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Biomedical subjects

E Gmelin

Publications and source records attributed to E Gmelin.

At least 19 recordsLinked to original sources
PubMed2004

[Computer-aided segmentation, form analysis and classification of 2975 breast microcalcifications using 7-fold microfocus magnification mammography].

PURPOSE: To classify mammary microcalcifications for the prediction of malignancy by using computer-aided analysis of morphometric characteristics. MATERIALS AND METHODS: Seven-fold microfocus magnification radiography (direct magnification) was performed on 2975 paraffin embedded microcalcifications. After digitization of the radiographic films and segmentation of the microcalcifications, the morphometric characteristics, such as circumference, surface and polar transformation with determination of the greatest and smallest radius, were measured. Using the classification and regression tree (CART) statistical analysis program, the calcifications were classified by computer on the basis of the morphometric characteristics and the known histological result. RESULTS: Benign conditions were essentially represented by small round calcifications with a greatest radius of < or = 114.2 microm, a smallest radius of > 18.5 microm and a circumference of < or = 462.3 microm. Using > 70 % microcalcifications classified in a patient by the computer as "malignant," CART increases the frequency of malignant conditions, with the diagnostic separation between benign and malignant at an Az value (surface below the ROC curve) of 0.7863. CONCLUSION: A computer-assisted classification of individual microcalcifications on the basis of morphometric characteristics can supplement the information for a computer assisted mammographic diagnosis (CAD).

Breast↗
PubMed2003

[Compression-free biplanar radiography of the breast specimen with a specimen device].

PURPOSE: To develop a device for specimen radiography of impalpable breast lesions with microcalcifications in order to perform compression-free radiography in two planes and to document the original orientation of the specimen on the radiographic film. MATERIALS AND METHODS: A curved plate with its radius equal to the film-focus-distance enables specimen radiography without compression and with minimizing artifacts induced by beam divergency. Adjustable markers can document the topographic orientation of the specimen on the radiographic film. RESULTS: The presented specimen device for biplanar radiography avoids interfering compression artifacts for both radiologist and pathologist. Documenting the original topographic orientation of the specimen on the film helps to guide the surgeon in cases requiring further resection. DISCUSSION: Biplanar specimen radiography without compression of the specimen measures the distance of microcalcifications to the margin of the resected tissue more accurately and thus provides a better basis for planning any necessary additional resection.

Breast↗
PubMed2001

DIMA enlargement mammography in microcalcifications: a prospective study with ROC analysis.

The purpose of this study was to investigate whether the four-fold magnification mammography (direct magnification, DIMA) technique would perform better than conventional 1.5-fold magnification mammography in the differentiation of breast microcalcifications into benign and malignant. Fifty patients with non-palpable microcalcifications detected by mammography were examined immediately prior to surgical biopsy using both a conventional (1.5-fold) and the DIMA (fourfold) magnification mammography techniques. The microcalcifications were classified by five experienced radiologists using morphological criteria. A receiver operating characteristics curve (ROC) analysis of the sensitivity and specificity of both techniques in assessing malignancy was then carried out. The DIMA mammography technique was slightly but non-significantly superior to the conventional method in detecting malignancy (p > 0.05). Coarse granular and pleomorphic calcifications were detected more frequently with the DIMA technique. Coarse calcifications were significantly more frequently associated with histologically benign findings, whereas fine granular calcifications were significantly more likely to be malignant lesions. Assessment of malignancy associated with microcalcifications using morphological criteria is not significantly improved by mammography techniques with higher magnification.

Biopsy↗
PubMed2000

[Radiographic image magnification as quality control of microcalcification imaging within the scope of histopathological control of breast biopsy tissue].

PURPOSE: Evaluation of specimen radiography as a quality control for the detection of microcalcifications by the pathologist during histopathological examination of breast biopsies. MATERIALS AND METHODS: 29 breast biopsy specimen with microcalcifications were radiographed using the magnification (x4) mammography System DIMA Plus MI I before and after the histopathological examination. Tissue with detected microcalcifications after the histopathological examination was reexamined histologically. RESULTS: In 55% (16/29) of all specimen we could identify missed microcalcifications. In 5 specimens the microcalcifications were missed completely. The radiologically detected areas of residual microcalcifications were reexamined histologically and in one case invasive parts of a carcinoma were detected, which primarily had been diagnosed as an in-situ carcinoma. In 6 cases the radiographs of the intraoperative specimen radiography were sent to the pathologist together with the biopsy. In these cases the rate of complete detection of the microcalcifications increased from 39% to 66%. CONCLUSION: Specimen radiography should be performed not only intraoperatively but also as part of the histopathological examination.

Biopsy, Needle↗
PubMed1999

[Digital subtraction angiography with carbon dioxide--basic principles, technique and clinical application].

Carbon dioxide digital subtraction angiography Carbon dioxide (CO2) digital subtraction angiography offers the possibility for diagnostic and interventional angiographic procedures in high risk patients for ionidated contrast material. As a gaseous contrast agent its physicochemical properties have special requirements concerning the radiologists knowledge, the X-ray equipment, the injector and the catheters. This article reviews the current literature concerning the history, physics and physiology, indications and contraindications, clinical use, adverse effects and possible complications of carbon dioxide digital subtraction angiography.

