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Biomedical subjects

M R Terk

Publications and source records attributed to M R Terk.

At least 19 recordsLinked to original sources
PubMed2000

Bone marrow response in treated patients with Gaucher disease: evaluation by T1-weighted magnetic resonance images and correlation with reduction in liver and spleen volume.

PURPOSE: To determine whether T1-weighted magnetic resonance (MR) images can demonstrate response in the marrow of patients with type 1 Gaucher disease treated with enzyme replacement therapy (ERT) and to determine whether a relationship exists between liver and spleen volume reductions and visible marrow changes. PATIENTS: Forty-two patients with type 1 Gaucher disease were evaluated on at least two occasions. Thirty-two patients received ERT. Of these patients, 15 had a baseline examination prior to the initiation of ERT. The remaining 10 patients did not receive ERT. DESIGN: T1-weighted and gradient recalled echo (GRE) coronal images of the femurs and hips were obtained. Concurrently, liver and spleen volumes were determined using contiguous breath-hold axial gradient-echo images. T -weighted images of the hips and femurs were evaluated to determine change or lack of change in the yellow marrow. RESULTS: Of the 32 patients receiving ERT, 14 (44%) demonstrated increased signal on T1-weighted images suggesting an increase in the amount of yellow marrow. If only the 15 patients with a baseline examination were considered, the response rate to ERT was 67%. Using Student's t-test a highly significant correlation (P<0.005) was found between marrow response and reduction in liver and spleen volume. CONCLUSIONS: Marrow changes in patients receiving ERT can be detected by T -weighted images. This response correlated with reductions in visceral volumes (P<0.0005).

Adult↗
PubMed2000

Diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression: are T(1)-weighted sagittal images sufficient?

The objective of this study was to determine whether T(1)-weighted sagittal images alone are adequate in the diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression. Ninety-four complete magnetic resonance (MR) studies of the spinal column (a complete study consisting of T(1)-weighted sagittal images, T(2)-weighted sagittal images, and T(1)- and/or T(2)-weighted axial images) and 94 T(1)-weighted sagittal images alone (a subset of the complete studies) from 57 consecutive cancer patients over the last 2 years with clinically suspected cord compression were blindly and independently evaluated by four radiologists. The complete MR studies were used as the standard. Overall, the sensitivity of T(1)-weighted sagittal images alone to vertebral metastasis (87%) was statistically greater than cord compression (70%) (p = 0.05), and statistically greater than epidural metastasis (46%) (p </= 0.02). The specificity for cord compression (97%) was greater than the specificity for epidural metastasis (89%) (p = 0.03), and greater than the specificity for vertebral metastasis (83%) (p </= 0.02). There was a strong trend for better detection of cord compression overall and better detection of vertebral metastasis in the cervical spine by the most experienced radiologist. Complete studies of the spine are necessary in the diagnosis of vertebral metastasis, epidural metastasis, and cord compression, particularly with less experienced radiologists.

Adult↗
PubMed1998

Gadolinium-enhanced MR imaging of traumatic hepatic injury.

OBJECTIVE: Our objective was to evaluate the use of contrast-enhanced MR imaging in the examination of a limited number of patients with hepatic trauma who had also undergone CT. CONCLUSION: The conspicuity of most lesions was better on contrast-enhanced MR imaging than on unenhanced MR imaging. Also, conspicuity on contrast-enhanced MR imaging was at least subjectively equivalent to that on CT.

Adult↗
PubMed1997

Injury of the posterior ligament complex in patients with acute spinal trauma: evaluation by MR imaging.

