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C Czerny

Publications and source records attributed to C Czerny.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Congenital and benign changes with regard to the pharynx].

DEVELOPMENT: The first part of this article is supposed to present a brief overview on the development of tissues and structures related to the pharynx, as far as they provide a better understanding of the most congenital lesions in this area of the body. BENIGN LESIONS: The second part of this article focuses on benign lesions originating in the pharynx or in neighbouring structures. Functional pharynx abnormalities are beyond the scope of this paper.

Humans↗
PubMed2000

[Malignant tumors of the pharynx].

BACKGROUND: Malignant tumors of the head and neck region are amongst the six most often occurring tumors of the body. They can be associated with the different anatomical compartments as well as different histologic types. The way of tumor spread of these malignancies depends on their histologic type and on the region. These compartments can be separated into the nasopharynx, the oropharynx, and the hypopharynx. Most of the malignant tumors belong to the squamous cell carcinomas, other histologic types are depicted less frequently. The histologic types of the other groups which are seen more often comprise of lymphomas and adenoid cystic carcinomas. The undifferentiated carcinoma of the nasopharynx is supposed to be a special type of tumor. The malignant tumors of the pharynx can also involve all three compartments. Beside these tumors, malignancies of mesenchymal origin can also be delineated. IMAGING MODALITIES: The imaging modalities most frequently used to detect these tumors and to clarify their extension are contrast enhanced computed tomography, magnetic resonance imaging, nuclear-medicine imaging modalities such as positron emission tomography. Other scintigraphic imaging methods play a less important role. CONCLUSION: The different imaging modalities of malignant pharyngeal tumors and of potentially infiltrated lymph nodes with the weightness on computed tomography and magnetic resonance imaging and their appearance in these imaging techniques shall be enhanced in this paper.

Humans↗
PubMed2000

Rheumatoid arthritis of the craniocervical region: assessment and characterization of inflammatory soft tissue proliferations with unenhanced and contrast-enhanced CT.

The aim of this study was to depict and characterize inflammatory soft tissue proliferations caused by rheumatoid arthritis (RA) in the craniocervical region by unenhanced and contrast-enhanced CT. Computed tomography of the craniocervical region was performed in 35 patients in the axial plane before and after the i.v. administration of contrast material. According to the densities and contrast enhancement of the inflammatory soft tissue proliferations, four groups were classified. Ancillary findings, such as a compression of the dural sac or spinal cord, erosions of the bony structures, and atlantoaxial subluxation, were also evaluated. Inflammatory soft tissue proliferations were depicted in 28 of 35 patients and could be differentiated by unenhanced and contrast-enhanced CT according to the above defined criteria: effusion in 6 patients (17%); hypervascular pannus in 8 (23%); hypovascular pannus in 5 (14%); and fibrous tissue in 9 patients (26%). A compression of the dural sac was seen in 11 (31%) patients; 3 of these had neurological symptoms. Erosions of the odontoid process were found in 20 (57%) patients; 16 (80%) of these also showed erosions of the atlas. Atlantoaxial subluxation was seen in 11 (31%) patients. Inflammatory soft tissue proliferations in the craniocervical region caused by RA can be reliably demonstrated and classified by unenhanced and contrast-enhanced CT, which can differentiate between joint effusion and various forms of pannus and depict ancillary findings. Computed tomography is an alternative method for patients unable to undergo an MRI examination.

Arthritis, Rheumatoid↗
PubMed2000

Subchondral bone and cartilage disease: a rediscovered functional unit.

The role of subchondral bone in the pathogenesis of cartilage damage has likely been underestimated. Subchondral bone is not only an important shock absorber, but it may also be important for cartilage metabolism. Contrary to many drawings and published reports, the subchondral region is highly vascularized and vulnerable. Its terminal vessels have, in part, direct contact with the deepest hyaline cartilage layer. The perfusion of these vessels accounts for more than 50% of the glucose, oxygen, and water requirements of cartilage. Bony structure, local metabolism, hemodynamics, and vascularization of the subchondral region differ within a single joint and from one joint to another. Owing to these differences, repetitive, chronic overloading or perfusion abnormalities may result in no pathological reaction at all in one joint, while in another joint, these same conditions may lead to osteonecrosis, osteochondritis dissecans, or degenerative changes. According to this common etiological root, similar pathological reactions beginning with marrow edema and necrosis and followed by bone and cartilage fractures, joint deformity, and insufficient healing processes are found in osteonecrosis, osteochondritis dissecans, and degenerative disease as well.

