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Biomedical subjects

A Neuhold

Publications and source records attributed to A Neuhold.

At least 37 records · Page 2Linked to original sources

[Magnetic resonance tomography in pulmonary hypertension].

We examined 23 patients with pulmonary hypertension of varying aetiology by MRI and compared the results with those of right heart catheterisation. The best correlation was obtained between right ventricular mural thickness and mean pulmonary pressure (R = 0.91, p = 0.001). There was significant correlation (R = 0.85, p = 0.001) for the diameter of the inferior vena cava, which was dilated in all patients with pulmonary hypertension. There was no significant correlation between mean pulmonary pressure and the diameters of the superior vena cava or the main pulmonary artery branches (R = 0.55 and 0.75 respectively, p less than 0.05). Amongst functional measurements there was a correlation between right ventricular ejection fraction and mean pulmonary artery pressure (R = 0.71, p = 0.001). There was no correlation between right ventricular end-systolic and end-diastolic volume. In all patients with pulmonary hypertension, dynamic flow sensitive gradient echo sequences showed the presence of tricuspid insufficiency. A further semiquantitative criterion for the presence of pulmonary hypertension in 4 patients (17%) was an abnormal signal from the main pulmonary artery in early to mid-systole shown on T1-weighted transverse sections.

Adult↗

Quantitative assessment of aortic regurgitation by magnetic resonance imaging.

Thirty patients with aortic regurgitation and 10 controls were examined using an 0.5 T superconducting magnet with ECG gating. In each case a multislice-multiphase spinecho study in sagittal-coronal double angulated projection (four-chamber equivalent) was performed to assess left and right ventricular volumes, ejection fraction and regurgitation fraction. Additionally, a blood-flow sensitive cine-study (gradient echo, FAME) was performed to visualize direction and area of regurgitant jet. Magnetic resonance imaging (MRI) data were compared with quantitative and qualitative assessment of aortic regurgitation by angiography, Doppler and colour flow mapping. Using the FAME mode MRI, we were able to detect the regurgitant jet as an area of signal loss within the left ventricle in all patients; moderate correlation to jet area was determined by colour flow mapping (R = 0.60, P less than 0.001). Determination of left and right ventricular end-diastolic, end-systolic and stroke volumes by MRI revealed excellent correlation with invasive data (R = 0.94, P = 0.0001). With MRI regurgitant fraction (RF) could be calculated from the difference between right and left ventricular stroke volumes, which showed good correlation with invasively determined RF (R = 0.91, P = 0.001) and with qualitative Sellers' scoring (R = 0.70, P less than 0.001), respectively. Thus MRI provides the basis for noninvasive detection and quantification of aortic regurgitation.

Adolescent↗

Combined use of spin-echo and gradient-echo MR-imaging in cervical disk disease. Comparison with myelography and intraoperative findings.

In a prospective study we compared the diagnostic value of combined gradient-echo (GE) and spin-echo (SE) MR imaging with cervical myelography in 30 patients with clinical signs and symptoms of cervical radiculopathy and/or myelopathy due to disk disease. Only patients who subsequently underwent surgery (anterior interbody approach) were included. By means of MRI the clinically relevant segment was identified in all cases, by means of myelography in all but two patients. Using both spin-echo (SE) and gradient-echo (GE) techniques it was possible to differentiate between bone tissue and disk material by MR in all but one. It is concluded that MRI-especially gradient-echo imaging is a viable alternative to cervical myelography and can be considered as an initial diagnostic procedure for suspected cervical disk disease.

Adult↗

EEG brain mapping in diagnostic and therapeutic assessment of dementia.

