MRI Findings of Immune Checkpoint Inhibitor-Induced Hypophysitis: Possible Association with Fibrosis

BACKGROUND AND PURPOSE

Hypophysitis is one of the well-known adverse effects of immune checkpoint inhibitors. Immune checkpoint inhibitor-induced hypophysitis frequently causes irreversible hypopituitarism, which requires long-term hormone replacement. Despite the high frequency and clinical significance, characteristic MR imaging findings of immune checkpoint inhibitor-induced hypophysitis have not been established. In the present study, we aimed to review and extract the MR imaging features of immune checkpoint inhibitor-induced hypophysitis.

MATERIALS AND METHODS

This retrospective international multicenter study comprised 20 patients with melanoma who were being treated with immune checkpoint inhibitors and clinically diagnosed with immune checkpoint inhibitor-induced hypophysitis. Three radiologists evaluated the following MR imaging findings: enlargement of the pituitary gland and stalk; homogeneity of enhancement of the pituitary gland; presence/absence of a well-defined poorly enhanced area and, if present, its location, shape, and signal intensity in T2WI; and enhancement pattern in contrast-enhanced dynamic MR imaging. Clinical symptoms and hormone levels were also recorded.

RESULTS

Enlargement of the pituitary gland and stalk was observed in 12 and 20 patients, respectively. Nineteen patients showed poorly enhanced lesions (geographic hypoenhancing lesions) in the anterior lobe, and 11 of these lesions showed hypointensity on T2WI. Thyrotropin deficiency and corticotropin deficiency were observed in 19/20 and 12/17 patients, respectively, which persisted in 12/19 and 10/12 patients, respectively, throughout the study period.

CONCLUSIONS

Pituitary geographic hypoenhancing lesions in the anterior lobe of the pituitary gland are characteristic and frequent MR imaging findings of immune checkpoint inhibitor-induced hypophysitis. They reflect fibrosis and are useful in distinguishing immune checkpoint inhibitor-induced hypophysitis from other types of hypophysitis/tumors.

New MRI Findings in Fukuyama Congenital Muscular Dystrophy: Brain Stem and Venous System Anomalies

BACKGROUND AND PURPOSE

Leptomeningeal glioneuronal heterotopia of the brain stem and cerebral migration abnormality were pathologically reported in Fukuyama congenital muscular dystrophy, but the radiologic assessments of the brain stem and cerebral venous system (which may be involved in the development of the anomaly) were insufficient. Here, we evaluated the brain stem and cerebral veins on MR imaging in patients with Fukuyama congenital muscular dystrophy.

MATERIALS AND METHODS

We retrospectively reviewed the MR imaging findings of 27 patients with Fukuyama congenital muscular dystrophy. We visually assessed the hypoplasia, superficial structures, and signal intensity of the brain stem on T2WI, FLAIR, and double inversion recovery images and the cerebral, superficial, and deep veins with and without hemorrhage on T2WI and SWI.

RESULTS

Brain stem fluffy structures were seen in 96.3% of the cases on T2WI. Superficial high signal intensity on T2WI and FLAIR images was seen in 96.3% and 92.6%, respectively. Abnormally located superficial vessels beneath the cortex were seen in 11.1% on T2WI. Hypoplasia of the superficial cerebral veins was noted in all patients who underwent SWI. Dilated and tortuous subependymal veins were seen in 40.0% on SWI. Hemorrhages were seen in 11.1% on T2WI and in 60.0% on SWI.

CONCLUSIONS

Superficial brain stem structural and signal abnormalities would be useful MR imaging findings to diagnose Fukuyama congenital muscular dystrophy as well as venous system abnormalities. Clinicians must keep in mind that this disease has a high risk of hemorrhage.

Interaction between APOE genotype and diabetes in cognitive decline

INTRODUCTION

Although diabetes and apolipoprotein E (apoE) are both significant risk factors for dementia, including Alzheimer's disease, it remains to be clarified how they are related to each other in contributing to the risk of dementia.

