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Biomedical subjects

F Prandini

Publications and source records attributed to F Prandini.

13 recordsLinked to original sources
PubMed1999

Cumulative effect of a weekly low dose of interferon beta 1a on standard and triple dose contrast-enhanced MRI from multiple sclerosis patients.

In patients with multiple sclerosis (MS), we assessed the short- and long-term effects of a weekly low dose of recombinant human interferon beta 1a (rh-IFN beta 1a) on the development of new magnetic resonance imaging (MRI) lesions enhancing at different gadolinium-DTPA (Gd) doses. Every 4 weeks, standard dose (SD) (0.1 mmol/kg of Gd) and triple dose (TD) (0.3 mmol/kg of Gd) Gd-enhanced brain MRI scans were obtained from 18 patients with relapsing-remitting MS for 3 months before treatment, 4 months after treatment initiation (treatment period [TP] I) and 4 months after 1 year of treatment (TP II) with 44 microg of rh-IFN beta 1a subcutaneously, once a week. The mean numbers of new enhancing lesions/patient/month were 1.4 (baseline), 1.1 (TP I) and 0.7 (TP II) on SD scans and 2.4 (baseline), 1.3 (TP I) and 0.8 (TP II) on TD scans. On average, treatment decreased the rate of new enhancing lesion appearance by 24% (SD scans) and 45% (TD scans) during TP I and by 52% (SD scans) and 66% (TD scans) during TP II. This study indicates that the effect of 44 microg of rh-IFN beta 1a given once a week on MRI-monitored MS activity increases over time. It also suggests that TD MRI is useful in detecting early treatment effect, that would otherwise be missed.

Adjuvants, Immunologic↗
PubMed1999

Short-term evolution of new multiple sclerosis lesions enhancing on standard and triple dose gadolinium-enhanced brain MRI scans.

We compared the short-term magnetic resonance imaging (MRI) evolution of new multiple sclerosis (MS) lesions enhancing after single dose (SD) (0.1 mmol/kg) or triple dose (TD) (0.3 mmol/kg) gadolinium-DTPA (Gd) to explore possible differences in the pathological substrates of acute MS lesions. Brain MRI scans were obtained at baseline and every 4 weeks for a 3-month period in 18 relapsing-remitting MS patients. At each time point, using two separate sessions, we obtained dual echo and T1-weighted scans before and after SD and TD of Gd. New enhancing lesions detected at month 1 and 2 were entered into the analysis. The presence of corresponding hypointense lesions on unenhanced T1-weighted scans and hyperintense lesions on T2/proton density (PD)-weighted images was assessed on the same scan and on the scans performed 1 month before and 1 month after the new lesion development. Persistence of enhancement was evaluated on the SD and TD scans obtained 1 month after new lesion appearance. One-hundred and sixty lesions were studied. Of these, 97 lesions were enhancing after both SD and TD (group A) and 63 lesions only after TD (group B). Thirty (31%) of the lesions enhancing after both SD and TD and ten (16%) of the lesions enhancing only after TD had corresponding T1-weighted lesions (P = 0.03). Of these lesions, 87% in group A and 40% in group B (P = 0.003) were not hypointense on the previous scans. No differences were found in the frequencies of corresponding T2/PD-weighted abnormalities (92% in Group A vs. 87% in Group B lesions). Of these hyperintense areas, 62% in group A and 56% in group B were not present on the previous scans. On follow-up scans, 52% of the lesions enhancing after SD and TD and 70% of the lesions enhancing only after TD did not show enhancement after the injection of both the doses of Gd (P = 0.02). The frequencies of corresponding T2/PD and T1-weighted abnormalities were higher in Group A than in Group B lesions, but the differences were not statistically significant. Our findings suggest that the pathological process is less severe in MS lesions enhancing only after TD injection than in those enhancing after the SD.

Adult↗
PubMed1999

Interferon beta treatment for multiple sclerosis has a graduated effect on MRI enhancing lesions according to their size and pathology.

OBJECTIVE: The ability of recombinant human interferon beta-1a (rh-IFN beta-1a) to suppress multiple sclerosis activity, evaluated from MRI, was assessed across a range of lesions enhancing at different gadolinium-DTPA (Gd) doses and with different sizes. METHODS: Every 4 weeks, standard dose (Sd; 0.1 mmol/kg Gd) and triple dose (Td; 0.3 mmol/kgGd) MRI were obtained from 18 patients with relapsing-remitting multiple sclerosis for 3 months before and 4 months after starting treatment with 44 microgram rh-IFN beta-1a subcutaneously, once a week. RESULTS: The total numbers of enhancing lesions were 145 and 126 on Sd scans and 278 and 192 on the Td scans obtained before and after treatment. The introduction of treatment decreased, on average, the rate of appearance of new enhancing lesions seen on Sd and Td scans by 37% (p<0.001). Treatment effects on new enhancing lesions seen on Td scans was, on average, 28% higher than on those seen on Sd scans. The distribution of lesion sizes on Td scans changed significantly during the treatment period (p=0.05), due to a marked decrease in the number of small lesions. CONCLUSIONS: The effect of 44 microgram rh-IFN beta-1a in reducing multiple sclerosis disease activity, as monitored by Gd enhanced MRI, is not homogeneous, but graduated according to the pathological characteristics and size of the lesions.

