located masses and proximal entrapment of the nerve in 11 cases (40%); isolated atrophy of the infraspinatus muscle was seen in association with posteriorly located masses and distal entrapment of the nerve in nine cases (33%). MR imaging may facilitate the diagnosis of suprascapular nerve entrapment in patients with shoulder pain of unclear origin when perineural masses and atrophy of the spinatus musculature are present.

Adolescent↗
PubMed1992

Current status of magnetic resonance imaging of the ankle and the hindfoot.

With the increasing use of magnetic resonance imaging (MRI) for examining the musculoskeletal system, numerous applications have been found in the evaluation of ankle and hindfoot problems. For example, MRI is ideal for assessing tendon disorders, which are common in this region. In addition, the technique allows accurate staging of osteochondral fractures, as well as both soft-tissue and bony neoplasms. Tarsal coalition can be readily evaluated and the type determined. Increasingly, arthritis and synovial abnormalities are coming under scrutiny with MRI; this is currently an area of avid interest. In this article the authors review the current status of MRI of the ankle and the hindfoot and illustrate a variety of these disorders.

Ankle Joint↗
PubMed1992

Current status of magnetic resonance imaging of the wrist.

Conventional imaging of the wrist has relied heavily on plain radiography, tomography, fluoroscopy and arthrography. More recently, computed tomography and magnetic resonance imaging (MRI) have been added to this armamentarium. In this article the authors review the normal anatomy of the wrist and demonstrate a variety of pathologic conditions that can be assessed with MRI, including avascular necrosis and tears of the intrinsic and the extrinsic ligaments and the triangular fibrocartilage. MRI of the wrist is still evolving rapidly, and its place in the work-up of wrist disorders is only now being defined.

Bone Diseases↗
PubMed1991

Automated percutaneous lumbar diskectomy.

The use of automated percutaneous lumbar diskectomy for the treatment of herniated lumbar disks is increasing. More than 3000 physicians have been trained to perform the procedure, and over 40,000 cases have been completed worldwide. This review describes the development of automated percutaneous lumbar diskectomy, the selection of appropriate patients, how the technique is performed, and its efficacy relative to other methods of treatment.

Humans↗
PubMed1990

Magnetic resonance imaging of the shoulder: rationale and current applications.

Because it can demonstrate a wide range of tissue contrast with excellent resolution, magnetic resonance (MR) imaging has revolutionized imaging in many areas of the musculoskeletal system and has generated excitement among those interested in the painful shoulder. Shoulder impingement syndrome and glenohumeral instability constitute the two major categories of shoulder derangements. Correct diagnosis requires the use of appropriate pulse sequences and imaging planes, proper patient positioning, and a satisfactory surface coil. In addition the imager must have a thorough understanding of shoulder anatomy and pathology. We present a summary of the current status of MR imaging of the shoulder including technical, anatomic, and pathologic considerations and a review of the pertinent literature.

Humans↗
PubMed1990

A prospective evaluation of the effectiveness of temporomandibular joint arthroscopy.

This is a prospective study to evaluate therapeutic arthroscopy for internal derangement of the temporomandibular joint (TMJ). Fifty-nine patients with 76 abnormal joints were evaluated preoperatively for pain, noise, maximal incisal opening (MIO), and deviation on opening. Preoperative and postoperative magnetic resonance imaging (MRI) scans were obtained for 29 joints. Patients were treated by superior joint arthroscopy, lysis of adhesions, lavage, and steroid injection, along with preoperative and postoperative splint and physiotherapy. Pain, noise, and motion were evaluated at three time periods: 1) early (10 to 30 days); 2) intermediate (1 to 6 months); and 3) late (greater than 6 months). At early, intermediate, and late follow-up, increase in MIO was statistically significant (P less than .05). Noise did not return in the majority of patients. Disc position, evaluated by MRI, did not appear to change in 25 of 29 joints and did not correlate with clinical outcome. The results of this study indicate that TMJ arthroscopy is effective in reducing pain and increasing motion in patients with TMJ internal derangement.

Adult↗
PubMed1990

Pseudopermeative skeletal lesions.

Permeative bone lesions are well known to radiologists and usually invoke a differential diagnosis that includes aggressive lesions such as round cell malignancies and infection. In contrast to permeative lesions, which demonstrate multiple small holes at the endosteal surface of the cortex secondary to a medullary process, we describe a series of 19 patients (seven with aggressive osteoporosis, eight with prior radiation therapy and four with hemangiomas) who demonstrated multiple tiny lucencies in the cortex which were superimposed on the medullary space and mimicked a permeative pattern radiographically. We termed this a pseudopermeative pattern. Recognition of a pseudopermeative pattern may allow a less sinister differential diagnosis to be considered and may avert unnecessary biopsy in many instances.

Adult↗
PubMed1990

Magnetic resonance imaging of the postoperative lumbar spine.

