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Biomedical subjects

P F New

Publications and source records attributed to P F New.

At least 19 recordsLinked to original sources
PubMed1988

Use of magnetic resonance imaging in psychiatry.

The authors report four cases in which magnetic resonance imaging (MRI) provided diagnostic information not apparent by X-ray CAT in clinical investigations of patients with neuropsychiatric disorders. The relative capabilities and contraindications for MRI and CAT are reviewed. The authors suggest that MRI is indicated 1) instead of CAT when there is suspicion of neuropathology that is better visualized by MRI because of its type or location and 2) after CAT when an atypical psychiatric symptom or presentation has not been definitively evaluated by means of CAT.

Aged↗
PubMed1988

The role of MR and CT in evaluating clival chordomas and chondrosarcomas.

Sixteen chordomas and nine chondrosarcomas of the clivus were evaluated with CT and MR either before (22 cases) or after (three cases) treatment with proton beam irradiation. The ability of these imaging techniques to provide information necessary to direct patient treatment was studied. The tumor was detected and its gross margins were identified by both techniques in all instances. No reliable diagnostic features allowing differentiation between these two tumors were encountered. MR generally was superior in defining the exact position of the brainstem and optic chiasm relative to the tumor, and it frequently provided superior information about tumor extension into the nasopharynx and cavernous sinus. CT was always better than MR in demonstrating tumoral calcification and in defining the exact anatomy of bone destruction. MR was generally superior to CT in demonstrating the position of the cavernous internal carotid artery relative to the tumor and often provided superior visualization of the vertebral and basilar arteries. In cases in which bone-induced artifact obscured the interface between the neural axis and tumor in the CT image, or in which the tumor had suprasellar extension and was likely to compress the optic chiasm and tracts, MR was of great value in planning irradiation therapy. The high occurrence of clinically asymptomatic signal intensity alterations in the MR studies of previously treated patients appears to limit the differential diagnostic value of this information. Given its greater availability and lower cost, CT appears to be the technique of choice for routine follow-up of previously treated patients.

Adolescent↗
PubMed1988

Angiographically occult arteriovenous malformations.

Eight cases of histopathologically proven arteriovenous malformations (AVM's) which were not visualized on angiography are presented. As is typical with these lesions, most of the patients in this series presented with hemorrhage, seizures, or episodic or progressive neurological symptoms suggestive of a neoplasm. The diagnosis of angiographically occult AVM was highly suspected preoperatively in each case based on the combination of computerized tomography (CT) and magnetic resonance (MR) findings. The CT scans in all cases showed moderately hyperdense lesions which enhanced mildly or moderately in a nonhomogeneous pattern with administration of contrast material. The MR image showed one or more bright areas interspersed with areas of low or absent signal peripherally or centrally on both T1- and T2-weighted images. The AVM was totally excised in seven patients and partially excised in one patient, with favorable results in all. The clinical management and differential diagnosis of angiographically occult AVM's are discussed. In patients with a clinical course and radiological studies suggestive of an occult AVM, removal of the lesion, if accessible, should be performed in order to rule out a neoplasm and prevent subsequent hemorrhage and progression of symptoms.

Adolescent↗
PubMed1986

MR and CT of occult vascular malformations of the brain.

The need for improved specificity in the diagnosis of "occult" vascular malformations led to the use of MR in suspected cases in order to determine MR's potential for improved diagnostic accuracy. Six patients with six lesions histologically diagnosed as vascular malformation after partial (1) or complete (5) microsurgical excision were studied by CT, MR, and selective magnification subtraction angiography. In all cases, the cerebral lesions were apparently solitary and were visible as focal lesions on both CT and MR. Since angiography failed to reveal the pathologic blood vessels of the lesions, and no arteriovenous shunting was evident, these lesions were termed vascular malformations occult to angiography (VMOTA). Angiography revealed a mass effect in only two cases. MR did not reveal additional vascular malformations missed by CT. In each case, MR, which was performed in an attempt to support the diagnosis suggested by CT, did in fact do so by revealing signal abnormalities indicative of nonacute hemorrhage within the lesion on T1- and T2-weighted pulse sequences. Although, as on CT, MR features of these lesions were found to be nonspecific, the MR criteria reinforced the probable diagnosis of VMOTA in an additional 30 cases that had shown similar nonspecific CT features. In this second group, excluded from this study, in which histologic verification was not obtained because of perceived hazards of surgery, the increased assurance regarding the diagnosis led to proton-beam therapy without histologic verification in 18 cases. It is concluded that MR can provide significant improvement in the accuracy of diagnosing VMOTA beyond that obtainable just by plain and contrast-enhanced CT.

