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Biomedical subjects

G Bachmann

Publications and source records attributed to G Bachmann.

At least 55 records · Page 3Linked to original sources
PubMed1998

[The diagnostic accuracy and therapeutic relevance of CT arthrography and MR arthrography of the shoulder].

PURPOSE: In glenohumeral instability, CT arthrography and MR arthrography of the shoulder joint were compared to assess accuracy in diagnosis of labral lesions and other internal derangements of the joint, and to evaluate relevance of both imaging methods for therapy. METHODS: 38 patients with symptoms of shoulder instability were examined clinically, arthrographically with CT and MRI, and arthroscopically. Arthrography with CT and MRI was performed in a double-contrast technique after single puncture and simultaneous injection of the contrast agents for both imaging methods. Type and extent of lesions on arthrographic imaging were criteria for planning therapy to a conservative, sole arthroscopic, or open surgical approach. RESULTS: Sensitivity in diagnosis of labral lesion (26 defects) was 85% in CT, 88% in MRI and 100% if both methods were used. Full-thickness tears of the rotator cuff were visualised in CT in 73%, and in MRI in 100%. Diagnostic accuracy increased from partial to complete to total defects. An open surgical approach was correctly predicted on MRI in 90% and on CT in 71%. A sole arthroscopic therapy was correctly foreseen on both arthrographic techniques in only 38% due to difficulties to assess glenohumeral ligaments. CONCLUSIONS: CT arthrography and MR arthrography were excellent for diagnosing labral lesions. MRI is superior to CT in the imaging of all joint structures. Surgical approach can be accurately predicted with both imaging methods but special surgical techniques cannot be effectively planned to replace diagnostic arthroscopy in all cases.

Adult↗
PubMed1998

Follow-up in carriers of the 'MELAS' mutation without strokes.

Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases, but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the future.

Adolescent↗
PubMed1998

Good luck rites in contemporary infertility.

OBJECTIVE: To explore whether contemporary women use good luck rites in the infertility situation. STUDY DESIGN: Prospective study in a tertiary infertility center where women were asked to describe any type of good luck act performed on the day of critical medical intervention (either intrauterine insemination or embryo transfer) to achieve pregnancy. RESULTS: Four hundred thirty-eight consecutive infertile women participated. Good luck rituals, as defined by patients, included prayer, wearing of objects, fantasies and other acts performed specifically on the day of the medical intervention. While 40% of the study population reported engaging in a good luck act prior to intrauterine insemination of embryo transfer, there was no significant difference in pregnancy rates observed in women reporting utilization versus nonutilization of fertility rituals. CONCLUSION: This study indicated that good luck rites are commonly performed by women undergoing infertility procedures on the day of a critical intervention. The fact of their common presence attests to their importance for the well-being of the individual; however, there is no evidence of direct benefit in terms of higher pregnancy rates. The possibility of secondary benefits needs to be explored further.

Ceremonial Behavior↗
PubMed1998

Estradiol-releasing vaginal ring delivery system for urogenital atrophy. Experience over the past decade.

OBJECTIVE: To critically assess the world literature on the efficacy and safety of the vaginal ring estradiol delivery system for the local treatment of urogenital atrophy due to hypoestrogenism. STUDY DESIGN: Published data over the past decade on the vaginal ring delivery system were reviewed. RESULTS: Data from comparative clinical trials indicate that the vaginal ring delivery system is comparable in efficacy, safety and tolerability to other vaginal delivery systems and may enhance compliance because of its ease of use. CONCLUSION: The vaginal ring delivery system offers an alternative to other vaginal delivery systems with the advantages of accurate and sustained dosing and minimal need for patient intervention.

Aged↗
PubMed1997

[Comparison of different MRT techniques in the diagnosis of degenerative cartilage diseases. In vitro study of 50 joint specimens of the knee at T1.5].

