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R Passariello

Publications and source records attributed to R Passariello.

At least 145 records · Page 8Linked to original sources
PubMed1990

Abdominal aortic aneurysm evaluation: comparison of US, CT, MRI, and angiography.

We studied 26 cases of abdominal aortic aneurysm with magnetic resonance imaging (MRI), computed tomography (CT), ultrasonography (US), and angiography. Data acquired were compared to those obtained at surgery. Diameter of the aneurysm was correctly defined in all cases by CT and MRI, while angiography underestimated the diameter of lesions without peripheral calcifications. Involvement of renal arteries was present in four cases and correctly diagnosed with MRI and angiography in all of them. CT did provide this information in three cases and US were not useful. Also, iliac arteries involvement was depicted by CT, MRI, and angiography in 10 out of 10 patients. Coronal sections of MRI provided comparable images to those of angiography. By comparing these different techniques we verified the good reliability of MRI as investigation tool for an accurate evaluation of aneurysms; its only limit lying in the poor capability of detecting calcifications.

Aged↗
PubMed1990

MR imaging of degenerative disorders of brainstem and cerebellum.

In pathologies such as progressive ataxias, clinical criteria are often not enough to provide the correct diagnosis. Therefore, we studied by means of MRI 30 normal volunteers and 19 patients affected by different progressive ataxias, diagnosed by typical standards. On all the subjects measurements were performed in order to identify normal and pathological ranges. Our experience confirms that typical involvement can be detected in the different kinds of progressive ataxias. Peculiar compromissions were found in spinocerebellar diseases, able to differentiate them from the forms mostly involving the cerebellum and brainstem. The differentiation between typical Friedreich and non-Friedreich diseases can also be suggested in most cases.

Adolescent↗
PubMed1990

Role of magnetic resonance imaging in the evaluation of aortic graft healing, perigraft fluid collection, and graft infection.

The authors report their preliminary experience in the use of Magnetic Resonance Imaging (MRI) in ten patients who underwent aortic reconstruction. Examinations were performed 1, 4, 12 and 24 weeks after surgery, to examine the presence, size, magnetic characteristics and evolution of periprosthetic collections. The results have shown that periprosthetic collection can be considered normal after aortic reconstructive surgery, because such a perigraft collection (PFC) was present in 90% of the patients studied 1 week after operation, and had disappeared within 24 weeks in all cases. The magnetic characteristics were evaluated by T1 [repetition time (TR) = 480 msec and echo time (TE) = 20 msec] and T2 weighted spin-echo sequences (TR = 1800 msec and TE = 70/120 msec). Variations in the magnetic characteristics, found in sequential examinations, correlated with modifications of the collection and suggested that it was originally blood. The MRI examination performed 24 weeks after surgery gave a low signal intensity in T1 and T2 weighted sequences (w.s.) suggesting periprosthetic fibrosis. These preliminary observations may constitute a starting point for better evaluation of the normal appearance and evolution of the periprosthetic fluid collections following aortic graft implantation and, may be useful for the early detection of infection especially in asymptomatic patients.

Aorta, Abdominal↗
PubMed1990

Comparison of Gd-BOPTA with Gd-DTPA in MR imaging of rat liver.

A new lipophilic compound, gadolinium benzyloxypropionictetraacetate (BOPTA), with a high rate of biliary excretion was assessed as a magnetic resonance (MR) hepatospecific contrast-enhancing agent and compared with Gd-DTPA (diethylenetriaminepentaacetic acid) in MR imaging of normal rats. T1-weighted spin-echo images obtained before and after administration of each contrast agent at doses of 0.25, 0.5, and 1.0 mmol/kg showed greater enhancement of the liver with Gd-BOPTA than with Gd-DTPA, with the advantage more evident at lower doses. Images obtained with an inversion recovery sequence at the null value of rat liver parenchyma after injection of 0.1- and 0.5-mmol/kg doses of the contrast agent provided better evidence of the greater and longer-lasting hepatic enhancement due to Gd-BOPTA when compared with that of Gd-DTPA. Gd-BOPTA is a potentially good contrast agent for obtaining prolonged enhancement of the liver, permitting studies during the long time needed to acquire conventional T1-weighted images.

Acetates↗
PubMed1990

Magnetic resonance imaging in the localization of undescended abdominal testes.

In children with nonpalpable undescended testes, preoperative localization is very helpful prior to surgical investigation both to reduce the time required for complete exploration and to plan the correct surgical procedure. Magnetic resonance imaging (MRI) was accomplished in 23 patients with a clinical diagnosis of cryptorchidism after ultrasonographic studies were inconclusive in identifying the undescended testis. An abdominal testis was correctly located in 16 cases. No structures resembling testicular parenchyma were detected in 4 instances. The surgical findings confirmed the absence of testes in 2 patients but showed 2 abdominal testes not seen by MRI. The movements of 5 patients caused inadequate MRI examinations, so these patients were not considered in the results. In our experience MRI proved to be effective in locating undescended abdominal testes with a diagnostic accuracy of 90%. Therefore MRI should be performed before any invasive diagnostic procedure. Lack of cooperation in young patients could reduce the accuracy of the procedure, so we think that sedation should be performed in children under 6 years of age.

