Biomedical subjects

Joachim Böttcher

Publications and source records attributed to Joachim Böttcher.

9 recordsLinked to original sources

PubMed2006

CAD for mammography: the technique, results, current role and further developments.

CAD systems, developed to assist the radiologist in the detection of suspicious lesions on mammograms, are currently controversially discussed. The highly sensitive detection of malignant structures including priors by CAD is linked with a low specific performance and a high rate of falsely positive markings. This causes controversial results regarding the effect of CAD systems for the diagnosing radiologist. This review aims to give an overview of the current literature, to state the currently discussed controversial results of CAD and to give an outlook on the next developments, which are not limited to senology, but include many other applications of CAD systems in radiology.

Artificial Intelligence↗

PubMed2006

Computerized digital imaging techniques provided by digital X-ray radiogrammetry as new diagnostic tool in rheumatoid arthritis.

PURPOSE: Our study evaluates digital x-ray radiogrammetry (DXR) and Radiogrammetry Kit (RK) as a new diagnostic method for the measurement of disease-related osteoporosis including quantification of joint space narrowing dependent on the severity of rheumatoid arthritis (RA). MATERIALS AND METHODS: A total of 172 unselected patients with RA underwent computerized measurements of bone mineral density (BMD) and metacarpal index (MCI) by DXR, as well as a semiautomated measurement of joint space distances at the metacarpal-phalangeal articulation (JSD-MCP 2-5), both were analyzed from plain radiographs of the nondominant hand. RESULTS: Correlations between DXR-BMD and DXR-MCI vs. parameters of RK were all significant (0.34 < R < 0.61; p < 0.01). An expected negative association was observed between RK parameters and the different scoring methods (-0.27 < R < -0.59). The maximum relative decrease in BMD vs. MCI as measured by DXR between the highest and lowest RA severity group was -27.7% vs. -27.5% (p < 0.01) for the modified Larsen Score, whereas the minimal value of relative DXR-BMD and DXR-MCI reduction could be documented for the Sharp Erosion Score (-20.8% vs. -26.8%; p < 0.01). The relative reduction of mean JSD-MCP using RK significantly varied from -25.0% (Sharp Erosion Score) to -41.2% (modified Larsen Score). In addition, an excellent reproducibility of DXR and RK could be verified. CONCLUSION: DXR in combination with RK could be a promising, widely available diagnostic tool to supplement the different scoring methods of RA with quantitative data, allowing an earlier and improved diagnosis and more precision in determining disease progression.

Adolescent↗

PubMed2006

Computerized quantification of joint space narrowing and periarticular demineralization in patients with rheumatoid arthritis based on digital x-ray radiogrammetry.

OBJECTIVES: The aim of our work was to evaluate digital x-ray radiogrammetry (DXR) for the quantification of disease-related periarticular demineralization and computerized analysis of joint space distances (JSDA) for the measurement of joint space narrowing as a new diagnostic method for the early detection of joint-associated alterations and for monitoring disease progression in patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: Digital radiographs in 313 patients with varying severity of RA were performed annually and assessed by 2 radiologists using modified Larsen and also the Sharp scores within an observation period of 3 years. The hand radiographs underwent measurements of bone mineral density (BMD) and metacarpal index (MCI) by DXR, as well as computerized JSDA at the metacarpal-phalangeal articulation (JSD-MCP) for a cross-sectional and longitudinal study design. RESULTS: Both DXR-BMD (-29.6%; P < 0.01) and DXR-MCI (-31.0%; P < 0.01) revealed a notable reduction dependent on the severity of RA (from grade 1 to grade 5 of the modified Larsen score); the severity dependent decrease of mean JSD-MCP ranged from -31.9% (P < 0.01; Sharp erosion part) to -39.1% (P < 0.01) for the modified Larsen score. Over an observation period of 3 years, a significant decrease of DXR-BMD (-22.3%) and DXR-MCI (-23.3%) as well as JSD-MCP mean (-17.5%) was observed (P < 0.05), whereas an accentuated decline of DXR and JSDA parameters was verified for patients without disease-modifying antirheumatic drugs or methotrexate therapy. CONCLUSION: Computerized analysis of hand radiographs by DXR and JSDA is a promising approach to assess the severity and to monitor the progression of RA because DXR and JSDA are timely able to measure periarticular demineralization and also narrowing of JSD-MCP dependent on the severity, the medical treatment and the course of RA.

Absorptiometry, Photon↗

PubMed2005

Assessment of skeletal age at the wrist in children with a new ultrasound device.