Angiography, Digital Subtraction↗
PubMed1999

[Detection of microcalcifications in breast specimens by 4-fold DIMA direct magnification radiography compared to 1.5-fold conventional magnification radiography].

AIMS OF STUDY: The purpose of this study was to investigate the efficacy of 4-fold magnification breast specimen radiography (direct magnification, DIMA) compared to conventional 1.5-fold magnification radiography in evaluating the presence or absence of carcinoma at the surgical margins by detection of microcalcification. METHODS: Fifty breast specimens with non-palpable microcalcifications were examined during surgical biopsy using both DIMA (4-fold) and conventional (1.5-fold) magnification specimen radiography. The number of detected microcalcifications of the whole specimen, of an area of 5 mm distance to the margins and of the area of the suspicious cluster of microcalcifications was counted and the results compared with the histological examination as a gold standard. RESULTS: In 50 specimen 2821 (1305 within 3 mm distance to the margins) microcalcifications were detected with the DIMA mammography technique compared to 1608 (446) microcalcifications with the conventional technique. This increased detection rate by DIMA-magnification radiography was accompanied by a decreased specificity in comparison to the conventional magnification radiography (33.3% DIMA versus 83.3% conventional) regarding the evaluation of presence or absence of carcinoma at the surgical margins. Differentiating the microcalcifications into calcifications belonging to the suspicious cluster and those that are located outside the cluster led to an increase in specificity (83.3% DIMA versus 100% conventional). CONCLUSIONS: The efficacy of breast specimen radiography in evaluating the presence or absence of carcinoma at the surgical margins by detection of microcalcification is not improved by 4-fold magnification radiography (direct magnification, DIMA) compared to conventional 1.5-fold magnification radiography due to an increase in false-positive results. Analysis of the attachment of the microcalcifications to the cluster can improve the specificity.

Biopsy↗
PubMed1999

[The demonstration of microcalcification in breast core biopsies: DIMA specimen radiography (7x) compared to the histopathological findings].

PURPOSE: Comparing the sensitivity in detecting microcalcifications in stereotactically guided core biopsy specimen of the breast of direct magnification (DIMA) specimen radiography (x7) with the histological examination. MATERIALS AND METHODS: In 52 patients 509 stereotactically obtained core biopsy (14-gauge) specimens of the breast were radiographed by direct magnification (DIMA) specimen radiography (x7) and examined histologically. RESULTS: In 188 specimen microcalcifications were detected by magnification radiography compared to 98 by histological examination. Only 3% of the specimen microcalcifications were seen exclusively in the histological examination. In core biopsies with malignancy the relative proportion of biopsies with radiologically detected microcalcifications was increased (59% versus 32%). CONCLUSION: Concerning the detection of microcalcifications in core biopsy specimen of the breast, the direct magnification (DIMA) radiography (x7) was superior compared to the histological examination. Due to the high relative proportion of biopsies with radiologically detected microcalcification and malignancy, we recommend a comprehensive histological examination of these specimen. Confirmation of microcalcifications in core biopsies should be achieved by magnification radiography to prove that the suspicious area in the breast was truly sampled. Specimen radiography simultaneously with the biopsy procedure can reduce the number of punctures in the process of documenting the presence of calcifications early in the biopsy procedure.

Biopsy↗
PubMed1995

[Transfemoral fenestration and stent implantation in aorto-iliac dissection].

Subacute left lower limb ischemia developed in a patient with aortic dissection. Angiography revealed a dissection of the aorta abdominalis and a severe stenosis of the left common iliac artery. The patient underwent successful percutaneous fenestration and intravascular stent placement. The patient is currently (4 month post-intervention) ambulating without any signs of the leg ischemia. Percutaneous balloon fenestration and, if necessary, stent placement should be considered as a treatment option and a alternative to surgery in selected cases.

Aortic Dissection↗
PubMed1995

Intermittent regional therapy with rt-PA is not superior to systemic thrombolysis in deep vein thrombosis (DVT)--a German multicenter trial.

In a prospective and randomized multicenter trial the efficacy of intermittent regional and systemic thrombolytic therapy for DVT was evaluated. 137 patients with phlebographically confirmed acute DVT above the calf region were treated with 20 mg of rt-PA for 4 h each day. Thrombolysis was applied either locally via a dorsal pedal vein of the firmly bandaged affected leg or systemically using a cubital vein. Treatment lasted for 4-7 days, and during this time unfractionated heparin was applied continuously with the dosage adjusted according to aPTT (1.5-2.0 times the normal value). A second phlebography was performed within 24 h after the end of treatment. Results were evaluated by an independent radiologist who was unaware of the treatment given. Significant thrombolytic results (e.g. lysis of more than 50% of the original thrombus and complete recanalization of all affected veins) were reached in only 1/3 of all patients. Rates of recanalization did not differ in both groups and bleeding complications occurred in 26.5%. We conclude that intermittent local or systemic application of 20 mg rt-PA seems to be ineffective in the treatment of DVT.

Adolescent↗