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L Bonomo

Publications and source records attributed to L Bonomo.

375 records · Page 21Linked to original sources
PubMedDate not supplied

[Isoflurane in angiography with magnetic resonance].

The authors investigated if the use of vasodilating drugs could increase Magnetic Resonance angiography (MRA) capabilities in demonstrating intracranial vessels. Twenty patients (mean age: 10 years) were examined with MRA: a vasodilating drug (isoflurane) was administered to 10 of them and 10 matched-pair subjects were selected as controls and submitted to MRA without receiving any drug known to increase cerebral blood flow. MRA was performed with a 1.5-T superconductive magnet; FISP 3D sequences were used in all cases. A multiple choice card was used by a reader reporting the following diagnostic information for the different segments of the intracranial vessels: 1) hyperintense and homogeneous vessel with high signal-to-noise (S/N) ratio; 2) hyperintense and heterogeneous vessel with high S/N ratio; 3) hyperintense vessel with low S/N ratio; 4) poor vessels depiction. Small vessels (ophthalmic arteries, A3, M3, M4, anterior communicating arteries and P2 segments) were better demonstrated with isoflurane than with conventional MRA. The results were compared with the Mann-Withney test: isoflurane MRA allowed good vessel depiction in 127 cases, versus 83 of conventional MRA; the difference was statistically significant. To conclude, the use of vasodilating drugs represents a new research field in MRA of the intracranial vessels.

Adolescent↗
PubMedDate not supplied

Resistance to recombinant alpha interferon therapy in idiopathic mixed cryoglobulinemia: reinduction of remission by natural alpha interferon both in antibody-positive and -negative patients.

A subset of patients treated with recombinant interferon alpha-2a (rIFN-alpha 2a) for idiopathic mixed cryoglobulinemia (IMC) developed clinical resistance to therapy after a sustained response. Neutralizing antibodies to rIFN-alpha 2a were found in the sera of three out of four such patients, and in none of the patients who remained responsive to treatment. rIFN-alpha 2a neutralizing antibodies appeared in serum samples of the former three patients 1, 5 and 6 months before evidence for clinical resistance, respectively. Antibody titres to rIFN-alpha 2a were consistently higher than those to natural interferon (nIFN). In the fourth patient with clinical resistance, neutralizing antibodies could not be detected by a very sensitive bioassay in any of several serum samples taken before and after relapse. All the four patients could be reinduced into remission by the administration of nIFN-alpha. These data indicate that mechanisms other than the production of neutralizing antibodies can mediate acquired resistance to IFN therapy. Furthermore, both antibody-related and -unrelated resistance can be overcome by switching to different species of IFN-alpha.

Antibodies↗
PubMedDate not supplied

[Staging of pulmonary apex tumors. Computerized tomography versus magnetic resonance].

Apical lung cancers account for about 5% of pulmonary lesions and can be divided into two groups: Pancoast and non-Pancoast lesions. Recently, the use of MRI has been suggested in combination with CT to stage this kind of lung cancer. In this paper the authors' experience is reported relative to the current role of MRI and CT in the staging of apical lung cancers. Twelve male patients (mean age: 60.5 years) with apical lung cancers underwent conventional X-ray, CT and MR examinations of the chest. CT and MR images were studied by two independent radiologists with specific experience; surgery was the gold standard in three patients and MR and clinical symptoms in the patients not referred for surgery. In 15/108 cases (13.8%) CT and MR findings were in disagreement but in 93/108 cases (86.2%) they were in agreement. The highest disagreement rate was observed in the study of apical chest wall infiltration (33.3%), while in the study of anonymous vein involvement CT and MRI were always in agreement. The correct assessment of the regional extent of apical lung cancers is mandatory for treatment planning. In this kind of tumors MRI can be considered the method of choice thanks to its high contrast resolution and multiplanar imaging capabilities.

Adult↗
PubMedDate not supplied

[Magnetic resonance in thoracic pathology: characterization by intensity values].