Adult↗
PubMed1986

Magnetic resonance imaging of the thoracical spinal cord and spine with surface coils.

We report the results obtained at 0.6 T with the use of surface coils in 77 patients who presented with obvious or suspected thoracic myelopathy. There were 16 patients with primary tumors diagnosed for the first time, 9 patients with residual tumors, 17 with metastatic neoplasms, 13 with hydrosyringomyelia, 5 with vertebral fracture and secondary pathology involving the cord, 5 with thoracic disc protrusions, 2 with multiple sclerosis, 2 with arteriovenous malformations, 2 with cystic arachnoiditis, and 6 with a variety of congenital abnormalities (low tethered cord, intradural lipoma, lipomyelomeningocele). The significantly improved signal to noise ratios provided by surface coils allow high quality thin section imagning which, combined with the high tissue contrast resolution obtainable with suitable pulse sequences, makes MR the preferred initial imaging technique over myelography and CT myelography. In an interesting spectrum of lesions, MR can obviate the need for traditional invasive procedures.

Adolescent↗
PubMed1985

Magnetic resonance imaging: present and future applications.

Magnetic resonance (MR) imaging has created considerable excitement in the medical community, largely because of its great potential to diagnose and characterize many different disease processes. However, it is becoming increasingly evident that, because MR imaging is similar to computed tomography (CT) scanning in identifying structural disorders and because it is more costly and difficult to use, this highly useful technique must be judged against CT before it can become an accepted investigative tool. At present MR imaging has demonstrated diagnostic superiority over CT in a limited number of important, mostly neurologic, disorders and is complementary to CT in the diagnosis of certain other disorders. For most of the remaining organ systems its usefulness is not clear, but the lack of ionizing radiation and MR's ability to produce images in any tomographic plane may eventually prove to be advantageous. The potential of MR imaging to display in-vivo spectra, multinuclear images and blood-flow data makes it an exciting investigative technique. At present, however, MR imaging units should be installed only in medical centres equipped with the clinical and basic research facilities that are essential to evaluate the ultimate role of this technique in the care of patients.

Abdomen↗
PubMed1985

MR imaging of the acoustic nerves and small acoustic neuromas at 0.6 T: prospective study.

To evaluate the capability of magnetic resonance (MR) in imaging normal acoustic nerves, 12 volunteers without signs or symptoms of intracranial disease were examined using a 0.6 T superconductive system. Several spin-echo (SE) pulse sequences were tested to identify the optimal sequence for demonstration of the acoustic nerve bundle. Repetition times (TRs) varied from 300 to 2000 msec and echo times (TEs) from 30 to 120 msec. A single-slice technique was used with 5 and 8 mm sections, one or two data acquisitions per projection, and axial and coronal imaging. The normal acoustic nerves were demonstrated readily by MR in axial and/or coronal sections. The distal parts of the nerves and tumors were imaged best with SE 1500/60. The medial extremities of the seventh and eighth nerves tended to be obscured in this sequence by brightening the cerebrospinal fluid signal adjacent to the brainstem, but they were demonstrated clearly with 500 or 800 msec TR and 30 msec TE. Five patients were studied who had hearing loss and evidence of retrocochlear disease. In four patients, MR imaging demonstrated five acoustic nerve tumors ranging in size from purely intracanalicular to a 12 mm cisternal component. In the fifth case, no tumor was identified by MR imaging or gas computed tomographic (CT) cisternography. Contrast-enhanced CT using a Siemens Somatom DR 3 or GE CT/T 8800 scanner failed to provide convincing evidence of tumor in any case, while gas CT cisternography was positive in all five tumors. All five acoustic neuromas were identified readily using the SE sequences that proved optimal for demonstration of normal nerves. This experience revealed that MR imaging can demonstrate the eighth nerve complex well and reliably. Single-slice (5 or 8 mm) technique is adequate, but multislice without tissue gaps (used recently) is more efficient. Small, even intracanalicular, acoustic neuromas are imaged effectively, indicating that the method is capable of superseding contrast CT cisternography, particularly with improving technology.

