Pathogenic FLNA variants affecting the hinge region of filamin A are associated with male survival.

Pathogenic variants in FLNA cause a diversity of X-linked developmental disorders associated with either preserved or diminished levels of filamin A protein and are conceptualized dichotomously as relating to underlying gain- or loss-of-function pathogenic mechanisms. Hemizygosity for germline deletions or truncating variants in FLNA is generally considered to result in embryonic lethality. Structurally, filamin A is composed of an N-terminal actin-binding region, followed by 24 immunoglobulin-like repeat units. The repeat domains are separated into distinct segments by two regions of low-complexity known as hinge-1 and hinge-2. Hinge-1 is proposed to confer flexibility to the otherwise rigid protein and is a target for cleavage by calpain with the resultant filamin fragments mediating crucial cellular signaling processes. Here, three families with pathogenic variants in FLNA that impair the function of hinge-1 in males are described, leading to distinct clinical phenotypes. One large in-frame deletion that includes the hinge leads to frontometaphyseal dysplasia in affected males and females, while two germline truncating variants located within the exon encoding hinge 1 result in phenotypes in males that are explained by exon skipping and under-expression of a transcript that deletes hinge-1 from the resultant protein. These three variants affecting hinge-1 indicate that this domain does not mediate cellular functions that, when deficientresult in embryonic lethality in males and that germline truncating variants in this region of FLNA can result in viable phenotypes in males.

FLNA-filaminopathy skeletal phenotypes are not due to an osteoblast autonomous loss-of-function.

Mutations in FLNA, which encodes the cytoskeletal protein FLNA, cause a spectrum of sclerosing skeletal dysplasias. Although many of these genetic variants are recurrent and cluster within the gene, the pathogenic mechanism that underpins the development of these skeletal phenotypes is unknown. To determine if the skeletal dysplasia in FLNA-related conditions is due to a cell-autonomous loss-of-function localising to osteoblasts and/or osteocytes, we utilised mouse models to conditionally remove Flna from this cellular lineage. Flna was conditionally knocked out from mature osteocytes using the Dmp1-promoter driven Cre-recombinase expressing mouse, as well as the committed osteoblast lineage using the Osx-Cre or Col1a1-Cre expressing lines. We measured skeletal parameters with µCT and histological methods, as well as gene expression in the mineralised skeleton. We found no measureable differences between the conditional Flna knockout mice, and their control littermate counterparts. Moreover, all of the conditional Flna knockout mice, developed and aged normally. From this we concluded that the skeletal dysplasia phenotype associated with pathogenic variants in FLNA is not caused by a cell-autonomous loss-of-function in the osteoblast-osteocyte lineage, adding more evidence to the hypothesis that these phenotypes are due to gain-of-function in FLNA.

Deletion of the last two exons of FGF10 in a family with LADD syndrome and pulmonary acinar hypoplasia.

Pulmonary acinar hypoplasia (PAH) and lacrimo-auriculo-dento-digital (LADD) syndrome have both been associated with loss-of-function variants in, or deletions of FGF10. Here we report a multi-generational family with seven members manifesting varying features of LADD syndrome, with one individual dying in early infancy of PAH. Whole genome sequencing in one family member identified a 12,158 bp deletion on chromosome 5p12 that removes two of the three exons of FGF10. Allele-specific PCR demonstrated that all affected family members, including the individual with PAH, carried the 12 kb deletion. We conclude the deletion is pathogenic and expands the mutational spectrum of FGF10 variants in LADD syndrome. The common mechanism underlying the variable clinical features of LADD syndrome is defective terminal branching of salivary and lacrimal glands and pulmonary acini, regulated by the TBX4-FGF10-FGFR2 pathway. The variable phenotypic expressivity of FGF10 haploinsufficiency from relatively benign to lethal is likely due to variation at other genetic loci.

Exon skip-inducing variants in FLNA in an attenuated form of frontometaphyseal dysplasia.

Pathogenic variation in the X-linked gene FLNA causes a wide range of human developmental phenotypes. Loss-of-function is usually male embryonic-lethal, and most commonly results in a neuronal migration disorder in affected females. Gain-of-function variants cause a spectrum of skeletal dysplasias that present with variable additional, often distinctive, soft-tissue anomalies in males and females. Here we present two, unrelated, male individuals with novel, intronic variants in FLNA that are predicted to be pathogenic. Their phenotypes are reminiscent of the gain-of-function spectrum without the skeletal manifestations. Most strikingly, they manifest urethral anomalies, cardiac malformations, and keloid scarring, all commonly encountered features of frontometaphyseal dysplasia. Both variants prevent inclusion of exon 40 into the FLNA transcript, predicting the in-frame deletion of 42 amino acids, however the abundance of FLNA protein was equivalent to that observed in healthy individuals. Loss of these 42 amino acids removes sites that mediate key FLNA functions, including binding of some ligands and phosphorylation. This phenotype further expands the spectrum of the FLNA filaminopathies.

Deletion of Exon 1 in AMER1 in Osteopathia Striata with Cranial Sclerosis.

