Mycotoxin contamination in the Arab world: Highlighting the main knowledge gaps and the current legislation

Since the discovery of aflatoxins in the 1960s, knowledge in the mycotoxin research field has increased dramatically. Hundreds of review articles have been published summarizing many different aspects, including mycotoxin contamination per country or region. However, mycotoxin contamination in the Arab world, which includes 22 countries in Africa and Asia, has not yet been specifically reviewed. To this end, the contamination of mycotoxins in the Arab world was reviewed not only to profile the pervasiveness of the problem in this region but also to identify the main knowledge gaps imperiling the safety of food and feed in the future. To the best of our knowledge, 306 (non-)indexed publications in English, Arabic, or French were published from 1977 to 2021, focusing on the natural occurrence of mycotoxins in matrices of 14 different categories. Characteristic factors (e.g., detected mycotoxins, concentrations, and detection methods) were extracted, processed, and visualized. The main results are summarized as follows: (i) research on mycotoxin contamination has increased over the years. However, the accumulated data on their occurrences are scarce to non-existent in some countries; (ii) the state-of-the-art technologies on mycotoxin detection are not broadly implemented neither are contemporary multi-mycotoxin detection strategies, thus showing a need for capacity-building initiatives; and (iii) mycotoxin profiles differ among food and feed categories, as well as between human biofluids. Furthermore, the present work highlights contemporary legislation in the Arab countries and provides future perspectives to mitigate mycotoxins, enhance food and feed safety, and protect the consumer public. Concluding, research initiatives to boost mycotoxin research among Arab countries are strongly recommended.

The transCampus Metabolic Training Programme Explores the Link of SARS-CoV-2 Virus to Metabolic Disease

Currently, we are experiencing a true pandemic of a communicable disease by the virus SARS-CoV-2 holding the whole world firmly in its grasp. Amazingly and unfortunately, this virus uses a metabolic and endocrine pathway via ACE2 to enter our cells causing damage and disease. Our international research training programme funded by the German Research Foundation has a clear mission to train the best students wherever they may come from to learn to tackle the enormous challenges of diabetes and its complications for our society. A modern training programme in diabetes and metabolism does not only involve a thorough understanding of classical physiology, biology and clinical diabetology but has to bring together an interdisciplinary team. With the arrival of the coronavirus pandemic, this prestigious and unique metabolic training programme is facing new challenges but also new opportunities. The consortium of the training programme has recognized early on the need for a guidance and for practical recommendations to cope with the COVID-19 pandemic for the community of patients with metabolic disease, obesity and diabetes. This involves the optimal management from surgical obesity programmes to medications and insulin replacement. We also established a global registry analyzing the dimension and role of metabolic disease including new onset diabetes potentially triggered by the virus. We have involved experts of infectious disease and virology to our faculty with this metabolic training programme to offer the full breadth and scope of expertise needed to meet these scientific challenges. We have all learned that this pandemic does not respect or heed any national borders and that we have to work together as a global community. We believe that this transCampus metabolic training programme provides a prime example how an international team of established experts in the field of metabolism can work together with students from all over the world to address a new pandemic.

Predictors of pharmacological treatment outcomes with atomoxetine or methylphenidate in patients with attention-deficit/hyperactivity disorder from China, Egypt, Lebanon, Russian Federation, Taiwan, and United Arab Emirates

BACKGROUND

The reduced availability of data from non-Western countries limits our ability to understand attention-deficit/hyperactivity disorder (ADHD) treatment outcomes, specifically, adherence and persistence of ADHD in children and adolescents. This analysis assessed predictors of treatment outcomes in a non-Western cohort of patients with ADHD treated with atomoxetine or methylphenidate.

METHODS

Data from a 12-month, prospective, observational study in outpatients aged 6-17 years treated with atomoxetine (N = 234) or methylphenidate (N = 221) were analysed post hoc to determine potential predictors of treatment outcomes. Participating countries included the Russian Federation, China, Taiwan, Egypt, United Arab Emirates and Lebanon. Factors associated with remission were analysed with stepwise multiple logistic regression and classification and regression trees (CART). Cox proportional hazards models with propensity score adjustment assessed differences in atomoxetine persistence among initial-dose cohorts.

RESULTS

In patients treated with atomoxetine who had available dosing information (N = 134), Cox proportional hazards revealed lower (< 0.5 mg/kg) initial dose was significantly associated with shorter medication persistence (p < 0.01). multiple logistic regression analysis revealed greater rates of remission for atomoxetine-treated patients were associated with age (older), country (United Arab Emirates) and gender (female) (all p < 0.05). CART analysis confirmed older age and lack of specific phobias were associated with greater remission rates. For methylphenidate, greater baseline weight (highly correlated with the age factor found for atomoxetine) and prior atomoxetine use were associated with greater remission rates.

CONCLUSIONS

These findings may help clinicians assess factors upon initiation of ADHD treatment to improve course prediction, proper dosing and treatment adherence and persistence.

TRIAL REGISTRATION

Observational study, therefore no registration.

