Biomedical subjects

Viola Valentini

Publications and source records attributed to Viola Valentini.

4 recordsLinked to original sources

PubMedDate not supplied

Ureteropelvic junction disease: diagnostic imaging.

Ureteropelvic junction disease is very frequent in pediatric age. Diagnosis is usually established on sonography; in most cases it is prenatal and confirmed at birth. On sonography, hydronephrosis and the site of obstruction is identified with morphofunctional information on renal parenchyma. In the past, urography was the reference examination for ureteropelvic junction disease, but its use is limited in pediatrics especially in prenatal study for radioprotection as well as for the limited glomerular filtration of neonatal kidney. CT and MRI as second level examinations do not find many indications, while angioscintigraphy is largely used to acquire functional data and, in combination with sonography, is basic for diagnosis as well as in follow-up of operated patients.

Child↗

PubMedDate not supplied

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.

Adult↗

PubMedDate not supplied

Diffusion and perfusion MR imaging.

Diffusion (DWI) and perfusion weighted (PWI) MR imaging, have come to have an increasingly important clinical role, especially in neurovascular imaging. Diffusion MR imaging does not evaluate hemodynamic parameters, but can be considered a functional technique because it provides information about the tissue functional structure at a microscopic level. In this technique, image contrast to a large extent depends on the diffusion coefficient, a parameter indicative of the characteristics of the stochastic thermic translational motion of water molecules (Brownian motion). Clinical perfusion measurement has been performed in almost all organs with different techniques. Over the last ten years, with the use of contrast media, considerable experience has been gained in the measurement of hemodynamics with MRI. At present, perfusion-MR imaging is one of the clinically most relevant procedures of functional MRI, whose application is gaining ground, owing to the increasing availability of necessary hardware and software. Physical and hemodynamic principles of the two techniques, pulse sequences necessary for their implementation and main applications in the imaging of CNS disorders are illustrated. While DWI and PWI alone can address numerous questions, their information is for the most part complementary to that provided by conventional MRI and their combination seems extremely promising.

Central Nervous System Diseases↗

PubMedDate not supplied

Combined diagnostic and therapeutic imaging in the diagnosis of venous sinus thrombosis in postpartum patients.

The case of a woman on day four post partum with sensorimotor deficit of the right side and CT evidence of a left temporofrontal hemorrhagic lesion, is presented. Attending physicians requested cerebral angiography. To better evaluate the clinical justification of requested imaging procedure the patient medical history and performed CT examination were carefully revised. According to this analysis and based on a clinicoradiological methodology, the request of a cerebral angiography was considered appropriate. The examination showed several radiological signs but a definitive diagnosis could not be established. Second choice imaging procedures were analyzed and MRI completed with MR-angiography was performed. It allowed to document transverse and sigmoid sinus thrombosis. Therefore, in the diagnosis of venous sinus thrombosis, MRI combined with MR-angiography was shown to be a method of first choice while angiography plays a major role in therapy for intravascular thrombolysis.

Adult↗