EEG brain mapping has been proven to be a valuable method in diagnostic and therapeutic assessment in dementia trials, because it is a readily available, inexpensive, high time-resolution method for objective and quantitative evaluation of the neurophysiological aspects of dementias. In 111 mildly to moderately demented patients diagnosed according to DSM-III as both degenerative [senile dementia of the Alzheimer type (SDAT)] and vascular [multi-infarct dementia (MID) type], we were interested in showing not only differences between SDAT and MID patients and normal controls but also the relationship between CT scans, EEG maps, clinical ratings and psychometric tests. CT measures included 10 cerebrospinal fluid (CSF) space variables as well as 17 cortical density measures (1.7 mm3 cubes, Hounsfield units). Clinical investigations consisted of the SCAG score/factors, the digit symbol substitution test, the trailmaking test and the digit span forward test. In brain maps, SDAT patients showed slightly to moderately more slow and less alpha and beta activity as well as a slowing of the dominant frequency (DF) and the centroid (C) than did normal controls. These findings were most prominent in parietal and temporal regions. MID patients exhibited markedly augmented delta/theta and attenuated alpha and beta activity and a slowing of the DF and C. These neurophysiological findings suggest a deterioration of vigilance. Differences between SDAT and MID patients were found mostly in measures concerning differences in the maps. Brain maps of correlation coefficients between CT and EEG variables demonstrated: the greater the anterior horn distance, lateral ventricle distance, and Evan's index, as well as the less cortical density, the more delta/theta and the less alpha and beta activity in the EEG. Moreover, the higher the delta/theta, the less alpha and beta activity, the higher the SCAG scores, and the worse the psychometric performance. From the pharmacological point of view, we observed a significant improvement in vigilance after administration of several nootropic drugs both in normal and pathologically aging subjects, which was associated also with improvement of psychopathometric scores. Based on multi-variante analysis of variance (MANOVA)/Hotlelling T2 we observed a drug's effect in different brain regions of MID and SDAT patients. Thus, pharmaco-EEG mapping mediates valuable information regarding if, how, when, in which dosage, and where a nootropic drug acts on its target organ--the aging human brain.

Aged↗

Classifying calcaneal tendon injury according to MRI findings.

Magnetic resonance imaging was performed on 28 patients with suspected calcaneal tendon injury prior to treatment. None of the patients were involved in competitive sports. All underwent clinical examination, some had had ultrasound or CT scans. We identified four types of lesions: type I, inflammatory reaction; type II, degenerative change; type III, incomplete rupture and type IV, complete rupture. Thirteen of the 28 patients underwent surgery and the diagnostic findings were verified. We recommend that type I, type II and type III lesions be managed conservatively, while type IV lesions should be operated in the young and active patient.

Achilles Tendon↗

[Diagnosis of arrhythmogenic right ventricular disease using magnetic resonance tomography].

In our study, 12 patients with ventricular arrhythmias, but without any documented cardiac disease, and 10 healthy volunteers were investigated by spin echo magnetic resonance tomography (MRT) using a 0.5 Tesla magnet. Axial T1-weighted spin-echo sequences, as well as double angulated, multislice-multiphase sequences were acquired. Left- and right-ventricular volumes were then evaluated by outlining the endocardium in an end-systolic and an end-diastolic frame. The right-ventricular free wall and the right-ventricular outflow tract were investigated for myocardial thickness and intramural fat.

Adipose Tissue↗

[MR tomography findings in lesions of the Achilles tendon].

The aim of this study was to determine the value of MRT in patients with lesions of the Achilles' tendon and to verify the findings, as far as possible, both surgically and histologically. By means of MRT it was possible to classify 28 patients into four groups. Incomplete tendon rupture could be distinguished from various stages of chronic degenerative changes. Clinical examination and MRT made it possible to define strictly the indications for surgery and to offer the patients treatment at an early stage.

Achilles Tendon↗

[Spondylitis: the clinical picture and follow-up assessment by magnetic resonance tomography].

MRI of proven spondylitis was performed in 39 patients. Acute spondylitis appeared hypointense on T1-weighted and hyperintense on T2-weighted images. Following intravenous application of Gd-DTPA, enhancement of the marrow and disk was seen. With progressive healing increasing signal was seen on T1-weighted images. This was caused by the presence of focal fat marrow representing the first sign of therapy response. Corresponding to the clinical healing process T1-signal increased due to fatty marrow, while the T2-signal decreased as well as the enhancement following Gd-DTPA application. Therefore, MR imaging can be recommended as the method of choice for early diagnosis of spondylitis and assessment of therapy response.

Adult↗

[Cine-MR for the quantification of regurgitation defects by a volume method].

We have examined 46 patients with angiographically confirmed regurgitant lesions (26 mitral insufficiency, 20 aortic insufficiency) using a 0.5 Tesla magnet. In each patient, multiplane and multiphase spin-echo sequences were obtained in a plane angled in the sagittal and coronal direction in the long axis of the heart; left and right ventricular volumes, ejection fractions and regurgitation fractions were calculated. In addition, a blood-flow sensitive gradient echo sequence was obtained in order to determine the direction and extent of the regurgitant jet. The data was compared with the results of angiography and echocardiography. By means of the gradient echo technique, MRI was able to show the regurgitant jet in every patient. There was a linear correlation between volumes determined by MRI and angiography. The best agreement was found for left ventricular contraction volume (R = 0.82, p is less than 0.0001). Comparison of the noninvasive and angiographic method showed a linear correlation for AI patients of R = 0.91 (p is less than 0.001), which is somewhat better than for patients with MI (R = 0.84, p less than 0.001). Semiquantitative grading of MI with a gradient echo technique showed a linear correlation with angiography of R = 0.73 (p less than 0.001), for AI there was agreement between both methods in 72% of cases. A comparison between MRI and colour Doppler sonography showed only moderately good correlation R = 0.69 (p less than 0.01).