Preclinical detection of Alzheimer's disease: hippocampal shape and volume predict dementia onset in the elderly

Structural deformity of the hippocampus is characteristic of individuals with very mild and mild forms of dementia of the Alzheimer type (DAT). The purpose of this study was to determine whether a similar deformity of the hippocampus can predict the onset of dementia in nondemented elders. Using high dimensional diffeomorphic transformations of a neuroanatomical template, hippocampal volumes and surfaces were defined in 49 nondemented elders; the hippocampal surface was subsequently partitioned into three zones (i.e., lateral, superior and inferior-medial), which were proximal to the underlying CA1 subfield, CA2-4 subfields plus dentate gyrus, and subiculum, respectively. Annual clinical assessments using the Clinical Dementia Rating scale (CDR), where CDR 0 indicates no dementia and CDR 0.5 indicates very mild dementia, were then performed for a mean of 4.9 years (range 0.9-7.1 years) to monitor subjects who converted from CDR 0 to CDR 0.5. Inward variation of the lateral zone and left hippocampal volume significantly predicted conversion to CDR 0.5 in separate Cox proportional hazards models. When hippocampal surface variation and volume were included in a single model, inward variation of the lateral zone of the left hippocampal surface was selected as the only significant predictor of conversion. The pattern of hippocampal surface deformation observed in nondemented subjects who later converted to CDR 0.5 was similar to the pattern of hippocampal surface deformation previously observed to discriminate subjects with very mild DAT and nondemented subjects. These results suggest that inward deformation of the left hippocampal surface in a zone corresponding to the CA1 subfield is an early predictor of the onset of DAT in nondemented elderly subjects.

Labeled cortical mantle distance maps of the cingulate quantify differences between dementia of the Alzheimer type and healthy aging

The cingulate gyri in 37 subjects with and without early dementia of the Alzheimer type (DAT) were studied by using MRI at 1.0 mm3 isotropic resolution. Groups were segregated into young controls (n = 10), age-matched normal controls (n = 10), very mild DAT (n = 8), and mild DAT (n = 9). By using automated Bayesian segmentation of the cortex and gray matter/white matter (GM/WM) isosurface generation, tissue compartments were labeled into gray, white, and cerebrospinal fluid as a function of distance from the GM/WM isosurface. Cortical mantle distance maps are generated profiling the GM volume and cortical mantle distribution as a function of distance from the cortical surface. Probabilistic tests based on generalizations of Wilcoxon-Mann-Whitney tests were applied to quantify cortical mantle distribution changes with normal and abnormal aging. We find no significant change between young controls and healthy aging as measured by the GM volume and cortical mantle distribution as a function of distance in both anterior and posterior regions of the cingulate. Significant progression of GM loss is seen in the very mild DAT and mild DAT groups in all areas of the cingulate. Posterior regions show both GM volume loss as well as significant cortical mantle distribution decrease with the onset of mild DAT. The "shape of the cortical mantle" as measured by the cortical mantle distance profiles manifests a pronounced increase in variability with mild DAT.

Early DAT is distinguished from aging by high-dimensional mapping of the hippocampus. Dementia of the Alzheimer type

OBJECTIVE

To determine the feasibility of using high-dimensional brain mapping (HDBM) to assess the structure of the hippocampus in older human subjects, and to compare measurements of hippocampal volume and shape in subjects with early dementia of the Alzheimer type (DAT) and in healthy elderly and younger control subjects.

BACKGROUND

HDBM represents the typical structures of the brain via the construction of templates and addresses their variability by probabilistic transformations applied to the templates. Local application of the transformations throughout the brain (i.e., high dimensionality) makes HDBM especially valuable for defining subtle deformities in brain structures such as the hippocampus.

METHODS

MR scans were obtained in 18 subjects with very mild DAT, 18 healthy elderly subjects, and 15 healthy younger subjects. HDBM was used to obtain estimates of left and right hippocampal volume and eigenvectors that represented the principal dimensions of hippocampal shape differences among the subject groups.

RESULTS

Hippocampal volume loss and shape deformities observed in subjects with DAT distinguished them from both elderly and younger control subjects. The pattern of hippocampal deformities in subjects with DAT was largely symmetric and suggested damage to the CA1 hippocampal subfield. Hippocampal shape changes were also observed in healthy elderly subjects, which distinguished them from healthy younger subjects. These shape changes occurred in a pattern distinct from the pattern seen in DAT and were not associated with substantial volume loss.

CONCLUSIONS

Assessments of hippocampal volume and shape derived from HDBM may be useful in distinguishing early DAT from healthy aging.

Comparison of computed tomography myelography and magnetic resonance imaging in the evaluation of cervical spondylotic myelopathy and radiculopathy

STUDY DESIGN

A cross-sectional retrospective radiologic study.

OBJECTIVES

To establish concordance rates between interpretations of computed tomography myelography and magnetic resonance imaging in patients with degenerative cervical spine disease.

SUMMARY OF BACKGROUND DATA

Observed discrepancies in interpretation of computed tomography myelography and magnetic resonance imaging question the reliability of comparisons between these two methods.

