Biomedical subjects

K G Hermann

Publications and source records attributed to K G Hermann.

4 recordsLinked to original sources

PubMed2007

[Imaging in ankylosing spondylitis].

In addition to the typical clinical symptoms, conventional x-rays and magnetic resonance imaging (MRI) are important for the diagnosis and management of ankylosing spondylitis (AS). While radiography is mainly useful for detecting chronic structural changes, MRI is, in addition, able to detect active inflammation. The detection of structural changes in the sacroiliac joints and, in part, the spine, remains the gold standard for the diagnosis of AS. The detection of active sacroiliitis or spondylitis in early disease stages is only possible using MR techniques such as STIR and T1 post-gadolinium sequences. Lateral radiographs of the spine are useful for detecting shiny corners and the characteristic syndesmophytes and ankylosis. The modified Stoke Anklyosing Spondylitis Spine Score (SASSS) is the best scoring method for quantifying such changes, allthough only the cervical and the lumber spine are evaluated with this method. MRI changes can also be quantified. New scoring methods are sensitive to change only 3 months after initiation of therapy with anti-TNF agents.

Humans↗

PubMed2006

[Ankylosing spondylitis--current state of imaging including scoring methods].

Conventional radiography and magnetic resonance imaging (MRI) are currently the most widely used imaging methods for the initial diagnostic evaluation and follow-up of patients with ankylosing spondylitis (AS). Scintigraphy, computed tomography (CT), and positron emission tomography (PET) only play minor roles, although some are being further developed. AS is characterized by inflammatory changes to the sacroiliac joints (SIJs) and spine, as well as asymmetrical arthritis of the peripheral joints and joints near the trunk. The diagnosis of AS is based on clinical parameters and the presence of chronic inflammatory changes to the SIJs on conventional radiographs. Typical radiographic changes also involve the spine. MRI depicts not only chronic changes, but also active inflammatory lesions, which are important for the diagnosis of early disease and precursors of AS. The scoring system of choice for quantifying spinal changes depicted by conventional radiography is the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). MRI allows the quantitative evaluation of changes involving the SIJs and the spine. Various MRI scoring systems have been proposed to quantify these changes, but they require further validation. This review article presents the imaging modalities used in AS patients, typical findings, and relevant methods of analysis. The most recent developments are discussed.

Diagnostic Imaging↗

PubMed2004

Evaluation of a wavelet-based computer-assisted detection system for identifying microcalcifications in digital full-field mammography.

PURPOSE: To evaluate a new wavelet-based computer-assisted detection (CAD) system for detecting and enhancing microcalcifications. MATERIAL AND METHODS: A total of 280 mammograms acquired by full-field digital mammography (Senographe 2000D; G.E. Medical Systems Milwaukee, Wisc., USA) were analyzed with and without a new wavelet-based CAD system for detecting and enhancing microcalcifications. The mammograms comprised roughly equal numbers of cases from each of the BIRADS (Breast Imaging, Reporting and Data System, according to the American College of Roentgenology) categories 1-5. Histologic confirmation was available for all of the 180 cases assigned BIRADS categories 3-5. Four readers interpreted all 280 images for suspicious microcalcifications using a scale of 1-5. The readers alternately assessed 5 images with and 5 without CAD. In a second reading immediately following the first, the readers had to reassess the 280 mammograms. The images that had already been interpreted without CAD were now presented with CAD and vice versa. The images were interpreted as soft copies on a diagnostic mammography workstation (Image Diagnost GmbH, Neufahrn/Munich, Germany). All images interpreted with CAD were presented with enhancement of microcalcifications by wavelet algorithms and prompting of microcalcifications. ROC (receiver operating characteristic) analyses were performed, and image interpretation time with and without CAD was measured. RESULTS: The overall time for interpretation required by all 4 readers together was 483 min with CAD compared to 580 min without CAD. ROC analysis revealed no significant advantage of CAD for the individual readers. Readers 3 (0.811/0.817) and 4 (0.799/0.843) had a slightly improved AUC (area under the curve) with CAD. Readers 1 and 2 had a slightly lower AUC with CAD (0.832 versus 0.861 and 0.818 versus 0.849). CONCLUSION: The CAD system significantly (P<0.05, t test) speeded up image interpretation with respect to the identification of microcalcifications, while the diagnostic quality remained almost identical under the study conditions.

Breast Diseases↗

PubMed1990

Impact of a clinical pharmacokinetic service on patients treated with aminoglycosides: a cost-benefit analysis.

In a prospective, randomized study, 75 adults receiving aminoglycosides were followed by a clinical pharmacokinetic service and 70 followed as controls. The two groups were similar in age, gender, height, and APACHE II score. A cost-to-charge ratio was used to derive direct costs of hospitalization and calculate cost-benefit. Excluded from this comparison were patients with incomplete acceptance of pharmacokinetic service recommendations and patients followed by other clinical pharmacists. Pharmacokinetic service patients had shorter hospitalizations (322.67 +/- 270.28 h; controls 442.89 +/- 536.81, p = 0.087) and febrile periods (50.05 +/- 79.38 h; controls 92.23 +/- 122.50, p less than 0.05). More pharmacokinetic service patients had adequate peak levels. Pharmacokinetic service direct costs were lower ($7,102.56 +/- 9,898.19; controls $13,758.64 +/- 22,874.31, p less than 0.05). Calculated direct cost of the service was $85.00/patient. Annual savings for 500 patients is $2,220,540.00.

Amikacin↗