Adult↗
PubMed1999

Natural interferon therapy: optic nerve ischemic damage?

The purpose of this study was the evaluation of retinal abnormalities during a treatment with natural interferon (IFN-alpha for chronic hepatitis C. Retinal hemorrhages and optic disk edema were found in a 40-year-old woman during IFN-alpha therapy. The disk edema and retinopathy resolved after the INF was discontinued. Although retinal abnormalities correlated with IFN therapy have been described recently by some authors, the pathogenesis is still unclear. Anterior ischemic optic neuropathy occurring in a patient treated with IFN is a probable complication of the therapy.

Adult↗
PubMed1998

A multi-centre longitudinal study comparing the sensitivity of monthly MRI after standard and triple dose gadolinium-DTPA for monitoring disease activity in multiple sclerosis. Implications for phase II clinical trials.

In this study we assessed the safety, efficacy and cost-effectiveness of the use of triple dose gadolinium-DTPA (Gd) in serial monthly brain MRI of patients with multiple sclerosis, such as could be selected for clinical trials. The number of enhancing lesions, the number of new enhancing lesions and the number of active scans were used to evaluate the sensitivity of the contrast-enhanced MRI to disease activity. The dose of Gd, and the effect of introducing a delay between the contrast injection and the scan were both appraised. Every 4 weeks for 3 months, and in two separate sessions, scans were obtained from 40 patients with relapsing-remitting or secondary progressive multiple sclerosis, 5 min (early) and 20 min (delayed) after a standard dose (0.1 mmol/kg) or triple dose (0.3 mmol/kg) Gd injection. There were 435 enhancing lesions (242 of which were new) on the early standard dose scans, 479 (263 new) on the delayed standard dose, 772 (365 new) on the early triple dose and 827 (404 new) on the delayed triple dose. There were 109 scans revealing active disease on the early standard dose scans, 112 on the delayed standard dose, 119 on the early triple dose and 120 on the delayed triple dose. Statistical simulations indicated that the sample sizes needed for both cross-over and parallel-group trials with similar powers are lower if serial monthly triple dose MRI is used. No side-effects were reported and no significant changes in blood test parameters were found throughout the study. This study shows that the serial use of triple dose Gd is safe, and that it increases the sensitivity of serial monthly enhanced MRI in detecting multiple sclerosis activity significantly. Its use should enable preliminary trials of experimental therapies for multiple sclerosis to be conducted in small patient populations, over a short period of time.

Adult↗
PubMed1998

MRI evolution of new MS lesions enhancing after different doses of gadolinium.

OBJECTIVE: To investigate the evolution of multiple sclerosis (MS) lesions enhancing after single dose (SD) or triple dose (TD) of gadolinium-DTPA (Gd). MATERIAL AND METHODS: For 3 months, 30 relapsing-remitting MS patients underwent 2 monthly MRI sessions, consisting of Gd-enhanced T1-weighted scans, after SD (i.e., 0.1 mmol/kg) in one session and TD (i.e., 0.3 mmol/kg) in the other. New enhancing lesions on month 1 and month 2 follow-up scans were studied and for them any persistence of enhancement was evaluated on the scans obtained the next month. RESULTS: In all, 151 lesions enhancing after both SD and TD and 91 lesions enhancing only after TD entered the analysis. After 1 month, for the 151 lesions enhancing after both SD and TD, 73 (48%) were not enhancing, 50 (33%) were still enhancing after both SD and TD and 28 (19%) were enhancing only after TD. For the 91 lesions enhancing only after TD, 61 (67%; P<0.005) were not enhancing, 16 (18%; P<0.01) were still enhancing only after TD and 14 (15%; P=NS) showed enhancement after both SD and TD. CONCLUSION: Enhancing lesions in patients with MS are heterogeneous. Those enhancing only after TD of Gd are characterized by a milder and shorter opening of the blood-brain barrier.

Blood-Brain Barrier↗
PubMed1998

A comparison between the sensitivities of 3-mm and 5-mm thick serial brain MRI for detecting lesion volume changes in patients with multiple sclerosis.

