Computer-aided diagnosis.

The evolution of logic thought in relation to the predominant recent advances in technology is analyzed. In fact, the computer was the prime mover of this major change. At present the use of sophisticated software has allowed to attain increasingly accurate levels of simulation of human reasoning. The computer has determined profound transformations in many sectors of work, study and research. Among these, it is extremely relevant how the computer has completely transformed medicine and the medical role, especially in the field of radiology. Expert systems are the most interesting and futuristic applications of artificial intelligence. These systems are able to reproduce on a computer the behavior of an expert human being. Some of the recent innovations introduced in the field of breast, thoracic and mainly neural pathology are illustrated.

Diagnostic imaging in the clinical management of patients at high risk for breast cancer.

Although being predominantly anecdotal, breast carcinoma shows a considerable component of multifactorial genetic transmission, referable to dominant autosomal inheritance. Among the genes responsible for hereditary breast cancer two main genes (BRCA1 and BRCA2) have already been identified. At present, genetic tests to identify known inherited mutations associated with breast tumor predisposition, are available. Asymptomatic subjects with genetic BRCA1/2 mutations represent a group at high risk; therefore it is now indispensable to work out adequate strategies of prevention and/or of early diagnosis. Besides education (information) and genetic counselling, there are three perspectives of intervention for these subjects: bilateral prophylactic surgery, pharmacologic prophylaxis and periodical diagnostic monitoring; unfortunately all of them are still burdened by limitations.

From normal morphology and function to the breast pathophysiology.

At present mammography is the only method validated by trials performed over several decades; however it is burdened by some limitations which at times make its integration with other diagnostic imaging procedures necessary. These procedures are able to enhance the organ morphology (digital galactography) or the organ function (US, color-Doppler US, MRI, PET, scintigraphy). Among the methods of "functional" support, an emerging role is played by nuclear medicine with the use of specific radiopharmaceuticals for breast scintigraphy, PET and-lymphoscintigraphy of sentinel lymph node.

Diagnostic imaging of breast implants: role of MRI.

The role of MRI in the evaluation of breast implants, based on the observations collected over a 2-year period at the "Istituto di Radiologia" of the "Università Cattolica del S. Cuore" of Rome, is reported. In women with breast implants both mammography and sonography have a lower diagnostic accuracy in the evaluation of the glandular parenchyma. At present, MRI plays a primary role in patients with breast implants for the diagnosis of rupture. Based on the international literature its sensitivity is 90-95% and the specificity is 95-100%. Therefore, it can be considered the gold standard procedure in the diagnosis of locoregional recurrence. In spite of the excellent sensitivity and specificity of MRI in the evaluation of patients with breast implants, the integration with information from clinical examinations and conventional imaging is required together with an exhaustive knowledge of this method whose development is still in progress.

Clinically nonpalpable breast tumors: global critical review and second look on microcalcifications.

Over a ten-year period a series of 350 nonpalpable breast lesions were examined to evaluate the positive predictive value of malignancy of the different mammographic findings and the incidence of carcinoma in situ in the different categories. Lesions were separated into opacities and microcalcifications. Surgical biopsy revealed the presence of carcinoma in 190 of 350 lesions with an overall PPV of 54% and a B/M ratio of 0.84. Within opacities, the PPV was 80.2% for spiculate opacities, 53.8% for irregular opacities, 34.7% for opacities with calcifications and 17.4% for parenchymal distortions. As many as 151 of 350 (46%) lesions were shown to be isolated microcalcifications on mammography with an overall PPV of 46% and a B/M ratio of 0.92. 42 of 80 malignant lesions were shown to be ductal carcinomas in situ (50%). According to data of the literature PPV for Le Gal and BI-RADS class 5 was 92% and 86.27%, respectively. Le Gal classification of microcalcifications intends to describe a sign with which a risk of malignancy is associated. In BI-RADS categorization the sign plays a prognostic role and for each class a diagnosticotherapeutic approach is suggested. Therefore a correct BI-RADS categorization can be of support for both radiologists and clinicians in the patient management.

Role of magnetic resonance imaging in the pre and postchemotherapy evaluation in locally advanced breast carcinoma.

The study was carried out to evaluate the response to preoperative chemotherapy of locally advanced breast cancer with MRI. The series included 45 women with locally advanced breast cancer who underwent MRI before and after neoadjuvant chemotherapy. Based on the volume of residual disease, the response to chemotherapy was classified as: complete response, partial response, minor response, no change and disease progression. Responses to neoadjuvant chemotherapy were compared to MRI findings and to prognostic factors. Based on MRI findings 8 patients were assigned to the complete response group, 16 to the partial response group, 11 to the minor response group, 9 to the no change group and 1 patient to the disease progression group. MRI showed 90.2% sensitivity, 100% specificity and 91.1% accuracy. The correlation between MRI findings and prognostic factors may be useful to predict cancer aggressiveness and to understand the natural history of different breast carcinomas.

