Biomedical subjects
T H Berquist
Publications and source records attributed to T H Berquist.
Magnetic resonance imaging of renal oncocytoma.
Two cases of renal oncocytoma studied by magnetic resonance imaging (MRI) suggest that this new imaging modality may prove useful in the preoperative diagnosis of oncocytoma and its differentiation from renal cell carcinoma.
Bilateral hemorrhagic parapelvic pseudocysts.
The development of bilateral parapelvic hemorrhagic pseudocysts with abdominal pain, systemic symptoms of malaise and fever, elevation of erythrocyte sedimentation rate and serum alkaline phosphatase, and decreased renal function is described in a patient taking anticoagulants. The symptoms and signs resolved with the resolution of the hemorrhagic pseudocysts. The bilaterality and selective localization of these hemorrhages suggest the existence of a specific pathogenesis. The advent of new imaging techniques in the last decade allows for a diagnosis and a better understanding of the pathologic processes that affect the renal sinus.
Imaging of adult cervical spine trauma.
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Magnetic resonance imaging of the wrist: normal cross sectional imaging and selected abnormal cases.
Using a small surface coil and limited field of view, the authors have generated 13 contiguous, 3 mm, transverse sections of the wrist of a cadaver. The identity of the structures recorded has been established by subsequent dissection of the cadaver. The article presents the 13 MR sections together with drawings identifying the recorded structures at each level. These anatomic sections are amplified by 7 transverse MR images showing alterations of the normal anatomy in clinical examples of wrist pathology.
MR imaging of the musculoskeletal system: a 5-year appraisal.
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In-111-labeled leukocyte scintigraphy in suspected orthopedic prosthesis infection: comparison with other imaging modalities.
When infection of prosthetic orthopedic implants is suspected, optimal management requires accurate confirmation or exclusion of infection. The authors retrospectively studied 98 patients with possible infection who underwent scanning with indium-111-labeled white blood cells (WBCs) and subsequently underwent surgery within 14 days. At surgery, 50 patients had infections, as determined by means of culture or histologic results. The diagnostic accuracy of In-111 scanning was compared with that of plain radiography, arthrography, three-phase bone scanning, and various clinical and laboratory findings classically associated with infection. Positive findings on In-111 WBC scans and elevated erythrocyte sedimentation rates were found to be the most predictive variables in the diagnosis of septic prostheses (P less than or equal to .001 and P less than or equal to .002, respectively). Likelihood ratio analysis more clearly demonstrated the superiority of In-111 WBC scanning, with positive and negative scans yielding likelihood ratios of 5.0 and 0.16, respectively.
The genesis of Kienböck's disease: evaluation of a case by magnetic resonance imaging.
We describe a patient in whom, despite normal initial radiographs, tomograms, bone scan, and magnetic resonance imaging, Kienböck's disease developed without the patient suffering an intercurrent injury. This case suggests that Kienböck's disease may not always develop acutely after a single injury but may have a more gradual onset.
Arthrographic study of painful total hip arthroplasty: refined criteria.
The criteria for a diagnosis of loosening or infection of hip arthroplasties on arthrographic study were further refined by a retrospective review of 178 arthrograms representing 170 patients. The 97 arthroplasties that were surgically evaluated form the basis of this report. With the refined criteria, subtraction arthrography had a sensitivity of 96% and specificity of 92% for demonstrating loosening of the femoral component and a sensitivity of 97% and a specificity of 68% for demonstrating loosening of the acetabular component. Pseudocapsule size and the presence of bursae were important factors influencing arthrographic interpretation. Arthrographic findings of pseudocapsule irregularity and the presence of nonbursal cavities were suggestive of infection but were not sensitive or specific. Laboratory evaluation of aspirated material was a more reliable predictor of infection, although its sensitivity was only 71%.
Magnetic resonance imaging in the diagnosis of disruption of the posterior tibial tendon.
Magnetic resonance imaging (MRI), a useful technique of studying soft tissues of the body, can be very effective in assessing the integrity of tendons. Usually a patient with a complete tear of the posterior tibial tendon has characteristic physical findings. In the patient presented, MRI demonstrated a complete disruption of the posterior tibial tendon, despite the absence of the commonly associated clinical findings. In view of the difficulties encountered with attempted tenography of the completely torn posterior tibial tendon, MRI provides a sensitive alternative diagnostic technique.
Pseudobursae: a useful finding in patients with painful hip arthroplasty.
A retrospective review of 178 consecutive subtraction hip arthrograms (175 patients) was performed to evaluate the significance of cavities or bursal communications (or both) with the pseudocapsule in patients with painful hip arthroplasty. Bursae and/or communicating cavities were shown in 75 (43%) of the 175 patients. Communicating irregular cavities were noted in 12 patients (nine infected), and smooth bursae or bursalike structures were noted in 63 patients. The most frequent bursal locations were the greater trochanteric region (32/63), supraacetabular region (18/63), and iliopsoas (12/63). Three patients had multiple bursae. Six of the 18 acetabular bursae were associated with previous dislocations. Twenty-seven patients with bursae had no radiographic findings of loosening or infection. Of these 27, 12 (44%) responded to local injection of anesthetic into the bursa and were judged clinically to have bursitis. Arthrography, with aspiration from the bursae or cavities and injection of anesthetic, provides additional information regarding painful hip arthroplasty and may prevent unnecessary surgery.
Magnetic resonance imaging of the temporomandibular joint: preliminary work.
