Is the "blooming sign" a promising additional tool to determine malignancy in MR mammography?

The aim of this study was to evaluate potential diagnostic relevance of blooming effect for verification of suspicious breast lesions in MR mammography (MRM). The MRM examinations of 1035 patients, all following the same imaging protocol (from 1994 to 2001) were retrospectively evaluated by two experienced radiologists in consensus. A total of 817 lesions showed a focal enhancement; of these, 793 were histologically verified after surgical intervention so that 514 malignant and 279 benign lesions could be evaluated. Using a 1.5-T Gyroscan ACS II-imager (Philips, Hamburg, Germany) and a double breast coil with the patient lying in a prone position, 0.1 mmol/kgbw Magnevist (Schering, Berlin, Germany) were injected into the cubital vein to obtain dynamic axial and coronal T1-weighted fast-field-echo images every minute up to 7 min after bolus injection. Blooming sign describes a progradient unsharpness of lesion borders initially sharply shaped and fast enhancing 7 min after bolus injection; 324 of 514 (63.0%) malignant lesions and 41 of 279 (14.7%) benign lesions revealed a blooming sign (sensitivity 63.0%, specificity 85.3%, accuracy 70.9%, positive predictive value 88.8%, negative predictive value 56.0%). Forty-one of 279 benign lesions showed a blooming sign; of these, there were 4 of 86 (4.7%) fibroadenomas, 2 of 21 (9.5%) phylloides tumours, 11 of 38 (28.9%) papillomas, 3 of 9 (33.3%) radial scars, 2 of 19 (10.5%) mastitis, 1 of 4 (25%) galactophoritis, 1 of 3 (33.3%) ADH and 19 of 99 (17.2%) mastopathic proliferations, respectively. Blooming sign is a phenomenon which should be taken into account when diagnosing MR mammographies because it might increase the ability to discriminate uncertain breast lesions; however, this effect can only be used as an additional item to other well-known effects such as plateau, washout and cancer corner.

[Evaluation of the primary diagnosis with a CAD-system in mammography]. / Evaluation der Primärbefundung durch ein CAD-System in der Mammadiagnostik.

PURPOSE: To assess the capability of the computer assisted detection (CAD) system to classify calcifications that are histologically verified as malignant and benign or are proven benign by magnification and follow up mammography. MATERIALS AND METHODS: Three groups of microcalcifications (MC) with and without associated masses were enrolled in the study. The cancer group included 141 screen-detected breast cancer cases. One benign group comprised 109 cases with histologically benign specimens obtained through a minimally invasive breast biopsy. A second benign group included 72 lesions with MC that appeared benign on magnification/compression views and were confirmed to be benign on follow-up mammograms over a period of at least 1.5 years. All mammograms were evaluated with a CAD system (Second Look version 3.5, CADx Medical Systems, Canada). RESULTS: CAD correctly detected 125 of 141 (89 %) cancer cases. Of the 16 false negative cases, CAD marked the location of the MC (which were associated with malignant mass) with a mass mark in 12 cases. For benign cases, CAD did not correctly mark the microcalcifications in 59 of the 109 lesions confirmed benign histologically (54.1 %) and in 39 of the 72 lesions established benign mammographically (54.2 %). Adenosis introduced the highest rate of falsely marked microcalcifications (62 %). CONCLUSION: Due to its limited specificity, CAD can still not be recommended for the primary classification of microcalcifications as malignant or benign. Nevertheless, the low false negative rate and rather high detection rate of malignant findings indicate some value of CAD for an independent second reading.

Comparison of peripheral bone and body axis skeleton in a rat model of mild-to-moderate renal failure in the presence of physiological serum levels of calcitropic hormones.

The skeleton is characterized by anatomic heterogeneity of metabolic turnover. Site-dependent differences in hormonal effects seem likely. Hyporesponsiveness of osteoclasts to parathyroid hormone (PTH) and probably calcitriol was recently demonstrated in the fifth lumbar vertebra of a rat model with moderate renal failure. We compared histomorphometric findings of the tibial head to these data. Histomorphometric measurements were carried out in sections of the right tibial head of pair-fed male Sprague-Dawley rats. Subtotally nephrectomized (SNx), parathyroidectomized (PTx), rats, which received either solvent or rat PTH(1-34) (100 ng/kg per hour) + calcitriol (5 pmol/kg per hour) via osmotic minipumps were compared with sham-operated controls. Results were compared with data from the fifth lumbar vertebra reported recently. Osteoclast numerical density and osteoclast surface density were lower in the tibial head and the lumbar vertebra of solvent-treated SNxPTx rats than in sham-operated controls (p < 0.05), and could not be returned to normal by the substitution of PTH + calcitriol (p < 0.05). On the other hand, there were differences between interventional effects on the tibial head and on the lumbar vertebra concerning parameters describing osteoblasts and trabecular bone volume. In the tibial head, osteoblast surface density was nearly unchanged in both interventions. Nevertheless, bone volume increased after SNxPTx without substitution of PTH + calcitriol (p < 0.05), and no further changes occurred after hormonal replacement. In contrast, osteoblast surface density in the lumbar vertebra was decreased slightly compared with values in sham-operated rats; a clear but nonsignificant increase occurred after the administration of calcitropic hormones. This was accompanied by unchanged trabecular bone volume after SNxPTx. Hormonal replacement, however, caused an increase in trabecular bone volume (p < 0.05), which represents an anabolic effect, which contrasts with findings from the tibial head. The different interventional effects on the lumbar spine and on peripheral bone, regarding the parameters reflecting the condition of osteoblasts, may be intrinsic to the uremic syndrome itself as well as to dissimilar growth manner, function, and mechanical requirements. The findings substantiate the site dependence of bone surface cell metabolism in renal failure and should be the subject of further study. Corresponding results with regard to bone resorption argue for a bone-site-independent, diminished response of osteoclasts to calcitropic hormones.

