Cranial Magnetic Resonance Imaging Examination Research Articles

Globus pallidus/putamen T1WI signal intensity ratio in grading and predicting prognosis of neonatal acute bilirubin encephalopathy.

This study sought to investigate the relationship between the globus pallidus/putamen T1 weighted image (T1WI) signal intensity ratio (G/P ratio) and the acute bilirubin encephalopathy (ABE) in neonates, and to develop a new strategy for the grading and prognosis of ABE based on the G/P ratio. A total of 77 full-term neonates with ABE were scored according to bilirubin-induced neurological dysfunction and divided into mild, moderate, and severe groups. Cranial magnetic resonance imaging examinations were performed and the G/P ratio was recorded. The follow-up reexaminations were carried out at 6 months, 1 year, and 2 years after the initial examination. The neonates were then divided into two groups, the good prognosis group and the kernicterus spectrum disorder (KSD) group, according to the evaluation of Gesell Developmental Schedules and Brainstem Audio Electric Potential at 6 months. The differences of G/P ratios were statistically significant, not only among the mild, moderate, and severe ABE groups for the initial examinations but also between the KSD and the good prognosis groups for the follow-up reexaminations. Therefore, the ABE grading model and prognosis predicting model could be established based on the G/P ratio. In the KSD group, the area under the receiver operating characteristic curve of the G/P ratio-based predicting model was 93.5%, the optimal critical point was 1.29, the sensitivity was 88.2%, and the specificity was 93.3%. The G/P ratio can be used as an indicating parameter for both the clinical grading of neonatal ABE and the assessment of neonatal ABE prognosis. Specifically, the G/P ratio greater than 1.29 indicates a KSD of neonatal ABE.

Clinical and imaging characteristics of optic nerve tumors as the differencial diagnosis of optic neuritis

Objective: To investigate the clinical and imaging features of optic nerve tumors that require differential diagnosis from optic neuritis. Methods: A retrospective case series study was conducted. Clinical data of patients diagnosed with optic nerve tumors from January 2017 to December 2021 at the Second Affiliated Hospital of Zhejiang University School of Medicine were collected. A total of 29 patients (39 eyes) with clinical and magnetic resonance imaging (MRI) findings similar to optic neuritis or optic neuropathy were included. There were 15 cases of optic nerve sheath meningioma (ONSM) (17 eyes), 4 cases of optic nerve glioma (ONG) (5 eyes), and 10 cases of infiltrative optic nerve lesions (ION) (17 eyes). All patients underwent best-corrected visual acuity (BCVA), anterior and posterior segment examinations, visual field examination, and orbital or cranial MRI examination. Patient data were observed and analyzed, treatment and follow-up information were recorded, and clinical and imaging features were summarized and compared with those of optic neuritis or optic neuropathy. Results: Among the 29 patients with optic nerve tumors, 10 were male and 19 were female, with an average age of (43.3±13.8) years and a range of 11 to 72 years. The follow-up time was 6.8 (2.0, 11.0) months, with a range of 1 to 33 months. Sixteen patients (21 eyes) with optic nerve tumors were initially misdiagnosed as having acute optic neuritis and showed poor response to steroid treatment. Of these, 9 cases (11 eyes) were ONSM, 4 cases (6 eyes) were ION, and 3 cases (4 eyes) were ONG. The diagnostic delay time was 7.1 (1.5, 12.0) months, with a range of 1 to 24 months. The main clinical symptoms of all affected eyes were acute vision loss in 23 eyes, slow vision loss in 5 eyes, transient blackouts in 4 eyes, and no obvious visual symptoms in 7 eyes. The median BCVA of all affected eyes was 0.1, ranging from light perception to 1.0. Fundus examination results showed optic disc edema in 34 eyes and normal optic disc in 5 eyes among the 39 eyes with optic nerve tumors. A total of 27 patients (33 eyes) completed visual field examinations, which revealed an enlarged physiological blind spot in 11 eyes, a concentric or tubular visual field contraction in 8 eyes, a diffuse decrease in light sensitivity in 7 eyes, an arcuate scotoma in 4 eyes, and a normal visual field in 3 eyes. All affected eyes completed orbital or cranial MRI examinations, which showed mild optic nerve thickening in 22 eyes, significant thickening in 6 eyes with distortion, and no significant thickening in 6 eyes. Contrast-enhanced T1-weighted imaging (T1WI) MRI showed optic nerve parenchymal thickening in 5 eyes, all of which were ONG, and 2 of them had optic nerve parenchymal enhancement. Optic nerve sheath thickening and enhancement without optic nerve parenchymal thickening or enhancement were observed in 28 eyes, including 17 eyes of ION and 11 eyes of ONSM. There were 6 eyes with no obvious optic nerve thickening, which were all ONSM, showing mild or significant thickening and enhancement of the optic nerve sheath without optic nerve parenchymal thickening or enhancement. Conclusions: Optic nerve tumors can present with ophthalmic clinical features similar to optic neuritis, such as optic disc edema, and demonstrate MRI findings that resemble those of optic neuritis. Therefore, differentiation between the two is crucial, based on differences in their natural course and response to steroid therapy.

