CT scans and the common cold?
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Common Cold↗
Biomedical subjects
D M Pelz
Publications and source records attributed to D M Pelz.
Direct sampling of the cavernous sinus in Cushing's disease.
Sampling of the petrosal sinus is a sensitive and accurate method of diagnosing Cushing's disease. Sampling of the inferior petrosal sinus has been performed with a steam-shaped no. 4 or 5 French soft catheter in some centres. However, a recent report described two patients who suffered major injury to the brain stem as a result such sampling. The authors describe a series of five patients who underwent simultaneous, direct sampling of the cavernous sinuses with a Tracker microcatheter (Target Therapeutics, Fremont, Calif.) for the diagnosis of Cushing's disease. No complications occurred in this small group. The authors conclude that this procedure is a safe and accurate means of diagnosing Cushing's disease; the technique is also helpful in locating adrenocorticotropin-producing microadenoma.
Adolescent↗
Stenosis of the carotid bifurcation: subjective assessment compared with strict measurement guidelines.
Preliminary results of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) have shown that endarterectomy is highly effective in preventing stroke in patients with 70% to 99% stenosis of the carotid bifurcation. These results are based on specific linear measurement criteria comparing the residual diameter of the lumen with that of the normal carotid beyond the bulb. These criteria may differ from subjective assessments of the severity of stenosis. Angiograms from 125 NASCET patients were analysed independently by three groups of reviewers. The first group consisted of three neuroradiologists, the second of two neurologists and one neurosurgeon and the third of three radiologists with neuroradiologic experience. The degree of stenosis was estimated, without measurement, as mild (1% to 29%), moderate (30% to 69%) or severe (70% to 99%), or the vessel was said to be occluded. These assessments were compared with the degree of stenosis as determined by the NASCET neuroradiologist on the basis of measurement. The subjective assessment of stenosis produced false-positive rates (for assessing stenosis of less than 70% as severe) ranging from 5% among the neuroradiologists to 16% among the radiologists. The false-negative rates (for assessing stenosis of 70% or more as less than severe) ranged from 12% to 22%. Therefore, a subjective rating of carotid stenosis may lead to erroneous estimation of the severity of disease. This problem has therapeutic implications, because carotid endarterectomy has been shown to benefit only patients with stenosis of greater than 70%, as assessed according to strict measurement guidelines.
Carotid Arteries↗
Endovascular therapy for intractable epistaxis.
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Angiography↗
Complication rates of DSA and conventional film cerebral angiography.
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Angiography, Digital Subtraction↗
Percutaneous lumbar nerve root blocks.
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Back Pain↗
Optic neuritis and orbital lesions: lipid-suppressed chemical shift MR imaging.
A derivative of the Dixon method, chopper fat suppression, was used in the magnetic resonance imaging evaluation of 40 patients: 37 with suspected optic nerve lesions, predominantly optic neuritis, and three with orbital lesions. In patients with optic neuritis, the technique was sensitive, allowing detection of 29 of 34 visual-evoked-response-confirmed lesions on T2-weighted lipid-suppressed images. There were no false-positive studies. Sensitivity for detection of optic neuritis was 89%; specificity, 100%; and accuracy, 86%. The technique was also useful for depicting inflammatory changes in the orbital apex due to fungal abscess and confirming the fatty nature of an extraconal dermoid tumor. A slight increase in noise and mild accentuation of susceptibility effects at interfaces of air, bone, and brain did not degrade images significantly. The chopper-based technique requires only standard imaging time and has usual spin-echo sensitivity. The results are comparable to short-inversion-time inversion-recovery imaging, without the constraints of sequence limitations or artifacts at fat and water interfaces.
Adipose Tissue↗
Arteriovenous malformations of the brain: recent results of endovascular therapy.
Results of embolization and subsequent surgical resection were reviewed in 38 patients with arteriovenous malformations (AVMs) of the brain during the past 3 years. Advanced techniques were used for embolization, including real-time digital subtraction angiofluoroscopy; directable microcatheters; and a mixture of microfibrillar collagen, polyvinyl alcohol sponge microparticles, and ethanol, in addition to acrylic glue. Embolization caused a permanent deficit in four patients (10.5%) (quadrantanopia [n = 3], cerebellar ataxia [n = 1]). Thirty-two patients (84%) underwent surgery after embolization, and 28 (74%) were completely cured, as assessed with postsurgical angiography. Twenty-five patients (66%) had either no deficit or no change in deficit after treatment. Two patients had worsening of a previous deficit after postembolization resection, two patients had mild weakness not previously present, and five patients had visual field defects. One patient developed Gerstmann syndrome after resection, and one patient with ataxia after embolization also had ataxia after surgical resection. Two patients died of complications due to surgical resection. Most of the AVMs in this series were large and complex. Embolization used predominantly as a preoperative procedure enabled complete resection, as achieved in the majority of these cases.
