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Biomedical subjects

H Höfer

Publications and source records attributed to H Höfer.

6 recordsLinked to original sources
PubMed1998

Minimally invasive stereotaxic vacuum core breast biopsy.

The purpose of our study was the assessment of the diagnostic value of vacuum core biopsy, which promises high accuracy by minimally invasive percutaneous excision of 1-2 cm3 of tissue. The materials used were a digital stereotaxic biopsy table (Fischer Imaging) and a Mammotome-gun (Biopsys). A total of 236 patients with 261 predominantly indeterminate lesions (indeterminate: 230; suspicious: 26; malignant: 5) underwent vacuum core biopsy (VCB). Verification was as follows: (a) demonstration of complete or partial removal of the lesion or replacement of the lesion by a small hematoma by comparison of the pre- and post-VCB mammogram; (b) reexcision of 45 malignant and 6 borderline lesions; (c) radiologic-histologic correlation; and (d) 6-month-follow-up mammograms in 129 cases. Two VCBs were not possible because very fine microcalcifications could not be visualized. Two puncture errors occurred which, however, were immediately recognized and VCB was repeated. Based on the above verification a 100 % accuracy was achieved. No relevant side effects occurred. Except for 2 cases mammographically hardly any scarring was visible. Based on the excellent accuracy and excellent tolerance of the procedure VCB appears to be the future method of choice for the workup of those indeterminate mammographically detected lesions that up to now have still required surgical biopsy.

Biopsy, Needle↗
PubMed1997

[Vacuum punch biopsy of the breast with a stereotaxic guide. A new procedure for percutaneous diagnostic biopsy based on 120 cases].

PURPOSE: To test the capabilities of vacuum core biopsy (VCB) in the diagnosis of mammographically indeterminate lesions. MATERIALS AND METHODS: 120 patients (131 lesions) were examined using VCB with 14G or 11G vacuum core. RESULTS: VCB was mostly performed because of indeterminate microcalcifications (67 cases) or soft tissue densities/architectural distortion (64 cases). 112 benign changes, 14 DCIS and 5 invasive carcinomas were found. Excellent accuracy was achieved (presently 100%), since complete excision of small lesions/areas (< or = 1 cm) or partial excision of larger lesions was possible. No relevant hematomas or infections occurred. Patients tolerated the painless procedure very well. DISCUSSION: This report confirms our previous experiences. This method promises to replace diagnostic open biopsy of indeterminate or suspicious nonpalpable lesions.

Adult↗
PubMedDate not supplied

Misleading changes of the signal intensity on opposed-phase MRI after injection of contrast medium.

OBJECTIVE: The effect of opposed-phase imaging on the interpretation of MR contrast studies is highlighted. MATERIALS AND METHODS: A model calculation is performed. It demonstrates the change of signal intensity of an average tumor before and after application of Gd-DTPA on an in-phase and an opposed-phase image, depending on the percentage of fat within the voxels. The effect is then demonstrated, using a small cotton stick soaked with water or a solution of contrast agent representing a tumor before and after i.v. application of Gd-DTPA. RESULTS: If an average enhancing tumor, which is surrounded by fat, occupies less than 50-60% of the slice thickness, it becomes undetectable on opposed-phase images. The reason is that due to signal cancellation on the opposed image, no signal change or even signal decrease results, while signal increase is visible on the in-phase image. CONCLUSION: In those areas of the body where significant partial volume of a tumor with fat may occur (such as for breast tumors growing along ducts, which are surrounded by fat), severe errors can result. Therefore we explicitly warn from using opposed-image sequences for MR contrast studies.

Contrast Media↗