OBJECTIVE: We undertook this study to use MR imaging to determine the frequency of injury to the posterior ligament complex of the thoracolumbar spine in patients who have undergone acute thoracolumbar trauma. SUBJECTS AND METHODS: Sixty-eight patients with varying severity of thoracolumbar trauma were examined prospectively. The majority of injuries were related to motor vehicle accidents. The second most common cause was falls. Patients were examined with plain radiography and MR imaging. In addition to conventional MR imaging sequences consisting of T1-weighted and fast spin-echo T2-weighted sagittal and axial images, a fat-suppressed T2-weighted sagittal sequence was performed. The findings were correlated with surgery in six cases and with follow-up clinical examination that included physical examination and conventional anteroposterior and lateral radiographs. RESULTS: Posterior ligament complex injury was detected in 53% (n = 36) of all patients. Such injury was most common in patients with flexion-distraction (n = 15) and patients with dislocation fracture (n = 4). Of the patients with dislocation fracture, all had posterior ligament complex injury. Of the 24 patients with burst fractures, posterior ligament complex tear occurred in 42% (n = 10). Of the 23 patients with compression fractures, 26% (n = 6) had posterior ligament complex tear. Injury to the interspinous ligaments occurred with decreasing frequency in patients with injury to the supraspinous ligament, flaval ligaments, posterior longitudinal ligament, and anterior longitudinal ligament. Surgical findings correlated with MR imaging in all six patients who underwent surgery. CONCLUSION: Injury to the posterior ligament complex, which is often encountered in patients with burst and compression fractures, can be reliably revealed by MR imaging.

Adult↗
PubMed1996

Magnetic resonance imaging of acute Maisonneuve fractures.

Magnetic resonance imaging (MRI) studies were performed on five patients with acute Maisonneuve fractures. All patients had sustained a twisting injury to their ankles and complained of ankle pain and pain over their proximal fibula. High quality images with excellent visualization of all the ankle ligamentous structures were obtained. MRI showed that the anterior inferior tibiofibular ligament was disrupted in all patients and the posterior inferior tibiofibular ligament was intact in three of five patients. Also, the anterior talofibular ligament was disrupted in all patients and the calcaneofibular ligament was ruptured in two of five patients. This raises the question of whether patients with Maisonneuve fractures have lateral ankle instability at long-term follow-up. Although the superficial deltoid ligament was disrupted in all patients, the deep deltoid ligament was intact in one patient, partially disrupted in one patient, and completely disrupted in three patients. The interosseous ligament was disrupted at the ankle in all patients, while the interosseous membrane was disrupted in the leg in all patients except one. This patient had an intact interosseous membrane despite rupture of the interosseous ligament at the ankle and the presence of a proximal one third fibula fracture.

Acute Disease↗
PubMed1996

Magnetic resonance imaging to detect avascular necrosis after open reduction and internal fixation of talar neck fractures.

Twenty-one consecutive patients with displaced talar neck fractures (12 Hawkins type II, 9 Hawkins type III) were prospectively evaluated with magnetic resonance (MR) scans performed between 3 days and 12 months after surgery. All patients underwent open reduction and internal fixation with titanium screws, except two who underwent fixation with stainless steel implants that were subsequently removed. All patients had plain radiographs. We classified the scans as follows: type A, no abnormal signal changes in the body of the talus; type B, signal changes in less than 25% of the body; type C, signal changes in 25% to 50% of the body; and type D, signal changes in greater than 50% of the body. Plain anteroposterior radiographs correlated well with MR scans in patients with type D scans, but an inconsistent correlation was noted with lesser degrees of signal changes (types A-C), with the MR scans being more accurate in displaying the volume of avascular bone. Scans obtained less than 3 weeks after injury were not helpful in assessing for avascular necrosis. We found that high-quality MR images of the talus were consistently obtained in the presence of titanium screws in contrast to images obtained with stainless steel implants. We use titanium screws in all talar neck fracture repairs, because they permit high-quality MR images. We believe that further study of patients with Hawkins type III fractures and Hawkins type II fractures with equivocal radiographic evidence of avascular necrosis is warranted to try to identify those patients at risk for collapse and perhaps to guide weightbearing recommendations.