Atrophy↗
PubMed1985

High-resolution surface-coil imaging of lumbar disk disease.

Seventeen patients with lumbar disk disease were studied using a prototype magnetic resonance (MR) surface coil. The high signal-to-noise ratio achieved with the surface coil permitted increases in spatial resolution to 0.9 X 0.9 mm in-plane resolution with 5 mm slice thickness. The surface coil was also compatible with multiplanar, multiecho imaging techniques. The spatial resolution achieved in this study was nearly equivalent to that achieved by state-of-the-art computed tomographic (CT) scanners, and MR showed a superior range of soft-tissue contrast. One significant limitation of MR was its inability to demonstrate small calcifications. Nevertheless, MR imaging provided diagnostic information comparable to CT or myelography in a completely noninvasive manner. With further technical advances, MR is likely to become the initial procedure of choice for evaluating patients with suspected lumbar disk disease.

Humans↗
PubMed1984

NMR imaging of intracranial hemorrhage.

Twenty-one intracranial hemorrhagic lesions were imaged at 0.15 and 0.6 T using inversion recovery (IR), spin echo (SE), and multiple SE (Carr-Purcell-Meiboom-Gill, CPMG) pulse sequences. Two subarachnoid hemorrhages (SAH), nine acute intraparenchymal hemorrhages (IPH), ten chronic IPH, and one subdural hematoma were studied. Acute SAH could not be identified on the T1-weighted, IR images but was clearly seen on a T2-weighted, CPMG image. Acute (7 days or less) intraparenchymal hematoma showed signal intensity on IR and CPMG images similar to white matter. The T1 and T2 times of acute intraparenchymal hematoma were also similar to white matter. Some small acute hematomas could not be distinguished from white matter on IR and CPMG images. Acute hemorrhagic tissue showed image intensities and relaxation times similar to gray matter. All acute hemorrhages were identified on CT. Chronic IPH lesions (14 days or more) showed high signal intensity, greater than white matter, on IR, SE, and CPMG images. The T1 of the chronic lesions was similar to the acute lesions but T2 was significantly longer (p less than 0.05). Available evidence suggests that the nonspecificity of acute IPH signal and relaxation times may not be restricted to our pulse sequences or magnetic field strengths.

Adult↗
PubMed1984

NMR imaging in temporal lobe epilepsy due to gliomas.

Magnetic resonance (MR) imaging has been shown to have greater sensitivity than X-ray CT in a broad range of intracranial pathologic processes. In regions in which CT is likely to suffer degradation of image quality due to a variety of bone artifacts, the advantages of MR are even more striking. Previous reports have emphasized the relative advantages of MR in studies of the posterior fossa. The present report documents the potential for similar advantages of MR in demonstration of middle fossa anatomy and in identification and characterization of temporal lobe lesions. In three patients with anterior temporal lobe gliomas and temporal lobe epilepsy, MR (even with the use of an early prototype, resistive system of 0.15 T) was clearly superior to contrast-enhanced CT in demonstrating the pathology. This considerably assisted preoperative evaluation.

Adolescent↗
PubMed1984

Interdural cyst of the lumbosacral region.

The purpose of this report is to call attention to the clinical, myelographic, and computed tomographic appearance of a very rare type of dural cyst within the lumbosacral spinal canal. We report this condition in three unrelated boys who presented with symptoms of cauda equina compression. Our experience suggests that these cysts are congenital in origin. Anatomically, the cyst wall consisted of a dura-like layer without arachnoid. There was a small ventral defect allowing incomplete communication with the compressed subarachnoid space. Cerebrospinal fluid-like fluid accumulated within the interdural cyst as a result of this communication. Treatment consisted of obliteration of the point of entry between cyst and subarachnoid space in all cases and partial cyst wall excision in one case. After operation, the two patients who had presented with long-standing sphincter disturbance had partial improvement in function and the child with a pain syndrome was completely relieved of symptoms.

Cauda Equina↗
PubMed1984

Spontaneous spinal subarachnoid hemorrhage and subdural hematoma. Report of two cases.

Two patients with spontaneous spinal subarachnoid hemorrhage are presented to emphasize the clinical and radiological features of this uncommon illness. Both had severe back pain at the onset. One patient had a subdural hematoma that compressed the conus medullaris and cauda equina, and was drained percutaneously; the other had clots in the subarachnoid space. The cerebrospinal fluid showed a polymorphonuclear pleocytosis that simulated septic meningitis. Complete spinal angiography failed to reveal a cause for the hemorrhages.