Neuronal intranuclear inclusion disease tremor-dominant subtype: A mimicker of essential tremor.

The GGC repeat expansion in the NOTCH2NLC gene has been identified as the genetic cause of neuronal intranuclear inclusion disease (NIID). Recently, this repeat expansion was also reported to be associated with essential tremor (ET). However, some patients with this repeat expansion, initially diagnosed with ET, were eventually diagnosed with NIID. Therefore, controversy remains regarding the clinical diagnosis of these expansion-positive patients presenting with tremor-dominant symptoms. This study aimed to clarify the clinical phenotype in tremor-dominant patients who have the GGC repeat expansion in the NOTCH2NLC gene. We screened for pathogenic GGC repeat expansions in 602 patients initially diagnosed with ET and systematically re-evaluated the clinical features of the expansion-positive probands and their family members. Pathogenic GGC repeat expansion in the NOTCH2NLC gene was detected in 10 probands (1.66%). Seven of these probands were re-evaluated and found to have systemic areflexia, cognitive impairment, and abnormal nerve conduction, which prompted a change of diagnosis from ET to NIID. Three of the probands had typical hyperintensity in the corticomedullary junction on diffusion-weighted imaging. Intranuclear inclusions were detected in all four probands who underwent skin biopsy. The NIID tremor-dominant subtype can be easily misdiagnosed as ET. We should take NIID into account for differential diagnosis of ET. Systemic areflexia could be an important clinical clue suggesting that cranial magnetic resonance imaging examination, or even further genetic testing and skin biopsy examination, should be used to confirm the diagnosis of NIID.

Exome first approach to reduce diagnostic costs and time \u2013 retrospective analysis of 111 individuals with rare neurodevelopmental disorders

This single-center study aims to determine the time, diagnostic procedure, and cost saving potential of early exome sequencing in a cohort of 111 individuals with genetically confirmed neurodevelopmental disorders. We retrospectively collected data regarding diagnostic time points and procedures from the individuals’ medical histories and developed criteria for classifying diagnostic procedures in terms of requirement, followed by a cost allocation. All genetic variants were re-evaluated according to ACMG recommendations and considering the individuals’ phenotype. Individuals who developed first symptoms of their underlying genetic disorder when Next Generation Sequencing (NGS) diagnostics were already available received a diagnosis significantly faster than individuals with first symptoms before this cutoff. The largest amount of potentially dispensable diagnostics was found in genetic, metabolic, and cranial magnetic resonance imaging examinations. Out of 407 performed genetic examinations, 296 (72.7%) were classified as potentially dispensable. The same applied to 36 (27.9%) of 129 cranial magnetic resonance imaging and 111 (31.8%) of 349 metabolic examinations. Dispensable genetic examinations accounted 302,947.07€ (90.2%) of the total 335,837.49€ in potentially savable costs in this cohort. The remaining 32,890.42€ (9.8%) are related to non-required metabolic and cranial magnetic resonance imaging diagnostics. On average, the total potentially savable costs in our study amount to €3,025.56 per individual. Cost savings by first tier exome sequencing lie primarily in genetic, metabolic, and cMRI testing in this German cohort, underscoring the utility of performing exome sequencing at the beginning of the diagnostic pathway and the potential for saving diagnostic costs and time.