Adult↗

Injury of the Achilles tendon: diagnosis with sonography.

We determined the diagnostic accuracy of sonography for the assessment of injury to the Achilles tendon. After anatomic investigations in three human cadavers, we performed a clinical study in 24 healthy volunteers and 73 symptomatic patients referred for achillodynia or signs of heel thickening or both in whom a clinical diagnosis of acute total rupture was excluded. High-resolution real-time sonography was performed and the results were compared with final clinical diagnoses (55 patients) and surgical findings (18 patients). Fifty-two of the patients had been involved in various sporting activities (long-distance runners, jumpers, and basketball players), three patients had familial hypercholesterolemia, five patients had systemic inflammatory disease, and 13 patients had no known underlying cause. Anatomic investigation demonstrated accurate assessment of tendon structure and thickness. Sonograms were abnormal in 53 patients (sensitivity, 0.72; specificity, 0.83), and the extent of structural disorders of the tendon could be assessed properly. Abnormalities occurred in the form of tendon swelling (45%), abnormal tendon structure (42%), rupture (15%), and peritendinous lesions (47%). No changes were detected in low-grade disease of short duration, which suggests symptoms caused by functional disorders. Sonography is valuable in the diagnosis of various lesions of the Achilles tendon and its surrounding tissue. Furthermore, it can be used to estimate the degree of tendon abnormality and to differentiate between functional and morphologic conditions.

Achilles Tendon↗

[Results of magnetic resonance and computerized tomography studies of augmentation plastic surgery of the anterior cruciate ligament using carbon fibers. II].

19 patients out of those described in part I were examined by MRI and CT. We quote MRI as an excellent new mean of imaging without exposure to ionising radiation which renders sufficient information about the internal knee-structures without surgical invasion. The signal density for the neoligament as well intraarticular as in the "over the top"-position gives evidence for the ingrowth of mesenchymal structures. The MRI diagnosis was proved by histological examination in 2 cases. Very good correspondence between clinic examination and the CT-images could be found. On top of that the tibial drilling holes could be shown in an excellent way. The CT-scan is a fine instrument to judge the postoperative state of the anterior cruciate ligament. The density measurement inside and outside the bone gives evidence for mesenchymal growth inside the carbon fibre structure and the existence of a new natural ligament.

Anterior Cruciate Ligament↗

[Taybi-Rubinstein syndrome: the value of the x-ray picture].

28 cases of Taybi-Rubinstein syndrome with different radiological appearances are presented along with radiological differential diagnosis. Broadening of the distal phalanx of the thumb (68%) and great toe (64%) was the most common radiological sign followed by incomplete fissures of the distal phalanges of the thumb and first toes. Radiological examination in association with clinical signs and laboratory investigations is an essential part in the diagnosis of the Taybi-Rubinstein syndrome.

Abnormalities, Multiple↗

[Magnetic resonance tomography of the craniocervical junction in chronic polyarthritis].

Magnetic resonance imaging and conventional radiographs and tomograms were correlated in 61 patients with chronic polyarthritis. Radiographs of the occipito-cervical junction only demonstrated bone lesions, erosions were detected on conventional tomograms. MRI was adequate for demonstration of bone abnormalities and soft tissue lesion and was especially suitable for detection of complications at the cervical spinal cord.

Adult↗

[Space-occupying lesions of the pineal region in magnetic resonance tomography].

Preoperative CT and MRI studies of 24 patients with space-occupying lesions of the pineal region were analysed. MRI demonstrated all 24 lesions, whereas CT could detect only 20 out of 24. MRI was superior to CT in assessment of size, localisation and relation to adjacent structures. No significant difference was found between CT and MRI in preoperative prediction of tumour histology.

Brain Neoplasms↗

MRI evaluation of pigmented skin tumors. Preliminary study.

Magnetic resonance imaging (MRI) was performed in 16 patients with pigmented skin lesions, seven with nodular melanomas, two with superficial spreading melanomas, two with subcutaneous melanoma metastases, and five with different benign pigmented nodular skin lesions. The results of MRI were compared with the histologic diagnoses. Signal intensities of the lesions were compared with subcutaneous fat, revealing a lower signal intensity of all lesions on T1-weighted images. Intensity measurements showed a significant (P less than .01) difference between benign and malignant lesions on T2-weighted images.

Adult↗