The authors examined prospectively 100 patients with lung diseases--50 of them benign and 50 malignant. The mean value of all lesions was measured with a constant region of interest (ROI); the muscle was considered as the reference tissue. Histopathology was the gold standard for the patients who underwent CT-guided needle biopsy and/or surgery; clinical-radiologic follow-up (average time: 2 years) was the gold standard for nonsurgical patients. A superconductive 1.5-T magnet with circular polarization body coil was used; T1- and T2-weighted spin echo images were acquired on the coronal and axial planes, respectively. The mean values with the constant ROI were measured both on the lesions and on the reference tissue to calculate and compare the T1-lesion/T1-muscle and T2-lesion/T2-muscle ratios in benign and malignant conditions. The t-test, the linear regression and correlation test and the analysis of variance were used to analyze the data. T1 benign lung disease/T1 muscle ratio was 1.21, while T1 malignant lung disease/T1 muscle ratio was 1.27, with no statistically significant difference. T2 benign lung disease/T2 muscle ratio was 2.63, while T2 malignant lung disease/T2 muscle ratio was 4.80: the difference was statistically significant (p < 0.001). To conclude, in chest diseases, the measurement of mean values in T2 allowed malignancy-indicative values (> 4 ratio) and positively benign values (< 2.5 ratio) to be identified.

Adenocarcinoma↗
PubMedDate not supplied

[Bedside thoracic radiography: a comparison between 3 different types of grid].

Bedside chest radiography accounts for an increasingly large portion of all chest X-ray examinations. Nevertheless, image quality is often poor mainly because of scattered radiations which decrease image contrast. Moreover, usually no grid is employed because of difficult beam alignment. This work was aimed at comparing different radiologic grids for bedside chest radiography. Fifty patients submitted to two bedside chest radiographs in 24 hours were studied. All the patients underwent the first exam with a Kodak InSight cassette with a newly-designed (columnar type) grid inside, while the second exam was performed with a conventional 8:1 focused lead-strip grid (Gilardoni) in 25 patients and with a 6:1 focused lead-strip grid (Gilardoni) in the extant 25 patients. Both grids were assembled in a Kodak InSight radiographic cassette. Three independent radiologists evaluated film quality, focusing on the depiction of some anatomical structures--e.g., the tracheobronchial tree, the retrocardiac lung, and devices. Seventy-five examinations were obtained for each grid and for each evaluated structure and graded as "good", "acceptable" and "poor". In the 6:1 vs columnar grid test, the highest rate of "good" and "acceptable"--i.e., diagnostic--findings was observed with the columnar grid in evaluating pulmonary vessels (71/75); the highest rate of "poor" findings was obtained with the same grid in evaluating tracheal bifurcation (43/75). In the 8:1 vs columnar grid test, the highest rate of diagnostic findings was shown by the conventional grid in evaluating retrocardiac lung parenchyma and by the columnar grid for pulmonary vessels (69/75); the highest rate of "poor" findings was obtained with the columnar grid in evaluating tracheal bifurcation (40/75). The statistical analysis of the results (Wilcoxon test) was made to compare the two conventional grids with the new columnar one. Statistically significant differences were observed between the 8:1 grid and the columnar grid to evaluate the bronchial tree. No differences were observed between the 8:1 grid and the columnar grid. Furthermore, to determine the effects of different degrees of grid decentering on image quality, a series of exposures was made using a lung-chest phantom. The grids, both the lead-stripe and the columnar one, were comparable. The higher-ratio grid proved better in evaluating tiny details. The columnar grid exhibited better tolerance to X-ray beam and to grid decentering.

Equipment Design↗
PubMedDate not supplied

[Neoplasms of the glomus caroticum: magnetic resonance angiography versus magnetic resonance].

This work was aimed at investigating the diagnostic role of Magnetic Resonance angiography (MRA) versus spin-echo images in the study of carotid paragangliomas. Ten patients affected with carotid paragangliomas were studied; surgery was the gold standard. MR examinations were performed with a superconductive 1.5 T magnet and a linear head coil. T1-weighted (TR 500 ms, TE 15 ms, 256 x 256 matrix) and T2-weighted (TR 2000 ms, TE 15/90 ms, 256 x 256 matrix) spin-echo sequences were acquired. TOF 3D (flash: FA 25 degrees, TR 30 ms, TE 7 ms) MRA images were acquired; coronal and sagittal images were rotated according to the MIP. Spin-echo images demonstrated the typical "salt and pepper" pattern in all cases. In 6 cases (lesion diameter > 3 cm) the vascular structures of the paragangliomas and carotid dislocation were clearly demonstrated by MRA. MRA also depicted carotid dislocation in all cases. In conclusion, in the evaluation of carotid paragangliomas > 3 cm diameter, MRA yields complementary information on vascular structures and dislocation of carotid vessels to spin-echo MR sequences.

Adult↗
PubMedDate not supplied

[Good health].

Explore the source record for details and available documents.

