[en] To analyze and discuss the use of different magnetic resonance (MR) strategies with gadolinium administration in the study of bone tumors with involvement of accompanying soft tissue, and to assess the value of these techniques in the characterization of the lesions by analysing their enhanced digital images. Sixty-two bone tumors were studied by MR with Dg-DTPA-BMA using different spatial and temporal resolutions. A conventional MR study was performed in 14 lesions (10 malignant and 4 benign), a multiple-slice dynamic study in 21 (19 malignant and 2 benign) and a single-slice dynamic study in 27 (21 malignant and 16 benign). The dynamic studies afforded parametric images, calculating the uptake factors and maximum velocities. These data were related to the benign or malignant behavior of the lesions and the histological type. The conventional studies provided anatomic information on the lesion and the tumor volume. The parametric images from the dynamic studies provided data on the perfusion of the different lesions. There were no statistically significant differences between the different histological types or the uptake parameters. Nor were there significant differences in the uptake values of malignant and benign lesions. The contrast-enhanced dynamic uptake studies improved temporal resolution, providing information on the perfusion of the bone lesions. the use of parametric images makes it possible to assess the changes in the signals of the pixels over time. The benign lesions with aggressive behavior have uptake values similar to those of malignant lesions. (Author) 13 refs

[en] We present a fatal case of intracranial air embolism produced by the passage of intravenous air to the arteries owing to the existence of a patent foremen ovale associated with pulmonary hypertension, which permitted a right-left shunt (paradoxical embolism). The pathophysiological mechanisms of pneumcephalus and paradoxical embolism are discussed and the pertinent literature is reviewed. (Author) 6 refs

[en] To present the magnetic resonance (MR) imaging findings in patients with chronic spinal abscess and the differential diagnosis with respect to intramedullary tumors. We present the case of a patients with chronic spinal abscess associated with nonspecific symptoms and the absence of fever. MR revealed several nodular lesions in the dorsal spinal cord. Spinal abscess is a rare lesion with a poor prognosis if not diagnosed and properly treated early. Its differential diagnosis with respect to intramedullary neoplasms is important since the clinical and MR features can mimic neoplastic disease, especially in chronic cases with nonspecific clinical findings and sterile culture. MR is the technique of choice in the diagnosis and characterization of this lesion. (Author)

[en] The authors studied the vascularization in three cases of pulmonary sequestration by means of helical computed tomography (CT) with CT angiography. The technique provided precise images of the anomalous systemic blood flow, suggesting that it is a valid substitute for conventional angiography in the preoperative study of pulmonary sequestrations. (Author)

[en] To determine the utility of the chemical shift technique in magnetic resonance imaging (MRI) to confirm small amounts of fat in extrahepatic intraabdominal tumours. 7 extrahepatic abdominal tumours that are suspected to have fat as seen in the axial computed tomography (TC) are analysed retrospectively. In order to confirm the fat content, the chemical displacement technique with gradient echo sequences (GE) in phase (P) and in opposite phase (OP) was used with MRI 1 T equipment. The tumours corresponded to renal angiomyolipoma (AML) (n=4), intraperitoneal liposarcoma (n=1), retroperitoneal liposarcoma (n=1) and intraabdominal extramedular hematopoiesis (n=1). To confirm the existence of fat in the tumours, we used a quantitative percentage variation parameter of the intensity of the signals (VIS) between the images in P and OP, according to the formula: IS₍p)-IS(_op)x100/IS₍op), where IS is the intensity of the signal. The chemical shift technique showed fat in the seven tumours. Upon visual inspection, all the tumoral areas that were suspected to have fat showed a notable difference in the signal intensity, being hypointense in OP and hyperintense in P. In these areas the average VIS percentage was 170% while in the rest of the tumour the average VIS percentage was 3%. The chemical shift technique with RG sequences can be easily used in MRI equipment and allows us to confirm if a specific abdominal tumour has fat, even if there is only a small quantity. (Author) 13 refs