METHODS

This study blindly and randomly evaluated cervical computed tomography myelography and magnetic resonance imaging in 20 patients referred for clinically diagnosed cervical spondylotic radiculopathy, myelopathy, or both. The discovertebral joints, facet joints, lateral recesses, cord size, spinal canal, and neural foramina also were evaluated with graded scales. All results were subjected to the kappa statistic for strength of agreement.

RESULTS

Agreement for interpretation of the discovertebral junction occurred in 144 of 240 sites (60%), indicating only moderately good intermethod concordance (kappa = 0.44). Intermethod agreement on the characterization of facet joint disease was only moderately good (143 of 160 sites; 89.4%; kappa = 0.52), and on characterization of lateral recess disease was poor (125 of 160 sites; 78.1%; kappa = 0.20). On degree of spinal canal compromise, there was agreement within one grade in 199 of 240 sites (82.9%; kappa = 0.42). Intermethod agreement on neural foraminal encroachment and cord size was only moderately good (kappa = 0.42 and 0.46, respectively). Computed tomography myelography tended to upgrade the spinal canal narrowing and neural foraminal encroachment.

CONCLUSIONS

For most parameters of interpretation, the degree of concordance between computed tomography myelography and magnetic resonance imaging is only moderately good, with discrepancies noted especially in the differentiation of disc and bony pathology. These methods should be viewed as complementary studies.

Hippocampal morphometry in schizophrenia by high dimensional brain mapping

Theories of the pathophysiology of schizophrenia have implicated the hippocampus, but controversy remains regarding hippocampal abnormalities in patients with schizophrenia. In vivo studies of hippocampal anatomy using high resolution magnetic resonance scanning and manual methods for volumetric measurement have yielded inconclusive results, perhaps because of the normal variability in hippocampal volume and the error involved in manual measurement techniques. To resolve this controversy, high dimensional transformations of a computerized brain template were used to compare hippocampal volumes and shape characteristics in 15 matched pairs of schizophrenia and control subjects. The transformations were derived from principles of general pattern matching and were constrained according to the physical properties of fluids. The analysis and comparison of hippocampal shapes based on these transformations were far superior to the comparison of hippocampal volumes or other global indices of hippocampal anatomy in showing a statistically significant difference between the two groups. In the schizophrenia subjects, hippocampal shape deformations were found to be localized to subregions of the structure that send projections to prefrontal cortex. The results of this study demonstrate that abnormalities of hippocampal anatomy occur in schizophrenia and support current hypotheses that schizophrenia involves a disturbance of hippocampal-prefrontal connections. These results also show that comparisons of neuroanatomical shapes can be more informative than volume comparisons for identifying individuals with neuropsychiatric diseases, such as schizophrenia.

Three-dimensional hippocampal MR morphometry with high-dimensional transformation of a neuroanatomic atlas

PURPOSE

To test automated three-dimensional magnetic resonance (MR) imaging morphometry of the human hippocampus, to determine the potential gain in precision compared with conventional manual morphometry.

MATERIAL AND METHODS

A canonical three-dimensional MR image atlas was used as a deformable template and automatically matched to three-dimensional MR images of 10 individuals (five healthy and five schizophrenic subjects). A subvolume containing the hippocampus was defined by using 16 landmarks that constrained the automated search for hippocampal boundaries. Transformation of the hippocampus template was automatically performed by using global pattern matching through a sequence of low-then high-dimensional translations, rotations, and scalings.

RESULTS

The average test-retest volume difference measured with the automatic method was 3.1%, compared with the manual test-retest difference of 7.1%. Correlation between automated and manually determined volumes demonstrated the validity of the automated technique (intraclass correlation coefficient = .86).

CONCLUSION

The automated method estimates hippocampal volumes with less variability (ie, lower variance) than that of manual out-lining.

Interactive segmentation of cerebral gray matter, white matter, and CSF: photographic and MR images

Digital photography of postmortem brain slices was compared with magnetic resonance imaging (MRI) for morphological analysis of human brain atrophy. In this study, we used two human brains obtained at autopsy: a cognitively defined nondemented control (70-yr-old male) and a demented Alzheimer's disease (AD) subject (82-yr-old female). For each of two brains, interactive manual image segmentation was performed by two observers on two image sets: (a) four coronal T1-weighted MR images (5 mm slices); and (b) four digitized photographic images from comparable rostrocaudal levels. Microcomputer image analysis software was used to measure the areas of three segmented cerebral compartments--gray matter (GM), white matter (WM) and CSF--for both image types. Resegmentation error was defined as the absolute difference between the areas derived from two segmentation trials divided by the value from trial 1 and multiplied by 100. This yielded the percent difference between the area measurements from the two trials. We found intra-observer agreement was better (error rates 1-18%) than inter-observer agreement (3-70%) with best agreement for WM and least for CSF, the smallest object class. MRI overestimated GM area relative to digitized photographs in the control but not the AD brain. The results define limitations of manual image segmentations and comparison of MRI with pathologic section photographic images.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part III. Reliability of a standardized MRI evaluation of Alzheimer's disease