Adolescent↗
Rupture of aneurysms following balloon embolization.
Three cases of complex aneurysms are presented in which balloon embolization therapy was associated with subsequent aneurysmal rupture, causing subarachnoid hemorrhage in two cases and a carotid-cavernous fistula in one. Two of these patients were treated directly by balloon embolization following surgical exploration. The third patient developed the fistula during postembolization volume expansion and heparinization.
Arteriovenous Fistula↗
The film-reporting session as a qualifying examination in diagnostic radiology.
To assess the value of a film-reporting session as a qualifying examination in radiology, 11 residents were allowed 1 hour to interpret and dictate reports on 20 test cases. Reports were marked by four examiners; two used a standardized marking scheme and two a simple pass or fail assessment. The marking schemes were compared and the scores were related to the level of training and performance on the American College of Radiology (ACR) practice examination. With pass or fail marking, there was 55% agreement between markers and poor correlation with the candidates' training level. There was 100% marker agreement using the standardized scheme and better correlation with the level of training. There was poor correlation with the ACR scores. Preliminary results suggest that a film-reporting session with standardized marking is feasible and may be a useful addition to current evaluation methods in diagnostic radiology.
Certification↗
Radiologic investigation of low back pain.
Low back pain is one of the commonest disorders, yet is the most confusing. The cost in work-time lost and in the search for and treatment of its many causes amounts to billions of dollars annually. The traditional techniques for anatomic visualization have been plain-film radiography and myelography, but they have limitations. The development of computed tomography and magnetic resonance imaging have substantially improved anatomic imaging. However, invasive procedures, such as discography, percutaneous nerve-root blocking and percutaneous facet injection, may be helpful in patients with disabling pain in whom noninvasive methods give negative findings, show abnormalities that do not correlate with the symptoms or identify multiple sites of disease. The invasive procedures are believed by some to be associated with too many complications. We have attempted to clarify the strengths and weaknesses of the currently available methods of investigating low back pain and the indications for their use.
Adult↗
Use of detachable balloons for proximal artery occlusion in the treatment of unclippable cerebral aneurysms.
Of 68 patients with unclippable aneurysms treated by proximal artery occlusion with detachable balloons, permanent occlusion was achieved in 65; of these patients, 37 had carotid artery aneurysms below the origin of the ophthalmic artery, 21 had aneurysms arising from the supraclinoid portion of the carotid artery, six had basilar trunk aneurysms, and one had a distal vertebral aneurysm. Examination for treatment selection included assessment of the circle of Willis by compression angiography and xenon blood flow studies, with the ultimate evaluation being test occlusion under systemic heparinization with the balloon temporarily placed in the desired position. Of 67 patients who underwent a formal occlusion test, eight with carotid artery aneurysms did not initially tolerate the occlusion test, and ischemic signs disappeared instantaneously with deflation and removal of the balloon. During test occlusion, two additional patients had ischemic events that proved to be embolic; these reversed immediately upon balloon deflation. Of the 65 patients in whom permanent occlusion was effected by detachable balloon, there were nine instances of delayed cerebral events. One of these was a seizure leading to respiratory arrest and resuscitation 3 days following occlusion in a patient who had presented with seizures. The other eight cases were delayed ischemic events; seven were completely reversed and one patient had residual weakness in one leg (1.5% permanent morbidity). Extracranial-intracranial bypass procedures were performed in 25 of the 65 cases. All aneurysms of the carotid artery below the level of the ophthalmic artery presented angiographic proof of complete thrombosis. Ten of 21 aneurysms arising from the supraclinoid portion of the carotid artery were completely thrombosed by proximal occlusion alone, without additional trapping procedures. Similarly, in three of six basilar trunk aneurysms, proximal occlusion alone initiated complete aneurysm thrombosis without trapping. The conclusion is that proximal balloon occlusion for unclippable cerebral aneurysms is a convenient, safe, and effective way of producing arterial occlusion in these cases.
Carotid Artery Diseases↗
Giant intracranial varices secondary to high-flow arteriovenous fistulae.