Abdomen↗
PubMed1990

Wernicke encephalopathy: MR findings in five patients.

Wernicke encephalopathy is a disease usually related to chronic alcoholism. The clinical diagnosis is often difficult to establish, and CT is unable to provide specific findings. MR follow-up studies in five patients affected by Wernicke encephalopathy were performed with the aim of establishing the sensitivity of MR in depicting the typical diencephalic/mesencephalic lesions. All subjects had MR imaging in the acute phase of the disease and were reexamined 6-12 months later, at which time they were in good health. Three of them also had CT scanning. On MR, hyperintense areas seen surrounding the third ventricle and aqueduct during the acute phase of the disease had disappeared or diminished on follow-up evaluations. The third ventricle and aqueduct were dilated. We suggest that these findings reflect the natural evolution of Wernicke encephalopathy. The MR findings in Wernicke encephalopathy enable early diagnosis of the disease, which has a positive effect on both treatment and prognosis.

Adult↗
PubMed1990

[Staging of bronchogenic cancer. Determination of mediastinal lymphatic involvement using magnetic resonance].

Twenty-five patients with bronchogenic carcinoma were prospectively studied by both CT and MR during 10 days preceding thoracotomy. MR scans included contiguous axial and coronal slices. Results of CT and MR studies were compared with the surgical and pathological findings. Although no significant difference was found between the two imaging methods for the evaluation of mediastinal nodes. MR appear to be superior to CT in the aortopulmonary and subcarinal node areas.

Adult↗
PubMed1990

[An animal model for the study of liver regeneration by magnetic resonance imaging].

Liver regeneration after partial hepatectomy was studied in rats by means of magnetic resonance (MR) imaging and T1 relaxation time. Fourteen hepatectomized rats were compared to sham operated ones and to controls which had not undergone any surgical treatment. The animals were imaged at 0.5 T, and inversion recovery (IR) technique was employed at the T-null of liver before surgery. T1 was determined in vitro with spectroscopy. Regenerating rat liver exhibited a significantly high increase in MR signal intensity and T1 values (p less than 0.05) 24 hours after surgery, returning to baseline values at 2 weeks. Sham operated animals and controls did not exhibit significant changes in signal intensity from baseline values (p greater than 0.05). These findings suggest that MR imaging is able to detect the pathophysiological changes occurring in liver parenchyma during the regenerating process and to monitor different stages of the hyperplastic process.

Animals↗
PubMed1990

[A comparative study between Gd-BOPTA, a biliary excretion contrast medium, and Gd-DTPA in the magnetic resonance imaging of the rat liver].

A new lipophilic compound, Gd-BOPTA, presenting a high rate (38.6%) of biliary excretion was tested as an hepato-specific MR contrast agent. Its adequacy was compared to that of Gd-DTPA in laboratory animals. T1-weighted spin-echo sequences (TR 220 ms, TE 20 ms) both before and after the administration of the 2 contrast agents (doses: 0.25, 0.5, and 1.0 mmol/kg) showed better liver enhancement with Gd-BOPTA than with Gd-DTPA. Gd-BOPTA superiority was more evident at lower doses, while at 1.0 mmol/kg a comparable enhancement was achieved. Inversion recovery sequence at the T-null of liver parenchyma before contrast (TR 800 ms, TE 30 ms, TI 100 ms) was performed after the injection of 0.1 and 0.5 mmol/kg of Gd-DTPA and Gd-BOPTA. This sequence allowed the good and long-lasting liver enhancement achieved with Gd-BOPTA to be even better demonstrated, while Gd-DTPA provided only a slight and early enhancement with 0.1 mmol/kg and returned to baseline values 60' after the injection of the highest dose (0.5 mmol/kg). Gd-BOPTA proved to be a good contrast agent to obtain prolonged liver enhancement, thus providing the radiologist with the long time needed to acquire conventional T1-weighted pulse sequences.

Acetates↗
PubMed1990

[Pathologic dilatation of the thoracic aorta: a study using magnetic resonance].

Magnetic resonance (MR) imaging provides detailed evaluation of cardiovascular structures, due to high intrinsic contrast between flowing blood and vessel's lumen. Early application have shown the clinical validity of the technique, with non-invasive, multiplanar imaging of large and medium sized vessels. In this study we evaluate the capabilities of MR in screening out patients with thoracic aorta enlargement. Examination has been performed in 16 patients, employing a 0.5 T superconductive unit, and acquiring images on axial, sagittal and coronal planes with 7 mm slice thickness. In 15 cases it was possible to detect the pathology and to characterize it according to type, location and extension. In 1 case it was no possible to make an accurate diagnosis for the presence of movement artefacts, due to poor patient's cooperation. In dissecting aneurysms the true and false lumen may be differentiated, with a good visualization of the intimal flap. The relation between the origin of the aortic branches and the aneurysm may also be ascertained.