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) has developed procedures for standardized imaging and reporting of magnetic resonance (MR) findings in Alzheimer's disease (AD) for use by neuroradiologists in multiple medical centers using a variety of MR equipment and field strengths. After initial pretesting, we revised the protocol, expanded the summary rating scale to seven points, and added more illustrations. Fourteen participating neuroradiologists evaluated 28 MR scans of elderly patients, giving us the basis for judging interrater agreement. We obtained acceptable intraclass correlations (greater than 0.79) for rating the size of the lateral and third ventricles and the temporal horn. Less satisfactory intraclass correlations occurred when rating other areas, including (1) global atrophy of the brain (0.70); (2) dilatation of the sulci of the temporal lobe (0.66); (3) frequency, location, and severity of white matter lesions (0.77); (4) sylvian fissure enlargement (0.70); and (5) cerebral sulcal dilatation (0.64). We also saw considerable variation in the reporting of cortical and lacunar infarcts. Despite careful design of the rating methodology and readings by experienced neuroradiologists, we did not find satisfactory interrater agreement for interpreting MR findings in elderly subjects. These findings may explain the difficulties encountered in applying similar subjective rating techniques that meet with success at one institution to multicenter studies. More objective and reproducible procedures are needed for interpretation of neuroimaging findings of AD in multicenter studies.

Pre- and postcontrast MR studies in tuberous sclerosis

The MR findings in eight patients with intracranial manifestations of tuberous sclerosis are reported. There were subependymal lesions in seven patients and peripheral lesions (i.e., cortical and subcortical) in all patients. All lesions were supratentorial. We emphasize two findings that have not been previously stressed. The signal intensity patterns of the subependymal lesions varied from patient to patient, but in all patients receiving intravenous contrast medium, the majority of these lesions enhanced. Although this finding may signify early breakdown of the blood-brain barrier with potential for lesion growth, the high frequency of enhancement challenges earlier concepts of equating this phenomenon with existence of actively growing giant cell astrocytomas. The peripheral lesions were more numerous than subependymal lesions. These lesions were nearly always hyperintense in the proton density weighted and T2-weighted images. Most notable is the fact that, in half of the lesions, signal intensity was also elevated in the T1-weighted image, an observation that has not been emphasized in previous reports. Although not pathologically confirmed this signal pattern may represent early stages of calcification within these lesions. Finally, unlike subependymal lesions, none of the peripheral lesions showed contrast enhancement.

High-intensity basal ganglia lesions on T1-weighted MR images in neurofibromatosis

Basal ganglia lesions, characterized on MR by increased signal intensity on T1-weighted images, were observed in seven patients with documented neurofibromatosis. These lesions most often involved the globus pallidus and internal capsules in a bilateral and symmetric fashion, and extended across the anterior commissure resulting in a "dumbbell" configuration. Smaller and less prominent foci of increased signal also were present on corresponding T2-weighted images. These lesions did not exhibit mass effect, edema, or enhancement with gadolinium-DTPA. They were not visible on CT (performed in two patients) and demonstrated no progression during a 2-year interval in three patients. Their signal characteristics and morphology suggest that they represent heterotopias containing Schwann cells and/or melanin deposits. Migrational abnormalities of these neural crest derivatives are known to occur in neurofibromatosis, and the presence of such heterotopias has been documented pathologically in patients with this disorder. While recent reports discuss foci of increased signal intensity on T2-weighted MR images in patients with neurofibromatosis, signal abnormalities on T1-weighted images have not yet been described. When lesions characterized by similar signal as well as morphologic characteristics are encountered on MR, the diagnosis of neurofibromatosis should be considered.

Focal signal-intensity variations in the posterior internal capsule: normal MR findings and distinction from pathologic findings

Cranial magnetic resonance (MR) imaging studies in 117 control patients were reviewed to evaluate for focal signal-intensity variations in the posterior internal capsule. Rounded foci of increased signal intensity were found near the junction of the posterior limb and retrolenticular portion of the internal capsule on axial T2-weighted images in 56% of patients imaged at 1.5 T and in 50% imaged at 0.5 T. Corresponding hypointense foci were found on T1-weighted images in 64% of control patients imaged at 1.5 T and in 69% imaged at 0.5 T. With all sequences, the foci were homogeneous and well defined, without mass effect, and bilaterally symmetric. Comparison was made with MR imaging studies in 32 patients with pathologic involvement of the posterior internal capsule region. Symmetric morphology and signal intensity, sharply defined margins, confinement to a characteristic location, signal intensity approximating that of cortical gray matter on T2-weighted images, and isointensity or hypointensity on spin-density-weighted images appear to characterize normal posterior capsular foci and distinguish them from foci of pathologic lesions. A region that stained less intensely than the surrounding internal capsule was noted in tissue blocks from two normal brain specimens, corresponding in morphology and position to the signal-intensity changes seen on MR images. The properties of this focus suggest that it may represent fibers of the parietopontine tract.