Role of magnetic resonance imaging in inflammatory carcinoma of the breast.

The study was carried out to assess the role of magnetic resonance imaging in the inflammatory carcinoma of the breast. 15 female patients with a clinical diffuse inflammatory process in the breast underwent mammography, sonography and dynamic magnetic resonance imaging. All inflammatory carcinomas showed a patch enhancement pattern and in 7/10 there were some areas of focal enhancement. A patch enhancement was observed in 2/5 cases of mastitis while in the other 3 cases nodular focal areas with peripheral enhancement were seen. The dynamic curves were always of wash-out type. Maximum signal intensity value was over 70% in 3/5 cases of mastitis and in 9/10 cases of inflammatory carcinoma. Our results suggest that the role of magnetic resonance imaging in the characterization of inflammatory processes of the breast is nonspecific, while it may be useful in the follow-up of mastitis.

MRI in insulin-dependent diabetic mastopathy. A case report.

A case of diabetic mastopathy studied with MR-mammography is described. It concerns a female patient with long-lasting (10-years) insulin-dependent diabetes mellitus. A non-tender, palpable firm-to hard mass of the left breast was found and studied with mammography, ultrasonography and MR-mammography. Surgical excision of the mass was performed. The mammogram revealed dense fibroglandular tissue bilaterally. Ultrasonography showed hypoechoic solid tissue in the region of palpable breast mass with marked posterior acoustic shadowing. MR-mammography showed a hypointense area of fibrosis with poor enhancement. Quantitative analysis revealed a typically benign gradual type dynamic curve. MR-mammography can be useful to differentiate diabetic mastopathy from malignant lesions. In women with diabetic mastopathy MR-mammography, clinical examination and careful follow-up may prevent surgical excision.

Role of magnetic resonance imaging in the diagnosis of recurrence after breast conserving therapy.

The sensitivity, specificity and accuracy of MRI in detecting breast cancer recurrence were analyzed. 40 patients undergoing breast conserving therapy were studied with MRI. Cytohistologic examinations of suspected local recurrence were carried out. In these patients, the clinical, mammographic and sonographic characteristics of local recurrence were nonspecific or dubious. All patients were examined at least 1 year after completion of radiation therapy. Qualitative and quantitative information was acquired with dynamic MRI. Statistical analysis was performed with the Student's t test. Breast cancer recurrence identified in 22 patients was confirmed on histology in all of them. There were only 2 cases of false positive results. MRI showed 95% accuracy, 100% sensitivity and 88.8% specificity with 5% false-positives and 100% negative predictive value. Dynamic MRI appears a valuable technique for differentiation of post-treatment changes in recurrent carcinoma and for guiding the histological confirmation.

MRI in phyllodes tumor of the breast. Case reports.

The purpose of this study was to reassess the role of MRI in 3 cases of cystosarcoma phyllodes. Three patients with a palpable large lump were studied with mammography, ultrasonography and MRI. In the 3 patients mammography showed a nonspiculate soft-tissue mass while a hypoechoic lobulated mass with cystic areas was visualized on sonography. Dynamic MRI demonstrated a multi-lobulated lesion rapidly and markedly enhanced on dynamic studies of contrast-enhanced T1-weighted imaging. T2WI showed inhomogeneous signal intensity with a hypointense area and internal septation in the solid portion. MRI enabled complete visualization of the tumor even in the region close to the chest wall, as well as clear delineation against the healthy glandular tissue.

Radial scar: from conventional imaging to the new techniques. Case reports.

The role of MR-mammography in radial scar was assessed in 4 female patients. All 4 patients showed mammographic findings of radial scar and underwent dynamic MR-mammography. MR-mammographic findings were compared with histopathological results. On MR-mammography a focal enhancing lesion with irregular margins, plateau or rapid wash-out time/signal intensity curves, with maximum signal intensity > 100% were documented in the 4 patients. The histological diagnosis identified i case of infiltrating lobular carcinoma, 1 case of atypical hyperplasia and 2 cases of typical hyperplasia. In the preliminary study, MR-mammography was superior to mammography in the assessment of the extent and margins of the lesions. However, in the 4 study patients it could not accurately differentiate between carcinoma and benign lesions. It should be observed that lesions suggestive of radial scar have to be removed by surgery.