Computed tomography in the diagnosis of cerebral abscess

Summary Computed tomography (CT) was performed 64 times on 22 patients with cerebral abscesses, using the 160x160 matrix EMI scanner. The diagnosis was based upon the demonstration of a localized low-attenuation area appearing, after the administration of contrast medium, as a high-attenuation annular rim ascribed to displaced and/or newly formed vessels, the so-called abscess membrane. CT is compared with the conventional diagnostic methods of neuroradiology. The differential diagnostic accuracy of CT is clearly superior to that of previous methods, including angiography, which, until now, we have considered the most accurate method.     

Computed tomographic evaluation of therapeutically induced changes in primary and secondary brain tumors

Summary A prospective study was initiated to evaluate computed tomography as a method for monitoring therapeutically induced changes in brain tumors. Early postoperative scans may be misleading in the evaluation of residual tumor because of trauma to the blood-brain barrier during operation. The size of the dominant mass (17/25), enhancement (11/25), edema (11/25), and ventricular distorition (14/25) were decreased in many patients after radiation therapy. Occasional tumors increased in size during radiation therapy (3/25). Enlargement of the lateral ventricles developed in 9 of 25 patients. Computed tomography offers definite advantages over nuclide brain scans, angiography and other diagnostic studies for evaluating therapeutically induced changes in brain tumors.Presented at the Sixty-second Scientific Assembly and Annual Meeting of the Radiological Society of North America, Chicago, 111., November 14–19, 1976. Supported in part by a grant from Pfizer Medical Systems, Inc.     

Computed tomography brain changes in Parkinsonian dementia

Summary In order to evaluate the relationship between brain atrophy and the motor and cognitive function in Parkinson's disease, we have evaluated CT changes in 132 consecutive patients and compared them to measures of physical and mental decline, using intercorrelations and variance analysis. The result demonstrated age as a most important factor relating to brain atrophy. After correction for this determinant, it became clear that the motor and cognitive parameters were interdependent but they affected similar CT parameters. The effect of motor decline was the stronger of the two and it was the only one which correlated with cortical atrophy. The results support the notion of subcortical changes underlying the dementia of Parkinson's disease.     

Computed tomography in acute cerebral ischemia

Summary Computed tomography (CT) is the first step in the radiological diagnostics of brain emergencies. We intend to study which pathophysiological changes are detected by CT and how CT contributes to prognosis and patient management in acute cerebral ischemia. We review recent publications about the role of CT in acute cerebral ischemia. Ischemic brain edema is associated with a decreased X-ray attenuation. Computed tomography is thus highly sensitive in detecting irreversibly damaged ischemic brain tissue. Patients showing large volumes of ischemic edema, exceeding one third of the middle cerebral artery territory, do not benefit from thrombolysis and have an increased risk of brain hemorrhage. The brain territory at risk from ischemia can be detected by CT angiography. To combine CT with CT angiography is a pragmatic approach which enables carefully directed treatment in acute cerebral ischemia.      

Computed tomography for small acoustic neuromas

Summary The minimal size of acoustic neuromas detectable by computed tomography (CT) is, according to the available literature, 1.5 to 2 cm. The new otoneurosurgical technic using the transtemporal and translabyrinthine approach necessitates an early diagnosis of neuromas protruding 1 cm or less into the cerebellopontine angle cistern. This seemed impossible with the available CT equipment. Eight proven acoustic neuromas 1 cm or less in diameter, detected with CT, are reported. Diagnostic criteria are elaborated. The study shows that small cerebellopontine angle tumors can be detected by use of CT machines of the newer generation which perform scanning with thin and overlapping slices.     

Computed tomography and aging: results in a normal elderly population

Summary CT studies on 212 normal elderly individuals were analyzed for ventricular enlargement and cortical atrophy. Results show a positive correlation between ventricular enlargement and age with greater degrees of ventricular enlargement and cortical atrophy in men as compared to women. While some degree of atrophy is common in normal elderly individuals it is mild, minimal, or noexistent in 86%.Supported in part by NIMH grant 2RO1 MHAG27281     

Computed tomography of spinal cord atrophy

Summary Spinal cord atrophy takes on several different forms which correlate closely with specific clinical features. The majority of them, however, can be categorized into three distinct patterns, diffuse (transverse myelopathy), hemi-(Brown-Sequard syndrome), or anterior (anterior spinal artery syndrome) atrophy. Until recently, the differential diagnosis had been made solely on the neurological examination. We present three cases of spinal cord atrophy, one in each category. Spinal computed tomography with metrizamide appears to be a reliable supporting diagnostic method for spinal cord atrophy.     

Computed tomography in the postoperative patient

Summary Nine cases of patients in whom intracranial infection was suspected after operation are presented. Lesions with ring enhancement were seen in all of these patients. The differentiation of enhancement, seen as a normal postoperative phenomenon, from residual neoplasia and cerebral abscess can be difficult. This can be resolved by serial and sequential-delayed CT, and thus unnecessary re-exploration may be prevented.     