Health Services↗
PubMedDate not supplied

[The peripheral circulation: ECG-gated magnetic resonance angiography].

This work was aimed at comparing magnetic resonance angiography (MRA) with and without ECG gating in the study of peripheral vessels. Ten volunteers, mean age 27.8 years, were examined with MRA of the femoral, popliteal and tibial segments. MRA was performed with a 1.5-T superconductive magnet, a transmit head coil and the TOF 2D technique. In all cases MRA was performed without cardiac gating and with different times of trigger delay (0, 20, 40, 70 and 200 ms). When comparing the different acquisitions, the number of vessels and the signal-to-noise (S/N) ratio were calculated. In the femoral segment, MRA without cardiac gating showed a mean of 7.7 vessels with 2.79 S/N ratio; MRA with 0 ms of trigger delay showed a mean of 13.1 vessels with 1.51 S/N ratio; MRA with 20 ms trigger delay showed a mean of 13.1 vessels with 1.52 S/N ratio; MRA with 40 ms trigger delay showed a mean of 13.2 vessels with 1.52 S/N ratio; MRA with 70 ms trigger delay showed a mean of 13.5 vessels with 1.50 S/N ratio; finally, MRA with 200 ms trigger delay showed a mean of 13.4 vessels with 1.50 S/N ratio. In the popliteal segment, the corresponding values were 6.4 vessels and 2.51 S/N ratio, 11.4 vessels with 1.54 S/N ratio, 11.3 vessels and 1.54 S/N ratio, 11.6 vessels and 1.52 S/N ratio, 11.8 vessels and 1.52 S/N ratio and, finally, 11.9 vessels and 1.52 S/N ratio. In the tibial segment, the corresponding values were 8.5 vessels and 1.84 S/N ratio, 14.4 vessels and 1.14 S/N ratio, 14.5 vessels and 1.17 S/N ratio, 14.5 vessels and 1.14 S/N ratio, 14.3 vessels and 1.17 S/N ratio and, finally, 14.5 vessels and 1.19 S/N ratio. To conclude, MRA with cardiac gating better visualized peripheral vessels whatever the trigger delay.

Adult↗
PubMedDate not supplied

[Malignant pulmonary neoplasms: diagnostic possibilities of magnetic resonance angiography].

The authors investigated the potentials of Magnetic Resonance Angiography (MRA) in the preoperative staging of malignant central lung neoplasms. Fifteen patients with malignant central lung neoplasms were submitted to MRA 48 hours before surgery, which was the gold standard. The patients were 7 women and 8 men; their mean age was 54.3 years (range: 39-65 years). MRA was performed with the 2D and 3D time-of-flight (TOF) technique. FLASH 2D sequences (FA 18 degrees, TR 40 ms, TE 10 ms, SL 4 mm) and FISP 3D sequences (FA 20 degrees, TR 30 ms, TE 3 ms, SL 1 mm) were used. The images were processed with the maximum intensity projection (MIP) and rotated on different planes with a 15 degrees step. A multiple choice card, implying preoperative reading by an MRA expert, was used; in the study of the relationship between neoplasms and contiguous vessels, only two diagnoses were possible--i.e., infiltrated, not infiltrated. This card included, in the preliminary phase, a code for each MRA pattern--i.e., the presence of a clear cleavage plane, vascular occlusion, stenosis, irregular vessel profile, turbulence and several of these patterns together. MRA was in agreement with surgery in 14/16 cases and overestimated two cases as infiltration. In our preliminary study, MRA had 100% sensitivity, 75% specificity and 87.5% diagnostic accuracy. To conclude, MRA proved to be a complementary tool to spin-echo MR sequences in the staging of malignant central lung neoplasms.

Adult↗
PubMedDate not supplied

[Assessment of the therapeutic effectiveness of alcohol administration in hepatocarcinoma: comparison of spiral computerized tomography and Doppler color ultrasonography].

PURPOSE: To investigate the comparative adequacy of spiral CT and color-Doppler US versus biopsy in assessing the efficacy of percutaneous ethanol injection (PEI) in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifteen patients with 30 known HCCs, 2-5 cm in diameter, underwent PEI. Arterial phase spiral CT and color-Doppler US were performed before treatment in all patients. Treatment efficacy was established on the basis of color-Doppler, spiral CT and percutaneous biopsy findings; biopsy was the gold standard. RESULTS: After PEI, 22 of 30 lesions which were negative for malignant cells at biopsy were completely necrotic at spiral CT and avascular at color-Doppler US. In the extant 8 lesions, which exhibited residual tumor tissue at biopsy, spiral CT detected early enhancement of the viable tumor portion in all cases. Color-Doppler US showed residual tumor vascularization in 4 of 8 lesions. CONCLUSIONS: Our results demonstrate that spiral CT, performed in the arterial phase, can improve the depiction of residual viable tumor tissue in HCCs treated with PEI, overcoming color-Doppler limitations.

