Apparent diffusion coefficient values can predict neuromotor outcome in term neonates with hypoxic-ischaemic encephalopathy.

AIM: To determine the apparent diffusion coefficient (ADC) in brain structures during the first 2 weeks of life and its relation with neurological outcome for hypoxic-ischaemic encephalopathy (HIE) in term neonates. METHODS: We retrospectively evaluated 56 term-born neonates. The ADC values were measured for 11 brain regions. The clinical outcomes at least 2 years of age were defined as normal outcome, mild disability and severe disability. The area under curves (AUCs) by ROC analysis were performed to predict the neurodevelopmental outcomes. The clinical outcomes were compared between favourable outcome and adverse outcome and also between normal outcome and unfavourable outcome. RESULTS: Thirty-four patients were judged as normal outcome, 10 as mild disability and 12 as severe disability. When the clinical outcomes were compared between favourable outcome and adverse outcome, the AUC on the 1st week was highest value at the thalamus. When the clinical outcomes were compared between normal outcome and unfavourable outcome, the AUC on the 1st week was highest at the thalamus. CONCLUSION: The ADC values in the thalamus in the 1st week can predict the neurological outcome. The ADC values in centrum semiovale on the 2nd week can be used to predict neurodevelopmental outcomes.

Verification of the ability of the new MRI classification system to predict neurodevelopmental outcome in very low-birth-weight infants.

BACKGROUND: Very low-birth-weight infants (VLBWI) are at high risk for adverse neurodevelopmental outcomes. A new, feasible and practical classification system for white matter injury has been reported by Martinez-Biarge et al. Therefore, we investigated the relationship between white matter injury and neurodevelopmental outcomes using this system. MATERIALS AND METHODS: We enrolled a consecutive series of VLBWI birth weights <1500 g between 2012 and 2015. Two radiologists evaluated the brain MRI obtained in the VLBWI at term-equivalent age. MRI findings were classified into six Grades (Grade 0, Ia, Ib, II, III, IV). The frequency of abnormalities in each Grade was examined. The neurodevelopmental outcome of the VLBWI was assessed at two years or older, and we investigated the presence of cerebral palsy (CP) and intellectual disability (ID), and other serious outcomes. We also calculated the simple kappa value before the raters were matched. RESULTS: Among 167 VLBWI, 131 met the eligibility criteria. 114 was Grade 0 (87%), 11 was Grade I (8.4%), 3 was Grade II (2.3%), 1 was Grade III (0.8%), and 2 was Grade IV (1.5%). The frequency of any abnormalities of intelligence in Grade 0 was 24%. The frequency of CP in Grade I was 18%. All Grade III and Grade IV cases had mild CP and an ID. The simple kappa value was 0.95. CONCLUSION: The prognostic value of the MRI scoring tool was limited. However, all Grade III and Grade IV cases had mild CP and ID. The results demonstrated an excellent inter-rater correlation.

The Incidence of Intraventricular Hemorrhage in Low-Birth-Weight Infants: Assessment by Magnetic Resonance Imaging.

PURPOSE: Intraventricular hemorrhage (IVH) is common in infants with a low-birth-weight (LBW) and has been suggested to cause major impairment not only of future motor development but also of cognitive function and learning ability. The purpose of the present study is to assess the frequency of IVH using magnetic resonance imaging (MRI) in LBW infants and its clinical neurodevelopmental outcomes. METHODS: We enrolled a consecutive series of 247 neonates with an LBW of < 1,500 g hospitalized in the newborn intensive care unit between 2010 and 2015. The presence of IVH was examined using T2* MRI at term-equivalent age (TEA). We then investigated the clinical outcome at ≥3 years of age and its correlation with the IVH grade. RESULTS: The overall incidence of IVH among LBW infants was 16.2%. The proportion of infants with IVH showing a favorable outcome did not differ significantly from that of infants without IVH. The proportion of neonates showing a poor outcome was 6.7% for those with IVH and 1.9% for those without IVH and 2.7% for those with and without IVH combined. CONCLUSION: We were able to clarify the frequency of IVH in LBW infants using MRI at TEA. We demonstrated the lower incidence of mortality and IVH, the higher incidence of a favorable outcome, and the lower incidence of poor outcome.

