摘要:

Purpose. Magnetic resonance imaging (MRI) has come to assume a position of major importance in the diagnostic process for multiple sclerosis (MS). The authors believe that a tendency toward overreliance on MRI results in isolation from clinical findings continues to result in both false‐positive and false‐negative diagnostic errors.Methods. To evaluate this, MRI results in newly referred patients with clinical findings suggestive, but not diagnostic, for MS, were studied prospectively.Results. Of 99 consecutive referrals for suspected MS, there were 3 false‐positive diagnoses of MS and 7 false‐negatives, when the MRis were read in isolation from specific clinical data. None of the scans in the false‐negative groups were normal. Representative images of both groups are provided.Conclusion. In newly referred patients who fall short of criteria for definite MS, it remains dangerous for both clinicians and radiologists to rely too heavily only on MRI results.

ISSN:1051-2284    

DOI:10.1111/jon19933281

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Color velocity imaging (CVI) is a new non‐Doppler ultrasound technique for vascular color flow imaging. Using information contained in the two‐dimensional B‐mode, gray‐scale image to determine velocity, CVI offers potential advantages over Doppler color flow imaging methods. In order to be used clinically, velocity determination with CVI must be validated by other current methods. A Doppler string phantom was studied with a Philips CVI ultrasound system. Velocity measurements were obtained by both CVI and duplex Doppler spectral analysis for constant string speeds from 10 to 200 cm/sec, at intervals of 10 cm/sec. Twenty separate estimates were obtained with each method, at each string speed. Linear regression assessed the relationship between estimated and actual string velocities, with CVI and spectral Doppler analysis yielding highly valid results (CVI = −0.713 + 1.000997 × phantom;r2= 0.9979). At all string speeds tested, the averaged estimated and the actual velocities for both methods were within the 95% confidence estimates. The range for the CVI 95% confidence limits from the regression line varied from ± 1.07 cmjsec at the lowest speed of 10 cmjsec (11.6%) to ± 7. 72 cm/sec at 200 cm/sec (3.87%). Based on in vitro testing, CVI is as accurate as Doppler spectral analysis for the estimation of flow velocity.

ISSN:1051-2284    

DOI:10.1111/jon19933289

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Physiological imaging of regional cerebral blood flow with single‐photon emission computed tomography (SPECT) has been proposed to be diagnostically useful in the evaluation of patients with dementia because of the frequent finding of temporal and parietal lobe hypoperfusion in patients with Alzheimer's disease (AD). A major limitation of SPECT to date has been the selection of patients using clinical criteria, which may be unreliable in excluding patients with non‐Alzheimer dementias from study. SPECT with the perfusion tracer123l‐N‐isopropyl‐p‐iodoamphetamine was used to study 16 dementia patients who were subsequently followed to autopsy, as well as 16 elderly control subjects. Eleven dementia patients had the diagnosis of AD confirmed by autopsy, while 5 had other, nonAD dementias. SPECT perfusion patterns were evaluated as regional ratios of lobar radioactivity counts normalized to either activity counts in the occipital lobes (occipital ratio) or activity counts in the entire tomographic slice (whole‐slice ratio). Results showed that the relative frontal perfusion differentiated non‐AD patients from control subjects and AD patients regardless of which ratio method was used, while temporal and parietal relative perfusion ratios were more effective at differentiating AD from non‐AD patients when the whole‐slice ratio was used, although the ratio used did not affect the differentiation of AD patients from control subjects. Scatterplots of the whole‐slice ratio in the right parietal and left temporal lobes showed no overlap between AD and non‐AD patients and control subjects. These results support the diagnostic utility of SPECT in the clinical evaluation of dementia patients, particularly in distinguishing AD from non‐AD dementias during life.

ISSN:1051-2284    

DOI:10.1111/jon19933293

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

A 9‐year‐old child with intractable focal epilepsy was studied for possible surgical treatment. Multiple electroencephalographic studies did not localize the epileptic focus. An ictal single‐photon emission computed tomography (SPECT) study with technetium 99m‐hexamethylpropyleneamineoxime demonstrated a focal area of hyperperfusion. Through three‐dimensional, functional to anatomical image‐matching techniques, the focus was overlaid on the magnetic resonance image localizing the cortical convolution responsible for the epileptogenic focus. Subdural electroencephalographic studies performed for seizure localization and functional mapping confirmed this location. This case emphasized the usefulness of ictal SPECT scans in patients with seizures nonlocalizable by electroencephalography being evaluated for epilepsy surgery.