Quantitative analysis of healthy olfactory sulcus depth, olfactory tract length and olfactory bulb volume in the paediatric population: a magnetic resonance study.

The aim of this study was to determine the normal reference values for olfactory sulcus depth, olfactory tract length and olfactory bulb volume in the paediatric population with routine magnetic resonance imaging (MRI) and determine the relationship, if any, between these values and patient sex and age. Ninety patients with a median age of 8 years (age range: 3-17 years), consisting of 45 males and 45 females with normal brain MRI scans were evaluated. The patients were divided into three subgroups based on age range, with n = 30 per subgroup; group 1: young children (3-6 years), group 2: children (7-11 years) and group 3: adolescents (12-17 years). In the cranial MRI examination of all groups, the right, left and total olfactory bulb volume values were measured in mm3, the right and left olfactory tract length values and the right and left olfactory sulcus depth values were calculated manually in mm. Demographic data including sex and age were recorded. There was no significant difference between the age groups in terms of sex. Right-left olfactory sulcus depth; right-left olfactory tract length and right-left total olfactory bulb volume values increased significantly when they are compared in terms of age groups (p < 0.0001, = 0.028; < 0.0001, < 0.0001; < 0.0001, < 0.0001; < 0.0001, respectively). There was no significant difference between right and left olfactory tract length and olfactory bulb volumes in all groups (p = 0.792 and p = 0.478), but the right olfactory sulcus depth was significantly larger than the left (p = 0.003). Especially as the age progresses, olfactory tract length and olfactory bulb volume dimensions of olfactory nerve and olfactory sulcus depth should be checked during diagnosis of respective illnesses in paediatric population.

Application of magnetic resonance imaging-compatible incubator in cranial magnetic resonance imaging for neonates: a multicenter prospective randomized clinical trial

Objective To study the safety and efficacy of magnetic resonance imaging (MRI)-compatible incubator in cranial MRI examination for neonates. Methods A total of 120 neonates who were hospitalized in three hospitals and needed to undergo MRI examination were randomly divided into a control group and an experimental group, with 60 neonates in each group. The neonates in the experimental group were transferred with MRI-compatible incubator and underwent cranial MRI examination inside the MRI-compatible incubator, and those in the control group were transferred using a conventional neonatal transfer incubator and then underwent MRI examination outside the incubator. The two groups were compared in terms of the primary efficacy index (total examination time), secondary efficacy indices (times of examination, MRI completion rate on the first day of use), and safety indices (incidence rate of adverse events and vital signs). Results There were no significant differences in total examination time, times of examination, and MRI completion rate on the first day of use between the two groups (P > 0.05). There were also no significant differences between the two groups in the incidence rate of adverse events and vital signs such as respiratory rate, heart rate, blood pressure, and blood oxygen saturation rate at different time points before and after examination (P > 0.05). Conclusions The use of MRI-compatible incubator does not significantly shorten the examination time of cranial MRI, but it does provide a relatively stable environment for examination with acceptable safety. There is a need for further studies with a larger population.

Application of vacuum stretcher combined with feeding in cranial magnetic resonance imaging examination for neonates: a prospective randomized controlled study

To study the effect and safety of vacuum stretcher combined with feeding in cranial magnetic resonance imaging (MRI) examination for neonates. A prospective study was performed for the neonates with hyperbilirubinemia, with a gestational age of >34 weeks and stable vital signs, who needed cranial MRI examination and did not need oxygen inhalation hospitalized in the Department of Neonatology, Children's Hospital of Zhejiang University School of Medicine, from September to November, 2019. The neonates were randomly divided into a vacuum stretcher combined with feeding group and a conventional sedation group. Vital signs were monitored before, during, and after MRI examination. The success rate of MRI procedure was recorded. A total of 80 neonates were enrolled in the study, with 40 neonates in the vacuum stretcher combined with feeding group and 40 in the conventional sedation group. The vacuum stretcher combined with feeding group had a significantly higher success rate of MRI procedure than the conventional sedation group (P<0.05). As for the neonates who underwent successful MRI examination, the fastest heart rate after examination in the vacuum stretcher combined with feeding group was significantly lower than that in the conventional sedation group (P<0.05), while there were no significant differences between the two groups in transcutaneous oxygen saturation, respiratory rate, and body temperature before and after MRI examination (P>0.05). No complications, such as apnea, acute allergic reactions, and malignant fever, were observed. Vacuum stretcher combined with feeding can improve the success rate of MRI procedure and reduce the use of sedatives, and meanwhile, it does not increase related risks.