Computed tomography in late-onset metachromatic leucodystrophy

Summary In late-onset metachromatic leucodystrophy (MLD), early clinical diagnosis is difficult since initial symptoms frequently consist of misleading nonspecific psychopathological alterations. On cranial computed tomography (CT), however, symmetrical attenuation decrease of the white matter and mild cerebral atrophy can already be found in an early stage of the disease, and may even precede clinical symptoms. On the basis of observations in four patients with late-onset MLD who were followed between 1 and 5 years, characteristic CT appearances in different stages of the disease are outlined and compared with the literature.     

Interobserver agreement in the assessment of cerebral atrophy on CT using bicaudate and sylvian-fissure ratios

To assess the interobserver variability of cerebral-atrophy measures on CT, three investigators measured the bicaudate ratio (BCR) and the sylvian-fissure ratio (SFR) on 20 CT studies of patients with ischaemic stroke. The intraclass correlation coefficient of BCR measurements was 0.82 [95 % confidence interval (CI) 0.75–0.94], and that of SFR measurements 0.69 (95 % CI 0.57–0.89). The range of pairwise-calculated Pearson correlation coefficients was smaller for measurement of the BCR (0.89–0.92) than for the SFR measurements (0.66–0.84). Received: 2 June 1998 Accepted: 4 October 1998     

Computed tomography in intracranial,supratentorial metastases in children

Summary This study compares the CT characteristics in a consecutive sample of supratentorial metastases (n=31) with primary tumors of the same location (n=49) in childhood. Postcontrast CT was performed in all but one of the metastases cases. In all but one of these children the location and type of primary tumor was known at time of occurence of cerebral metastasis. Primary CNS tumors (n=12) had a higher incidense of supratentorial metastatic spread than tumor originating elsewhere. Three children had diffuse subarachnoid seeding, while 28 had solid tumors (21 solitary, 7 multiple). The predilection location for the solid metastases was the gray-white matter junction (n=12). The following CT findings were significantly less frquuent in metastases than in primary tumors (P<0.05): Midline location, calcification and cyst formation. On the other hand bleeding, pronouced contrast enhancement and location in the gray-white matter junction were more frequent in the metastatic group (P<0.05).     

Computed tomography of complications caused by manufacturing defects in synthetic grafts

Two unusual cases of delayed synthetic graft complications resulting from manufacturing defects of knitted Dacron are presented. Computed tomography appears to be a suitable noninvasive alternative examination to angiography in this condition.     

MRI of patients with cerebral palsy and normal CT scan

Summary Three children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP.     

Computed tomography of the sternum and its articulations

The chest wall presents diagnostic difficulties for both the clinician and the radiologist. Because of normal variations in anatomy and ossification, analysis of the sternal region can be particularly confusing. We reviewed the normal computed tomographic (CT) appearance of the sternum in 354 patients. Important normal sternal variants included cortical unsharpness along the posterior aspect of the manubrium, lateral surfaces of the body, and at the sternal fibrocartilaginous articulations; soft tissue prominence at the junction of the sternum and costochondral cartilage; and bony sclerosis at the transitions from manubrium to body and from body to xiphoid. In seven patients with clinically significant sternal abnormality, key CT features were abnormal soft tissue mass (7/7), destruction or irregularity of the cortical contour (7/7), and abnormal increased attenuation of bone (1/7). CT should be the radiologic study of choice in patients with suspected abnormality of the sternum and its articulations.     

Descending tentorial herniation: Findings on computed tomography

Summary Descending tentorial herniation (DTH) can be diagnosed by computed tomography. Encroachment upon the lateral aspect of the suprasellar cistern is an early sign of impending tentorial herniation. Actual herniation is evidenced by rotation and shift of the brain stem with consequent widening of the crural and ambient cisterns on the side of the space-occupying lesion. In a more advanced stage of herniation, obliteration of cisternal spaces at the tentorial level will occur. Aqueductal compression secondary to the herniation will cause increased intraventricular pressure with widening of those parts of the lateral ventricles that are not exposed parts of the lateral ventricles that are not exposed to the compression by the mass; a characteristic finding is widening of the temporal horn on the side opposite the space-occupying lesion. Infarction in the territory of the posterior cerebral artery may complicate DTH.     

Computed tomography during Creutzfeldt-Jakob disease

Summary A case of extremely advanced Creutzfeldt-Jakob disease of the cortico-striato-cerebellar type is described. The different stages of the disease are documented by computer-tomography.     

