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Biomedical subjects

E Grabbe

Publications and source records attributed to E Grabbe.

At least 145 records · Page 8Linked to original sources
PubMed1994

[MR angiography of peripheral blood vessels].

MR angiography (MRA) of the extremities is in its infancy. The potential appears to be great, but several problems have to be solved before MRA can routinely be used as the definitive diagnostic procedure. MRA can detect arterial stenoses, occlusions, and determine their length. The degree of stenosis, however, is overestimated. Although the spatial resolution of MRA allows depiction of the tibial vessels, evaluation of their major branches is necessary for distal bypass surgery. The postoperative examination of patients with bypasses seems to be a practical alternative with regard to the established angiography techniques. At present, MRA is cost-effective, but not as readily available as conventional angiography. MRA technology continues to advance rapidly. With improved technology, judicious use, and appropriate patient selection, in the future MRA should assume a role in the evaluation of peripheral arterial occlusive disease.

Arterial Occlusive Diseases↗
PubMed1993

Epiphysial ossification centres in iliosacral joints: anatomy and computed tomography.

Bilateral apparently bony structures of different forms and sizes located in the inferior and superior ventral parts of the sacroiliac joints were observed on axial CT images of the pelvic region of juvenile patients. No other pathological changes were noted in the sacroiliac joints of these individuals. In one patient the bony structures could also be seen on a conventional plain radiograph. We also examined 3 juvenile autopsy specimens of this joint using radiology, CT, macroscopical evaluation and histology. In two of them, structures could be detected on the CT scans which were similar to those observed in the young patients. Macroscopic investigations revealed the structures to be secondary ossification centres located in the articular cartilage of the lateral part of the os sacrum at the levels of the first and third sacral segments. According to older anatomical literature, these epiphysial ossification centres contribute to the auricular surface of the lateral part of the os sacrum and the free lateral surface of the inferior sacral parts. They can be observed between the ages of 12 and 25 years and begin to synostose with the lateral part around the age of 18 years. In macerated juvenile specimens of the bony pelvis, free ossicles were not detectable in the region of the sacroiliac joints. Histological peculiarities of the ossification process observed are discussed. These physiologically occurring ossification centres are to be differentiated from pathological alterations appearing as bony or bone-like structures on CT scans.

Adolescent↗
PubMed1993

[Signal characteristics of malignant and benign lesions in dynamic 2D-MRT of the breast].

In a retrospective study of 400 dynamic MR examinations of the breast the signal/time ratio of 62 histopathologically correlated lesions (19 benign, 42 malignant) was evaluated. Points of evaluation were initial signal enhancement (1st and 2nd minute), post-initial signal appearance (2nd to 5th minute) and signal distribution (homogeneous, marginal). Based on these criteria, a point system was defined to help in the assessment of lesions in dynamic breast-MR imaging. The overall sensitivity of this method was 95.3%, the specificity to 89.5% and the accuracy to 93.5%. Pitfalls resulted in two cases of non-invasive carcinoma and in two patients with fibroadenoma.

Adenofibroma↗
PubMed1993

[Initial experiences with the MR "magnitude contrast angiography of the lower extremities].

45 patients with occlusive peripheral vascular disease were examined by MR angiography in a retrospective study. A FISP 3D sequence was used by acquiring a rephased and a dephased data set. The individual slices were post-processed by using a maximum-intensity-projection algorithm. The MRA results of the popliteal and tibioperoneal arteries were compared to conventional or digital angiography. In comparing these techniques MR angiography cannot be accepted for pre- and postoperative staging of patients with occlusive peripheral vascular disease. In future new MRA techniques may be useful in postoperative staging of patients with peripheral vascular stenosis.

Arterial Occlusive Diseases↗
PubMed1993

[Broadband ultrasound attenuation (BUA) in the diagnosis of osteoporosis].

The measurement of broadband ultrasound attenuation (BUA) of the calcaneus has been introduced as a new technique that provides information about both bone mass and structure without the use of ionizing radiation. BUA measurements of the calcaneus were obtained in 324 patients, 109 of whom had osteoporosis. Two hundred and fifteen patients served as control group. BUA values were compared with dual-energy X-ray absorptiometry (DXA) measurements of the lumbar spine, the neck and the heel. The precision error of BUA was 4.1%. The correlation with spinal bone mineral density was r = 0.49, with DXA of the neck r = 0.52 and of the calcaneus r = 0.56, respectively. Patients with osteoporosis showed a significant decrease in BUA compared with healthy subjects (61.4 dB/MHz vs 74.6 dB/MHz). Roc analysis demonstrated that BUA was inferior to DXA of the lumbar spine in detecting osteoporosis.

Absorptiometry, Photon↗
PubMed1993

[Imaging techniques in the diagnosis of functional disorders of the shoulder].

Modern imaging techniques such as ultrasound, computer tomography and magnetic resonance imaging serve an increasingly important role as an extension of conventional radiological methods for clarification of shoulder disorders. The precise representation of bony, cartilaginous and soft tissue injuries has become indispensable for successful therapeutic decision making. A stepwise employment of the various examination techniques of the shoulder should be utilized while keeping in mind the patient's particular complex of symptoms.