Diffusion restriction in the corticospinal tract and the corpus callosum of term neonates with hypoxic-ischemic encephalopathy.

BACKGROUND: Diffusion-weighted imaging performed shortly after brain injury has been shown to facilitate visualization of acute corticospinal tract injury known as "pre-Wallerian degeneration." OBJECTIVE: The aim of this study was to determine whether diffusion restriction in the corticospinal tract and corpus callosum occurs within the first 2 weeks after birth in neonates with neonatal hypoxic-ischemic encephalopathy. MATERIALS AND METHODS: We enrolled a consecutive series of 66 infants diagnosed with hypoxic-ischemic encephalopathy who underwent MRI. We evaluated diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values to assess the presence of restricted diffusion in the corticospinal tract and corpus callosum. Next, we compared ADC values in the corticospinal tract and in the splenium and genu of the corpus callosum of infants with abnormal pattern on MRI with those of control infants, who showed a normal pattern on MRI. We attempted to follow all infants with hypoxic-ischemic encephalopathy until 18 months of age and assess them using a standardized neurologic examination. RESULTS: After exclusions, we recruited 25 infants with abnormal MRI and 20 with normal MRI (controls). Among these 45 neonates, pre-Wallerian degeneration was visualized in the corticospinal tract in 10 neonates and in the corpus callosum in 12. The ADC values in the corticospinal tract in the first week were significantly lower than they were in the second week. Infants with pre-Wallerian degeneration in the corticospinal tract showed an unfavorable outcome. CONCLUSION: Pre-Wallerian degeneration was visualized in the corticospinal tract and corpus callosum and was associated with extensive brain injury caused by hypoxic-ischemic encephalopathy. The changes in signal were observed to evolve over time within the first 2 weeks. The clinical outcome of infants having pre-Wallerian degeneration in the corticospinal tract was unfavorable.

Compound heterozygous ADAMTS9 variants in Joubert syndrome-related disorders without renal manifestation.

BACKGROUND: Ciliopathies are the outcomes of defects of primary cilia structures and functions which cause multisystemic developmental disorders, such as polycystic kidney disease, nephronophthisis, retinitis pigmentosa, Joubert syndrome (JS), and JS-related disorders (JSRD) with additional organ involvement including oral-facial-digital syndrome and so on. They often share common and unexpected phenotypic features. CASE PRESENTATION: We report a 4-year-old-boy case with compound heterozygous variants of ADAMTS9. Unlike the cases with ADAMTS9 variants in the previous report, which identified that homozygous variants of ADAMTS9 were responsible for nephronophthisis-related ciliopathies in two cases, the current case did not have nephronophthisis nor renal dysfunction, and his clinical features, such as oculomotor apraxia, hypotonia, developmental delay, bifid tongue, and mild hypoplasia of cerebellar vermis indicated JSRD. CONCLUSIONS: The case suggested a possible association between the clinical presentation of JSRD and ADAMTS9-related disease, and it shows a wide spectrum of ADAMTS9 phenotype.

Morphological changes in the pons and cerebellum during the first two weeks in term infants with pontine and cerebellar injury and profound neonatal asphyxia.