Biomechanical Phenomena↗
PubMed1999

[The value of preoperative localization studies in primary hyperparathyroidism].

Bilateral neck exploration is the standard procedure in primary hyperparathyroidism. Using a bilateral approach, preoperative localization studies are not mandatory. A localized single gland disease is the basis for a minimally invasive procedure. Therefore preoperative localization techniques play an important role in planning (minimally invasive) first time exploration for primary hyperparathyroidism. The combination of (99 m)Tc-SestaMIBI scintigraphy with ultrasound allows correct localization of the parathyroid adenoma in 86 % of all single gland diseases. Multiple gland disease could be predicted in isolated cases only. Computerized tomography and magnetic resonance imaging could not improve the results. Surgery for persistent or recurrent hyperparathyroidism should only be performed after positive localization studies.

Diagnostic Imaging↗
PubMed1999

Long-term results of different treatment modalities in 37 patients with glomus jugulare tumors.

The results of different forms of treatment of 37 patients with previously untreated glomus jugulare tumors were compared retrospectively. According to the Fisch classification system, 6 patients presented with class B tumors, 19 class C and 12 patients with class D. Twenty-eight patients underwent surgery and 9 patients had primary radiation therapy (to 50 Gy). In 20 of the surgical cases (71%), radical tumor removal could be achieved and required no further treatment over a follow-up period of 8.6 years (range 2-15 years). Incomplete tumor resection with postoperative radiation therapy resulted in progressive tumor growth in three cases. One patient in this group experienced subarachnoid bleeding that had to be managed by salvage surgery. After primary radiation therapy, glomus jugulare tumors were still evident on magnetic resonance imaging scans, but showed no signs of disease progression. As a result of our experience, we found that a one-stage radical tumor resection performed in collaboration by otologic surgeons and neurosurgeons was the best treatment for patients with large glomus jugulare tumors.

Adolescent↗
PubMed1999

Discrimination between fluid, synovium, and cartilage in patients with rheumatoid arthritis: contrast enhanced Spin Echo versus non-contrast-enhanced fat-suppressed Gradient Echo MR imaging.

PURPOSE: The aim of this study was to compare fat-suppressed T1-weighted 3D-Gradient Echo (GE)-images and conventional T1-weighted contrast-enhanced SE images in the assessment of patients with rheumatoid arthritis in an attempt to improve discrimination of inflamed synovium, joint fluid, and cartilage. PATIENTS AND METHODS: 28 knee joints in 20 patients with rheumatoid arthritis were examined with a 3 D-GE-T1 weighted sequence with frequency-selective fat suppression (Flash 3D fat sat) and T1-weighted SE-sequences after intravenous gadolinium-containing contrast agent administration using a 1.5T system. Differentiation of cartilage, synovium, and joint effusion was assessed on both sequences qualitatively by two observers and quantitatively by signal intensity measurements. RESULTS: Qualititative analysis revealed higher grading rates for cartilage/fluid differentiation with fat-suppressed T1-weighted GE images than contrast enhanced T1-SE images. Quantitative analysis by measurements of contrast-to-noise ratios revealed significantly higher rates for the Flash 3D fat sat with regard to cartilage/fluid discrimination, significantly higher rates for T1-SE post-contrast for cartilage/synovium discrimination, and significantly higher rates for T1-SE post-contrast for synovium/fluid discrimination. CONCLUSION: 3D-GE-imaging with fat-suppressed T1 weighted sequences allows sufficient differentiation of cartilage and joint fluid in patients with rheumatoid arthritis without application of contrast agents and may assist in monitoring disease progression and response to therapy. The higher contrast to noise ratios of cartilage/synovium and synovium/fluid on T1-SE images following administration of gadolinium-containing contrast agents may improve detection of disease activity.

Adult↗
PubMed1999

Intracochlear position of cochlear implant electrodes.

There are many different types of cochlear implants available on the market today and they are constantly being re-evaluated and changed. Knowledge of the exact position of the electrode within the cochlea is important in order to improve the electrical stimulation of the hearing nerve by the implants. The stimulating electrodes are usually located peripherally within the scala tympani, although several attempts have been made to develop peri-modiolar located electrode arrays. In this study, our goal was to evaluate the intracochlear positions of Nucleus, Combi 40/Combi 40 +, and newly developed peri-modiolar positioned electrodes by inserting them into fresh human temporal bones. After insertion, the bones were then histologically processed with the electrodes in situ, following perilymphatic formalin perfusion and methylmethacrylate embedding. Sections of the bones 80-100 microm thick were prepared using a sawing, grinding and polishing technique. This technique resulted in excellent preservation of the inner ear structures and clear identification of each electrode. The different types of electrodes were then evaluated as to their insertion depth, trauma to cochlear structures and location in relation to the scala tympani walls.