Decreased olfactory bulb volume in patients with restless legs syndrome

Objective: Restless legs syndrome (RLS) is a chronic progressive movement disorder with a pathophysiology that is still not fully known. In recent years, a growing number of studies have suggested that the disease may be of a neurodegenerative nature. We aimed to measure olfactory bulb volume (OBv) in RLS using cranial magnetic resonance imaging (MRI). Methods: The study included 24 patients (11 males, 13 females) aged 18-60 years who were diagnosed with idiopathic RLS according to the criteria of the Restless Legs Syndrome Study Group (IRLSSG) 2014 and followed up by our neurology clinic, and 26 age-matched controls (12 males, 14 females). In the cranial MRI examination of both groups, the right, left and total OBv values were manually calculated in mm3. Results: While there was no significant difference between the right and left OBv values of the patient and control groups, the total OBv value of the patient group was found to be significantly lower compared to the control group (p=0.041). There was no significant difference between disease severity and OBv values. It was seen that right, left and total OBv values decreased significantly as the duration of the disease increased (p=0.001, p

Comparison of the Olfactory Bulb Volume and the Olfactory Tract Length Between Patients Diagnosed with Essential Tremor and Healthy Controls: Findings in Favor of Neurodegeneration.

PurposeEssential tremor (ET) is the most common movement disorder. In recent years, an increasing number of studies have shown that this disease also has a variety of non-motor findings and may be of a neurodegenerative nature. This study aimed to evaluate the olfactory bulb volume (OBV) and the olfactory tract length (OTL) and to demonstrate possible neurodegeneration in ET patients using magnetic resonance imaging (MRI).MethodsThe study included 30 ET patients (mean age=29.53±11.82 years) and 30 healthy controls (mean age=30.00±11.68 years). In the cranial MRI examination of both groups, the right, left and total OBV values ​​were measured in mm3 and the right and left OTL values ​​were calculated manually in mm.ResultsThere was no significant difference between the patient and control groups in the measured OBV values, but the OTL value of the patient group was statistically significantly lower than the control group.ConclusionOur study showed that the olfactory system might be involved in ET cases. We think that olfactory dysfunction, one of the non-motor symptoms in ET, can be clearly elucidated through both anatomical and functional studies, to be conducted with larger patient groups.

Magnetic Resonance Imaging-guided Stereotactic Biopsy: A Review of 83 Cases with Outcomes.

Background:The purpose of this study was to determine the relationship between the radiological and histopathological distribution of the cerebral lesions diagnosed with stereotactic biopsy (STB) procedure and its outcomes.Materials and Methods:In the current study, a retrospective analysis of 83 patients that underwent the STB in our clinic from January 2011 to December 2015 was made. T1-weighted contrast-enhanced cranial magnetic resonance imaging examinations were performed on patients on whom Leksell stereotactic frame system was installed. The histopathological and the radiological data derived from the STB procedure were classified.Results:In terms of localization, glial tumor (56.6%) was the most common lesion in all regions, except for the multifocal lesions. Contrary to the common knowledge, lymphoma (14.4%) was found to be the most common lesion among multifocal lesions. The success of obtaining positive STB samples in the current series was 95.2% and the complication rate was 3.6%.Conclusion:Had a routine computed tomography scan been performed on each patient in this series, the number of clinically insignificant small intracerebral hematomas would have probably been higher. Nevertheless, the rate of the STB sampling accuracy and the complication rate were similar to those reported in the relevant literature.

Evaluation of symmetrical increased echogenicity of bilateral caudothalamic grooves detected on cranial ultrasonography by comparing with susceptibility-weighted imaging.