Aged↗
PubMedDate not supplied

Pulmonary embolism: the role of computed tomography and magnetic resonance imaging.

The technological progress in Computed Tomography (CT) (spiral and electron beam) and Magnetic Resonance Imaging (MRI fast sequences) has stimulated their interest in the diagnosis of acute and chronic pulmonary embolism (PE). They are noninvasive procedures able to identify thrombi up to the level of segmental pulmonary branches. This result, albeit not ideal, is significant, in view of the lower clinical relevance of peripheral emboli as compared to more central locations, especially in the absence of peripheral venous thrombosis. Spiral CT allows satisfactory assessment of pulmonary branches with high sensitivity (65-100%), specificity (89-96%), positive predictive value (95%) and negative predictive value (80-100%) in the diagnosis of PE. MRI with spin-echo sequences has also a satisfactory sensitivity (75-90%), specificity (up to 100%), positive predictive value (86%) and negative predictive value (85%). Recently, MR angiography was shown to be able to depict smaller pulmonary branches (6th and 7th generation), even if its efficacy in the identification of emboli has not been demonstrated as yet. CT and MRI are bound to play an increasingly relevant role in the diagnosis of PE.

Humans↗
PubMedDate not supplied

[Optimization and diagnostic accuracy of computerized tomography with tridimensional spiral technique in the study of craniostenosis].

INTRODUCTION: Conventional Computed Tomography (CT) with three-dimensional (3D) reconstructions is considered the most complete and accurate imaging modality to diagnose craniosynostosis. However, the introduction of Spiral CT (SCT) opened new possibilities for 3D studies of the skull in pediatric patients with craniosynostosis. The purpose of our study is two fold: first, to optimize the scanning and imaging parameters to obtain diagnostic images in a single spiral scan; second, to assess the diagnostic accuracy of such images in the identification of normal and abnormal cranial vault sutures. MATERIAL AND METHODS: Seventy-eight pediatric patients (age range: 1-35 months; mean: 11.8 months) with craniosynostosis were submitted to SCT of the head. The images were acquired with the following parameters: 3- and 5-mm nominal slice thickness, 5-6 mm/s table feed (pitch 1-2), 165 mAs and 120 kV. Two different algorithms and increases were used for image reconstructions. A first set of images was reconstructed with 2-mm increases and a soft tissue algorithm: these images were used for brain studies and for 3D reconstructions. A second set of slices was reconstructed with 5-mm increases and a bone algorithm to visualize the sutures of the axial plane. The 3D images were processed with the Shaded Surface Display software with threshold values ranging 120-150 HU. All images were acquired with a single spiral scan lasting less than 30 seconds. Two blinded radiologists analyzed the 3D and the planar images independently to evaluate the course and depth of each cranial suture. The sensitivity, specificity and diagnostic accuracy of both 3D and planar SCT images were evaluated. The frequency of artifacts (the Lego effect, boiled egg, pseudoforamina, movement, and chainsaw artifacts) and their influence on the final diagnosis were studied on 3D SCT images. RESULTS: The diagnostic accuracy rates of 3D SCT images, by suture, were: sagittal 90.7%, metopic 100%, left lamboid 90.9%, right lamboid 93.9%, left coronal 85.7%, right coronal 91.1%. The diagnostic accuracy rates of the axial images, by suture, were: sagittal 90.7%, metopic 95.5%, left lamboid 86.4%, right lamboid 90.9%, left coronal 83.7%, right coronal 91.1%. The interobserver agreement on 3D images was: sagittal 91.1%, metopic 100%, left lamboid 88.9%, right lamboid 91.1%, left coronal 88.9%, right coronal 84.4%. The Lego effect artifact was the most frequent one (82%) and affected image evaluation in 6.3% of cases. CONCLUSIONS: Our results prove that 3D SCT is a very accurate technique for identifying normal and abnormal sutures and presents many advantages over conventional 3D CT in the examination of pediatric patients with craniosynostosis. The quality of 3D SCT images was adequate and the artifacts did not affect the final diagnostic yield significantly.

Child, Preschool↗