BACKGROUND: The morphological changes in the pons and cerebellum of neonates experiencing profound asphyxia in the early period of life remain to be clarified. PURPOSE: To assess the changes in the size of the pons and cerebellum during the first two weeks of life in term neonates with pontine and cerebellar injury caused by hypoxic-ischemic encephalopathy in comparison with a control group. MATERIAL AND METHODS: Two groups were investigated: a group with pontine/cerebellar injury (PCI) (n = 10) demonstrated by magnetic resonance imaging (MRI) diffusion-weighted imaging; and a control group without PCI - focal-multifocal white matter injury and a normal pattern (n = 24). The anteroposterior diameter (APD) and height of the pons and cerebellar vermis, and the transverse width of the cerebellum were measured twice in the first and second weeks of life. Differences between the groups were analyzed statistically using paired and unpaired Student's t-test at a significance level of P < 0.05. RESULTS: In the PCI group, the pontine APD and cerebellar vermian height were significantly decreased in the second week. An increase of pons and cerebellar size was evident during the first two weeks of life in the control groups. CONCLUSION: Infants with PCI and profound asphyxia show rapid decreases in pontine APD and cerebellar vermian height within the first two weeks of life.

Diffusion Restriction in the Optic Radiation of Term Neonates With Hypoxic-Ischemic Encephalopathy Demonstrated by Magnetic Resonance Imaging (MRI).

OBJECTIVE: There has been no previous report of diffusion restriction in the optic radiation of term neonates with hypoxic-ischemic encephalopathy. Here, using diffusion-weighted magnetic resonance imaging (MRI), we assessed diffusion restriction in the optic radiation within the first 2 weeks of life and estimated signal changes and the apparent diffusion coefficient in the optic radiation and lateral geniculate body using T1-weighted MRI. MATERIALS AND METHODS: Forty-five term neonates with hypoxic-ischemic encephalopathy underwent MRI twice during the first 2 weeks of life. Diffusion-weighted imaging and apparent diffusion coefficient were used to evaluate the presence of diffusion restriction in the optic radiation and lateral geniculate body. Apparent diffusion coefficient and T1 signal changes in the optic radiation and lateral geniculate body were also compared with those in 11 control neonates showing a normal pattern on MRI. RESULTS: Diffusion restriction in the optic radiation was observed in 29% (13/45) of the hypoxic-ischemic encephalopathy neonates at a median age of 3.5 days (range: 1-9 days). The apparent diffusion coefficient in the optic radiation of affected neonates was significantly reduced in comparison with the controls. In all neonates with optic radiation involvement, increased T1 signal intensity was observed in the optic radiation in the second week, and was also evident in in lateral geniculate body in 8 of those neonates. CONCLUSION: Diffusion restriction in the optic radiation is not rare among term neonates with hypoxic-ischemic encephalopathy, being visualized by diffusion-weighted imaging in the first week of life and also high-intensity T1 signal changes in the second week. This diffusion restriction in the optic radiation might be due to transsynaptic neuronal degeneration.

Pontine and cerebellar injury in neonatal hypoxic-ischemic encephalopathy: MRI features and clinical outcomes.

BACKGROUND: Perinatal hypoxic-ischemic encephalopathy (HIE) is a major cause of death and disability in infants. Magnetic resonance imaging (MRI) is valuable for predicting the outcome in high-risk neonates. The relationship of pontine and cerebellar injury to outcome has not been explored sufficiently. PURPOSE: To characterize MRI features of pontine and cerebellar injury and to assess the clinical outcomes of these neonates. MATERIAL AND METHODS: The retrospective study included 59 term neonates (25 girls) examined by MRI using 1.5-T scanner in the first two weeks of life between 2008 and 2017. Involvement of the pons and cerebellum was judged as a high signal intensity on diffusion-weighted image (DWI) and a restricted diffusion on an apparent diffusion coefficient (ADC) map. RESULTS: Pontine involvement was observed in the dorsal portion of pons in eight neonates and cerebellar involvement was observed in dentate nucleus (n = 8), cerebellar vermis (n = 3), and hemisphere (n = 1) in 11 neonates. Combined pontine and cerebellar involvement was observed in eight neonates and only cerebellar involvement in three. The pontine and cerebellar injuries were always associated with very severe brain injury including a basal ganglia/thalamus injury pattern and a total brain injury pattern. In terms of clinical outcome, all but four lost to follow-up, had severe cerebral palsy. CONCLUSION: Pontine and cerebellar involvement occurred in the dorsal portion of pons and mostly dentate nucleus and was always associated with a more severe brain injury pattern as well as being predictive of major disability.