METHODS

By reviewing the National Alzheimer's Coordinating Center (NACC) clinical records, we investigated whether diabetes affects cognitive decline depending on APOE genotype and their potential relationships with neuropathology.

RESULTS

A significant interaction between diabetes and APOE genotype exists, where diabetes affected cognitive decline in APOE3 carriers and APOE2 carriers, but not APOE4 carriers. Moreover, the presence of vascular pathology was increased by diabetes in APOE3 carriers, while APOE4 carriers nearly reached plateau levels irrespective of diabetes.

DISCUSSION

Diabetes accelerates cognitive decline, in part, through accelerating vascular impairment in non-APOE ε4 carriers, but such effects are negligible in APOE4 carriers, who themselves are already vulnerable to vascular impairment.

P17 In-hospital mortality and clinical features of Japanese patients with acute myocardial infarction diagnosed by universal definition in real world from kanagawa-acute cardiovascular registry (K-ACTIVE)

Background

Cardiac troponin (cTn) has been used as the preferred biomarker of myocardial injury for diagnosis of acute myocardial infraction (AMI) by universal definition. A large number of patients formerly classified by creatine kinase (CK) as unstable angina with the WHO criteria in Japan are now diagnosed by cTn as non-ST elevation myocardial infarction (NSTEMI). In this report, we aimed to understand its prevalence and clinical features of AMI diagnosed by using universal definition and the WHO criterial in real world. 

Method

This registry is a cross-sectional study of 53 facilities in Kanagawa prefecture of Japan. 4372 AMI patients were enrolled who received primary percutaneous coronary intervention (PCI) between October 1, 2015 and January 29, 2019. Patients were divided into 3 groups, 3268 patients with ST elevation myocardial infarction (STEMI), 628 patients with NSTEMI patients who satisfied the WHO criteria with CK elevation beyond twice upper limit of normal (NSTEMI + CK), and 476 patients with NSTEMI who didn’t satisfy the WHO criteria without CK elevation (NSTEMI-CK).

Result

Baseline clinical characteristics of the study patients are shown in Table 1. In-hospital mortality was significantly lower in patients with NSTEMI-CK (1.9%) than in STEMI (6.0%, P < 0.001) and NSTEMI + CK (5.3%, P < 0.004) (Figure 1). Kaplan-Meier analyses for 0-30 days of cardiac death are shown in Figure 2. From day 0, the Kaplan-Meier curves began to diverge in favor of NSTEMI-CK for up to 30 days.

Conclusion

AMI patients showed distinct clinical features depends on the type. We should be aware of the difference for the diagnosis of AMI by using universal definitions.

Table 1. 　 STEMI (n = 3268) NSTEMI + CK (n = 628) NSTEMI-CK (n = 476) STEMI vs NSTEMI + CK P value STEMI vs NSTEMI-CK P value NSTEMI + CK vs NSTEMI-CK P value Age(years) 68(59-77) 69(61-78) 70(61-79) 　 　 　 Male 76% 77% 75% 0.54 0.74 0.47 Concomitant diseases 　 　 　 　 　 　 Hypertention 65.4% 70.5% 69.3% 0.013 0.097 0.65 Diabetes 33.5% 36.5% 37.3% 0.15 0.11 0.78 Dyslipidemia 56.1% 61.2% 61.3% 0.018 0.03 0.96 Hemodialysis 2.3% 2.1% 6.8% 0.86 <0.001 0.01 Smoking 66.3% 63.1% 64.6% 0.13 0.48 0.62 Atrial fibrillation 9.6% 10.7% 14.4% 0.57 0.04 0.23 Previous MI 8.3% 17.3% 15.7% <0.001 <0.001 0.47 In-hospital mortality 6.0% 5.3% 1.9% 0.49 <0.001 0.004

Abstract P17 Figure 1. 2.

P278 Pharmacokinetics, pharmacodynamics and efficacy of OPC-61815, prodrug of tolvaptan for intravenous administration, in patients with congestive heart failure

Funding Acknowledgements

Otsuka Pharmaceutical Co. Ltd.

