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Biomedical subjects

M Mascalchi

Publications and source records attributed to M Mascalchi.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Cardiac-gated phase MR imaging of aqueductal CSF flow.

The direction of CSF flow within the cerebral aqueduct was studied by cardiac-gated magnetic resonance (MR) phase images in five healthy volunteers and 10 patients with presumably normal cerebral CSF circulation. Caudal CSF flow was observed during systole and cranial flow during diastole. Using phantom based calibrations of the imager, aqueductal CSF velocities of 3-5 mm/s were calculated. Cardiac-gated phase MR is a potentially major tool for the investigation of the CSF circulation.

Adult↗
PubMedDate not supplied

Lower cranial nerve palsy due to dissection of the internal carotid artery: CT and MR imaging.

Three patients with unilateral lower cranial nerve palsy underwent contrast enhanced CT and magnetic resonance (MR) imaging for the investigation of possible compressive pathology in the region of the jugular foramen. Computed tomography revealed a mural crescentic hypodensity of the corresponding internal carotid artery (ICA) in two patients and a faulty visualization of the vessel in one. Magnetic resonance revealed a corresponding hyperintense lesion expanding the wall and narrowing the lumen of the cervical ICA on both T1- and T2-weighted images. Dissection of the ICA was confirmed by angiography in all three patients. Among the possible etiologies of lower cranial nerve palsy, a dissecting hematoma of the cervical ICA must be considered, which can be diagnosed by CT and MR.

Aortic Dissection↗
PubMedDate not supplied

Mottled MR appearance of a hyperacute intracerebral hemorrhage at 0.5 T.

A hypertensive patient was examined by CT and magnetic resonance (0.5 T) within 3 h from stroke onset. Computed tomography revealed a thalamocapsular hemorrhage. Hematoma was isointense to the white matter on T1-weighted and hyperintense on T2-weighted spin echo images. The T2-weighted gradient echo images showed a mixture of hypointense and hyperintense signal. This latter aspect has not previously been reported and is probably related to abundant intracellular deoxyhemoglobin in clotted areas rich in red blood cells.

Acute Disease↗
PubMedDate not supplied

Contrast-enhanced time-resolved MR angiography of spinal vascular malformations.

PURPOSE: The purpose of this work was to assess the potential and limitations of a contrast-enhanced time-resolved MR angiography technique for evaluation of spinal vascular malformations. METHOD: Two patients with intramedullary arteriovenous (AV) malformations and three patients with dural AV fistula underwent four serial acquisitions, every 17-20 s, of 20-32 coronal 1.5- to 2-mm-thick partitions with a fast 3D SPGR sequence after injection of 0.2-0.3 mmol/kg paramagnetic contrast agent. This was followed by coronal 3D and sagittal or coronal 2D phase contrast (PC) MR angiography. RESULTS: No spinal vessels were visualized in the first (baseline) series. In patients with intramedullary AV malformations, the arterial feeders, nidus, and perimedullary draining veins were visualized in the second (early) series. In the third (intermediate) series, the arterial feeder vanished, whereas the intercostal and lumbar veins appeared. In patients with dural AV fistula, abnormal intraspinal vessel appeared in the third series and persisted, although less conspicuous, in the fourth (late) series. Contrast-enhanced time-resolved MR angiography demonstrated the venous components of the lesion with better conspicuity than 3D PC MR angiography, whereas it was inferior for visualization of arterial feeders. Moreover, indirect identification of the level of the dural AV fistula was possible only on the phase display of the 2D PC MR angiography. CONCLUSION: Contrast-enhanced time-resolved MR angiography is a useful complement to PC MR angiography for the evaluation of spinal vascular malformation.

Arteriovenous Fistula↗
PubMedDate not supplied

[High resolution and spirometric synchronization computerized tomography in chronic obstructive bronchopneumopathy].