Magnetic resonance imaging features of four neonates with total brain injury.

PURPOSE: The most severe form of profound asphyxia in neonates is now known as "total brain injury," which forms part of the clinical spectrum of hypoxic-ischemic encephalopathy (HIE). Although the magnetic resonance (MR) imaging features of total brain injury remain to be determined, a widespread hyperintensity of the supratentorial brain, known as the "white cerebrum sign," has been reported in diffusion-weighted images (DWI). METHODS: We examined four neonates who developed severe profound asphyxia. RESULTS: In the first week of life, all neonates showed the white cerebrum sign on DWI. A follow-up of these cases over a period of 1 month revealed diffuse bilateral multicystic encephalomalacia (MCE) as well as shrinkage of the basal ganglia and thalami (BG/T). These MR findings were common to all neonates, and all the neonates had severe adverse clinical outcomes. CONCLUSION: Neonates, who exhibit the white cerebrum sign on MR imaging due to profound asphyxia, develop major disabilities, and MCE with shrinkage of the BG/T suggests miserable outcomes.

The Yellow Scale Is Superior to the Gray Scale for Detecting Acute Ischemic Stroke on a Monitor Display in Computed Tomography.

RATIONALE AND OBJECTIVES: The purpose of this study was to compare the efficacy of the color scale with regard to focal detection with computed tomography in acute ischemic stroke. MATERIALS AND METHODS: Computed tomography images of the brain of 19 patients diagnosed with acute stroke, based on magnetic resonance diffusion-weighted images obtained within an onset of 24 hours, and the images of five normal patients were displayed in each color look-up table on a monitor. The detection of acute stroke was compared among 15 radiologists. The images were compared in the gray, green, yellow, red, and blue scales of the look-up tables. The observers recorded acute ischemic stroke as "present" or "absent." They also located the position of the stroke lesion and described the degree of their conviction as to whether a lesion existed. Detection was evaluated by receiver operating characteristic analysis. The area under the receiver operating characteristic curves was compared. In addition, reduced fatigue and the ease in image observation were compared. RESULTS: Compared to the other scales, the yellow scale had a significantly higher area under the receiver operating characteristic curve, which indicated that this scale allowed better detection of acute ischemic stroke. The gray scale produced the least fatigue in image observation. CONCLUSIONS: The detection of acute ischemic stroke is improved by changing the display monitor from the gray scale to the yellow scale. From the perspective of color psychology, yellow is associated with higher arousal, cheerfulness, confidence, creativity, and excitement. Therefore, the yellow scale may be suitable for a medical imaging display.

Diffusion pseudonormalization and clinical outcome in term neonates with hypoxic-ischemic encephalopathy.

BACKGROUND: Pseudonormalization of diffusion-weighted magnetic resonance imaging (MRI) can lead to underestimation of brain injury in newborns with hypoxic-ischemic encephalopathy (HIE), posing a significant problem. We have noticed that some neonates show pseudonormalization negativity on diffusion-weighted imaging. OBJECTIVE: To compare pseudonormalization negativity with clinical outcomes. MATERIALS AND METHODS: Seventeen term neonates with moderate or severe HIE underwent therapeutic hypothermia. They were examined by MRI twice at mean ages of 3 days and 10 days. We evaluated the presence of restricted diffusion, and also the presence or absence of pseudonormalization, by diffusion-weighted imaging at the time of the second MRI, and correlated the results with clinical outcome. RESULTS: DWI demonstrated no abnormality in seven neonates. Among the 10 neonates with abnormal diffusion-weighted imaging findings, 2 were positive for pseudonormalization and 8 were negative. Among neonates with normal diffusion-weighted imaging findings and with positivity for pseudonormalization, none had major disability. Among the eight neonates with pseudonormalization negativity, all but one, who was lost to follow-up, had major disability. CONCLUSION: Abnormal diffusion-weighted imaging with pseudonormalization negativity might be predictive of severe brain injury and major disability. The second-week MRI is important for the judgment of pseudonormalization.