On Behalf

OPC-61815 phase II investigators

Background/Introduction: Tolvaptan, a vasopression V2-receptor antagonist, is effective for congestion in patients with congestive heart failure (CHF), and hyponatremia in patients with CHF and SIADH. But, this drug is not readily soluble in water and not suited for development as an injection. OPC-61815, a prodrug of tolvaptan having improved water solubility, is suitable for intravenous administration.

Purpose

The phase-II clinical study (ClinicalTrials.gov Identifier: NCT03254108) was conducted to investigate the dose for intravenous administration of OPC-61815 achieving tolvaptan exposure equivalent to that for oral administration of tolvaptan 15-mg tablet in CHF patients.

Methods

This study was a multicenter, a double-blind, randomized, active-controlled, parallel-group comparison clinical pharmacology trial. Sixty patients aged between 20 and 85 years with CHF with volume overload despite the use of conventional diuretics were randomly assigned to four treatment cohorts to receive OPC-61815 at doses of 2, 4, 8, 16 mg (i.v.) or tolvaptan at 15 mg (p.o.). Both drugs were administered once a day for 5 days. The primary endpoint was to assess the dose of OPC-61815 equivalent to tolvaptan at 15 mg using Cmax and AUC24h values after the first administration. Pharmacodynamics (urine volume, urine osmolality, serum electrolyte concentration, biomarkers), efficacy (body weight change, congestive symptoms) and safety were also evaluated.

Results

The mean Cmax and AUC of the metabolite tolvaptan increased dose-dependently following single intravenous administration of OPC-61815 at 2, 4, 8, and 16 mg. Tolvaptan exposure (Cmax and AUC24h) on Day 1 following single intravenous administration of OPC-61815 at 16 mg was the closest and similar to that following single administration of tolvaptan 15-mg tablet. OPC-61815 increased urine volume from baseline, leading to decrease in body weight and improvement of lower limb edema. The incidence of treatment-emergent adverse events was 54.2% (26/48 subjects) in the OPC-61815 2 to 16-mg, and 83.3% (10/12 subjects) in the tolvaptan 15-mg groups. No clinically relevant changes from baseline were found in laboratory parameters, vital signs, or ECG findings.

Conclusions

Tolvaptan exposure on Day 1 following single intravenous administration of OPC-61815 at 16 mg was the most similar to that following single administration of tolvaptan 15-mg tablet. There was no marked difference in tolerability between OPC-61815 at 16 mg and tolvaptan 15-mg tablet, and no clinically significant problems were observed.

Increased levels of Aβ42 decrease the lifespan of ob/ob mice with dysregulation of microglia and astrocytes

Clinical studies have indicated that obesity and diabetes are associated with Alzheimer's disease (AD) and neurodegeneration. Although the mechanisms underlying these associations remain elusive, the bidirectional interactions between obesity/diabetes and Alzheimer's disease (AD) may be involved in them. Both obesity/diabetes and AD significantly reduce life expectancy. We generated App^NL-F/wt knock-in; ob/ob mice by crossing App^NL-F/wt knock-in mice and ob/ob mice to investigate whether amyloid-β (Aβ) affects the lifespan of ob/ob mice. App^NL-F/wt knock-in; ob/ob mice displayed the shortest lifespan compared to wild-type mice, App^NL-F/wt knock-in mice, and ob/ob mice. Notably, the Aβ42 levels were increased at minimum levels before deposition in App^NL-F/wt knock-in mice and App^NL-F/wt knock-in; ob/ob mice at 18 months of age. No differences in the levels of several neuronal markers were observed between mice at this age. However, we observed increased levels of glial fibrillary acidic protein (GFAP), an astrocyte marker, in App^NL-F/wt knock-in; ob/ob mice, while the levels of several microglial markers, including CD11b, TREM2, and DAP12, were decreased in both ob/ob mice and App^NL-F/wt knock-in; ob/ob mice. The increase in GFAP levels was not observed in young App^NL-F/wt knock-in; ob/ob mice. Thus, the increased Aβ42 levels may decrease the lifespan of ob/ob mice, which is associated with the dysregulation of microglia and astrocytes in an age-dependent manner. Based on these findings, the imbalance in these neuroinflammatory cells may provide a clue to the mechanisms by which the interaction between obesity/diabetes and early AD reduces life expectancy.

