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Biomedical subjects

P M Colletti

Publications and source records attributed to P M Colletti.

At least 19 recordsLinked to original sources
PubMed2000

Diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression: are T(1)-weighted sagittal images sufficient?

The objective of this study was to determine whether T(1)-weighted sagittal images alone are adequate in the diagnosis of vertebral metastasis, epidural metastasis, and malignant spinal cord compression. Ninety-four complete magnetic resonance (MR) studies of the spinal column (a complete study consisting of T(1)-weighted sagittal images, T(2)-weighted sagittal images, and T(1)- and/or T(2)-weighted axial images) and 94 T(1)-weighted sagittal images alone (a subset of the complete studies) from 57 consecutive cancer patients over the last 2 years with clinically suspected cord compression were blindly and independently evaluated by four radiologists. The complete MR studies were used as the standard. Overall, the sensitivity of T(1)-weighted sagittal images alone to vertebral metastasis (87%) was statistically greater than cord compression (70%) (p = 0.05), and statistically greater than epidural metastasis (46%) (p </= 0.02). The specificity for cord compression (97%) was greater than the specificity for epidural metastasis (89%) (p = 0.03), and greater than the specificity for vertebral metastasis (83%) (p </= 0.02). There was a strong trend for better detection of cord compression overall and better detection of vertebral metastasis in the cervical spine by the most experienced radiologist. Complete studies of the spine are necessary in the diagnosis of vertebral metastasis, epidural metastasis, and cord compression, particularly with less experienced radiologists.

Adult↗
PubMed1997

Injury of the posterior ligament complex in patients with acute spinal trauma: evaluation by MR imaging.

OBJECTIVE: We undertook this study to use MR imaging to determine the frequency of injury to the posterior ligament complex of the thoracolumbar spine in patients who have undergone acute thoracolumbar trauma. SUBJECTS AND METHODS: Sixty-eight patients with varying severity of thoracolumbar trauma were examined prospectively. The majority of injuries were related to motor vehicle accidents. The second most common cause was falls. Patients were examined with plain radiography and MR imaging. In addition to conventional MR imaging sequences consisting of T1-weighted and fast spin-echo T2-weighted sagittal and axial images, a fat-suppressed T2-weighted sagittal sequence was performed. The findings were correlated with surgery in six cases and with follow-up clinical examination that included physical examination and conventional anteroposterior and lateral radiographs. RESULTS: Posterior ligament complex injury was detected in 53% (n = 36) of all patients. Such injury was most common in patients with flexion-distraction (n = 15) and patients with dislocation fracture (n = 4). Of the patients with dislocation fracture, all had posterior ligament complex injury. Of the 24 patients with burst fractures, posterior ligament complex tear occurred in 42% (n = 10). Of the 23 patients with compression fractures, 26% (n = 6) had posterior ligament complex tear. Injury to the interspinous ligaments occurred with decreasing frequency in patients with injury to the supraspinous ligament, flaval ligaments, posterior longitudinal ligament, and anterior longitudinal ligament. Surgical findings correlated with MR imaging in all six patients who underwent surgery. CONCLUSION: Injury to the posterior ligament complex, which is often encountered in patients with burst and compression fractures, can be reliably revealed by MR imaging.

Adult↗
PubMed1996

Radiologic studies in acute fatty liver of pregnancy. A review of the literature and 19 new cases.

OBJECTIVE: Radiologic findings thought to be characteristic of acute fatty liver of pregnancy have been described in a limited number of cases. We describe wide experience with liver imaging of this disease. STUDY DESIGN: A retrospective review was performed on charts from 1982 to 1994 to identify those patients with acute fatty liver of pregnancy who had radiologic studies. RESULTS: Twenty-eight patients with acute fatty liver of pregnancy were identified, for an incidence of 1/6,692 births. Nineteen patients underwent at least one imaging study, and seven had more than one. Findings consistent with fatty infiltration of the liver are found in 3/11 patients with ultrasound, 5/10 with computed tomography (CT) and 0/5 with magnetic resonance imaging (MRI). Three patients with normal ultrasound scans subsequently had evidence of fatty filtration on CT scan. CONCLUSION: Detection of fat in the liver of patients with acute fatty liver of pregnancy with current imaging techniques is limited and did not contribute to the management of patients in this series. Further studies are necessary to define to role of MRI--in particular, spectroscopy.

Adult↗
PubMed1995

MR imaging of patients with type 1 Gaucher's disease: relationship between bone and visceral changes.