To assess symmetrical increased echogenicity of bilateral caudothalamic grooves (SIEBCG) detected on newborn cranial ultrasonography (CUS) using magnetic resonance susceptibility-weighted imaging (SWI). A total of 14 newborns (8 girls; 12 premature with mean gestational age of 30weeks and 5days, 2 mature) who were detected to have SIEBCG on routine serial CUS and underwent cranial magnetic resonance imaging (MRI) were recruited for the study. The cranial MRI examinations including SWI acquired on the same day of SIEBCG detection and serial CUS to assess the progress of SIEBCG lesions in the following 6month period were retrospectively evaluated and compared for the presence of germinal matrix hemorrhage. On SWI, solely one patient (7, 1%) had signal alteration on caudothalamic groove compatible with grade 1 germinal matrix hemorrhage. Two patients (14, 2%) had parenchymal (on cerebellar and parietal white matter) millimetric hemorrhagic foci. Seven patients (50%) had signs of presumptive hypoxic insult including hyperintense dots on centrum semiovale and periventricular white matter in five, and increased signal intensity on the globus pallidi in two, on T1-weighted images. Four patients (28, 6%) had normal findings. Of these, 10 patients became normal on follow-up CUS at postterm-equivalent age, whereas four were missing. Symmetrical increased echogenicity of bilateral caudothalamic grooves seen on newborn CUS may be the indicator of other pathologies as ischemic insult or focal parenchymal hemorrhage. In the presence of SIEBCG, further examination with SWI should be performed.

Braın abscess due to Streptococcus intermedius secondary to mastoiditis in a child.

BackgroundBrain abscess is a rare but serious, life-threatening infection in children. It may arise from parameningeal infections such as otitis media, sinusitis and mastoiditis.Case descriptionA ten-year-old boy with the diagnosis of glycogen-storage disease and obesity was admitted to the emergency room with complaints of vomiting, decreased level of consciousness, imbalance on walking. On neurological examination, the patient was ataxic. His cranial magnetic resonance imaging (MRI) examination showed mastoiditis on the right side and 39 × 34 mm abscess formation with surrounding edema on the right cerebellar hemisphere. The patient underwent surgery to drain the abscess, microbiological samples were obtained and empirical antibiotic treatment with vancomycin and piperacillin–tazobactam were started. Postoperative cranial MRI examination showed that the lesion regressed 10 × 10 mm with a reduction in the edema. On the second week of the treatment, the antibiotics were switched to vancomycin and meropenem because of the relapsing fever. The therapy was continued for 6 weeks. A final MRI (after completing antibiotherapy) showed resolution of the cerebellar abscess. The child’s clinical condition improved and he was discharged without any sequelae.Discussion and evaluationChildren with congenital heart disease and an immonocompromised state are particularly at risk. Streptococcus intermedius is usually a commensal microorganism in the normal flora of the mouth which can cause brain abscess rarely in children. Brain abscess induced mortality rates are still relatively high, even with the advancement of imaging technologies, the combination of surgical drainage and antimicrobial therapy.ConclusionThis case is one of the few reported cases of cerebellar abscess caused by S. intermedius in an immunocompetent child, due to its low virulence, a rare occurence and timely management resulting in fully healed.

Sudden deaths due to accidental intravenous injection of perfluorocarbon during MRI cranial examinations

Unexpected deaths of three patients happened at a magnetic resonance imaging (MRI) clinic during cranial examinations with gadolinium-based contrast media. A toxicological screening using liquid chromatography–tandem mass spectrometry (LC–MS–MS) and gas chromatography–mass spectrometry (GC–MS) for blood and urine samples collected during autopsy of the cases resulted negative. During the police investigation, it was learned that a special brand of perfluorocarbon (FC-770) had been in use at the radiological clinic for prostatic, genitals, and external soft tissue examinations, and could supposedly be available in the room where the cranial MRI examinations were performed. Histologically the lungs of the three victims showed alveolar edema associated with pulmonary venous air embolism. Using a target LC–MS–MS method, gadolinium-based contrast agents Gd-DTPA and Gd-DOTA were detected in blood samples and results showed lower levels of Gd-DTPA and Gd-DOTA when compared with literature data for that kind of MRI examinations. Free gadolinium (Gd3+) was also determined by inductively coupled plasma–mass spectrometry in blood samples showing also low levels. Perfluorocarbon FC-770 was determined in blood by headspace–GC–MS. Results showed the presence of 19.3, 20.9, and 20.0 μg/ml of FC-770 in blood of the three victims, estimating an injected dose of at least 230, 180, and 180 mg/kg, respectively. The smallest fatal dose established in an early experimental study was estimated to be 6.8 mg/kg. The investigations concluded that mistakenly intravenous injection of FC-770 led to the deaths of the three victims by a mechanism of pulmonary venous gas embolism secondary to the presence of non absorbable and high vapor pressure FC-770 in the pulmonary capillaries.

