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Biomedical subjects

R Erlemann

Publications and source records attributed to R Erlemann.

At least 55 records · Page 3Linked to original sources
PubMed1991

[A comparison between digital luminescence radiography and conventional myelography].

The potential of digital luminescence radiography in replacing conventional myelography was analyzed using ROC methodology. 95 conventional (CR), digital (DR) and edge enhanced digital (EDR) myelograms (49 disk herniations, 46 normal) were read independently by 5 radiologists; and a ROC analysis was performed. Higher confidence levels were used in making both correct and incorrect diagnoses with DR and EDR than with CR. However, no statistically significant differences between AUC (area under the curve) values obtained with the different techniques, were noted. The separate analysis of cervical and lumbar myelograms showed no significant differences between the different techniques. With DR and EDR, the sensitivity of 4 of 5 readers was somewhat higher in the lumbar but lower in the cervical region than with CR. Replacement of conventional by digital luminescence myelography seems possible; however, some decrease of sensitivity in the cervical region must be accepted.

Humans↗
PubMed1991

[Contrasts in the FLASH sequences in the study of musculoskeletal tumors: phantom study and theoretical calculations].

The contrast between samples simulating musculoskeletal neoplasms and muscle or bone marrow achieved with FLASH sequences, was analysed in phantom studies and was compared with theoretically calculated contrast with and without correction for flip angle distribution over the slice profile. The contrast was correlated closer with the flip angle than with TR or TE. For delineation of the tumour from muscle, only a FLASH sequence with a large flip angle following intravenous administration of Gd-DTPA can be recommended, if a tumour shows a clear Gd-DTPA uptake. With all FLASH sequences analysed, no sufficient contrast between "tumour" without Gd-DTPA uptake and muscle was obtained. Maximal contrast between "tumour" and bone marrow was achieved with small flip angles; and an additional peak was noted with large flip angles and short TR. Experimentally measured T2*-dependent contrasts were nearly identical with theoretically calculated contrasts without correction of flip angle distribution. For calculation of T1-dependent contrasts, correction of the flip angle distribution over the slice profile was of high value.

Bone Neoplasms↗
PubMed1991

[The x-ray morphology of parosteal osteosarcoma (POS)].

31 cases of parosteal osteosarcoma (POS) including both the differentiated and dedifferentiated variant were reviewed. Most patients were in the second and third decades of life. The tumours usually arose in the meta-diaphyseal (52%) and diaphyseal (33%) portion of long bones with a predilection for the knee (55%). Twenty-seven percent of patients showed involvement of the medullary cavity. 68% of lesions affected the bone cortex. A periosteal reaction was observed in 24% of patients. The characteristic but not pathognomic sign of a fine radiolucent line separating the tumour from the cortex was seen in only 48%. No characteristic radiographic features were evident that allowed a differentiation between the differentiated and the dedifferentiated POS. The presence or absence of medullary involvement was no a reliable diagnostic criterion. In all dedifferentiated POS, however, we observed a periosteal reaction.

Adolescent↗
PubMed1991

[The diagnostic reliability of the occipitomental radiograph of the paranasal sinuses. Correlation with magnetic resonance tomography].

100 conventional occipitomental radiographs of the paranasal sinuses were studied independently by five radiologists. Predictive values were determined, based on MRI as the gold standard. Sensitivity and specificity for detection of mucosal thickening in the sinuses were: maxillary sinus: 0.73/0.76, frontal sinus: 0.20/0.85, ethmoid sinus: 0.38/0.87, sphenoid sinus: 0.14/0.96. In the maxillary sinus polypoid thickening was demonstrated with a significantly higher sensitivity than that of diffuse mucosal thickening (0.82 versus 0.65, Chi-square-test, p less than 0.01). Because of the low predictive values the occipitomental view is insufficient to assessing mucosal thickening in the paranasal sinuses, with the exception of polypoid mucosal thickening in the maxillary sinus.

Adult↗
PubMed1991

[Deformities and trauma sequelae of the ankle joint in children and adolescents].

Knowledge of the normal development of the ankle joint is mandatory to understand the mechanism of injuries in children and adolescents. Some fractures (juvenile Tillaux's or two-fragment triplane fracture) occur only within a particular period of growth, which is determined by the degree of epiphyseal fusion. Tarsal coalitions are the deformities seen most frequently. Special radiographic techniques must be applied for the diagnosis. Ball and socket joint, tibiotalar slant and Trevor's disease are rare deformities, each of which is associated with a pathognomonic radiographic pattern. Some typical joint deformities may be seen in patients with neuromuscular disease. This has to be considered when nothing else is found in the clinical history.

Adolescent↗
PubMed1991

[Magnetic resonance tomography of the ankle joint].