PURPOSE: An experimental study was performed on joint specimens of the knee to assess the advantages and disadvantages of 14 generally available sequences in cartilage imaging. METHODS: Each of the 50 surgically exposed cadaveric joints of the knee was examined by the following sequences: T1, proton- and T2 weighted spin echo(SE) sequences, proton- and T2 weighted Turbo-SE, T1 weighted SE with fat suppression, MTC combined with T1-weighted SE and T2 weighted FLASH-2 D, STIR, FISP-3 D, FLASH-3 D (with fat suppression), and MR arthrography. We assessed the image quality by a scale, signal to noise-ratio of cartilage and joint fluid, and the accuracy in detection of cartilage lesions. Pathology and arthroscopy were reference methods to MRI, and demonstrated grade 1-4 lesions on 186 of 300 joint facettes. RESULTS: Advanced stages of cartilage lesions (65 grade 3 and 4 lesions) were detected by standard SE sequences in 67-94%. Application of volume techniques (FISP-3 D, FLASH-3 D), high definition matrix (512 pixel), MTC with FLASH-2 D and MR-arthrography improved the sensitivity up to 82-100%. Superficial lesions (65 grade 2 lesions) were demonstrated in 3-38%, and on MR arthrography in 45%. Structural changes (56 Grade 1 lesions) were recorded on MR) in only 10%. CONCLUSIONS: With regard to standard SE sequences, the detectability of cartilage lesions can be improved by techniques that use 512 matrices, selective cartilage imaging, and volume acquisition.

Aged↗
PubMed1997

[CT quantification of pleuropulmonary lesions in severe thoracic trauma].

PURPOSE: Computed quantification of the extent of pleuropulmonary trauma by CT and comparison with conventional chest x-ray--Impact on therapy and correlation with mechanical ventilation support and clinical outcome. METHOD: In a prospective trial, 50 patients with clinically suspicious blunt chest trauma were evaluated using CT and conventional chest x-ray. The computed quantification of ventilated lung provided by CT volumetry was correlated with the consecutive artificial respiration parameters and the clinical outcome. RESULTS: We found a high correlation between CT volumetry and artificial ventilation concerning maximal pressures and inspiratory oxygen concentration (FiO2, Goris-Score) (r = 0.89, Pearson). The graduation of thoracic trauma correlated highly with the duration of mechanical ventilation (r = 0.98, Pearson). Especially with regard to atelectases and lung contusions CT is superior compared to conventional chest x-ray; only 32% and 43%, respectively, were identified by conventional chest x-ray. CONCLUSION: CT allows rapid classification and quantification of pulmonary lesions after thoracic trauma and provides higher sensitivity and reliability. Because of the great correlation with the extent of artificial respiration in respect of duration and pressure, prognosis of the individual patient, as well as a differential therapy, appear possible.

Adolescent↗
PubMed1997

Endotracheal placement of balloon-expanded stents: an experimental study in rabbits.

The authors implanted balloon-expanded stents in the trachea of 10 rabbits for 1 day to 6 months. Follow-up included chest radiography, clinical examination, light microscopy, and scanning electron microscopy. Pneumothorax occurred in two cases after placement, marked stridor due to mucus plugging in all cases, signs of infection in three cases (two of which developed into pneumonitis), compression of the upper stent end in two cases, and moderate to severe mucus plugging in all cases. Microscopically, none of the stents was completely covered with epithelium even at 6 months. The high rate of complications may be a result of the rigid construction, which does not allow tracheal movement or adaptation of the stent shape to the shape of the trachea.

Animals↗
PubMed1996

[Traumatic hemarthrosis of the knee joint--clinical significance of nuclear magnetic resonance tomography].