An intracranial varix is rare and has been associated mostly with vein of Galen fistulae or arteriovenous (AV) malformations. The authors present eight cases of intracranial, pial or subpial AV fistulae with concomitant giant varices. Six were supratentorial and two were infratentorial. Only one case involved the vein of Galen. In six cases successful surgical and/or endovascular occlusion of the intracranial AV fistula was obtained, and one case was treated conservatively. Staging of surgery and postoperative hypotension were considered to be important in avoiding edema and hemorrhage following obliteration of a large AV shunt. One patient died from delayed postoperative intracerebral bleeding.
Adolescent↗
Magnetic resonance imaging in Down's syndrome.
100% of brains of Down's adults over age 40 will show Alzheimer-type neuropathologic changes in the frontal and temporal lobes. In an attempt to image these lesions, magnetic resonance imaging (MRI) was performed in seven patients with Down's syndrome, ranging in age from 17 to 45 years, using a resistive unit operating at 0.15 Tesla. All scans were within normal limits except for one 45 year-old patient with severe left temporal lobe atrophy. No areas of abnormal signal were seen in the frontal or temporal lobes and the white matter lesions commonly seen in elderly demented subjects were not visualized in this group. We conclude that these white matter lesions are likely coincidental and not causally related to Alzheimer's changes. The pathologic process leading to the formation and development of Alzheimer's changes in the brains of Down's adults may not be visible on magnetic resonance images.
Adolescent↗
Intraluminal thrombus of the internal carotid arteries: angiographic demonstration of resolution with anticoagulant therapy alone.
Fourteen patients with angiographically demonstrated thrombus in the cerebral vessels were treated immediately with anticoagulant or antiplatelet medication. Follow-up angiograms, obtained in eight cases, showed resolution of the thrombus in seven. In no patient did the thrombus progress to occlude the vessel completely, and no new distal emboli were identified on the follow-up angiograms. There were no new permanent neurologic events in these 14 patients while they were undergoing medical therapy. Six patients subsequently underwent delayed endarterectomy to treat underlying stenoses. Our experience indicates that the presence of intraluminal thrombus may not be a surgical emergency.
Adult↗
Unusual clinical manifestations of dural arteriovenous malformations.
Fourteen patients had classical angiographic findings of intracranial dural arteriovenous malformations (AVM's). They presented with unusual central neurological signs and symptoms, including visual disturbances, hemiparesis, speech disturbances, gait ataxia, diffuse increased intracranial pressure, and intracranial hemorrhage. In 12 of the 14 patients there was a direct correlation between the clinical presentation and the venous drainage characteristics of the AVM's. The symptoms were probably related to a regional steal phenomenon in two patients. Six patients had direct surgical excision of the dural AVM. Five patients underwent endovascular embolization of the malformation and, in one case, the AVM was removed surgically after embolization. In one patient, the external carotid artery in the neck was ligated. Ten of the 14 patients had substantial clinical improvement or cure. A complete anatomical obliteration of the malformation was obtained in seven cases. None of the patients deteriorated clinically after therapy.
Adult↗
Increased density of tentorium and falx: a false positive CT sign of subarachnoid hemorrhage.
Noncontrast computed tomographic (CT) findings in 10 patients with profound brain swelling or a mass effect revealed a high density of the falx and tentorium and thus suggested subarachnoid hemorrhage. Postmortem examinations performed shortly after the CT scans demonstrated no subarachnoid blood. A review of 100 CT scans drawn at random was carried out to assess the frequency of a hyperdense, noncalcified falx in the same population and failed to demonstrate this finding. Therefore, in the presence of profound brain swelling or a mass effect, factors other than subarachnoid hemorrhage may be responsible for increased density of the falx and tentorium on cranial CT head scans.
Adult↗
Diagnosis and endovascular therapy of vascular lesions in the cavernous sinus.
One hundred and twenty-eight lesions of the cavernous sinus were diagnosed and treated by endovascular embolization alone or combined with postembolization surgery. All patients presented with acute or subacute cavernous sinus syndrome. A complete angiographic evaluation included bilateral internal and external carotid and vertebral angiography. A total of 88 carotid-cavernous (c-c) fistulae (68 traumatic and 20 spontaneous) and 40 giant aneurysms were demonstrated. A complete anatomic cure or satisfactory clinical improvement was seen in 67 of 68 traumatic fistulae, in 14 of 20 spontaneous c-c fistulae and in 38 of 40 giant intracavernous aneurysms. An overall 15 per cent immediate and 2.7 per cent long-term morbidity with one death was observed. The technical and clinical complications involving endovascular therapy of each specific intracavernous vascular lesion are analyzed.
Adult↗