To define the clinical role of MRI of the ankle joint, a total of 88 patients was investigated. In the evaluation of ligamentous injury, MRI was inferior to established imaging methods. By contrast, it provided additional therapy-relevant information in the assessment of hemophilic arthropathy, osteochondritis dissecans, and inflammatory and neoplastic diseases of the ankle joint. In the latter conditions, MRI may make other more conventional methods of examining the ankle joint unnecessary.

Ankle Injuries↗
PubMed1991

[The radiologic evaluation of osteosyntheses].

Surgeons, orthopedic surgeons, and neurosurgeons employ a wide variety of different osteosynthetic devices in the treatment of fractures and in spinal surgery. In order to assess these instruments correctly, the radiologist should be aware of their purpose and normal appearance. The complications should be identified, such as delayed union, pseudarthrosis, dislocation, device loosening, fracture of the device, osteomyelitis, and re-fracture. To evaluate the fixation device adequately two plain radiographs are mandatory. Normal fracture healing and the most commonly used fixation devices, the abnormalities of fracture healing and their complications are discussed.

Fracture Fixation, Internal↗
PubMed1990

Response of osteosarcoma and Ewing sarcoma to preoperative chemotherapy: assessment with dynamic and static MR imaging and skeletal scintigraphy.

In 15 osteosarcomas and six Ewing sarcomas, response to preoperative chemotherapy was assessed with magnetic resonance (MR) imaging without and with gadolinium diethylenetriaminepentaacetic acid (DTPA) enhancement and with dynamic Gd-DTPA studies, and the results were compared with the scintigraphic findings. All studies were obtained prior to and following preoperative chemotherapy. Static MR imaging was of little value for assessment of response; reduction in signal intensity within soft-tissue masses on the T2-weighted spin-echo images indicated response with a sufficient degree of accuracy (71%) but low sensitivity, whereas an increase in signal intensity after Gd-DTPA administration indicated zones of viable tissue with low specificity. With three-phase skeletal scintigraphy, the findings in the perfusion and blood-pool phases were of no value, whereas the findings in the osseous phase allowed the prediction of response with an accuracy of 73.7%. Of all techniques employed, dynamic MR imaging had the highest degree of accuracy (85.7%) and was superior to scintigraphy, particularly in patients who were receiving intraarterial chemotherapy.

Adolescent↗
PubMed1990

Musculoskeletal neoplasms: fast low-angle shot MR imaging with and without Gd-DTPA.

In 121 patients, image contrast and contrast-to-noise ratios (C/Ns) obtained with gadolinium diethylene-triaminepentaacetic acid (DTPA)-enhanced and nonenhanced fast low-angle shot (FLASH) sequences were compared with those achieved with spin-echo (SE) sequences. Among FLASH sequences, contrast between neoplasms and muscle was sufficient with a flip angle of 90 degrees following administration of Gd-DTPA but was 61% lower than that with the T2-weighted SE sequence. High contrast levels were obtained between tumors and bone marrow or fat in sclerotic, calcified, and fibrotic lesions with the use of a flip angle of 90 degrees and in lytic lesions with a flip angle of 10 degrees, reaching 66% of the contrast level obtained with the T1-weighted SE sequence. C/N between tumor and surrounding tissue was always significantly lower with FLASH sequences than with the ideal SE sequences usually used for tumor delineation. Thus, a replacement of the T2-weighted SE sequences by FLASH sequences cannot be recommended. A replacement of the T1-weighted SE sequences by FLASH sequences seems possible but does not significantly reduce examination time.

Adolescent↗
PubMed1990

[Hemophilic osteoarthropathy with special reference to the elbow joint].

Hemophilia is a rare disorder, whereby recurrent bleedings into the joint can result in osteoarthropathy. Radiological changes consist of osteoporosis, enlargement of the epiphyses, irregularity of the subchondral bone surface, narrowing of the joint space, cysts, erosions, joint incongruence and joint deformity. The earlier and the more frequent bleedings have occurred that have not been treated adequately, the more of the changes mentioned above are present. In children, osteoarthropathy of the elbow is present in only about 50% of cases, and in the remaining cases the degree is mostly minimal or moderate. Differential diagnosis consists of juvenile rheumatoid arthritis in children, and rheumatoid arthritis and osteoarthritis in adults.

Adolescent↗
PubMed1990

[Conventional diagnosis of carpal luxation and instability].

The recognition of ligament disruption in carpal dislocation and the early diagnosis of carpal instability have had implications for the therapy since the evolution of differentiated surgical treatment concepts including ligament reconstruction. Plain radiography and the carpal instability series are helpful in the detection of ligament disruption. The radiological analysis is based on the configuration and arrangement of the carpals, the setting of their axes, and the detection of intercarpal gaps. Mechanisms and characteristic radiological findings in the different types of carpal dislocation and instability (scapholunate dissociation, palmar or dorsal intercalated segment instability) are demonstrated in relation to physiological appearance, and the value of conventional films in the diagnosis of carpal dislocation and instability is discussed.