PURPOSE: To assess the feasibility of spirometrically gated HRCT in patients with chronic obstructive pulmonary disease and to correlate the density measures with the results of pulmonary function tests. MATERIAL AND METHODS: Pulmonary function tests and spirometrically gated HRCT were performed, on the same day, in 20 patients with chronic obstructive pulmonary disease. Spirometrically gated HRCT scans at 90 and 10% of the patient's vital capacity were acquired, at three anatomical levels (carena, carena plus 5 cm, carena minus 5 cm). In each section, lung parenchyma was isolated from the other thoracic structures and from the main bronchi and a densitometric evaluation was applied to the regions of interest. A histogram showing the distribution of the pixel frequencies versus lung densities, the mean CT number and the pixel index at -910 HU (for scans acquired at 10% of the patient's vital capacity) and at -950 HU (for scans obtained at 90% of the patient's vital capacity) were obtained. Average acquisition time for the spirometrically gated HRCt was 15-20 minutes, average data processing time was 20 minutes. RESULTS: The mean CT number and the pixel index at -910 HU obtained at 10% of the patient's vital capacity correlated with the Tiffeneau index (r = 0.85; R = 0.78 respectively). The pixel index at -910 HU correlated also with the ratio of residual volume to total lung capacity (r = 0.65). The mean CT number and the pixel index obtained at 90% of the vital capacity correlated with the lung diffusion of carbon monoxide (r = 0.64 and r = 0.79 respectively). CONCLUSIONS: In our study, we found good correlation between the densitometric values obtained with spirometrically gated HRCT and the respiratory function tests routinely employed to assess the presence and the gravity of obstructive pulmonary disease. A good reproducibility of the data is guaranteed by the spirometical gating which enables standardization of the lung acquisition volume, and by the semiautomatic contour tracing program combined with an automated densitometric evaluation. The main disadvantages of the technique are the relatively long acquisition and evaluation times. Spirometrically gated HRCT densitometry is a promising tool for longitudinal studies of diffuse lung disease (pulmonary emphysema and fibrosis).

Adult↗
PubMedDate not supplied

Screening of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial ''Italung-CT''.

PURPOSE: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as ''Italung-CT''. MATERIALS AND METHODS: Sixty (47 males and 13 females, mean age 64+/-4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. RESULTS: and Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5 mm in diameter in 20 subjects, 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as a pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma. CONCLUSIONS: The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the ''Italung CT'' trial which has just begun.

Female↗
PubMedDate not supplied

[Loss of psychic autoactivation syndrome: bilateral lacunae of the neostriatum. Clinico-radiological study of 2 cases].

In two patients with lack of spontaneous activity and emotionality, without dementia or depression and in absence of other neurologic signs, the "athymormia syndrome" has been diagnosed. CT scan and MRI showed bilateral symmetrical lesions in basal ganglia. We discuss the possible pathophysiological basis of the syndrome and the recent data about the functional connections among basal ganglia, frontal cortex and limbic system.

Adult↗
PubMedDate not supplied

[MRI and HM-PAO SPECT in 20 patients with drug-resistant partial epilepsy].

Twenty consecutive patients with chronic partial seizures with onset before twenty years of age were investigated by means of 0.5 T MRI (20) and HM-PAO (19) in order to identify focal alterations amenable to surgical therapy. MRI evidentiated parenchymal lesions in 7 patients. Findings consistent with unilateral medial temporal sclerosis and cortico-subcortical parietal scars were found in two patients each. Small solid nodular lesions in the temporal lobe were observed in two patients. These and one additional patient with nodular partially cystic lesions in temporal lobe were administered a paramagnetic contrast agent (Gadolinium DPA) intravenously. In one case a contrast enhancement was observed. Histologic examination post surgery revealed a low grade glioma in one patient. HM-PAO SPECT examination showed area of abnormal captation in 9 of 19 patients. Aspects of EEG correlation with the MRI and SPECT findings are discussed. Our data supported the usefulness of magnetic resonance and SPECT imaging in the completion of pre-surgical assessment in this kind of patients.

Adult↗
PubMedDate not supplied

[Magnetic resonance study of lesions of the cervical spinal cord in multiple sclerosis].

Lesions consistent with demyelinating plaques were retrospectively identified in the cervical spinal cord of 15/49 patients (31%) with multiple sclerosis examined with cranial and cervical MR imaging. The lesions appeared as hyperintense areas on proton-density and T2-weighted images. Clinical signs and symptoms suggestive of spinal cord location of the demyelinating plaques were observed in 14 of the 15 patients presenting with spinal cord lesions at MR, and also in 11 of the 34 patients with negative MR findings. In 2 patients the cervical lesion was not associated with brain lesions at MR, while in 1 patient it was associated with medullary dilatation. Serial MRs revealed disappearance of the cervical hyperintense area in both patients, and reduction in medullary volume in the latter. Therefore, MR imaging of the cervical spinal cord is suggested as an useful examination in patients with suspected multiple sclerosis, particularly in those presenting with clinical signs and symptoms suggestive of spinal cord involvement.

Adult↗
PubMedDate not supplied

[Comparison of urokinase and tissue-type plasminogen activator in transcatheter arterial fibrinolysis].