Magnetic resonance imaging signs of presumed elevated intracranial pressure in dogs

The aim of this study was to describe magnetic resonance imaging (MRI) findings associated with presumed elevated intracranial pressure (ICP) in dogs and to evaluate whether MRI could be used to discriminate between dogs with and without elevated ICP. Of 91 dogs that underwent cranial MRI examination, 18 (19.8%) were diagnosed with elevated ICP based on neurological examination, fundoscopy and transcranial Doppler ultrasonography. The MRI findings that showed the strongest association with elevated ICP were mass effect (odds ratio [OR], 78.5), caudal transtentorial herniation (OR, 72.0), subfalcine herniation (OR, 45.6), perilesional oedema (OR, 34.0), displacement of the lamina quadrigemina (OR, 27.7) and effacement of the cerebral sulci (OR, 27.1). The presence of any two or more of the following MRI findings identified elevated ICP with a sensitivity of 72% and a specificity of 96%: compression of the suprapineal recess, compression of the third ventricle, compression of the fourth ventricle, effacement of the cerebral sulci and caudal transposition of the lamina quadrigemina. In conclusion, there is an association between MRI findings and elevated ICP in dogs; therefore, MRI might be useful to discriminate between dogs with and without elevated ICP.

Acute progressive midbrain hemorrhage after topical ocular cyclopentolate administration

Cyclopentolate is a synthetic anti-cholinergic agent widely used in ophthalmology clinics. It can cause cardiovascular side-effects such as hypertension, ventricular arrhythmias and tachycardias. A 55-year-old male lost his consciousness after topical cyclopentolate hydrocloride (1%) administration for routine fundoscopic examination in another center. An urgent cranial magnetic resonance imaging examination revealed a midbrain hemorrhage and he was transferred to our hospital. The Glasgow Coma Scale score was at 4 points at admission. The patient was transferred to the intensive care unit and mechanically ventilated. Despite vigorous medical treatment, spontaneous respiration and brainstem reflexes disappeared 12 h after his administration. A control cranial computerized tomography showed enlargement and opening of the hemorrhage into the ventricular system. The patient died on the 12th day of his administration. Systemic side-effects of topical ocular cyclopentolate administration and prevention methods were discussed with regard to the current literature.

Unidentified bright objects associated with features of neurofibromatosis 1

Unidentified bright objects are commonly observed on magnetic resonance imaging in young neurofibromatosis 1 patients, but their clinical and pathologic significance is largely unknown. Diagnostic features of neurofibromatosis 1 include café-au-lait spots, intertriginous freckling, Lisch nodules, neurofibromas, bony lesions, and optic glioma. We investigated the relationship between unidentified bright objects and other features of neurofibromatosis 1. Data from the National Neurofibromatosis Foundation International Database included 523 neurofibromatosis 1 patients between 2 and 20 years of age who had cranial magnetic resonance imaging examinations. The presence or absence of unidentified bright objects, diagnostic features of neurofibromatosis 1, and central nervous system neoplasms was known in these patients. Logistic regressive models were used to measure associations between unidentified bright objects and the other features while controlling for age. The occurrence of unidentified bright objects was associated with the number of diagnostic features, but most significantly with central nervous system neoplasms other than optic gliomas [odds ratio (OR) = 9.0, 95% confidence interval (CI) = 1.2-70], optic gliomas (OR = 2.1, 95% CI = 1.2-3.6), subcutaneous neurofibromas (OR = 2.0, 95% CI = 1.3-3.1), and Lisch nodules (OR = 1.6, 95% CI = 1.1-2.3). These findings suggest a common causal mechanism between unidentified bright objects and these cardinal clinical features in children with neurofibromatosis 1.

Cranial magnetic resonance imaging examination of normal term neonates: a pilot study.