High-intensity basal ganglia lesions on T1-weighted MR images in neurofibromatosis

Basal ganglia lesions, characterized on MR by increased signal intensity on T1-weighted images, were observed in seven patients with documented neurofibromatosis. These lesions most often involved the globus pallidus and internal capsules in a bilateral and symmetric fashion, and extended across the anterior commissure resulting in a "dumbbell" configuration. Smaller and less prominent foci of increased signal also were present on corresponding T2-weighted images. These lesions did not exhibit mass effect, edema, or enhancement with gadolinium-DTPA. They were not visible on CT (performed in two patients) and demonstrated no progression during a 2-year interval in three patients. Their signal characteristics and morphology suggest that they represent heterotopias containing Schwann cells and/or melanin deposits. Migrational abnormalities of these neural crest derivatives are known to occur in neurofibromatosis, and the presence of such heterotopias has been documented pathologically in patients with this disorder. While recent reports discuss foci of increased signal intensity on T2-weighted MR images in patients with neurofibromatosis, signal abnormalities on T1-weighted images have not yet been described. When lesions characterized by similar signal as well as morphologic characteristics are encountered on MR, the diagnosis of neurofibromatosis should be considered.

Water content and water structure in CT and MR signal changes: possible influence in detection of early stroke

Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p less than .01) and spin-spin (T2) relaxation time (r = .91, p less than .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.

MR imaging in infra-, para- and retrosellar mass lesions

To determine its diagnostic efficacy in infra-, para- and retrosellar mass lesions magnetic resonance (MR) imaging was compared with computed tomography (CT) in 39 cases. Thirty-six lesions were imaged with a Siemens 0.5 T superconducting unit, three with a 1.5 T unit. CT scanning was performed with third generation equipment. There were 28 neoplasms including eight pituitary adenomas with infrasellar extension, four meningiomas, four extensions from regional malignancies, three chordomas, three juvenile angiofibromas, three medial temporal gliomas, and one each of neuroma, epidermoid and metastasis. Eleven non-neoplastic masses included four vascular anomalies, three cholesterol granulomas, two arachnoid cysts, one sphenoid mucocele and one mixed sclerosing bone dystrophy with mass-like thickening of basisphenoid and basiocciput. While MR and CT were equally sensitive (100%), MR was superior in further delineating and characterizing a lesion. MR showed normal or abnormal blood vessels better than CT, and revealed changes of compact bone often quite satisfactorily. Effects on the brain parenchyma or CSF and airspaces were consistently well demonstrated. Provided absence of contraindications MR should be the primary radiologic screening test in suspected mass lesions of above location.

The effect of hemodynamically significant carotid artery disease on the hemodynamic status of the cerebral circulation

Although the presence of a hemodynamically significant carotid artery lesion is commonly used as an indicator of impaired cerebral circulation, the effect of such lesions on cerebral perfusion pressure and cerebral blood flow has never been determined accurately. We used positron emission tomography (PET) to study 19 patients with unilateral hemodynamically significant carotid artery disease (greater than 66% diameter reduction) and no evidence of cerebral infarction. According to PET measurements in the cerebral hemisphere distal to the lesion, 7 patients had normal cerebral hemodynamics, 8 had reduced perfusion pressure with normal blood flow, and 4 had reduced blood flow. Neither the percent stenosis nor the residual lumen diameter in the carotid artery was a reliable indicator of the hemodynamic status of the cerebral circulation. However, a significant relationship was found between the PET measurements of cerebral hemodynamics and the arteriographic circulation pattern (p = 0.006). The role of hemodynamic factors in the pathogenesis and treatment of cerebrovascular disease cannot be determined from the severity of carotid artery disease alone.

In vivo delineation of facial fractures: the application of advanced medical imaging technology

Advanced medical imaging technology has important advantages over ordinary skull radiography and conventional tomography in the study of facial fractures. Computer-based imaging methods, including computed tomography and magnetic resonance imaging, provide exquisite soft tissue contrast, superior geometrical accuracy, and freedom from overlapping shadows, and permit computer reformating of images. The advantages of computer-based medical imaging for study of facial fractures are identified and illustrated with computed tomographs. Three-dimensional surface reconstruction methods applied to serial high-resolution computed tomography scans of facial fractures are described and evaluated.

The skeletal anatomy of mandibulofacial dysostosis (Treacher Collins syndrome)

Three-dimensional osseous surface re-formation imaging from CT scans was used to examine the facial skeletons of 14 living patients with mandibulofacial dysostosis. Partial to complete aplasia of the zygomatic process of the temporal bone, mild hypoplasia to aplasia of the frontal process of the zygoma, antimongoloid slant of the transverse orbital axis, and hypoplasia of the medial pterygoid plates and muscles are common to all patients examined. Deformities of the zygoma, zygomatic process of the frontal bone, mandible, and lateral pterygoid plates and muscles vary from minimal to severe, including aplasia. The body of the zygoma is the least affected part of the bone. Right-left asymmetry characterizes these deformities in all patients. The most consistent skeletal aplasia (cleft) in mandibulofacial dysostosis involves the zygomatic process of the temporal bone rather than the zygoma itself.