Carpal Bones↗
PubMed1990

[The examination technique and normal morphology of the ligaments in MRT of the wrist].

The normal ligamentous anatomy and an efficient examination technique for the wrist are demonstrated with reference to examinations conducted in healthy volunteers. Only the ulnar complex, the radial collateral ligament, the distal intercarpal ligaments and the radial parts of the palmar and dorsal V-ligaments are adequately visualized. Thus, limited specificity means that static high-resolution MRI of the wrist cannot at present be considered an adequate examination method for the evaluation of unexplained wrist pain and instability. So far MRI can only play a key role in the diagnosis of lesions of the ulnar complex.

Humans↗
PubMed1990

[Thoracic sarcoidosis].

Sarcoidosis is essentially a granulomatous disease of unknown etiology. The pathogenesis is assumed to consist in an abnormal immune reaction to a still unidentified antigen. The commonest manifestations of sarcoidosis are mediastinal and hilar lymphadenopathy and pulmonary infiltrates. The complex variety of clinical presentations of sarcoidosis means that the differential diagnosis has to include a wide range of entities. The clinical and radiological features of thoracic sarcoidosis are described, and the spectrum of relevant investigations is discussed. With respect to radiological diagnosis, computed tomography, with its higher sensitivity than other techniques, is of particular value for the precise determination of the morphological correlate of pulmonary and nodal changes and their functional relevance.

Diagnosis, Differential↗
PubMed1989

Gadolinium-DTPA in rheumatoid arthritis and related diseases: first results with dynamic magnetic resonance imaging.

Thirty-four joints (19 knees, 15 wrists) of 31 patients suffering from rheumatoid arthritis and related disorders were examined prior to and following intravenous administration of Gadolinium-DTPA (0.1 mmol/kg body weight). T1-weighted spin-echo sequences and the gradient-echo technique FLASH were applied. FLASH scanning was used for the registration of the time-dependent changes of signal intensity following Gd-DTPA. Synovial proliferations exhibited a rapid and marked increase of signal intensity whereas fatty tissue, bone marrow, muscle and synovial effusion demonstrated only minor changes, causing enhanced contrast between synovial pannus and joint effusion or other neighbouring structures. Within the synovial pannus, ratios (absolute signal increase) of 131.3 +/- 53.4% and 122.9 +/- 51.1% were found in T1-weighted spin-echo and in FLASH sequences respectively. The average signal increase gradient of pannus (108.2 +/- 70.6%/min) was significantly (p less than 0.001) different from muscle (13.4 +/- 7.8%/min), fatty tissue (10.2 +/- 8.4%/min), bone marrow (5.5 +/- 7.1%/min), and joint effusion (14.7 +/- 7.8%/min).

Adipose Tissue↗
PubMed1989

Two-stage therapy in the treatment of sacral tumors.

Sacral tumors are rare and may be clinically overlooked for a long period, because the symptoms and signs are often mild and non-specific. This led to frequent errors in clinical diagnosis and a long delay between the onset of symptoms and treatment. On presentation the lesions frequently expanded the anterior cortex, however, in most patients the periosteum of the sacrum and the presacral fascia form an unbroken barrier for a tumor. The pelvic viscera are not infiltrated by the tumor until late. Wide excision is difficult and often causes urogenital and/or anorectal dysfunction, but preserving the sacral nerve roots often leads to local recurrence. Surgical wide excision with a combined anterior-posterior approach is considered the treatment of choice for large lesions with significant anterior intrapelvic extension. This paper reports data resulting from the treatment of five large sacral tumors with comments on the results.

Adult↗
PubMed1989

[The x-ray morphology of chondromyxoid fibroma].

29 cases of chondromyxoid fibroma (CMF) from the material submitted to the Bone Tumour Register in Münster were reviewed. The tumour was observed most frequently in the second and third decades of life, with a slight female preponderance in our series. The diaphyseal and metaphyseal regions of the lower limb were most commonly affected, with a particular predisposition for the knee. The lesions were located eccentrically in 71% showed cortical expansion in 72%, and pseudotrabeculation in 51% of cases. The lytic patterns were classified as Lodwick IA in 35%, as Lodwick IB in 45%, as Lodwick IC in 17% and as Lodwick II in 3% of cases. Due to the absence of characteristic radiographic features, the differential diagnosis from aneurysmal bone cyst, giant cell tumours and non-ossifying fibroma is often difficult. Radiographic findings would however indicate benignity and, therefore, help to differentiate the lesion from chondrosarcoma, to which it bears strong histological similarity.

Adolescent↗