OBJECTIVE: Because treatment is now available for patients with Gaucher's disease, methods of follow-up have become important in making treatment decisions. Bone abnormalities (infarct and avascular necrosis) tend to be irreversible while visceral volumes are not, suggesting that it may be useful to follow patients with visceral volume determinations. In order to do so, the relationship of one to the other must first be understood. The purpose of this paper is to determine the relationships between bone and visceral changes identified with MR imaging. MATERIALS AND METHODS: Sixty-two consecutive patients from 1 to 78 years old with type 1 Gaucher's disease were studied by MR imaging. The examination consisted of two parts: T1-weighted MR images and gradient-echo coronal MR images of the hips and femurs, and axial breath-holding MR images of the abdomen that allowed measurement of hepatic and splenic volume. The bone changes were classified and were correlated with the liver and spleen volumes. Specific imaging features of the liver and spleen were noted and correlation sought. RESULTS: A statistically significant difference in liver size was found between patients with and without avascular necrosis. A statistically significant correlation was also found between liver size and avascular necrosis. Patients with marrow changes classified as grade 2 or higher were significantly more likely to have avascular necrosis. Nineteen percent of patients had splenic nodules and 7% had hepatic nodules; however, there was no correlation between the nodules and bone changes. CONCLUSION: MR imaging showed a statistical relationship between marrow changes, liver size, and avascular necrosis in patients with type 1 Gaucher's disease. Knowledge of this relationship may be used in dosage and treatment considerations in the follow-up and clinical management of these patients.

Adolescent↗
PubMed1994

Parceling of mesial frontal motor areas during ideation and movement using functional magnetic resonance imaging at 1.5 tesla.

Finger movement-related responses were identified in three discrete sites of mesial frontal cortex in 7 normal subjects using high resolution functional magnetic resonance imaging. During imagination of the same movements there was a differential response with rostral areas more active than caudal areas. Humans have multiple motor areas in mesial frontal cortex that subserve different functions in motor planning and execution.

Adult↗
PubMed1994

MRI-derived ventricular volume curves for the assessment of left ventricular function.

To assess the utility of double oblique, ECG-gated 1H magnetic resonance (MR) derived volume curves for assessing LV function, cardiac short axis images were acquired with a fast field echo technique. We applied this methodology to assess left ventricular function in three groups: normals, patients with left ventricular hypertrophy, and dilated cardiomyopathy. Six slices with 16-20 phases per RR interval were analyzed, representing the initial 75-80% of the cardiac cycle. For each slice, the endocardial border of the left ventricular (LV) chamber was manually traced. Using Simpson's rule, the total LV volume at a given phase was determined considering the traced area, thickness and position in three-dimensional space of each of the six constituent slices. The calculated volumes were plotted against time and the stroke volume, ejection fraction and cardiac output were determined. The volume vs time plots for the systolic and diastolic portions of the curve were individually fit to third degree polynomials using a least squares approximation. From the fit curves, the following data were extracted: the mean slope (dV/dT) during filling and emptying, and the time to 1/4, 1/3 and 1/2 filling and emptying. These parameters are valuable indices of the functional status of the myocardium; thus, accurate and useful estimates of LV function can be obtained using MRI derived volume curves in normal and abnormal states.

Cardiac Volume↗
PubMed1994

Magnetic resonance imaging in pregnancy.

MR imaging can be important to demonstrate nonpelvic, pelvic, and fetal abnormalities in the pregnant patient. New, faster techniques expand diagnostic capabilities. Although no convincing evidence for fetal injury has been demonstrated, a rational approach to MR imaging in pregnancy is proposed in this article.

Adolescent↗
PubMed1993

Magnetic resonance angiography of the neck veins.

Time of flight, reduced matrix (64 x 256) MR angiography of the neck veins was performed in four normal subjects and four patients with neck vein thrombosis, either from indwelling catheters (n = 3) or intravenous drug abuse (n = 1). In each case, satisfactory images were acquired. Typical examination times of 3-6 min were required. MR angiography of neck veins gives a unique display of venous anatomy, including collateral veins and occlusions.

Adult↗
PubMed1993

Evaluation of suspected musculoskeletal neoplasms using 3D T2-weighted spectral presaturation with inversion recovery.

This study evaluated the use of the Spectral presaturation with inversion recovery (SPIR) technique with T2-weighting in 43 pathologically proven cases of suspected musculoskeletal neoplasm. Both primary and secondary malignant neoplasms as well as benign neoplasms were studied. The MR features exhibited by this technique are discussed. The images were evaluated by two experienced MRI specialists and graded as to utility into one of four categories as compared to conventional T1- and T2-weighted sequences. In the majority of cases this technique was found to be helpful or extremely helpful. The most useful features of this technique were the elimination of chemical shift artifact, the improved ability to evaluate superficial lesions or the extension of lesions into subcutaneous fat, and substantially improved visualization of both bone marrow and bone cortex interfaces. T2-weighted, fat suppressed imaging proved to be a useful new tool for evaluating musculoskeletal neoplasms.

Adolescent↗
PubMed1993

Giant extra-adrenal pheochromocytoma: magnetic resonance imaging with gadolinium-DTPA enhancement.