Projection angiograms of blood labeled by adiabatic fast passage

A surface coil on the neck causes adiabatic fast passage in blood as it flows by through a magnetic field gradient. This allows separation of blood and stationary tissue images of the head. Coronal and sagittal images of a volunteer are presented showing the vertebral and common, internal and external carotid arteries in projection views.

Correction of positron emission tomography data for cerebral atrophy

Because positron emission tomography (PET) provides measurements per unit volume of intracranial contents, these measurements may be affected by the inclusion of metabolically inactive CSF spaces in the volume in which they are made. Thus, PET measurements of CBF and metabolism may be artifactually lowered in normal aging and dementia, which are both associated with significant brain atrophy. We describe a method to correct global PET data, averaged over several tomographic slices, for cerebral atrophy by using measurements of CSF space volume obtained with quantitative x-ray computed tomography. The importance of making such a correction is demonstrated using PET measurements of CBF and oxygen metabolism obtained in normal young, normal elderly, and demented subjects.

Hydrocephalus and mental retardation in craniosynostosis

We prospectively studied craniosynostosis, regardless of neurologic status, by cranial computed tomography or psychometric testing in 56 children. None of the 27 children with simple craniosynostosis (single or multiple suture involvement) had evidence of hydrocephalus on CT scan. Of the 24 patients with simple craniosynostosis who underwent psychometric testing, 17 were of average intelligence; six were in the low average range. The single mentally retarded child had a history of severe perinatal asphyxia. Hydrocephalus occurred more frequently (five of 23 cases) in children with complex craniosynostosis syndromes, including Pfeiffer syndrome, Crouzon syndrome, and kleeblattschädel deformity. More striking than hydrocephalus, however, was the finding of dysmorphic ventricular dilation in eight patients, including the three children with Apert syndrome and four with Crouzon syndrome. Nineteen of the 25 children with complex craniosynostosis syndromes receiving psychometric testing were of normal intelligence. Four children with borderline normal intelligence had either hydrocephalus or ventricular dilation. The two children with mental retardation were sisters with Crouzon syndrome whose family included other retarded individuals. This study indicates that the incidence of hydrocephalus and mental retardation in craniosynostosis is lower than reported previously.

The moyamoya syndrome associated with irradiation of an optic glioma in children: report of two cases and review of the literature

We report two cases of the moyamoya syndrome which became clinically apparent after irradiation of an optic glioma during childhood. A summary of 14 cases of this syndrome following irradiation of intracranial tumors is also presented. Nine of these cases were optic gliomas; five were found in children with neurofibromatosis, another disorder that has a strong association with the moyamoya syndrome. The effectiveness of irradiation of optic gliomas in childhood is not definitely established. The possibility of inducing serious vascular disease is a further reason for caution when considering irradiating these tumors.

Utilization characteristics of a superconductive MR system undergoing initial clinical trial

The authors describe their initial 7 month experience with magnetic resonance (MR) imaging using a superconductive MR system. Factors affecting system utilization were scheduled and unscheduled downtime, specific system characteristics, and physician experience with the new technology. Technical improvements that reduced the duty cycle and radiologist experience in tailoring examinations have improved patient throughput by reducing the average patient study time by approximately 40% during the 7 month survey. These considerations have important economic consequences for patients and operators of MR equipment.

Multispectral analysis of magnetic resonance images

Magnetic resonance (MR) imaging systems produce spatial distribution estimates of proton density, relaxation time, and flow, in a two dimensional matrix form that is analogous to that of the image data obtained from multispectral imaging satellites. Advanced NASA satellite image processing offers sophisticated multispectral analysis of MR images. Spin echo and inversion recovery pulse sequence images were entered in a digital format compatible with satellite images and accurately registered pixel by pixel. Signatures of each tissue class were automatically determined using both supervised and unsupervised classification. Overall tissue classification was obtained in the form of a theme map. In MR images of the brain, for example, the classes included CSF, gray matter, white matter, subcutaneous fat, muscle, and bone. These methods provide an efficient means of identifying subtle relationships in a multi-image MR study.

Computed tomography in chronic seizure disorder caused by glioma

Since the introduction of computed tomography (CT) in 1974, 137 patients underwent cortical resection for intractable epilepsy. The CT scans of 32 of these patients demonstrated an isolated calcified or hypodense lesion of unknown origin. The mean interval from onset of the seizure disorder to surgery was 11 years. The referring physicians frequently considered these lesions to be of nonneoplastic origin, which usually delayed surgical management. Twenty-six of the 32 patients, however, proved to have a cerebral glioma, seven showing anaplastic changes. Because the majority of these patients were found to have a neoplasm and especially because the CT scan could not distinguish between a well-differentiated glioma and those with anaplastic changes, we recommend early surgical treatment in patients with chronic seizure disorders who are found to have an isolated lesion of unknown origin on CT scan.