4329Mega-studies in heart failure, effect dilution in examination of new therapies

Aims

All phase 3 studies in patients with acute heart failure (AHF) and HF with preserved ejection fraction (HFpEF) have failed in the last decades. We explore the likelihood that the negative results are due to chance and/or to study size and dilution of statistical power.

Methods and results

First, using simulations, we examined the probability that a positive finding in phase 2 would result in studying truly effective drugs in phase 3. We simulated phase 2 studies under six scenarios where the range of true relative risk (RR) for an outcome of interest varied from 0.5 (major benefit) to 1.15 (some harm). The proportion of simulated studies where the RR <0.8 (we assumed that a 20% or greater risk reduction reflects an effective drug) ranged from 6% to 42% across the six scenarios studied. To further simulate “real life” clinical research, we simulated a continuous surrogate outcome that was linearly related to the true RR in each simulation of each scenario. Regardless of criteria considered for a positive phase 2 trial, results suggest that even in our worst-case scenario, where overall only 6% of drugs taken into phase 2 are effective, roughly 20% of phase 3 studies, if appropriately powered, should have yielded positive results. Given this, we then explored study size in AHF research, as a potential explanation for the high failure rate in these studies. Comparison of published phase 2 and 3 clinical trials with registries in AHF suggest that populations in both large and small trials differ from “real life”. Meta-regression models suggest that both control event rates, and in the serelaxin program as an example, treatment effects, decline with increasing study size greatly reducing power (figure). This effect dilution might be explained by an increasing proportion of patients enrolled in studies who cannot benefit from the study drug.

Figure 1. Power at two-sided 0.05 significance level to detect an effect size of hazard ratio of 0.65 (left) or 0.8 (right) with a placebo event rate of 10% (top) and 20% (bottom) at N=100 at various treatment effect dilutions with increasing sample size.

Conclusion

These data suggest that it is unlikely that the very high rate of negative AHF phase III trials can be explained by chance alone. Potentially, our tendency to increase sample size does not necessarily increase statistical power, due to more heterogenous populations leading to reduced event rates and treatment effects.

P2666Association of out-of-hospital cardiac arrest occurrence time and the survival in all-Japan utstein registry: difference between international resuscitation guidelines 2005 and 2010

Background/Introduction

Previous studies have shown that out-of-hospital cardiac arrest (OHCA) occurring at night have poor outcomes compared with OHCA occurring during daytime. On the other hand, nationwide OHCA outcomes have gradually improved in Japan.

Purpose

We sought to examine whether one-month survival of OHCA differed between daytime and nighttime occurrences, and they differed between the periods of International Resuscitation Guidelines 2005 and 2010.

Methods

Using the All-Japan Utstein Registry between 2005 and 2015, adult OHCA patients whose collapse was witnessed by a bystander and the call-to-hospital admission interval was shorter than 120 min were included in this study. OHCA patients were divided by period of the International Resuscitation Guideline 2005 and 2010. Guideline 2005 included years from 2006 to 2010, while Guideline 2010 included years from 2011 to 2015. The primary outcome was one-month survival with favorable neurological outcome, defined as Cerebral Performance Category scale of 1 or 2. Daytime, evening, and night were defined as 0700 to 1459 h, 1500 to 2259 h, and 2300 to 0659 h, respectively.

Results

Among 479,046 cases, 20.3% revealed OHCA occurring at night. OHCA patients occurring at night had lower rate of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator use than those occurring at both daytime and evening. In addition, of those who received bystander CPR, higher rate of patients received CPR by family members. OHCA patients occurring at night in both guideline periods had significantly worse one-month survival than those occurring during daytime (reference) (adjusted odds ratio, 0.69, 0.64; 95% confidence interval 0.65–0.72, 0.61–0.67; P<0.001, P<0.001, Guideline 2005 and 2010 respectively). OHCA patients occurring during daytime in Guideline 2010 had better one-month survival than those in Guideline 2005 (adjusted odds ratio, 1.29; 95% confidence interval 1.24–1.34; P<0.001).