Aged↗
PubMed1983

Nuclear magnetic resonance imaging in central nervous system disease.

From the preliminary work of many investigators, it appears that proton nuclear magnetic resonance (NMR) imaging will have wide application in the diagnostic assessment (and potential management) of patients with vascular, neoplastic, and demyelinating diseases of the central nervous system (CNS). Findings in isolated cases and small series suggest that NMR imaging may play a role in the evaluation of patients with other CNS conditions including hydrocephalus, malformations, infections, developmental and metabolic disorders, and degenerative processes. Because of the dynamic nature of disease processes involving the CNS, the precise meaning of NMR image parameters (rho, T1, and T2) remains unclear. A comprehensive study correlating NMR images in neurologic disease with precise neuropathologic examination is required. In the future, with accurate quantitative measurements of these NMR parameters, in vivo imaging may provide insight into the dynamic nature of neurologic disease.

Central Nervous System Diseases↗
PubMed1983

Nuclear magnetic resonance (NMR) imaging of Arnold-Chiari type I malformation with hydromyelia.

Saturation recovery nuclear magnetic resonance (NMR) images and metrizamide computed tomography (CT) scans were obtained in an adult patient with a clinical history suggestive of syringomyelia. Both NMR and CT studies showed low lying cerebellar tonsils. The CT study demonstrated central cavitation of the spinal cord from the midthoracic to midcervical levels but could not exclude an intramedullary soft tissue mass at the cervico-medullary junction. The NMR images in transverse, coronal, and sagittal planes demonstrated extension of an enlarged central spinal cord cerebrospinal fluid space to the cervico-medullary junction. This was felt to be strong evidence for exclusion of an intramedullary soft tissue mass and in favor of a diagnosis of Arnold-Chiari Type I malformation with hydromyelia. The noninvasive nature of spinal cord and cervico-medullary junction evaluation with NMR is emphasized.

Adult↗
PubMed1983

Nuclear magnetic resonance (NMR) imaging of tumors in the posterior fossa.

Nuclear magnetic resonance (NMR) images were obtained in 12 patients with mass lesions in the posterior fossa and the results compared with X-ray computed tomography (CT). Inversion recovery T1-weighted images demonstrated abnormalities in six of six intrinsic lesions and three of six extrinsic lesions. Spin echo T2-weighted images demonstrated abnormalities in two of two intrinsic lesions and four of five extrinsic lesions. Saturation recovery T1-weighted images were normal in two of two intrinsic lesions and two of four extrinsic lesions. Overall, NMR detected 11 of 12 lesions. Two intrinsic tumors detected by NMR were not detected by CT evaluation. Two small extrinsic tumors required CT gas cisternography for detection.

Astrocytoma↗
PubMed1983

Potential hazards and artifacts of ferromagnetic and nonferromagnetic surgical and dental materials and devices in nuclear magnetic resonance imaging.

The risks to patients with metal surgical implants who are undergoing nuclear magnetic resonance (NMR) imaging and the artifacts caused by such implants were studied. Twenty-one aneurysm and other hemostatic clips and a variety of other materials (e.g., dental amalgam, 14 karat gold) were used. Longitudinal forces and torques were found to be exerted upon 16 of the 21 clips. With five aneurysm clips, forces and torques sufficient to produce risk of hemorrhage from dislocation of the clip from the vessel or aneurysm, or cerebral injury by clip displacement without dislodgement were identified. The induced ferromagnetism was shown to be related to the composition of the alloys from which the clips were manufactured. Clips with 10-14% nickel are evidently without sufficient induced ferromagnetism to cause hazard. The extent of NMR imaging artifacts was greater for materials with measurable ferromagnetic properties, but metals without measurable ferromagnetism in our tests also resulted in significant artifacts. Dental amalgam and 14 karat gold produced no imaging artifacts, but stainless steels in dentures and orthodontic braces produced extensive artifacts in the facial region.

Aneurysm↗
PubMed1983

1H Nuclear magnetic resonance imaging in multiple sclerosis.

Major advances have been made in the diagnosis of MS by using NMR imaging, suggesting that this noninvasive method will permit staging of MS lesions and that conclusions from newer therapeutic trials may be drawn more accurately than heretofore possible.

Adult↗