Safe use of iodinated and gadolinium-based contrast media in current practice in Japan: a questionnaire survey.

PURPOSE: To help establish consensus on the safe use of contrast media in Japan. MATERIALS AND METHODS: Questionnaires were sent to accredited teaching hospitals with radiology residency programs. RESULTS: The reply rate was 45.4% (329/724). For contrast-induced nephropathy (CIN), chronic and acute kidney diseases were considered a risk factor in 96.7 and 93.6%, respectively, and dehydration in 73.9%. As preventive actions, intravenous hydration (89.1%) and reduction of iodinated contrast media dose (86.9%) were commonly performed. For nephrogenic systemic fibrosis (NSF), chronic and acute kidney diseases were considered risk factors in 98.5 and 90.6%, respectively, but use of unstable gadolinium-based contrast media was considered a risk factor in only 55.6%. A renal function test was always (63.5% in iodinated; 65.7% in gadolinium) or almost always (23.1; 19.8%) performed, and estimated glomerular filtration rate (eGFR) was the parameter most frequently used (80.8; 82.6%). For the patients with risk factors for acute adverse reaction (AAR), steroid premedication or/and change of contrast medium were frequent preventive actions, but intravenous steroid administration immediately before contrast media use was still performed. CONCLUSION: Our questionnaire survey revealed that preventive actions against CIN were properly performed based on patients' eGFR. Preventive actions against NSF and AAR still lacked consensus.

The incidence of contrast-induced nephropathy (CIN) following transarterial chemoembolisation (TACE) in patients with hepatocellular carcinoma (HCC).

PURPOSE: The purpose of this retrospective study was to investigate the incidence of contrast-induced nephropathy (CIN) caused by transarterial chemoembolisation (TACE) in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: One hundred forty-one patients treated between 2005 and 2008 undergoing 305 consecutive sessions of TACE were enrolled. CIN was defined as an increase in the serum creatinine level of more than 0.5 mg/dl or more than 25 % from baseline within 3 days after TACE without any other identifiable cause of acute kidney injury. RESULTS: CIN by the present definition was observed after 2.6 % of the TACE sessions. No patient showed clinical signs or symptoms of acute renal failure, or required haemodialysis. None of the patients with an estimated glomerular filtration rate of <60 ml/min/1.73 m(2) developed CIN. CONCLUSION: The present study suggests that TACE is a relatively safe procedure in terms of the risk of CIN under vigorous periprocedural hydration and that the incidence of CIN is comparable to that of AKI associated with intravenous CM administration. KEY POINTS: • CIN would be lower for non-coronary arterial intervention than for coronary intervention. • The present study suggests that the CIN rates following TACE are low. • The incidence of CIN is comparable to that after intravenous CM administration.

Characterization of carotid artery plaque components on magnetic resonance imaging using signal intensity of the phantom as a reference.

RATIONALE AND OBJECTIVES: To evaluate the properties of plaque by the use of magnetic resonance imaging (MRI), it is necessary to use a material with stable signal intensity (eg, muscle or submandibular gland) as a reference. However, there may be differences between individuals. Therefore, we used a small phantom set on the circumference of the neck as a reference. The signal intensity ratio (SIR) methods using the phantom as a reference were reviewed for discrimination of the properties of plaque in the carotid artery. MATERIALS AND METHODS: Three phantoms (phantom 1: water; phantom 2: 5 µmol gadopentetate dimeglumine; and phantom 3: 2.5 µmol gadopentetate dimeglumine) were set around the neck. SIR was calculated for each region of interest and compared according to pathological grade. RESULTS: The method using a phantom as a reference reduced the standard deviations of tissue ratios to 0.16 from 0.27 in comparison with the method using muscle and showed a close correlation with pathological grade. In addition, the agreement rates with pathological grade and grades from each SIR using signal intensity of the phantom as a reference were higher than using signal intensity of the muscle as a reference to 0.86 from 0.63 for two-dimensional images and to 0.86 from 0.71 for three-dimensional images. CONCLUSIONS: The method described here reduced error compared to the method using muscle as a reference, and the results were closely correlated with pathological grade.