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Preoperative staging of rectal carcinoma by computed tomography and 0.15T magnetic resonance imaging. Preliminary report.
A prospective study was done on 34 patients using magnetic resonance imaging (MRI) and computed tomography (CT) preoperatively to stage patients with known rectal carcinoma. The study was done to determine the accuracy and clinical usefulness of CT and MRI. The Thoeni staging method was used. Twenty-four of 30 cases were staged correctly by CT. Sixteen of 27 were staged correctly by MRI. CT detected lymph node metastases in six of 15 cases with one false-positive. MRI detected lymph node metastases in two of 15 patients with one false-positive. CT was the preferred examination, and was useful in some cases. These cases included patients with small tumors who were considered for local excision and patients with extensive disease who were candidates for preoperative or intraoperative radiation treatment. MRI demonstrated extensive disease, as did CT in our later cases.
Evaluation of the prostate by magnetic resonance imaging.
Forty-seven male patients with suspected prostatic disease underwent magnetic resonance imaging (MRI) of the pelvis on a Picker resistive magnet operating at 0.15 T; 33 had histologically proved adenocarcinoma, 12 benign prostatic hypertrophy, 1 a transitional cell carcinoma, and 1 a seminoma. Eleven normal subjects also were included in the study. The study attempted to (1) define the MRI characteristics of the normal prostate, benign prostatic hypertrophy, and prostatic adenocarcinoma, (2) evaluate various pulse sequences in imaging the prostate, and (3) compare MRI findings with clinical, pathologic, and computed tomography results. Various pulse sequences, including inversion recovery and spin-echo with short and long TE and TR, were used. MRI was sensitive in detecting intracapsular and extracapsular prostatic disease. The finding of inhomogeneous signal texture throughout the gland was a sensitive but nonspecific finding for adenocarcinoma. A focal nodule with prolonged T1 and T2 relaxation times was the most specific MRI finding for adenocarcinoma. Extracapsular spread of neoplasm was often demonstrated, and because of its superior soft-tissue contrast ability, MRI was more accurate than computed tomography in delineating extracapsular extension.
Imaging-assisted percutaneous biopsy of the thoracic spine.
Confirmation of tissue pathologic changes often is necessary before appropriate therapy can be instituted for lesions of the thoracic spine. Plain film roentgenography and computed tomography provide the key information needed for the percutaneous biopsy procedure. The location and type of bone involvement (lytic or sclerotic) and the presence or absence of a soft tissue mass determine the imaging technique and the choice of needle to use for safe and accurate performance of the procedure. In 26 patients with thoracic spinal or paraspinal lesions (or both), biopsy was done with use of fluoroscopic or computed tomographic guidance. The overall accuracy was 90%. Pneumothorax occurred in two patients. Percutaneous biopsy is a rapid, safe technique for diagnosis of lesions of the thoracic spine.
Modern imaging and endoscopic biopsy techniques in Egyptian mummies.
Egyptian mummies have been popular subjects of radiographic investigation since 1896. Computed tomography (CT) and magnetic resonance imaging (MRI) have recently been added to the growing list of modern techniques used to study these relics. The Minnesota Mummy Project was organized to examine four well preserved Egyptian mummies dating from the XVIIIth (1575-1308 B.C.) and XXVth (715-663 B.C.) Dynasties. Plain radiographs and CT scans were obtained on all specimens. One individual was selected for additional endoscopic and microscopic correlation with CT findings in the thoracic cavity. The collapsed heart was identified by CT. A percutaneous biopsy of the heart was then performed with a flexible fiberoptic endoscope, passed through a small hole drilled into the chest wall. Microscopy of prepared ventricular specimens revealed striated muscle fibers consistent with myocardium. These results emphasize the utility of CT as a noninvasive paleoradiologic tool. Another mummy was examined by MRI to search for minute quantities of residual moisture possibly trapped within the desiccated tissues. Only a free-induction-decay signal could be obtained, but this was insufficient to generate an image. Thus, it appears that present MRI is not suitable for the paleopathologic investigation of dehydrated structures.
Magnetic resonance imaging of osteosarcomas. Comparison with computed tomography.
This study was done to describe the magnetic resonance imaging (MRI) characteristics of osteosarcomas and to determine the clinical usefulness of MRI in the evaluation of patients with these tumors. Ten patients with osteosarcomas were examined with a Picker MRI scanner (0.15 Tesla resistive magnet). All had computed tomograms available for comparison. For demonstrating tumor extent in marrow, MRI was superior to computed tomography (CT) in 60% and about equal to CT in 40%. For defining soft tissue mass, MRI was superior to CT in 40% and about equal to CT in 60%. Direct sagittal and coronal images on MRI and superior contrast differences between tumor and normal tissues with MRI were the reasons for the advantage of MRI in these instances. CT was superior in all cases for demonstrating calcifications. Overall, MRI is better than CT for defining local extent of osteosarcomas. It is of greatest value in the peripheral skeleton, in the medullary canal, and in soft tissues.
Magnetic resonance imaging of musculoskeletal trauma.
Magnetic resonance imaging has unique capabilities for evaluating musculoskeletal trauma. It can clearly delineate tears and hemorrhage in muscles, ligaments, and tendons and can provide clinically useful information in patients with joint injuries. Other developing applications include evaluation of compartment syndromes, injuries of peripheral nerves and blood vessels, and chronic sequelae of trauma. If a correct technical approach is employed, MRI has a clinical role that is complementary to other imaging modalities.