Search PubMed⌕ Search

Biomedical subjects

P Vassallo

Publications and source records attributed to P Vassallo.

33 records · Page 2Linked to original sources
PubMed1990

Mediastinal tumors: sensitivity of detection with sonography compared with CT and radiography.

The purpose of this prospective study was to evaluate the sensitivity of mediastinal sonography compared with computed tomography (CT) and chest radiography in the detection of mediastinal tumors. The sonograms, CT scans, and chest radiographs of 182 patients were interpreted blindly by three observers, and the results were compared. The proportion of diagnostic sonographic examinations varied for the different mediastinal compartments from 85% (subcarinal region) to 96% (supraaortic region). The sensitivities of sonography and chest radiography, respectively, for each compartment, with CT as the reference method, were as follows: supraaortic region, 98% and 67%; paratracheal region, 89% and 69%; aorticopulmonary window, 81% and 62%; prevascular region, 92% and 46%; subcarinal region, 69% and 31%; pericardial region, 100% and 67%; posterior mediastinum, 6% and 6%; and paravertebral region, 11% and 44%. These results show that sonography is superior to chest radiography in the diagnosis of mediastinal tumors. In certain mediastinal regions (supraaortic, pericardial, prevascular, and paratracheal), sonography is so sensitive that CT and magnetic resonance examinations may be obviated in patients with equivocal radiographic findings.

Adolescent↗
PubMed1990

Musculoskeletal neoplasms: fast low-angle shot MR imaging with and without Gd-DTPA.

In 121 patients, image contrast and contrast-to-noise ratios (C/Ns) obtained with gadolinium diethylene-triaminepentaacetic acid (DTPA)-enhanced and nonenhanced fast low-angle shot (FLASH) sequences were compared with those achieved with spin-echo (SE) sequences. Among FLASH sequences, contrast between neoplasms and muscle was sufficient with a flip angle of 90 degrees following administration of Gd-DTPA but was 61% lower than that with the T2-weighted SE sequence. High contrast levels were obtained between tumors and bone marrow or fat in sclerotic, calcified, and fibrotic lesions with the use of a flip angle of 90 degrees and in lytic lesions with a flip angle of 10 degrees, reaching 66% of the contrast level obtained with the T1-weighted SE sequence. C/N between tumor and surrounding tissue was always significantly lower with FLASH sequences than with the ideal SE sequences usually used for tumor delineation. Thus, a replacement of the T2-weighted SE sequences by FLASH sequences cannot be recommended. A replacement of the T1-weighted SE sequences by FLASH sequences seems possible but does not significantly reduce examination time.

Adolescent↗
PubMed1990

[The diagnosis of deep venous thrombosis of the lower extremities using high-resolution real-time and CW-Doppler sonography. Accuracy and limitations].

The combination of high-resolution real time and continuous wave (CW) Doppler sonography is particularly valuable for the detection of venous thrombosis in the lower limbs. A total of 235 venous sonograms were prospectively compared with phlebography (gold standard) and indicated a sensitivity and specificity of 93%-100% and 96%-99%, respectively, depending on the thrombosis site. The positive and negative predictive values ranged between 90% and 97% and 97% and 100%, respectively. The value of real-time venous sonography, which basically entails assessing venous compressibility for the exclusion of thrombosis, is limited in the presence of small non-occlusive thrombi by the elasticity of the surrounding anatomic structures and the sonographic visibility of the veins. It is also evident that partial thrombosis in readily visualized veins (e.g., the inguinal region) is more obvious with sonography than phlebography. In addition, the proximal end of acute, extensive thrombus with poor collateral circulation is better visualized by sonography.

Adolescent↗
PubMed1990

[Diagnostic imaging of mediastinal tumors. Sensitivity and specificity of sonography in comparison with computed tomography and conventional x-ray diagnosis].

The purpose of this prospective study was to evaluate the sensitivity of mediastinal sonography compared to CT and chest radiography in the detection of mediastinal tumors. The sonograms, computed tomograms and chest radiographs of 182 patients were interpreted blindly by three observers and the results of all three procedures were compared. The proportion of diagnostic sonographic examinations varied in the different mediastinal compartments from 85% (subcarinal region) to 96% (supra-aortic region). The sensitivities of sonography and chest radiography (using CT as the gold standard) in the imaging of mediastinal tumors for each compartment were as follows: supra-aortic region: 98% and 67%; paratracheal region: 89% and 69%; aorticopulmonary window: 81% and 62%; prevascular region: 92% and 46%; subcarinal region: 69% and 31%; pericardial region: 100% and 67%; posterior mediastinum: 6% and 6%; paravertebral region: 11% and 44%. These results show that sonography is superior to chest radiography for the diagnosis of mediastinal tumors. In certain mediastinal regions (supra-aortic, pericardial, prevascular and paratracheal region), sonography is so sensitive that CT and MR examinations may be avoided in cases with equivocal radiographic findings.