A prospective study was performed on 94 patients with hemarthrosis of the knee to assess the value of MR imaging (MRI) in detection of bleeding sources and selection of therapy modalities. Patients were examined clinically within a week after knee trauma; the investigations performed included puncture of the joint to confirm hemarthrosis, a conventional X-ray to exclude fractures, MRI and arthroscopy. MRI was performed for diagnosis of acute lesions, definition of bleeding sources by morphological criteria, and allocation of patients to conservative or surgical therapy. Arthroscopy was performed to control MRI, to visualize bleeding sources, and to maintain therapy if necessary. The 94 patients were found on arthroscopy to have a total of 123 bleeding sources, which were correctly defined by MRI in each of 107 cases as an acute lesion communicating with the joint space; 16 bleeding sources were not found and there were 10 false-positive reports. In keeping with our treatment strategies, arthroscopy disclosed lesions requiring surgical therapy in 77 of 94 patients (82%) and lesions that would be adequately treated by conservative therapy in 17 of 94 patients (18%). MRI predicted surgical or conservative therapy correctly before arthroscopy in 83 of 94 patients (88%). In conclusion, MRI has a high predictive value in definition of acute lesions that will lead to hemarthrosis of the knee. This noninvasive method allows screening out of the relatively small portion of patients without severe lesions, who then do not have to be subjected to further invasive therapy.

Adolescent↗
PubMed1996

[Clinical value of conventional radiology and MRI in assessing osteochondrosis dissecans stability].

A prospective study was performed on 72 patients with osteochondritis dissecans (OD) of the knee and ankle to compare plane radiography, MRI and arthroscopy before therapeutic procedures. Special interest was placed on the assessment of fragment stability with radiological methods for staging related therapy. OD was localized in 46 cases on the femoral condyle and in 26 cases on the talus. Radiological methods were performed simultaneously and shortly before definite arthroscopical therapy. Using conventional radiography, OD of the condyles was staged according to the classification of Rodegerdts and Gleissner and OD of the talus suggested by Berndt and Harty. MRI staging was performed by morphology of the interface of the OD. Arthroscopical staging based on the classification of Guhl. There was an excellent correlation between the stages in MRI and arthroscopy, showing correct prediction of stable and unstable fragments in 92%. In contrast, fragment stability could not be efficiently assessed by conventional radiology because fragments could be stably fixed in cases of bony separation. MRI is indicated before performance of staging-related therapy of OD to select patients with stable fragments for conservative therapy and those with unstable OD for surgical therapy.

Adolescent↗
PubMed1996

[Value of arthro-CT in decision for arthroscopic or open stabilization in ventral shoulder instability].

A prospective study was performed on 30 patients with anterior instability of the shoulder to assess the diagnostic value of preoperative arthro-CT. One special diagnostic problem was the definition of diagnostic criteria for arthroscopic or open surgery. Arthro-CT of the shoulder was performed with a double-contrast technique. Visualization of labral tears, bony lesions, glenohumeral ligaments and disruption of the rotator cuff was registered. Findings of arthro-CT were verified by diagnostic arthroscopy. Therapy consisted of either arthroscopic or open surgery depending on the lesion pattern found in diagnostic arthroscopy. The most common cause of anterior instability (90% of cases) was damage of the ventro-caudal labral complex, which was diagnosed by arthro-CT with a sensitivity of 93% and a positive predictive value of 93%. Specificity and negative predictive value were reduced to 33%; the overall accuracy was 87%. In all, 16 patients were successfully treated using arthroscopic stabilization because whereas 14 patients required open surgery because diagnostic arthroscopy contraindicated an arthroscopic approach. The preoperative arthro-CT failed to define all criteria mandatory for the decision for arthroscopic or open surgery because pathoanatomy of the joint was not sufficiently demonstrated with the current technique of arthro-CT.

Adolescent↗
PubMed1996

The clinical and genetic correlates of MRI findings in myotonic dystrophy.

Amplification of an unstable CTG trinucleotide repeat sequence in a protein kinase gene on chromosome 19 has recently been recognised as the molecular basis of myotonic dystrophy (DM), a multi-system disorder with a wide spectrum of muscular and extramuscular manifestations. The CTG expansion of 40 patients was assessed by direct genotype analysis of the white blood cell DNA and correlated with MRI of the brain and muscles, and with functional clinical data. Cerebral pathology on MRI consisted of diffuse atrophy (68%), subcortical white matter lesions (65%), wide Virchow-Robin spaces (38%) and thickening of the skull (35%). Cerebral atrophy and extent of white matter disease correlated significantly with mental retardation, duration of disease and CTG fragment amplification. MRI of the muscular system showed fatty degeneration of different degrees in neighbouring muscles causing a mosaic pattern of the thigh in 38% and the calf in 44%. Muscular changes on MRI were strongly correlated with muscular impairment but less strongly with CTG expansion. Changes on MRI reflect the stage of development of tissue pathology in DM, modified by defect of the DM gene. Pathology on MRI is strongly correlated with functional deficits.