Magnetic resonance (MR) imaging is a powerful diagnostic tool for patients with the failed back surgery syndrome. The multiplanar imaging capability, superior soft-tissue contrast resolution, and excellent tissue characterization are its major advantages. It displays the changes caused by surgical intervention as well as associated postoperative findings, many of which cause the failed back surgery syndrome. Most recently, gadolinium-DTPA-enhanced MR imaging of the spine, combined with noncontrast MR imaging, has shown heretofore unparallelled sensitivity and accuracy.

Humans↗
PubMed1989

Magnetic resonance imaging of the knee: current status, new directions.

A number of techniques for magnetic resonance imaging of the knee are reviewed. Spin-echo imaging sequences are at present the most widely used and are capable of demonstrating a wide range of pathology including cruciate and collateral ligament tears, meniscal abnormalities, and synovial disease. Fast scan imaging provides effective T2-weighting without the time penalty of T2-weighted spin-echo imaging. These fast scan techniques have also permitted the development of novel sequences including radial techniques and three-dimensional Fourier transform/volume acquisition (which may potentially become the imaging technique of choice in the knee). Inversion recovery may play an important role in evaluating cartilage disorders in the future. The strengths of each technique are discussed together with possible clinical applications.

Humans↗
PubMed1989

Automated percutaneous lumbar discectomy.

Lumbar spine disc disease has traditionally been treated surgically by laminectomy and manual removal of the offending disc material. Chymopapain was extensively used to decompress the disc pressure in a relatively noninvasive manner, but has been abandoned due to serious complications, including anaphylaxis and paraplegia. Onik introduced automated percutaneous discectomy in 1985. This procedure has proved safe and efficacious for treating lumbar disc disease without complications. It is performed on an out-patient basis under local anesthesia with minimal rehabilitation time. The success rate reported in a multiinstitutional study with one year follow-up is approximately 75%. The majority of failures occur in patients with free fragments or spinal stenosis - both of which can be diagnosed preoperatively with good imaging examinations. Hence, the success rate can be expected to improve if preoperative imaging is relied upon to help choose appropriate patients. Over 30,000 percutaneous discectomy procedures have been performed. The only complication reported, disc infection, developed in fewer than 0.2% of cases. Automated percutaneous discectomy has the potential to treat a vast number of patients with lumbar disc disease who otherwise would have laminectomies.

Fluoroscopy↗
PubMed1989

MRI of the knee in diffuse pigmented villonodular synovitis.

Magnetic resonance imaging (MRI) was performed on 11 patients with surgically proven pigmented villonodular synovitis (PVNS) of the knee. PVNS was diagnosed on the basis of presence of hemosiderin, joint effusion, and hyperplastic synovium without significant joint destruction. MRI provided a detailed map of the distribution of the disease within the joint, emphasizing the common occurrence of the disease behind the cruciate ligaments and in synovial cysts in the popliteal fossa. MRI aided in preoperative planning and postoperative follow-up for residual and recurrent disease. Nine additional cases of joint hemorrhage, hemophilia, desmoplastic tumors, and synovial chondromatosis were included to delineate differential diagnostic criteria.

Adult↗
PubMed1989

Coronoid process hyperplasia: CT studies.

Coronoid process hyperplasia is a disorder that causes restricted jaw movement due to enlargement of the coronoid process of the mandible, which impinges on the zygomatic arch with mouth opening. The cause is unclear. Computed tomographic (CT) findings in three patients with this disorder (two bilateral, one unilateral)--including a 3-year-old boy who may be the youngest patient with this disorder ever reported--include an enlarged coronoid process, with sclerosis and erosion of the zygomatic arch. CT is an effective and rapid method for establishing the diagnosis.

Adult↗
PubMed1989

Retrorenal colon: implications for percutaneous diskectomy.

It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.

Adolescent↗
PubMed1989

Temporomandibular joint: morphology and signal intensity characteristics of the disk at MR imaging.

Magnetic resonance (MR) imaging has been used in the temporomandibular joint (TMJ) primarily to define the disk position. This report examines altered morphology and signal intensity characteristics of the TMJ disk as they relate to the severity of internal derangement. Two hundred sixteen joints in 133 patients with a history of such derangement. were imaged with MR. Disk position, signal intensity, morphology, and the presence of osteoarthritis were determined for each joint. The normal disk was not anteriorly displaced and had a normal "bow-tie" shape. A grade 1 disk was anteriorly displaced and had a normal shape; a grade 2 disk was anteriorly displaced and had an abnormal shape. Forty (19%) joints were considered normal; none of these exhibited osteoarthritis. One hundred thirty-nine (64%) joints were grade 1; osteoarthritis was found in 17%. Thirty-seven (17%) were grade 2; osteoarthritis was found in 95%. All forty normal joints had high or intermediate signal intensity in the disk. Osteoarthritic joints had a higher percentage of disks with diminished intensity (P less than .0001). Severe or untreated osteoarthritis is known to be a complication of TMJ internal derangements; hence this grading system seems to correlate with the severity of internal derangement.

Adult↗