ISSN:1051-2284    

DOI:10.1111/jon199332100

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Single‐photon emission computed tomography (SPECT) was used to investigate the feasibility of the technetium 99m‐hexamethylpropyleneamineoxime (99mTc HM‐PAO) split‐dose method to evidence changes in regional cerebral blood flow during a motor activation task, in comparison with a quantitative method using the inhalatory xenon‐133. Four subjects were studied twice with both methods, at rest and during finger opposition movements. On the activated cerebral hemisphere, a significant increase in regional cerebral blood flow was observed over the motor cortical areas. The average increases were + 28.1 ± 5.6% for the xenon‐133 method and + 12.3 ± 5.2% for the99mTc HM‐PAO method. By using the linearization algorithm for the99mTc HM‐PAO method, a mean increase of + 22.5 ± 8.9% was calculated. This study demonstrated that the split‐dose method allows the motor activation SPECT studies with99mTc HM‐PAO to be done in a single session.

ISSN:1051-2284    

DOI:10.1111/jon199332103

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Eighty subjects‐30 migraineurs during the attack, 30 patients in the interictal period, and 20 healthy volunteers‐were studied using two technologies for functional assessment: transcranial Doppler ultrasound and magnetoencephalography. Transcranial Doppler studies showed an increased mean flow velocity at rest (p<0.05) in the middle cerebral artery on the side of the headache and a decreased vasomotor response to C02 (p<0.001) on the same side compared to control subjects. Biomagnetic measurements of somatosensory evoked fields of 11 patients and 11 control subjects in this study did not demonstrate differences between migraineurs and the control group in current flow or latency measures. The data from this study tend to support the hypothesis of vascular disease as a primary underlying deficit in migraine.

ISSN:1051-2284    

DOI:10.1111/jon199332109

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The impact of transcranial Doppler ultrasound (TCD) on the management of 107 consecutively referred patients with suspected vertebrobasilar ischemia was studied. Physicians who referred patients for TCD of the posterior circulation were interviewed before and after being given the results of the TCD examination. Management plans devised prior to knowledge of the TCD results were compared to those devised after TCD results were given. Management changed in 42% of the patients after TCD results were given, and there was a 58% reduction in the use of angiography (p = 0.04) and a 128% increase in the use of aspirin (p = 0.005). Changes in the use of anticoagulants and other diagnostic or therapeutic approaches were not significant. TCD appears to have a significant impact on the management of patients with suspected vertebrobasilar ischemia.

ISSN:1051-2284    

DOI:10.1111/jon199332115

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Two patients developed central pontine signal changes on magnetic resonance imaging (MRI), one after heart transplantation and one during the puerperium. In one, no lesion was found in the pons at necropsy. The other recovered clinically and the MRI lesion resolved completely. These cases raise the possibility that rapid electrolyte and biochemical perturbations can give rise to transient edema in the central pons. If more severe or chronic, the edema may cause permanent myelin damage, so‐called myelinolysis.

ISSN:1051-2284    

DOI:10.1111/jon199332123

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:1051-2284    

DOI:10.1111/jon199332127

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Four patients who had carbon monoxide intoxication were examined by brain magnetic resonance imaging (MRI) and computed tomography (CT). Three were unconscious in the acute stage of intoxication. On regaining consciousness. neuropsychological symptoms and signs remained. In these patients, T2‐weighted MRI demonstrated hyperintensity lesions in the cerebral cortex, most prominent in the watershed zone. The fourth patient had only memory disturbance and was not unconscious during the acute intoxication. The T1‐weighted MRI showed hyperintensity in the bilateral pallidal regions. MRI demonstrated lesions more clearly than did CT.

ISSN:1051-2284    

DOI:10.1111/jon199332128

出版商:Wiley    

年代:2016

数据来源: WILEY