Adolescent↗
PubMed1990

[Thoracic sarcoidosis].

Sarcoidosis is essentially a granulomatous disease of unknown etiology. The pathogenesis is assumed to consist in an abnormal immune reaction to a still unidentified antigen. The commonest manifestations of sarcoidosis are mediastinal and hilar lymphadenopathy and pulmonary infiltrates. The complex variety of clinical presentations of sarcoidosis means that the differential diagnosis has to include a wide range of entities. The clinical and radiological features of thoracic sarcoidosis are described, and the spectrum of relevant investigations is discussed. With respect to radiological diagnosis, computed tomography, with its higher sensitivity than other techniques, is of particular value for the precise determination of the morphological correlate of pulmonary and nodal changes and their functional relevance.

Diagnosis, Differential↗
PubMed1990

Cystic pelvic mass in a patient having recurrent carcinoma of the cervix.

The diagnostic difficulties encountered with atypical tumor growth are reported in a 29-year-old female with recurrent carcinoma of the uterine cervix. Following a Wertheim-Meigs procedure and resection of local tumor recurrence eight months later, a second recurrence was detected on CT as a purely cystic lesion in the left pelvic wall. Although the size of the cyst subsequently increased, the patient remained asymptomatic until slight pain developed in the left leg 28 months after initial therapy. One month later, limping was noticed; plain radiography showed a large osteolytic lesion of the left hip and on I.V.U., a dilatation of the left renal collecting system was observed. Pelvic CT showed only minimal solid tissue components within a large cyst. Multiple needle aspirations of the cyst and cytological examinations of the fluid obtained showed no evidence of tumor cells. A definitive histological diagnosis of metastasizing squamous cell carcinoma was only reached after surgery.

Adult↗
PubMed1989

Mediastinal tumors: biopsy under US guidance.

Percutaneous biopsies of mediastinal tumors were successfully performed under sonographic guidance in 14 of 21 patients. In 10 of 11 malignant lesions, malignancy was determined by means of cytologic and histologic examination of the specimens obtained. A histologic diagnosis was reached in seven patients with malignant mediastinal tumors, including all four cases of Hodgkin lymphoma. Mediastinal biopsy under sonographic guidance is a technically simple, rapid, and accurate procedure, but its application is limited to tumors of the anterior mediastinum.

Biopsy, Needle↗
PubMed1988

[Efficient use of flash sequences in the staging of bone and soft tissue tumors].

Delineation of neoplasms from normal tissue is possible using Flash sequences. These sequences prove useful in preoperative staging of bone tumours and soft tissue tumours. However, contrast between neoplastic and surrounding normal tissue is lower than in optimal selected spin-echo sequences. Flash-90 sequence is superior to Flash-10 sequence in the demonstration of intraosseous extension of predominantly sclerotic, calcified and purely fibrous tumours. In contrast, Flash-10 sequence proves superior for the demarcation of osteolytic tumours with minimal fibrous tissue content. Delineation of extraosseous tumour masses against muscle can best be achieved using Flash-90 sequence after intravenous administration of Gadolinium-DTPA. Flash-90 sequence enables sharp demarcation of extraosseous masses of bone tumours against surrounding fat, whereas Flash-10 sequence proves useful in the delineation of non-lipomatous soft tissue tumours against normal fat.

Bone Neoplasms↗
PubMedDate not supplied

Ophthalmic complications after surgery for nasal and sinus polyposis.

PURPOSE: To describe ophthalmic complications after nasal and sinus surgery. METHODS: Four cases with orbital complications were retrospectively selected from among more than 2000 cases of orbital pathologies. RESULTS: Motility disturbances due to extraocular muscle injury occurred in two patients after intranasal ethmoidectomy and in one patient after a Caldwell-Luc procedure. In the fourth case an orbital apex syndrome was noted after intranasal ethmoidectomies. CONCLUSIONS: Ophthalmic complications may occur after nasal and sinus surgery, even using an endoscopic procedure. Successful handling of these complications could be reached by on their early recognition and treatment.

Adult↗