Cadaver↗
PubMed1999

Magnetic resonance imaging of the postoperative hip.

Magnetic resonance imaging (MRI) of the postoperative hip for delineation of various pathological conditions has been established in addition to conventional radiography and computed tomography. MRI provides superior soft-tissue contrast than the other imaging modalities, and it can be used for visualization of structures and pathological entities that cannot be depicted by conventional radiography and computed tomography. These entities include bone marrow changes such as bone marrow edema and avascular necrosis, and infiltration of the bone marrow by tumor recurrence or infections after insertion of metallic osteosynthetic material. The image quality of MRI, which is reduced as result of artifacts caused by metal alloys, can be optimized by using spin-echo or fast spin-echo sequences, and by adapting phase- and frequency-encoding directions in cases where metallic osteosynthetic materials were used. MRI, in addition to computed tomography and conventional radiography, appears to be a valuable tool for imaging the different pathological conditions of the postoperative hip, including after implantation of metallic osteosynthetic material.

Arthroplasty, Replacement, Hip↗
PubMed1999

Magnetic resonance imaging of the postoperative knee.

Due to the recent development of arthroscopic techniques in meniscal surgery and anterior cruciate ligament reconstruction, an increasing number of postoperative patients are referred for a magnetic resonance examination of the knee because of recurrent injury. Contrary to the nonoperative patient, T2-weighted sequences and, in unequivocal cases, magnetic resonance arthrography play the most important role in the evaluation of a possible meniscal retear. In patients with anterior cruciate ligament reconstruction, the changes of the magnetic resonance appearance of the anterior cruciate ligament graft during the first year after surgery must be considered in the diagnosis of retears. Recent developments in articular cartilage defect repair and the possible role of magnetic resonance imaging in the follow-up are discussed.

Anterior Cruciate Ligament↗
PubMed1999

Dry versus conventional laser imagers: film properties and image quality.

The authors compared image quality and stability with a dry laser imager versus a conventional wet laser imager. Hard copies of 56 magnetic resonance imaging and computed tomographic studies were analyzed for gray-scale distribution and temperature stability. Results with the dry laser imager did not reach the quality of results with a wet laser imager, but the performance and ecologic criteria were sufficient to make use of this technique advantageous.

Calibration↗
PubMed1999

MR arthrography of the adult acetabular capsular-labral complex: correlation with surgery and anatomy.

OBJECTIVE: Our purpose was to describe the appearance of the acetabular capsular-labral complex on MR arthrography and to correlate this appearance with surgical findings in adult patients and with gross anatomic findings in cadavers. SUBJECTS AND METHODS: MR arthrography of the hip joint was performed in 40 patients and six cadavers. All patients underwent subsequent arthrotomy of the hip. MR arthrography consisted of a T1-weighted three-dimensional gradient-echo sequence in both the coronal oblique and sagittal oblique planes after intraarticular injection of a 2 mmol/l solution of gadopentetate dimeglumine. The normal and pathologic appearance of the capsular-labral complex was assessed, and the labra were evaluated on the basis of morphology, signal intensity, presence of a tear, and attachment to the acetabulum. MR arthrography findings were correlated with the surgical results in all patients and with the anatomic sections of the cadaveric hip joint specimens. RESULTS: MR arthrography images of the T-weighted three-dimensional gradient-echo sequences allowed visualization of the anatomic structures. The normal labrum was triangular, without any sublabral sulcus, and of homogeneous low signal intensity. A recess between the labrum and the joint capsule could be identified in instances in which no thickened labrum was present. Labral lesions included labral degeneration, a tear, or a detached labrum either with or without thickening of the labrum. The sensitivity for detection and correct staging of labral lesions with MR arthrography in the patient study was 91%; the specificity, 71%; and the accuracy, 88%. CONCLUSION: MR arthrography with T1-weighted three-dimensional gradient-echo sequences allows excellent assessment of the normal and pathologic acetabular capsular-labral complex.

Acetabulum↗
PubMed1999

Osteometry of the mandible performed using dental MR imaging.

