Ultrasound Elastography in Breast Cancer Diagnosis

Ultrasound elastography is an established method for characterization of focal lesions in the breast. Different techniques and analyses of the images may be used for the characterization. This article addresses the use of ultrasound elastography in breast cancer diagnosis. In the first part of the article the techniques behind both strain- and shear-wave-elastography are explained and followed by a section on how to obtain adequate elastography images and measurements. In the second part of the article the application of elastography as an adjunct to B-mode ultrasound in clinical practice is described, and the potential diagnostic gains and limitations of elastography are discussed.

Is 0.6T magnetic resonance mammography adequate in the detection of breast cancer?

PURPOSE

To evaluate whether relevant diagnostic information can be achieved when using magnetic resonance mammography (MRM) on mid-field as a supplement to conventional imaging and clinical examination in women with primary breast cancer.

MATERIAL AND METHODS

30 women (55 breasts containing 49 malignant tumors) planned for uni- or bilateral mastectomy were examined with dynamic MRM on mid-field, 0.6T. The women were examined with mammography (M) and ultrasonography (US) prior to MRM. The descriptions of the conventional examinations were evaluated retrospectively, whereas the MRM was evaluated prospectively, with knowledge of the M+US findings. Imaging findings suggesting malignancy were registered and correlated with pathology after mastectomy. A home-made rating system for evaluation of the detected lesions was tested.

RESULTS

MRM detected seven additional malignant tumors, failed to detect three lesions and characterized four as gray-zone lesions according to the rating system. Sensitivity of finding the tumors with M+US was 79.0%, with a PPV for malignant tumors of 84.4%. One breast in which MRM found a malignant tumor had not initially been examined with US. Sensitivity with MRM was 91.6%, with a positive predictive value of malignant tumors of 97.7%.

CONCLUSION

MRM on mid-field seems to improve the detection of cancers when used as a supplement to M+US in women with primary breast cancer. We believe that the results are fair compared to MRM on high-field, although further research and refinement are needed.

Prevalence of silicone breast implant rupture among Danish women

The durability of silicone gel-filled breast implants is of concern, but there are few epidemiological studies on this issue. To date, most of the relevant findings are derived from studies of explantation, which suffer from bias by including women with symptoms or concerns about their implants. As part of a long-term magnetic resonance imaging study of the incidence of rupture, this study involved 271 women with 533 cosmetic breast implants who were randomly selected from among women who underwent cosmetic breast implantation from 1973 through 1997 at one public and three private plastic-surgery clinics in Denmark. The prevalence of rupture was determined from the first magnetic resonance screening. The images were evaluated by four independent readers, using a standardized, validated form. The outcomes under study were rupture, possible rupture, and intact implant. Ruptures were categorized as intracapsular or extracapsular. Overall, 26 percent of implants in 36 percent of the women examined were found to be ruptured, and an additional 6 percent were possibly ruptured. Of the ruptured implants, 22 percent were extracapsular. In multiple regression analyses, age of implant was significantly associated with rupture among second- and third-generation implants, with a 12-fold increased prevalence odds ratio for rupture of implants that were between 16 and 20 years of age, compared with implants between 3 and 5 years of age. Surgitek implants (Medical Engineering Corporation, Racine, Wis.) had a significantly increased prevalence odds ratio of 2.6 for rupture, compared with the reference implants. No significant association was found with the position (subglandular or submuscular) or the type of implant (single- or double-lumen). Extracapsular ruptures were significantly associated with a history of closed capsulotomy (p = 0.001). In the future, the authors plan to examine the women in their cohort with a second magnetic resonance imaging scan to establish the incidence of rupture, a parameter unknown to date in the literature, and to further characterize those factors associated with the actual risk of rupture.

Liver volume, portal vein flow, and clearance of indocyanine green and antipyrine in hyperthyroidism before and after antithyroid treatment

BACKGROUND

The aim of the study was to examine liver volume, portal vein flow, and indocyanine green (ICG) and antipyrine clearance in hyperthyroidism before and after antithyroid drug treatment.

METHODS

Liver volume and blood flow in the portal vein were investigated in nine fasting patients with hyperthyroidism by means of computed tomography scan and Doppler ultrasound, respectively. ICG clearance was estimated by bolus injection of ICG (0.5 mg/kg body weight) and antipyrine clearance with a one-sample technique. All patients were investigated before and after 3 months of antithyroid treatment, when euthyroidism had been achieved. The Wilcoxon matched-pairs test was used for statistical analysis.

RESULTS

The median liver volume increased by 238 (155-289) ml (median, 95% confidence interval), corresponding to 19%, and the weight by 5.0 (0.0-8.0) kg (8%), and the antipyrine clearance decreased by 8 (3.1-34.4) ml/min (16%). These changes were all significant (P < 0.05). The relation between liver volume and body weight increased from 19.9 (16.5-23.7) ml/kg to 21.4 (17.1-21.9) ml/kg (P = 0.11). The liver blood flow as estimated by ICG clearance and Doppler ultrasound was not altered significantly after the treatment period (P = 0.07 and 0.77, respectively).

CONCLUSIONS

The liver volume increased by 19% in nine hyperthyroid patients during treatment with antithyroids. Antipyrine clearance was reduced by 16%, whereas liver blood flow, as estimated by ICG clearance and Doppler ultrasound examination of portal vein flow, was not significantly altered. A differential regulation of liver volume and oxidative metabolic capacity in hyperthyroidism was seen.

[Computed tomographic cholangiography. An alternative non-invasive diagnostic method in ductus choledochus calculi]

Computed tomographic cholangiography has not been mentioned as a diagnostic procedure in the demonstration of common bile duct calculi. Computed tomographic cholangiography demonstrated both calcified and non-calcified common bile duct calculi in two patients. Computed tomographic cholangiography can be employed in investigation of biliary tract disease in selected cases where endoscopic retrograde cholangiography is not possible and ultrasound and ordinary computed tomography fail.