Predictive features in mild senile dementia of the Alzheimer type

Forty-three subjects with mild senile dementia of the Alzheimer type, diagnosed and staged by clinical research criteria, were studied with clinical, psychometric, EEG, visual evoked potential, and CT measures. During the 12 months following entry into the study, 21 subjects progressed to moderate or severe dementia, 21 remained mild, and one was lost to follow-up. Many of the clinical and psychometric measures of impairment were predictive of the progression to moderate or severe dementia. Electrophysiologic and CT measures were not. In a discriminant function analysis, the scores on two measures (the digit symbol subtest of the Wechsler Adult Intelligence Scale and an Aphasia Battery) correctly predicted the stage of dementia 1 year later in 95% of the subjects.

Brain parenchymal density measurements by CT in demented subjects and normal controls

Parenchymal density measurements of 14 regions of gray and white matter from each cerebral hemisphere were made from CT scans of 25 subjects who had varying degrees of dementia as measured by a global Clinical Dementia Rating, and also from CT scans of 33 normal control subjects. There were few significant differences between the two groups in the mean density value for each of the regions examined, although several individual psychometric tests did correlate with density changes. Moreover, for six regions in the cerebral cortex, and for one region in the thalamus of each hemisphere, we found no significant correlation between the gray-white matter density difference and dementia. There was, however, a loss of the discriminability between the gray and white matter with an increase in the size of the ventricles. These findings may be attributed to the loss of white matter volume.

The longitudinal orbital CT projection: a versatile image for orbital assessment

The newer generation of CT scanners allows reconstruction of images in coronal, sagittal, and oblique planes from a single set of axial scans. These computer-generated images are described as reformatted. We have found an oblique image reformatted along the plane connecting the apex of the orbit and the center of the globe to be especially useful in assessing orbital disorders. We have named this image the longitudinal orbital projection. This projection allows direct visualization of the inferior rectus muscle and orbital floor in acute and old orbital trauma. With the image produced life size, direct measurements of enophthalmos and proptosis can be made preoperatively and postoperatively, thereby facilitating planning and follow-up. The projection is also useful in combination with other planes of reformation for the localization of tumors. The longitudinal orbital projection is now a routine part of the CT examination of the orbit in our institution. Whereas it already has become an invaluable aid in the diagnosis and follow-up of congenital and acquired orbital lesions, the longitudinal orbital projection promises to clarify the effects of trauma on the inferior rectus muscle and globe position.

Aging, dementia, and brain atrophy: a longitudinal computed tomographic study

Studies involving linear measurements of ventricular size and a volumetric measurement of the cerebrospinal fluid (CSF) space were performed on elderly subjects with mild dementia of the Alzheimer type and on age-matched controls. Forty-five subjects were studied twice at a 1 year interval; linear ventricular measurements showed not only a greater degree but a more rapid evolution of brain atrophy in individuals with mild dementia as compared with controls. An additional 12 normal subjects were studied twice over a 1 year period with volumetric estimates of the CSF space, which demonstrated development of significant brain atrophy within 1 year, while linear measurements on the same scans showed no significant change. The volumetric method is regarded as a more sensitive indicator of brain volume and is potentially useful in further studies in dementia.

Lateral disk herniation into the lumbar intervertebral foramen: differential diagnosis

Lateral disk herniation into the intervertebral foramen if not recognized may result in a negative surgical exploration. The condition is readily recognized by computed tomography (CT), which demonstrates a soft-tissue mass in the intervertebral foramen, focal protrusion of the posterolateral margin of the disk into the foramen, absence of dural sac deformity, and occasionally the presence of calcium or gas in the intervertebral foramen. The differential diagnosis includes metastatic neoplasm, primary neoplasm, and conjoined root sheath anomaly. Features that enable CT differentiation of these conditions from lateral disk herniation are described. Myelography is useful in the identification of a conjoined root sheath.

Brain atrophy in dementia judged by CT scan ranking

In order to further investigate the relationships of brain atrophy, age, and dementia, computed tomographic (CT) scans on two groups of subjects aged 65-80 years were rank-ordered according to ventricular and sulcal size. Each group contained subjects with mild senile dementia of the Alzheimer type (SDAT) and matched controls. In both experiments there was a strong correlation between these rank orders, ventricular size, and the clinical dementia rating. There was also a weaker but significant correlation between rank ordering and sulcal size. This suggests that brain atrophy in excess of that normal for age alone occurs in early SDAT.

Evaluation of the suprasellar cistern by computed tomography

The normal suprasellar cistern is a five- or six-pointed, starshaped, fluid-filled structure as demonstrated by computerized axial tomography (CAT). At various levels the normal suprasellar cistern contains the major intracranial vessels and their anastomotic channels, the optic nerves, chiasm, and infundibular stalk. The existence of lesions, either intrinsic structures of or extrinsic structures contiguous to the suprasellar cistern can be detected by their effect on the normal anatomy of the suprasellar cistern or by filling defects produced when studied with metrizamide cisternography.

Volumetric measurements of the cerebrospinal fluid spaces in demented subjects and controls

Forty-seven subjects 65 to 80 years of age, of whom 20 were demented and 27 were normal, were studied by computed tomography. Volumetric indices of ventricular (V%) and sulcal size (S%) were determined by pixel counts without knowledge of clinical status. V% was 5.30 (+/- 1.92) for the controls and 10.46 (+/- 4.78) for the demented subjects. S% was 6.14 (+/- 2.51) for the controls and 10.61 (+/- 3.32) for the demented subjects. In each case, differences between the two groups were significant (P less than 0.0001). When a subsample of 29 scans were analyzed using linear and volumetric measurements, the linear measurements showed less pronounced differences between the demented subjects and the controls. These findings explain the conflicting results of different investigators concerning variations in ventricular and sulcal size in dementia and normal aging.