Adult↗
PubMed1990

[Clinically manifest or silent primary and secondary syringomyelia. The magnetic resonance findings].

The MR scans were retrospectively reviewed of 40 patients who had been diagnosed as having syringomyelia. Our results demonstrate that syringomyelia can be found in asymptomatic patients as well as in many with atypical symptomatology. Our study stresses MR efficacy in investigating this pathologic condition. As a matter of fact, MR allowed us to visualize the cavity, its extension, the eventual association with Arnold Chiari type-I malformation and/or syringobulbia. In all cases cord enlargement and the presence of septations could also be demonstrated. In most cases the possible pathogenesis of syringomyelia could also be supposed.

Adolescent↗
PubMed1989

Hemispheric asymmetries and schizophrenia: a preliminary magnetic resonance imaging study.

A magnetic resonance imaging (MRI) study of 20 chronic schizophrenic outpatients (5 women and 15 men) and 20 healthy volunteers, individually matched for age and sex, was conducted. Schizophrenics showed a statistically significant lateral ventricular enlargement and smaller corpus callosum: brain ratio than controls. There were no statistically significant differences in hemispheric measurements between groups. Nevertheless, we found a wider right frontal width versus the left in the patient group but not in the control group, and more frontal protuberances in the right hemisphere in the patient group. Possible meanings and implications of these findings for a pathophysiological hypothesis are discussed.

Adult↗
PubMed1989

[Magnetic resonance of the prostate: critical evaluation of diagnostic possibilities].

The authors retrospectively reviewed 140 MR examinations of the prostate to assess the presence of similar findings in the different patients affected with the same prostatic disease. In 35 patients with acute phlogosis, MR imaging showed enlargement of peripheral gland, with increased signal intensity on T2-weighted images, while reduced peripheral gland with low signal intensity was demonstrated in chronic phlogosis. Five patients presented roundish cystic lesions, with clear-cut outlines, clearly distinguishable from the surrounding parenchyma. Benign Prostatic Hyperplasia (BPH) was observed in 32 cases. 52% of them had multiple nodules with high signal intensity, 40% had hyperintense enlarged central glands, with no evidence of BPH nodules, and the remaining 8% presented single/multiple nodules with low signal intensity. In 56 patients with prostatic carcinoma the tumor extent ranged from 18-20 mm nodules to 5-6 cm masses with involvement of periprostatic adipose tissue or surrounding organs. The smallest lesions were always found in the peripheral gland and had low signal intensity on T2-weighted sequences. In spite of the different findings in the patients affected with BPH, the study proved MR imaging to be able to distinguish the various patterns of the different prostatic diseases.

Adolescent↗
PubMed1989

[MR characterization of breast pathology using inversion recovery sequence].

As yet, a valid tissue characterization of human breast diseases has not been possible with conventional MR techniques. On the basis of the experimental thesis according to which fibroadenomas and carcinomas have a slight, though significant, difference in T1 relaxation times, we employed specific inversion recovery sequences at the T null of the breast glandular and adipose tissues, to enhance the differences in the signal intensities of the various pathologies. We examined 16 (6 cystic dysplasias, 5 fibroadenomas, 3 carcinomas, and 1 phylloid fibroadenoma) selected patients with the above-mentioned sequences in addition to the routine T1- and T2-weighted spin echo sequences. The following conclusions were reached by evaluating the characteristic signal intensities: MR spin echo sequences allow solid lesions to be distinguished from cystic ones; MR inversion recovery sequences allow fibroadenomas to be distinguished from carcinomas with 88% accuracy.

Adenofibroma↗
PubMed1989

Magnetic resonance imaging of abdominal aortic grafts.

The widespread use of abdominal aortic grafting procedures and increasing awareness of related complications suggests the need for a reliable and non-invasive diagnostic technique which will allow early detection of both occlusive and non-occlusive complications. Ultrasound is generally used with satisfactory results, but has several limitations, whereas MRI has shown great promise in the study of cardiovascular disease, being non-invasive, multiplanar and multiparametric. The present research aims to evaluate MRI in the follow-up of abdominal aortic grafts, attempting to define its significance as a screening procedure in non-selected patients. MRI is reliable in ascertaining the normality of the graft as well as the complications, these being partial or total thrombosis, pseudoaneurysms and perigraft collections. The data obtained are highly satisfactory and are almost always superior to those achieved with ultrasound and CT.

Aorta, Abdominal↗