A cohort study of tibialis anterior tendon shortening in combination with calf muscle lengthening in spastic equinus in cerebral palsy

The aim of this study was to evaluate the outcome of combined tibialis anterior tendon shortening (TATS) and calf muscle-tendon lengthening (CMTL) in spastic equinus.Prospectively collected data was analysed in 26 patients with hemiplegic (n = 13) and diplegic (n = 13) cerebral palsy (CP) (GMFCS level I or II, 14 males, 12 females, age range 10–35 years; mean 16.8 years). All patients had pre-operative 3D gait analysis and a further analysis at a mean of 17.1 months (±5.6 months) after surgery. None was lost to follow-up. Twenty-eight combined TATS and CMTL were undertaken and 19 patients had additional synchronous multilevel surgery. At follow-up 79% of patients had improved foot positioning at initial contact, whilst 68% reported improved fitting or reduced requirement of orthotic support. Statistically significant improvements were seen in the Movement Analysis Profile for ankle dorsi-/plantarflexion (4.15°, p = 0.032), maximum ankle dorsiflexion during swing phase (11.68°, p < 0.001), and Edinburgh Visual Gait Score (EVGS) (4.85, p = 0.014). Diplegic patients had a greater improvement in the EVGS than hemiplegics (6.27 -vs- 2.21, p = 0.024).The originators of combined TATS and CMTL showed that it improved foot positioning during gait. The present study has independently confirmed favourable outcomes in a similar patient population and added additional outcome measures, the EVGS, foot positioning at initial contact, and maximum ankle dorsiflexion during swing phase. Study limitations include short term follow-up in a heterogeneous population and that 19 patients had additional surgery. TATS combined with CMTL is a recommended option for spastic equinus in ambulatory patients with CP.     

Signs of cerebral atrophy on single-photon emission tomography

Cerebral atrophy often coexists with other brain disorders and by itself may alter the pattern of cerebral perfusion. If unrecognized, it may confound diagnoses based on brain single-photon emission tomography (SPET). In this retrospective study, we describe and evaluate criteria for the diagnosis of cerebral atrophy on technetium-99m hexamethylpropylene amine oxime brain SPET studies. The SPET scans of 11 patients with cerebral atrophy and ten controls were evaluated for the presence of a prominent interhemispheric fissure, presence of prominent cerebral sulci, separation of thalamic nuclei, and pronounced separation of caudate nuclei. The SPET studies were interpreted by two independent observers blind to the findings of magnetic resonance imaging, which provided the final diagnosis of cerebral atrophy. The combination of the four scintigraphic signs was accurate in the diagnosis of cerebral atrophy in 95% of the cases and had a sensitivity of 91% and a specificity of 100%. Correspondence to: S. Sostre     

脑性瘫痪的MRI特征

目的:探讨脑性瘫痪(脑瘫)患儿的头颅MRI表现及其与脑瘫类型的关系。方法:回顾性分析81例脑瘫患儿的临床资料与MRI表现。结果:81例脑瘫患儿MRI异常率为85.2%,痉挛型双瘫、四肢瘫、偏瘫、不随意运动型脑瘫、共济失调型脑瘫、肌张力低下型脑瘫和混合型脑瘫MRI异常率分别为92.9%、100%、100%、60%、87.5%、50%和81.8%。各类型脑瘫的MRI异常表现不同,痉挛型双瘫以脑室周围白质软化(PRL)为主,偏瘫型突出表现为单侧脑损伤,四肢瘫表现为广泛、弥漫、双侧脑损伤,不随意运动型表现为基底节病变或PVL,共济失调型绝大部分存在先天性小脑发育不全。结论:MRI有助于评价各型脑瘫的病理特点,对脑瘫病因的推测有帮助。     

The impact of walking devices on kinematics in patients with spastic bilateral cerebral palsy

Increased anterior pelvic and trunk tilt is a common finding in patients with bilateral cerebral palsy especially during walking with assistive devices. As previous studies demonstrate various gait alterations when using assistive devices, the assessment of surgical interventions may be biased when the patients become independent of (or dependent on) assistive devices after therapy. Furthermore, some of these patients in fact are able to walk without devices even though in daily life they prefer to use them. Consequently, for such patients the classification into GMFCS level II or III may be ambiguous. The specific aim of this study was therefore to assess the influence of the use of forearm crutches and posterior walker during walking and to set this influence in relation to outcome effects of surgical intervention studies.26 ambulatory patients with spastic bilateral CP (GMFCS II–III) were included who underwent 3D gait analysis. All patients used forearm crutches or posterior walkers in everyday life even though they were able to walk without assistive devices for short distances.Independent of the type of assistive devices, the patients walk on average with more anterior trunk tilt and pelvic tilt (7° ± 6° and 3° ± 2°) and with a maximum ankle dorsiflexion decreased by 2° (±3°) when walking with assistive devices, enhancing the mal-positioning present without device. Oppositely, the knees on average are more extended by 6° (±4°) when using the assistive devices.These effects have to be taken into account when assessing gait patterns or when monitoring the outcome after intervention as assistive devices may partially hide or exaggerate therapeutic effects.