Differentiation of mammographically suspicious lesions: evaluation of breast ultrasound, MRI mammography and electrical impedance scanning as adjunctive technologies in breast cancer detection.

AIM: Various modalities are used as an adjunct to mammography for differentiation of potentially suspicious breast lesions. Electrical impedance scanning (EIS) is a new technique based upon the principle that cancer cells exhibit altered local dielectric properties and thus show measurably higher conductivity values. The accuracy of differentiation of benign and malignant breast lesions was evaluated to determine whether EIS duplicates or supplements the results obtainable from ultrasound (US) or magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred mammographically suspicious lesions were examined using US, MRI and EIS. Definitive histology was acquired through either lesion biopsy or surgical excision. RESULTS: Fifty of 62 malignant lesions were correctly identified using EIS (81% overall sensitivity), 24/38 benign lesions were correctly identified as benign (63% specificity). Negative predictive value and positive predictive value of 67 and 78% were observed, respectively. kappa-factor evaluation revealed a value of 0.82 between MRI and EIS and 0.62 between US and EIS. CONCLUSIONS: EIS may be a valuable adjunct for differentiation of suspicious mammographic lesions. Based upon the calculated kappa-factor, EIS results supplement US examinations. Artifacts (superficial skin lesions, poor contact, air bubbles) currently result in the high false-positive rate of EIS.

Electrical impedance scanning for classifying suspicious breast lesions: first results.

It has long been established that cancer cells exhibit altered local dielectric properties compared with normal cells. Consequently, different electrical conductivity and capacitance are measurable in malignant vs normal tissues. In this study we evaluated the reliability of electrical impedance scanning (EIS), a new technology, for the classification of suspicious lesions: differentiating benign from malignant, and as a primary means of detection of breast cancer. Fifty-two women with 58 sonographically and/or mammographically suspicious findings were examined using electrical impedance scanning. Two different examination modes of TransScan TS2000 (Siemens, Erlangen, Germany), the standard-resolution mode for a routine overview examination, and the targeted high-resolution mode for a local examination of the suspicious lesion were used. All patients were additionally imaged by MR mammography (MRM) and underwent core-biopsy and/or surgical treatment after the EIS examination. With respect to the histopathological findings (29 malignant and 29 benign lesions) 27 of 29 (93.1%) malignant lesions were correctly identified using the high-resolution mode of EIS, whereas 19 of 29 (65.5%) benign lesions were correctly identified as benign (10 of 29 benign lesions showed as false-positive findings). Negative and positive predictive values of 90.5 and 73.0% were observed, respectively. Using the standard-resolution mode 22 of 29 malignancies were correctly detected (sensitivity 75.9%), whereas 22 of 29 were correctly identified as benign (specificity 72.4%). Electrical impedance scanning appears to be a promising new technology providing a relatively high sensitivity for the verification of suspicious mammographic and/or sonographic lesions especially using the high-resolution mode for local examinations. Artifacts, such as signals from superficial skin lesions, poor contact, and air bubbles, are currently a limitation.

Physiological doses of calcium regulatory hormones do not normalize bone cells in uraemic rats.

BACKGROUND: Low bone turnover despite normal parathyroid hormone (PTH) concentrations has been found in many patients with end-stage renal failure. Hyporesponsiveness to the calcaemic action is also a known feature of uraemia. Hyporesponsiveness of bone surface cells involved in bone modelling has not been demonstrated to date. It was the purpose of this study using a rat model of moderate renal failure to investigate whether doses of PTH and calcitriol that reverse the effect of parathyroidectomy on calcaemia also normalize bone surface cell activity. MATERIALS AND METHODS: Sham-operated pair-fed male Spraque-Dawley rats were compared with subtotally nephrectomized (SNX), parathyroidectomized (PTX) rats that received either solvent or calcitriol (5 pmol kg -1 h-1) + 1,34 rat PTH (100 ng kg -1 h-1) by osmotic mini-pump. Histomorphometric measurements were carried out in the vertebral body (L5). RESULTS: In SNX/PTX animals, calcitriol + 1,34 rat PTH caused a modest increase in serum calcium (S-Ca) within the normal range. Osteoclast surface per cent was significantly lower in solvent-treated SNX/PTX rats than in sham-operated controls [3.7 +/- 2.8 osteoclast surface/bone surface (OcS/BS%) vs. 6.3 +/- 3.9], and this was not normalized by PTH + calcitriol (3.3 +/- 3). In contrast, osteoblast surface per cent and osteoid surface per cent were increased over values in sham-operated rats; as a result, co-administration of calcitriol and 1,34 rat PTH caused a highly significant increase in fractional bone volume (BV/TV). CONCLUSIONS: The results show that administration of PTH and calcitriol in doses that raise serum calcium fails to normalize the percentage of osteoclast surface, but was effective in raising osteoblast number and osteoblast volume in experimental renal failure. The results argue for abnormal response of bone cells to calcium-regulating hormones and/or the action of factors other than calcium regulatory hormones in the genesis of skeletal abnormalities of renal failure.