Adult↗
PubMed1995

MR imaging of patients with type 1 Gaucher's disease: relationship between bone and visceral changes.

OBJECTIVE: Because treatment is now available for patients with Gaucher's disease, methods of follow-up have become important in making treatment decisions. Bone abnormalities (infarct and avascular necrosis) tend to be irreversible while visceral volumes are not, suggesting that it may be useful to follow patients with visceral volume determinations. In order to do so, the relationship of one to the other must first be understood. The purpose of this paper is to determine the relationships between bone and visceral changes identified with MR imaging. MATERIALS AND METHODS: Sixty-two consecutive patients from 1 to 78 years old with type 1 Gaucher's disease were studied by MR imaging. The examination consisted of two parts: T1-weighted MR images and gradient-echo coronal MR images of the hips and femurs, and axial breath-holding MR images of the abdomen that allowed measurement of hepatic and splenic volume. The bone changes were classified and were correlated with the liver and spleen volumes. Specific imaging features of the liver and spleen were noted and correlation sought. RESULTS: A statistically significant difference in liver size was found between patients with and without avascular necrosis. A statistically significant correlation was also found between liver size and avascular necrosis. Patients with marrow changes classified as grade 2 or higher were significantly more likely to have avascular necrosis. Nineteen percent of patients had splenic nodules and 7% had hepatic nodules; however, there was no correlation between the nodules and bone changes. CONCLUSION: MR imaging showed a statistical relationship between marrow changes, liver size, and avascular necrosis in patients with type 1 Gaucher's disease. Knowledge of this relationship may be used in dosage and treatment considerations in the follow-up and clinical management of these patients.

Adolescent↗
PubMed1994

Magnetic resonance imaging of the foot and ankle.

This article describes the application of MR imaging to musculoskeletal imaging, specifically, imaging of the foot and ankle. The instrumentation, safety, and imaging techniques are discussed with specific attention to fat suppression, three-dimensional Fourier transform images, dynamic imaging, magnetization transfer contrast, and MR angiography. Normal and abnormal osseous, ligamentous, and tendonous anatomy is discussed and illustrated.

Adipose Tissue↗
PubMed1993

Magnetic resonance angiography of the neck veins.

Time of flight, reduced matrix (64 x 256) MR angiography of the neck veins was performed in four normal subjects and four patients with neck vein thrombosis, either from indwelling catheters (n = 3) or intravenous drug abuse (n = 1). In each case, satisfactory images were acquired. Typical examination times of 3-6 min were required. MR angiography of neck veins gives a unique display of venous anatomy, including collateral veins and occlusions.

Adult↗
PubMed1993

Evaluation of suspected musculoskeletal neoplasms using 3D T2-weighted spectral presaturation with inversion recovery.

This study evaluated the use of the Spectral presaturation with inversion recovery (SPIR) technique with T2-weighting in 43 pathologically proven cases of suspected musculoskeletal neoplasm. Both primary and secondary malignant neoplasms as well as benign neoplasms were studied. The MR features exhibited by this technique are discussed. The images were evaluated by two experienced MRI specialists and graded as to utility into one of four categories as compared to conventional T1- and T2-weighted sequences. In the majority of cases this technique was found to be helpful or extremely helpful. The most useful features of this technique were the elimination of chemical shift artifact, the improved ability to evaluate superficial lesions or the extension of lesions into subcutaneous fat, and substantially improved visualization of both bone marrow and bone cortex interfaces. T2-weighted, fat suppressed imaging proved to be a useful new tool for evaluating musculoskeletal neoplasms.

Adolescent↗
PubMed1993

Giant extra-adrenal pheochromocytoma: magnetic resonance imaging with gadolinium-DTPA enhancement.

A case report of a 35-yr-old male presenting with moderate hypertension and a giant extra-adrenal pheochromocytoma is discussed. The patient was treated by chemotherapy and surgery with regression of the lesion and clinical relief of symptoms. Initial magnetic resonance imaging (MRI) with gadolinium-DTPA enhancement revealed a large complex pelvic mass. Follow-up examination following chemotherapy three months later demonstrated partial regression. The MRI findings and the pattern of gadolinium-DTPA enhancement are discussed.