[en] To review the radiological features of the phyllodes tumor, correlating them with the clinical presentation, histological type and response to treatment. Fifty phyllodes tumors in 29 patients aged 16 to 59 years (mean: 41 years) were analyzed retrospectively. The series included 12 cases of recurrence, 1 of bilateral tumor and 6 of multiple tumor. Forty-five lesions were studied by mammography and 36 by ultrasound. Clinically guided fine-needle aspiration cytology was performed in 8 cases. The pathological diagnosis was obtained by means of surgical biopsy in every case (31 benign and 19 malignant). Twenty-four patients underwent postoperative clinical and radiological follow-up for a mean period of 32 months. Mammography revealed the presence of a nodule or mass in 42 cases, asymmetrical density in two and a generalized increase in density in one: Multifocal lesions were detected in six cases. The size varied widely, with masses measuring >5 cm showing a greater probability of malignancy (p<0.01). Calcifications were observed in 13% of the cases. Ultrasound revealed the presence of heterogeneous, hypoechoic nodules, with cystic areas in five tumors, all of which were malignant (p<0.01). Local recurrence was detected in 31% of the cases and bone metastases in one. The phyllodes tumor is an uncommon fibroepithelial tumor that has a potential for recurrence and distant metastasis. Mammographic and ultrasound features are similar to those of the fibroadenoma, a lesion with which it is occasionally associated. Multiple lesions are not infrequent and it can present with calcifications. The presence of cystic areas and a tumor size of >5 cm are the only radiological findings that are statistically associated with malignancy. The recurrence rate is greater in malignant tumors than in benign lesions, especially in patients treated by tumor resection. (Author) 28 refs

[en] Th primary thyroid lymphoma is a rare neoplasm, above all in children. We present a case of a child with Burkitt's thyroid lymphoma as the only manifestation of this disease, associated to lymphocytic thyroiditis. Clinically, it initiated as a rapidly growing goiter with compressive symptomatology. The X-ray findings are described: hypoechoic and hypodense multiple nodes that affect the right thyroid lobe and isthmus, with extraglandular extension to the vascular space and to the mediastinum. The differential diagnosis is considered with other more frequent thyroid pathologies in this age group. (Author) 14 refs

[en] Granular cell tumors (GCT) of the breast are uncommon benign neoplasms that are usually indistinguishable from breast cancer with respect to their clinical and radiological presentation. FNAB can be a usefull diagnostic tool, but histological examination is essential for the correct diagnosis. This benign tumor should be considered among the diagnostic possibilities in the presence of a lesion with mammographic and ultrasonographic indications of highly probable malignancy. We present three cases of breast GCT that mimicked primary breast cancer. Benign neoplasm was diagnosed and local excision was carried out rather than mastectomy and lymphadenectomy. (Author) 9 refs

[en] Congenital urethral polyps are uncommon lesions, very few cases of which have been previously reported in the literature. We present two cases of congenital urethral polyps in children, describing the clinical and radiological features and the diagnostic method employed, as well as reviewing the literature. (Author) 6 refs

[en] To value the changes in the morphology and size of the hypophysis gland and the sella turcia with respect to age in both sexes. 273 individuals were studied using magnetic resonance imaging without pathology in the hypothalamus-hypophysis axis, obtaining images of the sella turcia on sagittal and coronal planes. The size of the hypophysis gland, the gland morphology, the inclination of the hypophysis stalk, the height of the sella turcia and the base of the sella were valued, carrying out a comparative statistical analysis of each variable between both sexes and between age groups. The size of the hypophysis gland is significantly larger in women than in men. In women the size decreases as the age increases, except the length of the gland which increases. In men there are no significant statistic differences between the different age groups, except the length of the gland which increases. The width of the hypophysis remains constant both in women and men. The glandular morphology is more frequently convex on a sagittal plane than on a coronal plane and more so in women than in men. There is a slight inclination of the hypophysis stalk in 94.9% of the cases, with an average inclination of 4 degrees. The height of the sella turcia increases with age in both sexes and it is possible to find an excavation of the base of the sella in 41.7% of the healthy individuals, with an average excavation of 2 mm. The morphology and the normal size of the hypophysis gland, the stalk and the sella turcia vary according to age and sex. This knowledge is important, especially if used as indirect signs of hypophysis pathology (micro adenomas). (Author) 34 refs