In this longitudinal study the authors evaluated the sensitivity of 3-mm and 5-mm magnetic resonance imaging (MRI) of the brain in the detection of lesion load changes over time in multiple sclerosis (MS). The authors also correlated the changes detected with these two techniques with the changes in disability. Eighteen patients with MS underwent two MRI examinations of the brain--one at entrance into the study and one follow-up examination. At both sessions, images with 24 contiguous slices 5 mm thick and another with 40 contiguous axial slices 3 mm thick were consecutively acquired. On the same occasions, the patients' Expanded Disability Status Scale (EDSS) scores were rated. MR images with slices 3 mm thick showed higher lesion loads than those with slices 5 mm thick at both entrance and follow-up examinations (median, 13.4 vs 12.8 ml and 17.5 vs 17.0 ml, respectively; p < 0.0001). The correlation between MRI and EDSS changes was significant for both MRI acquisition schemes (3 mm, r = 0.64; 5 mm, r = 0.59). The data suggest that acquisition of thinner slices does not significantly increase the sensitivity of MRI of the brain in the detection of lesion load changes in MS.

Adult↗
PubMed1998

Intraobserver and interobserver variability in measuring changes in lesion volume on serial brain MR images in multiple sclerosis.

PURPOSE: We evaluated the intraobserver and interobserver variability in measuring long-term changes in the volume of brain lesions on 5- and 3-mm-thick MR sections in patients with multiple sclerosis. METHODS: Eighteen 18 patients were scanned on two separate occasions with a mean interval of 16.4 months between the two examinations. In each session, a scan with 24 contiguous 5-mm-thick axial sections and another with 40 contiguous 3-mm-thick axial sections was acquired consecutively without moving the patient. We assessed MR lesion load by using a semiautomated local thresholding technique. RESULTS: Lesion volume was significantly higher on images with 3-mm-thick sections than on those with 5-mm-thick sections both at baseline and at follow up. Significant increases in total lesion volume were observed during the follow-up period on images obtained with both 5- and 3-mm-thick sections. The intra- and interobserver variability in measurements of changes in lesion volume was significantly higher on images with 5-mm-thick sections than on those with 3-mm-thick sections. CONCLUSION: Our data indicate that the acquisition of thinner sections increases the reliability of the assessment of changes in brain lesion load on MR images in patients with multiple sclerosis.

Adult↗
PubMed1997

The effect of imprecise repositioning on lesion volume measurements in patients with multiple sclerosis.

In this study, we evaluated the effect of imprecision in patient repositioning encountered in real life on multiple sclerosis (MS) lesion volumes measured from MRIs. We also evaluated two putative methods for reducing the variability in these lesion volume measurements: first, a reduction of slice thickness (from the conventional 5 mm to 3 mm) and second, the application of a new repositioning technique based on the use of head immobilization shells. We evaluated the errors in lesion volume by scanning 10 patients a total of four times using the two slice thicknesses and two repositioning methods (conventional and using a head immobilization shell). The mean absolute percentage difference between two corresponding scans was 6.8% (range, 1.24 to 11%) using conventional slice thickness and repositioning, 4.1% (range, 0.7 to 5.56%) using conventional slice thickness and head immobilization shells, 2.6% (range, 0.8 to 6.66%) using the conventional repositioning technique and 3-mm slice thickness, and 1.4% (range, 0.2 to 6.14%) using slice thickness of 3 mm and head immobilization shells. These mean absolute differences were significantly different (p = 0.0008). Our results indicate that the effect of repositioning errors of the order of those that can be encountered in the daily life situation of clinical trials affects significantly lesion load measurements in MS and that the combined use of thinner slices and more accurate repositioning techniques can markedly improve the reproducibility of such measurements.

Adult↗
PubMed1996

Triple dose of gadolinium-DTPA and delayed MRI in patients with benign multiple sclerosis.