Anatomical characterization of athetotic and spastic cerebral palsy using an atlas-based analysis.

PURPOSE: To analyze diffusion tensor imaging (DTI) in two types of cerebral palsy (CP): the athetotic-type and the spastic-type, using an atlas-based anatomical analysis of the entire brain, and to investigate whether these images have unique anatomical characteristics that can support functional diagnoses. MATERIALS AND METHODS: We retrospectively analyzed the DTI of seven children with athetotic-type, 11 children with spastic-type, and 20 healthy control children, all age-matched. The severity of motor dysfunction was evaluated with the Gross Motor Function Classification System (GMFCS). The images were normalized using a linear transformation, followed by large deformation diffeomorphic metric mapping. For 205 parcellated brain areas, the volume, fractional anisotropy, and mean diffusivity were measured. Principal component analysis (PCA) was performed for the Z-scores of these parameters. RESULTS: The GMFCS scores in athetotic-type were significantly higher than those in spastic-type (P < 0.001). PCA extracted anatomical components that comprised the two types of CP, as well as the severity of motor dysfunction. In the athetotic group, the abnormalities were more severe than in the spastic group. In the spastic group, significant changes were concentrated in the lateral ventricle and periventricular structures. CONCLUSION: Our results quantitatively delineated anatomical characteristics that reflected the functional findings in two types of CP.

CT findings of small bowel strangulation: the importance of contrast enhancement.

The purpose of this study is to illustrate computed tomography (CT) findings suggestive of small bowel strangulation. We have performed the precontrast and postcontrast CT with single and multidetector CT scanners and evaluated the bowel wall changes and mesentery changes and correlated them with the operative findings. The direct CT findings suggestive of small bowel strangulation included high-density bowel wall on precontrast scans; lack of, or diminished contrast enhancement of the involved bowel wall; localized mesenteric fluid accumulation (mesenteric congestion); and localized pneumatosis. The indirect CT signs included C- or U-shaped loops with mesenteric vessels converging toward the obstruction site, ascites, target sign, two adjacent collapsed round loops, and whirl sign. We particularly emphasize the importance of contrast enhancement of bowel mucosa for early diagnosis to differentiate strangulation from a mechanical obstruction without bowel ischemia, and also the importance to differentiate proximal secondary gas-filled dilated small bowel loops from distal primary involved fluid-filled small bowel loops because these two types of small bowel loops are present in the single peritoneal cavity. As early recognition of small bowel strangulation may help improve the patient outcome because the involved bowel loops can be preserved without resection, it is essential to become familiar with the CT signs suggested small bowel obstruction strangulation.

Radiological diagnosis of large-bowel obstruction: neoplastic etiology.

Large-bowel obstruction (LBO) is a relatively common abdominal emergency. The CT exam has become the most important imaging modality for the diagnosis of LBO, following abdominal ultrasound and plain radiography. The recent multi-detector CT (MD-CT) is able to clarify the etiology of LBO and to help in deciding how to treat LBO. Therefore, it is important for the radiologists to become familiar with the imaging findings of LBO, including plain radiograph and CT, due to various causes. In this article, we have shown the characteristics of the radiological findings including plain radiograph, barium study, and CT as well as their correlations with pathologic findings of LBO. The etiology of LBO is usually divided into neoplastic diseases and nonneoplastic diseases. However, the most common cause is the neoplastic etiology. Now, we can afford the critical information concerning the level of obstruction, its cause, the viability of the involved bowel loops, and a decision-making regarding the therapy for patients with LBO, using MD-CT high technology.