This pilot study's aim was to determine, using magnetic resonance imaging (MRI), if and to what extent asymptomatic intracranial hemorrhage occurs in normal term neonates after uncomplicated vaginal deliveries. Eight normal, term, vaginally delivered infants and three cesarean-section deliveries used as controls underwent cranial MRI. No sedation was administered. Small subdural hematomas of the falx cerebri or tentorium cerebelli were found in half of those with an uneventful vaginal delivery. Pediatric follow-up, on average 3.9 years after the MRI study was performed, demonstrated normal growth and development. It appears that more data is needed to confirm the observation that the intracranial hemorrhages described should not be considered the etiology for neurologic abnormalities present in symptomatic neonates.

The evaluation of congenital double elevator palsy with magnetic resonance imaging

Orbital and cranial magnetic resonance imaging (MRI) was performed in nine patients with congenital double elevator palsy. On orbital MRI examination, superior rectus (SR) and inferior rectus (IR) muscles were specifically evaluated with sagittal and coronal views. Bell’s phenomenon was present in three cases and four patients had positive forced duction tests. The vertical recti did not show any difference in either size or signal intensity when compared to controls. There was no denervation atrophy in the SR muscle. On cranial MRI examination, we were unable to demonstrate any abnormal signal intensity. The results of this study suggest that a paretic SR muscle is unlikely to be responsible for the clinical picture in congenital double elevator palsy, since a paretic SR muscle causing such a severe limitation of upgaze would be expected to have denervation atrophy.

Magnetic resonance imaging of cerebral associative white matter bundles employing fast-scan techniques.

Rapid scan techniques have introduced new sequence parameters as well as novel contrast concepts into everyday magnetic resonance imaging (MRI). In particular contrast characteristics of fast-spin echo (FSE) sequences showed some significant differences when compared to conventional spin echo images. The purpose of this work was to demonstrate the capabilities of FSE MRI in identifying and characterizing the in vivo anatomy of the main cerebral associative systems. Between March and November 1995, 20 healthy adult volunteers (12 males, 8 females, mean age 35 years) were submitted to a cranial MRI examination (1.5 Philips Gyroscan NT). In all cases axial and coronal 2-dimensional FSE T2-weighted and 2-dimensional inversion recovery FSE T1-weighted images were obtained. All MRI images were examined by a neuroradiologist (G. Dal Pozzo) for the depiction of the following compact white matter fiber bundles: anterior commissure, corpus callosum, superior fronto-occipital fasciculus, cingulum, fornix, mammillothalamic tract, uncinate fasciculus, superior and inferior longitudinal fasciculus. All these associative pathways could be well identified on T2-weighted images due to a lower signal intensity with respect to the surrounding white matter. On T1-weighted images only the corpus callosum, the anterior commissure and the fornix could always be identified. Correlation with myelin-specific colorations (Luxol fast blue stains) in anatomic atlases and a review of the literature on the myelinization process during infancy indicate that the short T2 relaxation times of the aforementioned cerebral associative systems may be due to heavy myelination and high fiber density. The correct visualization of interintrahemispheric associative white matter fiber bundles may play an important role in white matter disorders like dys- and demyelinating diseases and in the spreading of vasogenic edema and/or tumor being useful for their staging.

Periventricular white matter changes and oropharyngeal swallowing in normal individuals.

Cranial magnetic resonance imaging (MRI) has revealed patchy periventricular white matter lesions or "unidentified bright objects" (UBOs) in otherwise neurologically intact individuals. Quantitative videofluoroscopic swallowing evaluations and cranial MRI examinations were studied in 49 neurologically normal volunteers (ages 43 to 79 years). Total swallowing duration (TSD) and its subcomponents of oral transit duration (OTD), stage transition duration (STD), and pharyngeal response duration were measured for liquid and semisolid swallows. MRIs were graded from 0, or no UBOs, to 3, or multiple and confluent lesions. The effect of the presence of UBOs on swallowing durational measures and risk factors was analyzed with age differences accounted for statistically (ANCOVA). TSD and OTD for semisolids were significantly differentiated by MRI score (P less than 0.009 and P less than 0.047, respectively). That is, a demonstrable effect was found for an increased number of UBOs on duration of oropharyngeal swallowing in normal individuals.