OBJECTIVES: To evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) or delayed MRI increase the number, size, and conspicuousness of enhancing lesions in patients with benign multiple sclerosis. METHODS: T1 weighted brain MRI was carried out on 20 patients with benign multiple sclerosis (expanded disability status scale < 3 with a disease duration > 10 years) in two sessions. In the first session, one scan was obtained before and two scans five to seven minutes and 20-30 minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, the same procedure was repeated with 0.3 mmol/kg Gd-DTPA (triple dose). RESULTS: Nine enhancing lesions were found in seven patients (35%) using the standard dose of Gd-DTPA. The numbers of enhancing lesions increased to 13 (P = 0.03) and the number of patients with such lesions to eight (40%) on the delayed standard dose scans. On the early triple dose scans, we found 19 enhancing lesions in 10 patients (50%). The number of enhancing lesions was significantly higher (P = 0.01) than that obtained with the early standard dose. The number of enhancing lesions was 18 and the number of "active" patients 11 (55%) on the delayed triple dose scans. The enhancing areas increased progressively from the early standard dose scans to the delayed triple dose scans. The contrast ratios of the lesions detected in early standard dose scans was lower than those of lesions present in the early (P = 0.01) and delayed (P = 0.04) triple dose scans. CONCLUSIONS: More enhancing lesions were detected in patients with benign multiple sclerosis with both delay of MRI and the use of triple dose of Gd-DTPA suggesting that the amount of inflammation in the lesions of such patients is mild and heterogeneous.

Gadolinium DTPA↗
PubMed1995

Transcranial Doppler sonography and magnetic resonance angiography in the assessment of collateral hemispheric flow in patients with carotid artery disease.

BACKGROUND AND PURPOSE: The aim of this investigation was to compare the respective efficacy of transcranial Doppler sonography (TCD) and magnetic resonance angiography (MRA) for the assessment of intracranial hemodynamics in patients with extracranial occlusion or severe stenosis of the internal carotid artery (ICA). METHODS: Twenty-five patients with unilateral ICA occlusion (n = 20) or tight stenosis (n = 5) demonstrated by duplex scanning or angiography were studied with both TCD and MRA. Three-dimensional time-of-flight MRA was used for the evaluation of extracranial-intracranial ICAs. Collateralization through the circle of Willis was investigated by means of selective two-dimensional MRA with presaturation of the carotid siphon, ophthalmic artery, or basilar artery. TCD was performed according to published standards: Anterior, middle, and posterior cerebral arteries were insonated through the temporal window, and carotid siphon and ophthalmic artery were assessed through a transorbital approach. Collateralization through the anterior circle of Willis was assumed if anterior cerebral artery flow was reversed, through the external carotid artery if ophthalmic artery flow was reversed, and through the basilar artery if the ratio of ipsilateral to contralateral posterior cerebral artery velocity was greater than 50%. TCD and MRA were performed by different investigators unaware of the results obtained with the other technique. RESULTS: In every case time-of-flight MRA demonstrated the ICA occlusion or stenosis. There was an excellent correlation (kappa = 0.64) between TCD and MRA in assessing the hemodynamic contribution of the anterior part of the circle of Willis, whereas MRA was unable to detect the anastomotic pathway of the ophthalmic artery (kappa = 0.32). The contribution of the posterior communicating artery was difficult to assess with both techniques, but in three cases only MRA showed unequivocal evidence of collateralization. In three cases of middle cerebral artery stenosis TCD was superior to MRA in demonstrating the patency of the vessel. CONCLUSIONS: TCD and MRA should be considered complementary techniques. Combining the findings of both examinations may help to better understand the changes in intracranial hemodynamics produced by extracranial carotid occlusion. The contribution of the ophthalmic pathway, although important for the intraorbital structures, is probably of limited functional significance to the hemispheric blood supply.

Adult↗
PubMedDate not supplied

[Magnetic resonance myelography. Preliminary experience].

Three-dimensional (3D) MR Myelography is a new technique using constructive interference steady-state (CISS) sequences, which are characterized by a symmetric flow compensation enhancing CSF signal intensity compared with neural and extradural structures. 3D myelographic projections with different rotation angles are obtained from the 3D dataset with a mathematical algorithm called maximum intensity projection (MIP). Myelographic projections yield a global view of subarachnoid spaces and of root sleeves with no intrathecal contrast agent injection. This study was aimed at assessing the feasibility, the clinical value and the diagnostic accuracy of 3D MR Myelography in comparison with conventional myelography. From September 1992 to January 1994, thirty-five myelograms were performed. The study population consisted of 10 volunteers, 8 patients with traumatic brachial plexus lesions, 7 with herniated disks (4 lumbar and 3 cervical disks), 4 with sacral radicular cysts, 2 with spinal vascular malformations, 3 with extramedullary intradural neoplasms (2 cervical neuromas and 1 cervical meningioma) and 1 with an intramedullary tumor (a conus medullaris ependymoma). All patients underwent SE MRI and conventional myelography (22 lumbar injections, 3 cervical injections of nonionic iodinated contrast agent) followed by CT (CT myelography). This trial demonstrates the feasibility of 3D MR myelography in the study of the cervical and lumbar spine: its results are comparable to those obtained with conventional myelography also in some specific indications like traumatic brachial plexus injuries, where invasive conventional myelography is usually thought to be essential.

Algorithms↗