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Biomedical subjects

C M Citrin

Publications and source records attributed to C M Citrin.

At least 19 recordsLinked to original sources
PubMed1990

MR imaging of CSF-like choroidal fissure and parenchymal cysts of the brain.

The purposes of this study were to delineate the MR characteristics of CSF-like parenchymal or fissural cysts of the brain and to correlate them with the clinical findings. Clinical data and MR images of 34 patients with these abnormalities were reviewed. Pathologic correlation was not available. Two types of cystic lesions were identified and separated by location: medial temporal lobe cysts arising in or near the choroidal fissure (26 patients) and parenchymal or pseudoparenchymal cysts not related to the choroidal fissure (eight patients). The choroidal fissure cysts simulated intraparenchymal cysts on axial images but their extraaxial location was well portrayed on the coronal images. Choroidal fissure cysts had a characteristic spindle shape on sagittal images. The other cysts were found in the temporal lobe (seven patients) or thalamus (one patient) and appeared parenchymal but situated close to the subarachnoid space. These lesions were round or ovoid. There was no abnormal enhancement in 10 patients studied with gadopentetate dimeglumine. Coronal images were most useful, revealing the cysts as focal CSF-intensity lesions expanding the choroidal fissure of the temporal lobe. All the cysts appeared to represent incidental findings that did not correlate with the clinical signs and/or symptoms that prompted the imaging evaluations. The MR characteristics of CSF-like cysts are important to recognize so that they are not confused with other, more serious entities, such as intraaxial cystic tumors, infarctions, or parasitic lesions.

Adolescent↗
PubMed1987

Magnetic resonance planned thalamotomy followed by X-ray/CT-guided thalamotomy.

Magnetic resonance imaging (MRI) is currently the optimal neuroradiologic technique for visualizing the anterior and posterior commissure for defining the AC-PC line. CT is the optimal technique for electrode and probe guidance during stereotactic thalamotomy. Various possibilities of transferring or overlying MRI and CT are outlined which in some future might result in more refined methods of CT-MRI guidance for stereotactic surgery.

Humans↗
PubMed1987

Adrenoleukodystrophy: correlating MR imaging with CT.

The effect on the brain of the sex-linked recessive form of adrenoleukodystrophy was studied in 40 boys, 4-18 years old. All underwent computed tomography (CT) scanning; six underwent magnetic resonance (MR) imaging. MR showed a high sensitivity in demonstrating white matter disease. Auditory pathway disease was characterized as involvement of the lateral lemniscus and medial geniculate body, and visual pathway disease was characterized by lateral geniculate body, Meyer loop, and optic radiation involvement. Contrast-enhanced CT still proved to have a greater capacity (at this time) to show the active, advancing form of the disease and concomitant calcifications. This large CT series also demonstrated the broad and variable expressions of adrenoleukodystrophy, which allowed the unification of previously described atypical forms of the disease.

Adolescent↗
PubMed1987

The MR appearance of CSF flow in patients with ventriculomegaly.

The purpose of this study was to investigate the MR imaging appearance of mobile CSF in the ventricular system in patients with ventriculomegaly caused by brain atrophy and extraventricular obstructive hydrocephalus. Pulsatile CSF often has decreased intensity relative to less mobile areas of CSF, particularly on T2-weighted scans. At times, the flow-related signal dropout causes striking heterogeneity in the appearance of CSF. This has been termed the CSF flow-void sign (CFVS) and is most likely caused by spin-phase shifts and time-of-flight effects created as a result of CSF turbulence and increased velocity of CSF pulsatile flow. The effect is most pronounced in areas where a larger volume of CSF moves through a small channel or foramen, such as the aqueduct of Sylvius or foramen of Magendie. The scans of 40 patients with ventriculomegaly caused by brain atrophy or extraventricular obstructive hydrocephalus were reviewed for the presence of the CFVS. All patients had the CFVS in the aqueduct of Sylvius on T2-weighted spin-echo sequences. The sign was present in the fourth ventricle in 96%, in the third ventricle in 70%, in the foramen of Magendie in 65-77%, and in the foramina of Monro in 33%. The sign was more pronounced in patients with larger ventricles but could not be used to differentiate patients with brain atrophy from those with extraventricular obstructive hydrocephalus.

Adult↗
PubMed1987

Physiology of the CSF flow-void sign: modification by cardiac gating.