A case report of a 35-yr-old male presenting with moderate hypertension and a giant extra-adrenal pheochromocytoma is discussed. The patient was treated by chemotherapy and surgery with regression of the lesion and clinical relief of symptoms. Initial magnetic resonance imaging (MRI) with gadolinium-DTPA enhancement revealed a large complex pelvic mass. Follow-up examination following chemotherapy three months later demonstrated partial regression. The MRI findings and the pattern of gadolinium-DTPA enhancement are discussed.

Adult↗
PubMed1993

Morton neuroma: evaluation with MR imaging performed with contrast enhancement and fat suppression.

PURPOSE: To evaluate clinically suspected Morton neuroma with contrast material-enhanced magnetic resonance (MR) images. MATERIALS AND METHODS: Fifteen patients with clinically suspected Morton neuroma underwent examination with conventional T1- and T2-weighted MR imaging and a combination of fat suppression and administration of gadopentetate dimeglumine. A T1-weighted spectral presaturation with inversion recovery sequence was used for fat suppression. RESULTS: In six patients, a tumor that conformed to the clinical findings was seen in the interdigital space; surgical findings in these patients correlated closely with the imaging findings in all patients. Patients without positive findings on MR images tended to have less typical clinical findings and received nonsurgical treatment. In all patients, the lesions were best depicted with the combination of contrast-enhanced imaging and fat suppression; conventional MR images either entirely failed to demonstrate the lesions or demonstrated the lesions less clearly. CONCLUSION: In patients who need imaging confirmation of a clinically suspected Morton neuroma, the combination of fat suppression and contrast enhancement provides reliable high-contrast images.

Adipose Tissue↗
PubMed1992

MR imaging in rhinocerebral and intracranial mucormycosis with CT and pathologic correlation.

Three cases of mucormycosis, two in diabetics and one in an intravenous drug abuse patient, are presented. Magnetic resonance imaging proved to be useful in all cases, as was computed tomography. In one case, extremely low signal was detected from the fungal mass. It is surmised that this appearance was a result of high concentrations of iron and manganese. The low-signal area simulated air in paranasal sinuses; however, CT displayed a mildly enhancing soft tissue mass and allowed the correct diagnosis to be made. In another patient, pontine infarction was demonstrated by MR. In the third case the MR findings of mucormycosis involving the basal ganglia are shown and correlated with CT. Subsequent imaging studies demonstrated reduction of the mass, corresponding to clinical improvement.

Adult↗
PubMed1992

Magnetic resonance of the inferior vena cava.

MRI was performed in 54 patients with abnormalities of the inferior vena cava (IVC). These included 16 patients with extrinsic IVC compression, 32 patients with intrinsic IVC abnormalities, and 6 patients with IVC dilatation. All patients had spin-echo imaging, and 21 had MR angiography. While presaturated spin-echo images showed intrinsic lesions to advantage, collateral vessels were best appreciated with MR angiography. The IVC is well evaluated with MRI techniques.

Adenocarcinoma↗
PubMed1991

Cardiac calcifications: difficult MRI diagnosis.

Magnetic resonance imaging (MRI) and computed tomography (CT) were performed in 40 patients with a variety of cardiovascular diseases. These imaging modalities were compared to investigate their relative value in the assessment of cardiovascular diseases. Of these 40 patients, 7 were found by CT to have detectable cardiovascular calcifications. These patients included one calcified mitral stenosis, one calcified coronary artery, one calcified type B aortic dissection, two calcified myocardial infarctions, and two patients with calcific pericarditis. In several cases, MRI was misleading because of difficulty in detecting calcifications. We present a series of cases illustrating a limitation of MRI in identifying diagnostically and clinically important cardiovascular calcifications.

Adolescent↗
PubMed1991

Halfscan: clinical applications in MR imaging.

A series of phantom experiments was performed to evaluate the effects of half-Fourier scanning, also known as Halfscan, on signal-to-noise and in-plane resolution. Resolution was not demonstrably effected with the available phantoms and signal-to-noise was seen to vary as the square root of time independent of the implementation of Halfscan. Evaluation of the Halfscan technique was made using data from 240 patients. The technique was found to "salvage" examination in an estimated 70% of uncooperative patients where motion artifact or other patient concerns would have precluded clinically useful studies. Halfscan was also combined with other techniques such as increased number of signal acquisitions, prolonged repetition times and three-dimensional Fourier transform technique.

Artifacts↗
PubMed1991

Cardiac MRI cine and color Doppler in valvular disease: correlative imaging.

Cardiac cine field echo MRI and color Doppler were performed in 13 patients with aortic regurgitation (n = 4) or multiple valvular diseases (n = 9). The size, shape, and direction of regurgitation jets correlated well. Color Doppler was better able to follow flow jets in oblique planes. Cine MRI was better able to evaluate patients with marked cardiac dilatation.

Aortic Valve Insufficiency↗