BACKGROUND: Determination of skeletal development in children is important. The most common method of evaluation uses the standards of Greulich and Pyle (G and P) to assess the left hand radiograph. Numerous assessments may be made during follow-up. OBJECTIVE: The aim of our study was to compare the accuracy of a new sonographic method with the standard radiographic method. MATERIALS AND METHODS: Seventy consecutive patients (age 6-17 years; 34 girls, 36 boys) underwent radiography of the left hand, followed by sonographic examination of the same hand using the BonAge system (Sunlight Medical Ltd., Israel). This system evaluates the relationship between the velocity of sound passing thorough the distal radial and ulna epiphysis and growth, using gender- and ethnicity-based algorithms. One experienced paediatric radiologist analysed the radiograph and assigned bone age scores based on the G and P atlas for the whole left hand and for the distal radius alone. The radiologist was blinded to the chronological age (CA), height of the patient and the BonAge result. Correlation between BonAge and G and P was undertaken. RESULTS: In 65 patients, BonAge measurement could be performed successfully. In five patients, the scanning process was impossible using the ultrasound device. The r(2) (r is the Pearson correlation coefficient) of the BonAge ultrasound measurement and the G and P method was 0.82. The averaged accuracy (i.e. absolute difference in years between G and P reading and BonAge ultrasonic results) was calculated. Results were similar for boys and girls: 1.0+/-0.8 years for the whole left hand and 0.8+/-0.7 year for the distal radius. On average, the difference between BonAge and CA is the same as the difference between G and P and CA, i.e. 1.4 years. CONCLUSIONS: The BonAge device demonstrates the ability of ultrasound to produce an accurate assessment of bone age. The results are highly correlated with skeletal age evaluated conventionally using the G and P method. Obvious advantages of the ultrasound device are objectivity, lack of ionizing radiation, and easy accessibility.

Adolescent↗

PubMed2005

Influence of image-capturing parameters on digital X-ray radiogrammetry.

The purpose of this study was to evaluate the importance of different image-capturing conditions, which might influence the characteristics of radiographs and, consequently, impact calculations of bone mineral density (BMD) and Metacarpal Index (MCI) using digital X-ray radiogrammetry (DXR). Radiographs of the left hand of deceased males were acquired three times using systematically varied parameters: 4-8 miliamp seconds (mA); 40-52 kV; film-focus distance (FFD); 90-130 cm; film sensitivity, 200/400; and different image modalities (conventional vs original digital radiographs as well as digital printouts). Furthermore, the interradiograph reproducibility using both conventional equipment and printouts vs originals of digital images and the intraradiograph reproducibility (either conventional or digital printouts) were evaluated. All BMD and MCI measurements were obtained with the DXR technology. The interradiograph reproducibility of DXR-BMD using conventional images under standardized conditions (6 mAs; 42 kV; 1 m FFD; film sensitivity of 200) was calculated to be coefficient of variation (CV) = 0.49% for Agfa Curix film and CV = 0.33% for Kodak T-MAT-Plus film, whereas reproducibility error using digital images ranged from CV = 0.57% (digital printouts; Philips) to CV = 1.50% (original digital images; Siemens). The intraradiograph reproducibility error was observed to be CV = 0.13% (conventional; Kodak film) vs CV = 0.27% (digital printouts; Philips). The BMD calculation was not noticeably affected by changes of FFD, exposure level, or film sensitivity/film brand, but was influenced by tube voltage (CV = 0.99% for Kodak film to CV = 2.05% for Siemens digital printouts). No significant differences were observed between the BMD and MCI data. DXR provides measurements of MCI and BMD with high precision and reproducibility. The measurements are unaffected by all tested image-capturing conditions, with the exception of tube voltage. In addition, different digital image devices clearly have an effect on DXR reproducibility.

Bone Density↗

PubMed2004

Autofluorescence spectroscopy in whole organs with a mobile detector system.

RATIONALE AND OBJECTIVES: Autofluorescence can be exploited to obtain spectroscopic information about tissues or organs in a noninvasive fashion. The knowledge of normal organ patterns is a prerequisite for subsequent characterization of pathological states, eg, inflammation or tumors. Therefore, the aim of this study was to investigate the autofluorescence properties of healthy organs in mice. MATERIALS AND METHODS: Organs from C57Bl/6 mice were removed in toto and stored in physiologic sodium chloride solution on ice (non-perfused specimens). Investigations were performed with a custom-made mobile fluorescence detector. Excitation-emission matrices (EEMs) were measured in selected organs (bladder, brain, kidney, liver, and spleen) (n = 5). Afterwards, single-emission spectra were obtained in selected organs (bladder, colon, brain, kidney, liver, and spleen) and peak fluorescence signal intensities were calculated (n = 9). RESULTS: EEMs showed that excitation at wavelengths from 300-310 nm (emission spectra in all samples of bladder and brain; probably caused by collagen/elastin) and from 350-360 nm (emission spectra in all samples with the exception of spleen; probably caused by NAD(P)H) seem to be best suited for autofluorescence measurements in organs. The single-emission spectra measurements were noticeably different in terms of occurrence (yes/no response) and intensity of fluorescence emission peaks in different organs. CONCLUSION: Combined autofluorescence measurements of collagen/elastin (for structural information) and NAD(P)H (for functional information) allow conclusions about the target organs. Therefore, autofluorescence measurements seem to be a diagnostic tool feasible for characterization of tissue.