Low-intensity signal seen within areas of narrowing within the ventricular system has been termed the CSF flow-void sign. This decreased signal is related to CSF flow and turbulence. Seven normal volunteers were examined, and the changes that occurred in the appearance of the CFVS were noted when data acquisition was modified by cardiac gating. Flow-void patterns within the internal cerebral veins and basilar artery were also examined. The results of this study confirm that CSF flow is related to cardiac systole and diastole. An increase in hypointensity is seen in the areas of the aqueduct of Sylvius and the foramen of Magendie during the time at which the systemic arterial pulse wave is transmitted into the brain. The physiology of this observation is related either to a direct hydraulic effect of the venous system on the CSF or to filling and expansion of the thin-walled cerebral venous system. Hypointensity or an increase in the width of the basilar artery and internal cerebral veins during systolic data acquisition was also noted. The mechanism of this phenomenon is related to propagation of the systemic arterial pulse wave.

Cerebral Ventricles↗
PubMed1987

The MR appearance of syringomyelia: new observations.

Fifty-eight patients with spinal cord cavities were studied with MR imaging. Patients were separated into four groups, and the appearance of the cavities were compared. There were 24 patients (41.4%) with communicating syringomyelia (associated with the Chiari I malformation). Sixteen patients (27.6%) had posttraumatic syringomyelia, nine patients (15.5%) had associated tumors, and nine patients (15.5%) had idiopathic syringomyelia. The characteristics of each syrinx, the spinal cord, and the appearance of the cerebellar tonsils were analyzed on T2- and T1-weighted images. There is a striking similarity in the appearance of many syrinx cavities regardless of the cause. Characteristics that were found in some patients in every group included areas of increased intensity on T2-weighted images, the presence of the CSF flow-void sign (CFVS) in the syrinx cavity, eccentric cavities, "beaded" cavities, and cord enlargement. Tonsillar ectopia alone does not indicate that a syrinx is of the "communicating" type, since it was present in two of 16 patients (13%) with trauma and in two of five patients (40%) with tumors. T1-weighted images were most useful in evaluating the anatomic characteristics of the syrinx and the cerebellar tonsils. Most syrinx cavities involved the cervicothoracic junction. The average length was between five and nine vertebral segments (depending on category) but varied between one and 20 vertebral segments. T2-weighted images revealed areas of increased intensity in the spinal cord in 13 patients without tumors. Two of these cases were shown to represent gliosis on histopathologic review. The CFVS was present in the syrinx cavities of 23 patients (40%), probably reflecting pulsatile movements of the syrinx fluid. It has been proposed that such movements are a cause of syrinx propagation, and the observation of the CFVS may have prognostic significance. The development and progression of the CFVS was documented in serial MR examinations in one patient over an 18-month period. The theories of syrinx development and propagation are reviewed.

Adolescent↗
PubMed1987

MR and CT evaluation of intracranial sarcoidosis.

Fourteen patients with CNS manifestations of neurosarcoidosis were evaluated by MR imaging and CT. Evaluations were done on a 0.5-T superconductive magnet with T1- and T2-weighted sequences. CT with contrast was obtained in all patients. The granulomatous lesions were classified by location into basilar, convexity, intrahemispheric, and periventricular white-matter involvement. Hydrocephalus with or without an associated lesion was also noted. MR determined the presence of disease in all patients (100%), but was less accurate than CT in depicting disease in two patients (14%). CT determined the presence of disease in 12 patients (85%) and was less accurate than MR in delineating hypothalamic involvement in two patients and periventricular white-matter disease in three patients. There was great variability in the appearance of intracranial sarcoidosis on MR. Three patients had lesions that were isointense or hypointense (relative to cerebral cortex) on both T1- and T2-weighted images while nine patients had lesions that were hyperintense on T2-weighted images. Convexity involvement and hydrocephalus were well documented by both CT and MR. These results indicate that both MR and CT are helpful in fully evaluating a patient with suspected intracranial sarcoidosis.

Adult↗
PubMed1979

Direct coronal computed tomography of the orbits employing a dedicated head scanner.

A number of articles have been written on the topic of orbital computed tomography (CT), most of which have emphasized transaxial sections. Recently, especially since whole body scanners have become widely distributed, numerous articles have been written on coronal sections of the orbits. This article discusses the method of obtaining coronal CT sections of the orbits employing a dedicated head scanner and demonstrates the results that can be obtained employing this technique.