Conclusions

One-month survival with favorable neurological outcome in OHCA patients occurring at night remains to be significantly worse than those occurring during daytime, even improved by the periods during daytime. CPR training for the family members should be more expanded and strengthened against the night time imperfection.

P6354Decreased beneficial effects of oral heart failure medications in patients with acute decompensated heart failure and hyperglycemia: results from an international observational cohort

Background

Hyperglycemia is common, regardless of diabetes mellitus (DM), and is associated with increased mortality in patients with acute heart failure (AHF). Current oral heart failure (HF) medications improve the outcome in patients with AHF. However, the relationships between HF medications, admission glucose levels, and prognosis in AHF patients remained unknown.

Purpose

This study sought to investigate the effect of oral HF medications on relationships between hyperglycemia at admission and 1-year all-cause mortality in patients with AHF.

Methods

From the GREAT (Global Research on Acute Conditions Team) registry, 13840 patients presenting with AHF whose admission glucose levels were available were included and followed up for 1-year all-cause mortality. Hyperglycemia was defined as a glucose levels of ≥7 mmol/L for patients without history of DM and ≥10 mmol/L for those with history of DM. Patients with hypoglycemia (defined as a glucose levels of ≤4 mmol/L, n=193, 1.4%) were excluded in this analysis.

Results

There were 6418 (%) patients with hyperglycemia and 7229 (%) patients with normoglycemia. One-year mortality was higher in patients with hyperglycemia than those with normoglycemia (1911 [30%] and 1821 [25%], respectively). Even after adjustment, the risk for 1-year mortality was significantly higher in hyperglycemia (HR 1.14, 95%-CI 1.04–1.26, P=0.008) compared with normoglycemia. Detrimental effects of hyperglycemia on 1-year mortality were more severe in de novo AHF patients than in patients with history of HF (p for interaction 0.004). Oral HF medications (beta blockers and/or angiotensin converting enzyme inhibitors/angiotensin receptor blockers) at discharge were effective in AHF patients with normoglycemia regardless of history of HF. Oral HF medications at discharge are very effective in de novo AHF patients with hyperglycemia and less effective in acute decompensated HF patients with hyperglycemia (Figure).

HF medications and 1-year mortality

Conclusions

Hyperglycemia at admission is associated with increased risk for 1-year mortality. Current oral HF medications are effective in most of subgroups, though they were less effective in patients with acute decompensated HF and hyperglycemia. These patients might need more aggressive therapies to improve outcomes.

Acknowledgement/Funding

This work was supported by a research fellowship from Japan Heart Foundation (E.A.)

P1701Sex-related difference in receiving bystander cardiopulmonary resuscitation and clinical outcome among out-of-hospital cardiac arrest patients

Background

Early studies from US and Europe have reported that female out-of-hospital cardiac arrest (OHCA) patients were less likely to receive bystander cardiopulmonary resuscitation (CPR). However, little is known about sex-related difference in receiving CPR and clinical outcome among adult OHCA patients in Japan.

Methods

This study was a nation-wide, population-based observational study of OHCA in Japan from 2011 to 2015. We included all adult cardiogenic OHCA patients. We excluded patients witnessed by emergency medical services (EMS) from the present analysis. To account for the age-related difference, we stratified by age category: 18–39, 40–64, 65–79, and ≥80. To examine the association between patient sex and neurological outcome at 30-day, we fitted multivariable logistic regression model with adjustment for age, bystander CPR status, first document rhythm, dispatcher instruction and EMS response time.