Surgical anatomy of the craniofacial dysostoses: insights from CT scans

Six patients with midface retrusion secondary to craniofacial dysostoses were evaluated by computer assisted tomography (CT) before and after surgery. Computer reformated life-size images were generated for linear measurements and for assessing the encroachment upon the orbit of the anterior and middle cranial fossae, the lateral displacement of the ethmoids, and the retrusion of the maxilla. Dynamic ocular CT demonstrated alterations in the angle of divergence of the optic nerve with globe movement which made measurements of that angle an unreliable assessment of hypertelorism. Surgical separation of the midface from the base of the skull was shown to be a fracture within the palatine bones between its horizontal and pyramidal processes. The integrity of the antral walls was preserved in all patients, in contrast to the comminution seen with traumatic LeFort III fractures. CT evaluation of patients with midface retrusion has further defined the nature of their anomalies, facilitated operative planning, demonstrated the osteotomies in vivo and reduced radiation exposure.

Functional anatomy of the cerebral cortex by computed tomography

The authors describe the morphological characteristics that allow recognition of the individual computed tomography slice and determine its sequence in the series. In addition, each slices is "assembled" by defining the different cortical gyri, sulci, and cortical functional areas (based on Brodmann's maps). This work lays the foundation for correlative studies of location of lesions and the clinical picture.

Angiography in the diagnosis and management of extracranial vascular lesions of the head and neck

The angiographic features of various lesions of the head and neck are presented. Angiographically, cavernous hemangiomas display large venous lakes with calcified phleboliths. Arteriovenous malformations reveal massive tumor stain with well delineated feeding vessels from multiple systems. Chemodectomas and juvenile nasopharyngeal angiofibromas are clearly vascular with homogenous tumor staining in the capillary phase. Angiography of cavernous hemangioma, AVM, chemodectoma, and angiofibroma is diagnostic and may preclude the need for tissue biopsy. Angiographically neurilemmomas are less vascular with non-homogenous tumor stain. Carcinomas are typically avascular. The use and benefits of arterial embolization in the management of these lesions is presented.

Glomus jugulare and vagale

The therapeutic results in 72 patients with glomus jugulare and nine with glomus vagale have indicated a surgical cure rate of 80% in the former and 100% in the latter. Radiotherapy demonstrated a 65% tumor response rate and a 25% cure rate histologically and clinically. Embolization with Gelfoam beads in seven patients resulted in diminished tumor size and arterial circulation from the external carotid system. However, in all cases the tumor persisted. Embolization diminished intraoperative bleeding. Nevertheless, the use of embolization as a palliative modality demonstrated significant symptomatic relief in aged, debilitated patients and in all patients with large inoperable glomus jugulare tumors.

Computerized tomography in the evaluation of head and neck lesions

The development of computerized tomography (CT) has been called the most important contribution to medical diagnostic techniques since Roentgen discovered the X-ray in 1895. Over the past several years, the growth in technology and literature concerning computerized tomography has been rapid. CT is useful in evaluation of head and neck lesions such as lesions of the paranasal sinuses, the nasopharynx, base of skull, the larynx and neck areas. It is also useful in evaluation of intracranial complications of head and neck diseases. CT has added the horizontal plane in the evaluation of these lesions. The ease of obtaining CT scans and its non-invasiveness are advantages. The most important single feature of CT that distinguishes it from other radiographic techniques is the capability of imaging of soft tissue. CT demonstration of bone destruction is not superior to polytomography. The transaxial orientation of CT planes seems to be particularly useful in certain locations such as the pterygopalatine fossa. CT is an additional diagnostic tool, but it has limitations of other radiologic techniques in differentiating histologic types. In this series, one case of ethmoiditis resembled carcinoma. In another, radiation necrosis was indistinguishable from intracranial metastasis. As technology advances in the use of CT, its application in head and neck lesions will be increasing.

The effect of size, histologic elements, and water content on the visualization of cerebral infarcts

We correlated the radiologic and pathologic examination of 13 human brains, analyzing the size, different histologic elements, and water content in 40 ischemic and hemorrhagic infarcts. Acute infarcts appear in the computerized cranial tomographic (CT) image as low density areas due to high content of fluid, however, a histological-chemical correlation is not concomitant. The addition of blood in hemorrhagic infarcts may result in a normal CT image. Subacute infarcts appear as low density areas, with lower attenuation values due to the presence of large amounts of lipids. Subacute lesions with prominent mineral deposits may be negative on CT scan. Chronic infarcts also appear as low density areas due to cavitation and residual fats. Attenuation values are slightly higher than those of subacute infarcts, possibly due to gliosis. Infarcts smaller than 2 cm in diameter are usually not visualized.