Eye Diseases↗
PubMed1979

Computed tomography of the visual pathways.

Many articles have discussed the anatomy and pathology of the orbits. Although this area is exquisitely visualized via computed tomography, the bulk of the visual apparatus lies behind the optic canal. A variety of pathologic conditions will manifest themselves by changes in the visual fields. This article demonstrates the normal anatomy of the visual pathways within the brain by CT scanning and correlates various changes that cause visual field defects.

Adult↗
PubMed1979

Computed tomographic presentation of granulomatous reaction from intraventricular shunt.

A case is presented in which the patient was diagnosed as having a large mass lesion arising in the region of the quadrigeminal plate. The patient had been shunted in the past for hydrocephalus. The computed tomographic picture was that of a primary brain neoplasm. At surgery extensive granulation tissue was found. The similarity between the CT presentation of this inflammatory mass and a neoplasm is emphasized.

Brain Diseases↗
PubMed1979

Use of computerized axial tomography (CAT scan) in evaluating therapy of orbital pseudotumor.

Two patients with orbital pseudotumor, demonstrated by computerized axial tomography (CAT scan), are presented. This radiological technique was further used to demonstrate the complete resolution (Case 1) and marked regression (Case 2) of the orbital masses after steroid therapy. CAT scan characteristics of orbital pseudotumor were discussed and contrasted with the findings in thyroid ophthalmopathy. It is our recommendation that patients with CAT scan and clinical characteristics of orbital pseudotumor should be treated with systemic steroids and resolution of the inflammatory lesion should be corroborated by a repeat scan in atypical cases. Orbital surgery and other invasive studies should be used in those patients in whom there is no objective improvement in the disease process.

Diplopia↗
PubMed1977

Scleral thickening: a CT sign of orbital pseudotumor.

Orbital pseudotumor is a benign inflammatory lesion of the orbit. Computed tomography is a new method for evaluation of orbits. Scleral uveal rim thickening with contrast enhancement was found in eight of 15 patients with pseudotumor (53%). Similar rim thickening was seen in one postoperative patient and two cases of recent trauma. Therefore, the sign presumably represents inflammation. It was not seen in 47 cases of thyroid disease and 66 cases of neoplasm.

Bone Diseases↗
PubMedDate not supplied

Deviation of the rectosigmoid colon simulating a presacral tumor: report of a case.

The rectosigmoid colon has a potential for a great deal of mobility and variation of position. This is partially due to the wide variation in length and distal attachment of the sigmoid mesocolon. When anterior or lateral deviations of the distal sigmoid and rectum are found on barium-enema examinations, the possibility of anomalous fixation of the rectosigmoid should be considered.

Abdominal Neoplasms↗
PubMedDate not supplied

Computerized tomography in the evaluation of pituitary adenomas.

Computerized tomography during the past few years has been unequivocally been proven to be of extreme value in the evaluation of intracranial disease. Despite earlier reports, accuracy of diagnosis in the area of the sella turcica is found to be high despite the close proximity of both bony and air-containing structures. Correlation between computed tomographic images, angiography and pneumoencephalography has been performed and demonstrates that CT scans with a low margin of erro depict the relationships of pituitary adenomas to the surrounding brain parenchyma. The continued importance of angiography, and to some degree pneumoencephalography, in the diagnosis of pituitary tumors is discussed.

Adenoma↗
PubMedDate not supplied

High resolution orbital computed tomography.

The latest generation CT scanners allow for spatial and contrast resolution within the orbit that has not previously been available. Utilization of these technological advances in association with appropriate techniques enables visualization of vascular and neural structures within the orbits that have not previously been emphasized in the literature. The CT scans were generated in both axial and coronal planes, using either 1 or 2 mm thick sections. All images were generated using ultrahigh resolution scanning techniques, available on the Picker 1200-SX scanner. The primary advantage of this system is the availability of secondary collimation of the X-ray beam at the detector, limiting detector aperture to only 1.3 mm. This, in association with utilization of the small focal spot and high sampling rate, aids in the visualization of divisions of the third and fifth nerves, as well as in the visualization of the sixth nerve within the orbit. Several branches of the ophthalmic artery within the orbit are also identified, including the infratrochlear and supratrochlear artery as well as the central retinal artery.

Humans↗