BACKGROUND AND PURPOSE: On cross-sectional and panoramic reformatted images from axial (dental) CT scans of the mandible it may be difficult to identify the inferior alveolar neurovascular bundle (IANB) in patients lacking a clear-cut bony delimitation of the mandibular canal. Dental MR images are comparable to dental CT scans, which directly show the IANB; however, measurements of length may not be reliable owing to susceptibility artifacts and field inhomogeneities in the oral cavity. Therefore, the accuracy of length measurements on dental MR images was compared with that on dental CT scans and direct osteometry. METHODS: Dental T1-weighted MR imaging using a high-resolution turbo gradient-echo sequence and dental CT were performed in six anatomic specimens. The axial scans were reformatted as panoramic and cross-sectional reconstructions on a workstation and characteristic cross sections were obtained from all mandibles. The longest axis in the bucco-lingual and apico-basal directions, the distances from the top of the mandibular canal to the top of the alveolar ridge and from the bottom of the mandibular canal to the base of the mandible, and the diameter of the bone cortex at the alveolar ridge were measured with direct osteometry on the cross sections and compared with measurements on corresponding MR and CT reformatted images. RESULTS: The correlation between direct osteometry and dental MR and CT was strong, except for the bone cortex diameter at the top of the alveolar ridge, where only a moderate correlation was found. Means of comparable length measurements were not significantly different among the three methods. CONCLUSION: The accuracy of length measurements in the jaw bones obtained using dental MR is comparable to that of dental CT and is not significantly different from direct osteometry. Thus, dental MR is a potential alternative to CT for dental imaging.

Alveolar Process↗
PubMed1998

[Diagnostic imaging of the larynx. Normal anatomy of the regional spread of pathologic changes].

The primary goal of diagnostic imaging of the larynx is analysis of submucosal structures that are not visible by clinical or endoscopic means. Therefore, image analysis of the larynx should only be performed under knowledge of the results of clinical diagnosis. The anatomic relationships of the laryngeal skeleton, the intrinsic structures, and the surrounding soft tissue are presented synoptically.

Carcinoma, Squamous Cell↗
PubMed1998

[Clinical and diagnostic imaging of labrum lesions in the hip joint].

Labral lesions are common findings in residual hip dysplasia, indicating biomechanical decompensation of the hip joint. MR-Arthrography has shown an excellent accuracy of over 90% to detect these lesions. Nevertheless, so far clinical sings, radiological diagnosis and therapeutical consequences are not well known. In a prospective study, patients suspicious for labral lesions were evaluated using a standard clinical protocol, including history, clinical signs, radiography and MR-Arthrography. Clinical signs were tested by six criteria and two provocation tests. In 11% patients clinical suspicious was wrong. Best agreement with MR-Arthrography was found for "knife sharp" groin pain (100%), impingement test (100%) and painful giving way (83%). 35% of patients showed minor (grade 2) and 52% severe (grade 3 and 4) dysplasia. Independent from grade of dysplasia, no or only slight arthrosis (grade 0 and 1) was found in 64% of patients. In 16% a single acetabular cyst could be detected on radiographs, which all could be identified as intraosseous ganglia on MR-Arthrography. Labral lesions type A (post traumatic) were found in 23% of the patients with only no or minor dysplasis (grade 1 and 2), whereas labral lesions type B (dysplastic) were found in 67% of the patients with severe dysplasia (grade 3 and 4). Clinical signs for labral lesions are typical but can also be observed in other pathologies of the hip joint. Based on the findings of this study, we recommend radiographic evaluation for dysplasia and MR-Arthrography in patients with clinical suspicion for labral lesions of the hip joint.

Acetabulum↗
PubMed1998

[MRI arthrography in labrum lesions of the hip joint. Method and diagnostic value].

Magnetic Resonance imaging with its excellent soft tissue contrast represents the method of choice for examination of intraarticular and periarticular structures of joints. However, conventional MR-imaging without intraarticular contrast application is not suitable for the diagnosis of labral lesions. MR-arthrography (MRA) of the hip clearly demonstrates labral pathology by distension of the joint space and entrance of the contrast medium into the lesion. Multiplanar 3-D-gradient echo sequences enable visualisation of the most important cranio-ventral portion of the labrum. With the MRA labral lesions can be subdivided into different, clinically relevant stages. Furthermore accompanying lesions (intra- and extraosseous ganglia, stress-bone marrow-edema) can be demonstrated. In our study including operatively verified cases, MRA showed excellent sensitivity (90%) and accuracy (91%) in detecting labral lesions. So far no complication occurred with more than 100 MRA's. Therefore this technique represents the method of choice for the radiological evaluation of labral lesions of the hip joint. In this review the technical details and results of our MRA method will be presented.

Acetabulum↗