The transcatheter injection of fibrinolytic agents is now the treatment of choice of the acute occlusions of the peripheral arteries. We retrospectively compared the efficacy and safety of two fibrinolytic agents (urokinase and recombinant tissue-type plasminogen activator) in 83 consecutive patients: 37 with occlusion of surgical bypass grafts, 36 with occlusion of atheromatous vessels, 5 with post-angioplasty occlusion, 2 with post-traumatic thrombosis, 2 with cardiogenic emboli and 1 with thrombophilia. Recanalization was achieved in 55 of 59 (93%) patients treated with urokinase and in 21 of 24 (88%) patients treated with recombinant tissue-type plasminogen activator (p > 0.05). The latter provided a more rapid recanalization than urokinase but was also responsible for the complications observed in all 10 (12%) patients. These results indicate that urokinase is to be preferred to recombinant tissue type plasminogen activator for routine arterial transcatheter fibrinolysis.

Adult↗
PubMedDate not supplied

[Dixon's technic for fat suppression. Its potential applications in combination with gadolinium-DTPA].

Modification of the Dixon technique enables the reconstruction of water and fat images operating at midfield strength. The technique was combined with intravenous administration of gadolinium-DTPA in five patients with lumbosacral spine conditions, four patients with soft tissue neoplasms and three with skeletal neoplasms; all patients were examined at 0.5 T. Mean attenuation of fat signal in T1-weighted images was 85% and implied a redistribution of the gray-scale dynamic range. This allowed easier appreciation of normal and abnormal enhancement in both areas containing fat tissue and areas without it. This was useful in the evaluation of fresh scars in two patients recently submitted to lamino-discectomy and of the prevertebral extension of the inflammatory process in one patient with spondylodiscitis. In the patients with soft tissue neoplasms the combination of fat suppression and Gadolinium was helpful to assess lesion size. Finally, in the patients with skeletal neoplasms fat-suppressed images obviated for the lesion disappearance observed on conventional T1-weighted SE images after contrast administration. The combination of intravenous administration of gadolinium-DPTA with Dixon's fat-suppression technique is a new promising capability of midfield MRI.

Adipose Tissue↗
PubMedDate not supplied

Epidermal nevus syndrome: MR of intracranial involvement.

Focal thickening of the calvarium, hypoplasia of the white matter, cortical calcifications, and a leptomeningeal drape that enhanced after contrast injection were demonstrated by MR in the parietooccipital region ipsilateral to a facial sebaceous nevus in a patient with epidermal nevus syndrome.

Adolescent↗
PubMedDate not supplied

[Reconstruction of the anterior cruciate ligament using the patellar tendon: its magnetic resonance evaluation].

MRI of the knee was performed in 30 patients who had been submitted to arthroscopically-guided reconstruction of the anterior cruciate ligament from patellar tendon. The autograft structure was investigated and MR results were correlated with clinical findings. Partial/total meniscectomy had been carried out in 21/30 cases. The patients were imaged at various postoperative intervals (3-24 months) by means of an 0.5-T magnet (GE MR Max Plus) in full knee extension and internal rotation. Sagittal and axial T1-weighted images (slice thickness: 3 mm) were combined with real-time reconstruction which better demonstrated the whole graft. T2-weighted coronal images (slice thickness: 5 mm) were also acquired. In each patient the following clinical variables were considered: anterior drawer sign, Lachman test, pivot shift, degree of leg extension, and finally functional recovery. The following MR variables were then considered: structure and alignment of bone tunnels, structure and signal intensity of the graft, degree of synovial inflammation, structure and signal intensity of the posterior cruciate ligament and finally structure of the menisci and/or meniscal residues. Symptoms-MR correlation suggests that the different outcome of surgical reconstruction may depend on the correct alignment of the tibial and femoral bone tunnels and on good meniscal condition. Bone tunnels must be located on the same plane, posterior and parallel to the slope of the intercondylar roof, since angulation causes the latter to impact the graft during knee extension, with inflammation and risk for rupture. As for menisci, tiny residues or total ablation overload tha graft, whose signal increases and whose synovia becomes inflamed. The latter pattern is always distinguished from that of the autograft, whose signal intensity seems not to change in time. In conclusion, MR proved an accurate and non-invasive technique to image this kind of postoperative knee, since metallic artifacts do not reach the joint space.

Anterior Cruciate Ligament↗
PubMedDate not supplied

MRI and SPECT investigations of the CNS in SLE patients.

Twenty-two SLE patients were examined with Magnetic Resonance Imaging (MRI) and Single Photon Emission Computed Tomography (SPECT). Multifocal areas of cerebral blood flow (CBF) defects were found in 81.8% of the patients. These alterations were present in patients with severe neurological disorders, in those with neuropsychiatric symptoms only, and also in asymptomatic cases. Anticardiolipin antibodies (aCL) were detected in all patients, but no correlation was found between serum aCL positivity and neurological involvement. The high incidence of cerebral blood flow disorders found in asymptomatic patients, and their poor correlation with the MRI alterations suggest a primary defect of CBF in these patients.

Adolescent↗