Arthrography↗
PubMed1992

Digital radiography in urologic imaging: radiation dose reduction on urethrocystography.

Digital luminescent radiography (DLR) is a new form of digital radiographic technology which can be used as an alternative to conventional radiologic systems; it replaces conventional screen-film systems by photostimulable phosphorus. Due to the linear dynamic range of photostimulable phosphorus, x-ray examinations can be performed with significantly lower radiation exposure. In this study radiation dose was reduced by about 90% using DLR for urethrocystography.

Humans↗
PubMed1992

[Experiences with digital luminescence radiography (DLR) in pediatric radiology].

X-ray examinations represent a variety of indications with different demands on exposure latitude, spatial and contrast resolution of screen-film-system combinations in paediatric radiography. The value of digital luminescent radiography (DLR) was compared to conventional x-ray examinations carried out with screen-film-systems, speed class 200, by analysing matched digital and conventional exposures in 200 abdominal, 600 skeletal and 300 chest examinations. The exposure of DLR was reduced to 50% of conventional exposure. Analysing the results in abdominal and skeletal radiography, DLR proved to be diagnostically equivalent to conventional radiography despite the reduction in exposure dose. DLR of the newborn chest compared to conventional x-ray studies was not always sufficient due to lower digital spatial resolution.

Adolescent↗
PubMed1992

[Apophyseal elements of the sacroiliac joint in the computed tomographic image].

Between the ages of 12 and 18 years apophyseal elements appear within the SI joints which fuse subsequently with the sacrum. These apophyses could be demonstrated during two autopsies on juveniles and were seen in 7 CT examinations of patients between the ages of 15 and 19. On CT they appeared as narrow, round or band-like opacities situated on the ventral aspect of the joint. The differentiation of these normal findings from pathological changes within the SI joints is discussed.

Adolescent↗
PubMed1992

[Comparative studies with quantitative computed tomography and dual-energy x-ray absorptiometry on bone density in renal osteopathy].

Measurements of bone density were carried out in 25 patients on dialysis for terminal renal insufficiency, using quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA). Unlike in subjects with normal kidneys, there was no significant correlation between these methods in this series. Ten patients showed an increase in bone density of the vertebral spongiosa on QCT measurements, which was interpreted as due to osteosclerotic bone changes in renal osteopathy. QCT showed advantages over DXA in demonstrating these changes.

Absorptiometry, Photon↗
PubMed1992

[The tilted screen-cassette ("grid cut-off" effect). A problem of bedside thoracic diagnosis].

Tilting of a grid during portable radiography leads to uneven exposures, and errors greater than 3 degrees can lead to errors in interpretation. Differentiation from abnormal findings can be made by recognising exposure difference of extrathoracic comparable areas. The difficulties caused by tilting of the grid can be reduced by increasing the film focus distance and by using suitable grids. A new cassette holder with an integrated balance makes it possible to correct tilting of the grid rapidly and effectively. This results in improved image quality which can be applied not only to conventional exposure systems but is also of advantage when using digital methods.

Diagnostic Errors↗
PubMed1992

[The value of digital luminescence radiography within the scope of traumatologic follow-up examinations].

At the present time we cannot unhesitatingly recommend the general use of digital luminescence radiography in traumatological follow-up examinations. Marked drawbacks of this method are, for example, sudden changes in contrast in the marginal areas of osteosynthesis material, occasional limitations in the detailed assessment of spongious structures and problems in respect of imaging geometry. By modifying the image processing parameters, increasing the image matrix and enlarging the format spectrum, however, these problems should be capable of being resolved in the future. Positive features, on the other hand, are even now the possibility of reducing the dosage to a marked degree in many traumatological follow-up examinations, especially in children and adolescents, and in case of conservatively treated fractures. In the long run we can foresee the routine use of digitalised examination methods on traumatology coupled with the possibility of storage in an image filing and communication system, although this is at present not yet feasible due to lack of requisite experience and the cost of the necessary equipment.

Computer Systems↗
PubMed1992

[The place of computed tomography and magnetic resonance tomography in the diagnosis of bone sequestra].

Conventional radiographs of 45 patients with chronic osteomyelitis, mostly of posttraumatic origin, were compared with computed tomography (CT) and operative findings. In addition, magnetic resonance imaging (MRI) was performed in 6 of these patients. In 28 patients (65%) bony sequestra were identified and in most cases histologically confirmed by surgical exploration. CT proved to be the method of choice for the preoperative diagnosis of sequestra in patients with chronic osteomyelitis. MRI provided no significant additional diagnostic information, its advantage appears to be a more detailed and accurate imaging of the extent of the intra- or extraosseous inflammation, thereby facilitating surgical planning.

Adult↗
PubMed1990

[Computed tomography and magnetic resonance tomography in cases of pelvic tumors unconnected with organs].

Computed tomography (CT) will remain the method of choice in cases of parapelvic masses. It allows to identify the extent and the relationship of the mass to the neighbouring structures. Some cases serve to point out the utility of CT in demonstrating findings useful in distinguishing various types of tumours. MRT is compared to CT in visualizing the contrast between tumour and bone marrow as well as surrounding soft tissues, especially muscle. Furthermore, MRT may be helpful in early detection of the cartilage cap of an osseous mass and tumour recurrence.

Humans↗