Adult↗
PubMed1993

Morton neuroma: evaluation with MR imaging performed with contrast enhancement and fat suppression.

PURPOSE: To evaluate clinically suspected Morton neuroma with contrast material-enhanced magnetic resonance (MR) images. MATERIALS AND METHODS: Fifteen patients with clinically suspected Morton neuroma underwent examination with conventional T1- and T2-weighted MR imaging and a combination of fat suppression and administration of gadopentetate dimeglumine. A T1-weighted spectral presaturation with inversion recovery sequence was used for fat suppression. RESULTS: In six patients, a tumor that conformed to the clinical findings was seen in the interdigital space; surgical findings in these patients correlated closely with the imaging findings in all patients. Patients without positive findings on MR images tended to have less typical clinical findings and received nonsurgical treatment. In all patients, the lesions were best depicted with the combination of contrast-enhanced imaging and fat suppression; conventional MR images either entirely failed to demonstrate the lesions or demonstrated the lesions less clearly. CONCLUSION: In patients who need imaging confirmation of a clinically suspected Morton neuroma, the combination of fat suppression and contrast enhancement provides reliable high-contrast images.

Adipose Tissue↗
PubMed1992

MR imaging in rhinocerebral and intracranial mucormycosis with CT and pathologic correlation.

Three cases of mucormycosis, two in diabetics and one in an intravenous drug abuse patient, are presented. Magnetic resonance imaging proved to be useful in all cases, as was computed tomography. In one case, extremely low signal was detected from the fungal mass. It is surmised that this appearance was a result of high concentrations of iron and manganese. The low-signal area simulated air in paranasal sinuses; however, CT displayed a mildly enhancing soft tissue mass and allowed the correct diagnosis to be made. In another patient, pontine infarction was demonstrated by MR. In the third case the MR findings of mucormycosis involving the basal ganglia are shown and correlated with CT. Subsequent imaging studies demonstrated reduction of the mass, corresponding to clinical improvement.

Adult↗
PubMed1992

Magnetic resonance of the inferior vena cava.

MRI was performed in 54 patients with abnormalities of the inferior vena cava (IVC). These included 16 patients with extrinsic IVC compression, 32 patients with intrinsic IVC abnormalities, and 6 patients with IVC dilatation. All patients had spin-echo imaging, and 21 had MR angiography. While presaturated spin-echo images showed intrinsic lesions to advantage, collateral vessels were best appreciated with MR angiography. The IVC is well evaluated with MRI techniques.

Adenocarcinoma↗
PubMed1991

Halfscan: clinical applications in MR imaging.

A series of phantom experiments was performed to evaluate the effects of half-Fourier scanning, also known as Halfscan, on signal-to-noise and in-plane resolution. Resolution was not demonstrably effected with the available phantoms and signal-to-noise was seen to vary as the square root of time independent of the implementation of Halfscan. Evaluation of the Halfscan technique was made using data from 240 patients. The technique was found to "salvage" examination in an estimated 70% of uncooperative patients where motion artifact or other patient concerns would have precluded clinically useful studies. Halfscan was also combined with other techniques such as increased number of signal acquisitions, prolonged repetition times and three-dimensional Fourier transform technique.

Artifacts↗
PubMed1991

Primary lymphoma of the cervix: MRI findings with gadolinium.

MRI evaluation of primary cervical lymphoma has not been reported. We report such a case of primary cervical lymphoma, a lesion well seen and well delineated from normal tissue by MRI. Although primary lymphoma of the cervix is a rare entity, the disease does exist and can be well demonstrated by MRI. We evaluated the MR appearance of this lesion with both nonenhanced and gadolinium-enhanced imaging.

Adult↗