Results

There were 339,317 adult cardiogenic, not EMS-witnessed OHCA patients (median age, 80; female, 43.5%) in Japan from 2011 to 2015. Overall, 171,122 (50.4%) received CPR by citizen, 34,283 (10.1%) had initial shockable rhythm, and 11,421 (3.4%) had favorable neurological status at 30-day. Female patients were more likely to receive bystander CPR (vs. male; 53.8% vs. 47.8%), and were less likely to have initial shockable rhythm (5.2% vs. 13.9%) and favorable neurological status at 30-day (1.8% vs. 4.6%) (all; p<0.001). With stratification by age category, elderly female patients (aged ≥65) were more likely to received bystander CPR (P<0.001), whereas male patients were more likely to received bystander CPR among patients aged <40. Multivariable logistic regression analysis showed that female patients had a lower rate of favorable neurological status at 30-day, compared to male patients in all age categories (all; P<0.05).

Sex difference in bystander CPR Overall Male (n=191,672) Female (n=147,645) p-value All (n=339,317) 50.4% 47.8% 53.8% <0.001 Aged 18–39 (n=6,216) 56.0% 56.9% 53.5% 0.02 Aged 40–64 (n=50,320) 48.5% 48.5% 48.3% 0.69 Aged 65–80 (n=105,141) 46.5% 45.5% 48.3% <0.001 Aged ≥80 (n=177,640) 53.2% 49.0% 56.7% <0.001

OR for neurological outcome at 30-day

Conclusion

Unlike the situation in Europe and US, female OHCA patients, especially elderly female, were more likely to receive bystander CPR in Japan. However, female patients had worse clinical outcome after OHCA. Further investigations including in-hospital treatment are needed to clarify the sex-difference in clinical outcome after OHCA.

Acknowledgement/Funding

None

P2569Self-adhesive bi-layered dressing incorporating amnion-derived mesenchymal stromal cells for the treatment of heart failure: a pre-clinical proof of concept study

Introduction

Mesenchymal stromal cell (MSC) transplantation is a promising treatment to promote myocardial repair. Among various sources, the amnion has an advantage in mass production of high-quality MSCs due to its large initial cell-yield and prenatal nature of isolated cells. In addition to the powerful tissue-repair potential, amnion-derived MSCs (AMSCs) exhibit a robust immunomodulative ability, enabling allogeneic transplantation without immunosuppressive reagents. We here report a novel bioengineering technique to deliver AMSCs for myocardial repair by epicardial placement of self-adhesive, bi-layered, AMSC-incorporating dressings (AMSC-dressing), which is fabricable on-site (Figure A).

Methods and results

AMSC-dressing was fabricated by spreading AMSC suspension on the inner layer of a fibrin sealant film, composed of fibrinogen and thrombin. Due to the resulting adhesive AMSC-fibrin complex, the AMSC-dressing firmly adhered to the heart surface without the need for suture or additional glue. The outer collagen layer of the film facilitated the easy handling and also protected the AMSC-fibrin complex from external damage. We applied a 1 cm2 dressing containing 0, 1, 2 or 4 millions of rat AMSCs to a rat ischemic cardiomyopathy model (4 weeks post coronary artery ligation). Intramyocardial (IM) injection of 4 millions of AMSCs and sham treatment were also conducted. Echocardiography and catheterization consistently demonstrated that AMSC-dressing therapy improved cardiac function and reduced heart dilatation in a dose-dependent manner compared to the sham control. Furthermore, this therapeutic effect exceeded that of IM injection (Figure B). Histological analyses revealed that AMSC-dressing therapy resulted in augmented myocardial tissue repair (increased neovascularization, attenuated pathological fibrosis and reduced cardiomyocyte hypertrophy) compared to IM injection and sham groups. These effects were associated with increased upregulation of a range of tissue repair-related genes including Il10, Cxcl12, Igf1, Timp1, Hif1a, Tgfb, Mmp2, Hgf, Fgf2 and Vegf. Of note, it was elucidated that both initial retention and subsequent survival of donor AMSCs were enhanced by the dressing technique compared to IM injection. In addition, in vitro studies demonstrated that culturing in a fibrin glue not only enhanced upregulation of tissue-repair genes of AMSCs but also improved their survival against environmental stress through activating the Akt/PI3K cell-survival pathway.