Animals↗

PubMed2003

Influence of size and depth on accuracy of electrical impedance scanning.

Cancer cells exhibit altered local dielectric properties which can be assessed using electrical impedance scanning (EIS). The study was aimed at clarifying influence of lesion size and depth on EIS performance. From a series of 387 lesions (129 malignant and 258 benign) from 363 patients being sonographically and/or mammographically evaluated, size and depth information was not available in 112 lesions, size was available in 86 lesions and additional depth information was available in 189 lesions, respectively, while performing EIS. Lesions were either histologically verified or had a follow-up of at least 2 years. One hundred three of 129 malignant lesions and 165 of 258 benign lesions were correctly detected (sensitivity 79.8%, specificity 64.0%, accuracy 71.9%). Sensitivity without knowledge of size and depth was 64.6% (10 of 16 malignant lesions detected). This value increased to 76.2% (32 of 42) with knowledge of the size and further increased to 85.9% with knowledge of size and depth (61 of 71). Specificity values in the three subgroups were almost similar: 64.6 (62 of 96), 65.9 (29 of 44), and 62.7% (74 of 118), respectively. Accuracy rises from 63.6% (without knowledge of size/depth) to 71.1 and 74.3% (with size knowledge and with size and depth knowledge, respectively). Accuracy of EIS improved significantly by including sonographical information about depth and size into the analysis. Ultrasound examination should be performed prior to EIS.

Breast Diseases↗

PubMed2003

Electrical impedance scanning-application of this new technique for lymph node evaluation in children.

BACKGROUND: Precise assessment of lymph nodes is crucial to the choice of therapy and prediction of outcome in cases of malignancy. Electrical impedance scanning (EIS) is being experimentally investigated for potential use as a diagnostic tool for differentiation of malignant lesions. Malignancies show different electrical properties with changes in conductivity and capacitance that can be analysed by EIS. Using a TransScan TS-2000 (TransScan Medical, Migdal Ha'Emek, Israel, distributed by Siemens-Elema AB, Solna, Sweden), EIS has been used in various studies for the identification of breast cancer as well as for characterisation of superficial lesions. OBJECTIVE: To evaluate the reliability of EIS for classifying lymph nodes in a pediatric population with sonographically suspicious lesions and to prove its accuracy. MATERIALS AND METHODS: The study population consisted of 77 children (42 boys, 35 girls) aged 1.1-17.1 years. All EIS results were compared to either histopathological findings or long-term follow-up investigations. RESULTS: Sensitivity for malignancies using EIS was 75% and specificity was 87%. The negative predictive value was 93% and the positive predictive value was 60%. CONCLUSIONS: This study suggests the potential usefulness of EIS as an additional imaging modality for the differentiation of lymph-node diseases in children. The histopathological spectrum of malignant lymph node transformation in children compared to studies in adults, and the characteristic meltdown in inflammatory or granulomatous transformed nodes, pose challenges to differentiation based on sonographic evaluation, and also to EIS classification.

Adolescent↗

PubMedDate not supplied

Normative data for digital X-ray radiogrammetry from a female and male German cohort.

This study presents German reference data for digital X-ray radiogrammetry (DXR) differentiated by males as well as females, and quantifies for gender-specific and age-related differences including all DXR parameters. This study also documents the effects of different X-ray settings (e.g., radiographs of the wrist or the hand) on DXR measurements. There were 2085 patients who were prospectively enrolled (954 females and 1131 males) from a data pool of 11,915 patients with radiographs of the nondominant hand or wrist. All patients underwent measurements of bone mineral density (BMD), cortical thickness, bone width, and the metacarpal index (MCI) using DXR technology. These data showed a continuous age-related increase of the DXR parameters to the point of peak bone mass, then a continuous decline beyond the peak bone mass with accentuated age-related cortical bone loss in women. Peak bone mass is reached at approximately 30-34 yr for women and 45-49 yr for men. In addition, men had a significantly higher DXR BMD (mean: +12.8%) compared with woman in all age groups. Regarding the impact of various X-ray settings (e.g., X-ray(wrist) vs. X-ray(hand)), no significant difference was observed between both groups, men as well as women. The development of digital imaging technology has enabled more precise measurements of several radio-geometric features. The present study estimated normative reference values for DXR in German Caucasian women and men. Based on this reference data, a valid and reliable quantification of disease-related demineralization based on measurements of DXR BMD and MCI is now available for the Caucasian ethnic group.

Absorptiometry, Photon↗