Paul C. Hajek

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The capability of 1.5-T MR imaging to detect focal defects in articular cartilage was investigated with cadaveric knees with and without intraarticular injection of saline and gadolinium-DTPA (Gd-DTPA). Full-thickness cartilage lesions ranging in diameter from 1 to 5 mm were surgically created in the femoral articular surfaces. Images were acquired with a(More)
Ninety-eight brain contusions in 17 patients served as a data base for a comparative study of MR and CT for defining brain contusions. MR was the more sensitive technique, detecting 98% of the brain contusions compared with only 56% by CT. CT was slightly better for showing hemorrhagic components, documenting 77% of hemorrhages compared with 71% for MR. The(More)
The radiomorphological appearance of fibrous metaphyseal defects (FMDs) is demonstrated by long-term follow-up studies. A characteristic radiomorphological course rather than a typical single appearance can be established. These findings correlate well with the duration of these tumor-like lesions; therefore, the radiological findings allow conclusions to(More)
We describe the morphologic changes that follow division of the transverse carpal ligament in patients with carpal tunnel syndrome. Fifteen hands in 12 patients with carpal tunnel syndrome were studied with magnetic resonance imaging before operation and for 6 weeks after operation. Eight hands were studied at 8 months after operation. Carpal arch width,(More)
One hundred fifty-eight magnetic resonance (MR) imaging studies of the spine were reviewed to assess the frequency and distribution of focal deposits with signal behavior typical of fat in the axial bone marrow. In addition, three fresh cadaveric spines were evaluated with MR imaging and subsequently sectioned for anatomic and histologic correlation.(More)
Eighteen patients with multiple myeloma (clinical stages 1-3) and a control group of 21 persons underwent magnetic resonance imaging (MRI) studies of the lower thoracic and lumbar spine. This was done to determine the potential benefit of MRI in addition to conventional radiographs, tomograms, computed tomography and nuclear scans. In addition to focal(More)
Ultrasound (US) proved highly effective for detection, localization, and delineation of enlarged lymph nodes of the neck. Infiltration of adjacent structures, specifically the common, internal, and external carotid arteries, and the neck muscles was reliably demonstrated. Benign and malignant lymph node enlargement could not be differentiated. US(More)
Sonography and computed tomography play complementary roles in imaging mass lesions in the salivary glands and their surroundings. Ninety per cent of parotid tumors originate from the superficial lobe, and we consider sonography to be the method of choice for imaging these lesions. The sensitivity of high-resolution sonography in detecting intraparotid(More)
Three-dimensional computer reconstruction of magnetic resonance images (MRI) of ten cadaveric specimens was used to determine carpal tunnel volume and carpal arch width. Magnetic resonance images-acquired data were compared with direct measurement of cadaveric carpal canal volume by means of a silicone-injection technique. Mean MRI three-dimensional(More)
The ability to distinguish bowel from other intraabdominal structures is essential for the accurate diagnosis of intraabdominal disease with MR. Because perfluorochemicals have no protons, they cause no MR signal. Since they are immiscible with water, they create a signal void in bowel independent of bowel contents and thus are suitable as oral contrast(More)