Adolescent↗
PubMed1996

An anatomical approach to oophorectomy during vaginal hysterectomy.

Oophorectomy is not always performed at the time of vaginal hysterectomy because of technical difficulties encountered in visualizing the ovaries and clamping and ligating the infundibulopelvic ligament. After uterine removal, a method that simplifies the approach involves separating the round ligament along the avascular space from the fallopian tube and ovary, then ligating the infundibulopelvic ligament separately from the round ligament, rather than clamping and ligating the infundibulopelvic and round ligaments together.

Adnexa Uteri↗
PubMed1996

Better performance through amblyopic than through normal eyes.

Spatio-temporal interpolation reconstructs the (complete) motion path of objects presented discontinuously, e.g. under stroboscopic illumination or in television. Interpolative vernier stimuli were created by presenting two line segments with a temporal delay instead of a spatial offset. Ten amblyopic patients had to indicate whether the lower segment of the moving target was offset to the left or right relative to the upper segment. For five patients we also measured thresholds for a conventional moving vernier. Five normal subjects were measured with sharply focused and blurred interpolative verniers. At low velocities of interpolative vernier targets, results of amblyopic eyes are inferior to those of normal eyes. However, 9 out of 10 patients perform better using their amblyopic than using their normal eye at high velocities. In control subjects, blurred stimuli yield results similar to those of amblyopic eyes, indicating a similarity between (optical) blur and the mechanisms underlying amblyopia. Thresholds for conventional vernier targets of amblyopic observers, on the other hand, are constant over the whole velocity range for both normal and amblyopic eyes, with a better performance of the normal eye at all velocities. The consequences for models of amblyopia are discussed.

Adult↗
PubMed1996

The role of magnetic resonance imaging and scintigraphy in the diagnosis of pathologic changes of the mandible after radiation therapy.

A prospective study of 85 patients with oral cancer, treated with high-dose radiation therapy, was performed to assess the value of magnetic resonance imaging (MRI) and scintigraphy for diagnosis of pathologic changes in the mandible. During postradiotherapeutic monitoring, radiation osteomyelitis occurred in 12 cases, tumor recurrences infiltrating the mandible in five cases, and progressive periodontal disease in nine cases. MRI permitted early diagnosis of radiation osteomyelitis in 11 out of 12 cases; only two cases were false positive. In scintigraphy with 99mTc-HDP, all alterations of the mandible, such as osteoradionecrosis, tumor infiltration, and periodontitis, showed a high uptake, resulting in a sensitivity of up to 100%, but a low specificity of 57%. Scintigraphy permitted assessment of the extension and location of the lesions. Both methods were superior to conventional radiography and clinical examination and should be integrated into a comprehensive follow-up program after radiation therapy.

Adult↗
PubMed1996

[MRI in hemarthrosis of the knee joint: assessment of cause of bleeding, injury pattern and therapy].

PURPOSE: Patients with hemarthrosis of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy. METHODS: A prospective study was performed on 120 patients who underwent MRI and arthroscopy. Joint lesions and bleeding sources were documented separately on a standardised form. RESULTS: Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight lesions in 13% to 40% of the cases. Single, combined and bland lesions were accurately diagnosed in MRI which permitted a correct prediction of surgical and conservative therapy in 96% and 80%. CONCLUSIONS: Morphological criteria in MRI permit identification of bleeding sources in hemarthrosis of the knee. Different lesion patterns can be separated for the planing of therapy.

Adolescent↗