Conclusion

AMSC-dressing therapy enhanced both quantity and quality of donor cell engraftment, leading to the augmented therapeutic efficacy, compared to the current method. Furthermore, this technique is user-friendly and requires no specialized equipment at the treating hospital, highlighting its great potential to be a widely-adopted, standard treatment for heart failure. Further development of this advanced cell therapy towards clinical application is justified.

Acknowledgement/Funding

British Heart Foundation, Heart Research UK, Japan Agency for Medical Research and Development, Kaneka Corporation

Domain Wall Based Spin-Hall Nano-Oscillators

In the last decade, two revolutionary concepts in nanomagnetism emerged from research for storage technologies and advanced information processing. The first suggests the use of magnetic domain walls in ferromagnetic nanowires to permanently store information in domain-wall racetrack memories. The second proposes a hardware realization of neuromorphic computing in nanomagnets using nonlinear magnetic oscillations in the gigahertz range. Both ideas originate from the transfer of angular momentum from conduction electrons to localized spins in ferromagnets, either to push data encoded in domain walls along nanowires or to sustain magnetic oscillations in artificial neurones. Even though both concepts share a common ground, they live on very different timescales which rendered them incompatible so far. Here, we bridge both ideas by demonstrating the excitation of magnetic auto-oscillations inside nanoscale domain walls using pure spin currents. This Letter will shed light on the current characteristic and spatial distribution of the excited auto-oscillations.

Radiologic and Pathologic Features of the Transmantle Sign in Focal Cortical Dysplasia: The T1 Signal Is Useful for Differentiating Subtypes

BACKGROUND AND PURPOSE

The transmantle sign is a characteristic MR imaging finding often seen in focal cortical dysplasia type IIb. The transmantle sign is typically hyperintense on T2WI and FLAIR and hypointense on T1WI. However, in some cases, it shows T1 high signal. We evaluated the imaging and pathologic findings to identify the causes of the T1 high signal in the transmantle sign.

MATERIALS AND METHODS

We retrospectively reviewed the preoperative imaging data of 141 consecutive patients with histologically proved focal cortical dysplasia. We selected 25 patients with focal cortical dysplasia with the transmantle sign and divided them into groups based on the pathologic focal cortical dysplasia subtype and T1 signal of the transmantle sign. We evaluated the clinical, radiologic, and pathologic findings, including the number of balloon cells and dysmorphic neurons and the severity of gliosis or calcifications and compared them among the groups.

RESULTS

Nine of the 25 patients had a T1-high-signal transmantle sign; the other 16 patients did not. All 9 patients with a T1-high-signal transmantle sign were diagnosed as type IIb (group A). Of the 16 patients with no T1-high-signal transmantle sign, 13 were diagnosed as having type IIb (group B), and the other 3 patients, as type IIa (group C). The number of balloon cells was significantly higher in group A than in the other groups, but there were no differences regarding dysmorphic neurons, the severity of gliosis, or calcifications.

CONCLUSIONS

Approximately 6% (9/141) of this patient series had a T1-high-signal transmantle sign, and all were type IIb. The signal may reflect a rich density of balloon cells. This finding could support the differentiation of subtypes, especially type IIb.

First Monte Carlo Global QCD Analysis of Pion Parton Distributions

We perform the first global QCD analysis of parton distribution functions (PDFs) in the pion, combining πA Drell-Yan data with leading neutron electroproduction from HERA within a Monte Carlo approach based on nested sampling. Inclusion of the HERA data allows the pion PDFs to be determined down to much lower values of x, with relatively weak model dependence from uncertainties in the chiral splitting function. The combined analysis reveals that gluons carry a significantly higher pion momentum fraction, ∼30%, than that inferred from Drell-Yan data alone, with sea quarks carrying a somewhat smaller fraction, ∼15%, at the input scale. Within the same effective theory framework, the chiral splitting function and pion PDFs can be used to describe the d[over ¯]-u[over ¯] asymmetry in the proton.