Osteopathia striata with cranial sclerosis (OSCS) is an X-linked dominant condition characterised by metaphyseal striations, macrocephaly, cleft palate, and developmental delay in affected females. Males have a more severe phenotype with multi-organ malformations, and rarely survive. To date, only frameshift and nonsense variants in exon 2, the single coding exon of AMER1, or whole gene deletions have been reported to cause OSCS. In this study, we describe two families with phenotypic features typical of OSCS. Exome sequencing and multiplex ligation-dependent probe amplification (MLPA) did not identify pathogenic variants in AMER1. Therefore, genome sequencing was employed which identified two deletions containing the non-coding exon 1 of AMER1 in the families. These families highlight the importance of considering variants or deletions of upstream non-coding exons in conditions such as OSCS, noting that often such exons are not captured on probe or enrichment-based platforms because of their high G/C content.

Multicentric plasmacytoma in a harbor porpoise Phocoena phocoena off the coast of Whidbey Island, Washington State, USA.

Necropsy of a female adult pregnant harbor porpoise Phocoena phocoena revealed a multicentric plasmacytoma. The plasmacytoma infiltrated the cranial lung lobes, mediastinal lymph nodes and the spleen. Diagnosis was based on gross, histopathologic and immunohistochemical studies. Histopathology revealed a diffuse proliferation of atypical pleomorphic neoplastic round cells with plasmacytic features. Positive immunohistochemistry with anti-CD79a and anti-CD20 antibody markers and anti-multiple myeloma oncogene 1 (MUM-1) for plasmacytoma confirmed this neoplasm to be of B-cell origin. This is the first recorded case of a plasmacytoma in a harbor porpoise. Routine viral screening was negative via standard PCR for herpesvirus and reverse transcriptase PCR for morbillivirus. Retroviral screening was not performed.

A defect in myoblast fusion underlies Carey-Fineman-Ziter syndrome.

Multinucleate cellular syncytial formation is a hallmark of skeletal muscle differentiation. Myomaker, encoded by Mymk (Tmem8c), is a well-conserved plasma membrane protein required for myoblast fusion to form multinucleated myotubes in mouse, chick, and zebrafish. Here, we report that autosomal recessive mutations in MYMK (OMIM 615345) cause Carey-Fineman-Ziter syndrome in humans (CFZS; OMIM 254940) by reducing but not eliminating MYMK function. We characterize MYMK-CFZS as a congenital myopathy with marked facial weakness and additional clinical and pathologic features that distinguish it from other congenital neuromuscular syndromes. We show that a heterologous cell fusion assay in vitro and allelic complementation experiments in mymk knockdown and mymkinsT/insT zebrafish in vivo can differentiate between MYMK wild type, hypomorphic and null alleles. Collectively, these data establish that MYMK activity is necessary for normal muscle development and maintenance in humans, and expand the spectrum of congenital myopathies to include cell-cell fusion deficits.

Quantification of transmission risk in a male patient with a FLNB mosaic mutation causing Larsen syndrome: Implications for genetic counseling in postzygotic mosaicism cases.

We report the case of a male patient with Larsen syndrome found to be mosaic for a novel point mutation in FLNB in whom it was possible to provide evidence-based personalized counseling on transmission risk to future offspring. Using dideoxy sequencing, a low-level FLNB c.698A>G, encoding p.(Tyr233Cys) mutation was detected in buccal mucosa and fibroblast DNA. Mutation quantification was performed by deep next-generation sequencing (NGS) of DNA extracted from three somatic tissues (blood, fibroblasts, saliva) and a sperm sample. The mutation was detectable in all tissues tested, at levels ranging from 7% to 10% (mutation present in ∼20% of diploid somatic cells and 7% of haploid sperm), demonstrating the involvement of both somatic and gonadal lineages in this patient. This report illustrates the clinical utility of performing targeted NGS analysis on sperm from males with a mosaic condition in order to provide personalized transmission risk and offer evidence-based counseling on reproductive safety.

Autosomal dominant frontometaphyseal dysplasia: Delineation of the clinical phenotype.

Frontometaphyseal dysplasia (FMD) is caused by gain-of-function mutations in the X-linked gene FLNA in approximately 50% of patients. Recently we characterized an autosomal dominant form of FMD (AD-FMD) caused by mutations in MAP3K7, which accounts for the condition in the majority of patients who lack a FLNA mutation. We previously also described a patient with a de novo variant in TAB2, which we hypothesized was causative of another form of AD-FMD. In this study, a cohort of 20 individuals with AD-FMD is clinically evaluated. This cohort consists of 15 individuals with the recently described, recurrent mutation (c.1454C>T) in MAP3K7, as well as three individuals with missense mutations that result in substitutions in the N-terminal kinase domain of TGFß-activated kinase 1 (TAK1), encoded by MAP3K7. Additionally, two individuals have missense variants in the gene TAB2, which encodes a protein with a close functional relationship to TAK1, TAK1-associated binding protein 2 (TAB2). Although the X-linked and autosomal dominant forms of FMD are very similar, there are distinctions to be made between the two conditions. Individuals with AD-FMD have characteristic facial features, and are more likely to be deaf, have scoliosis and cervical fusions, and have a cleft palate. Furthermore, there are features only found in AD-FMD in our review of the literature including valgus deformity of the feet and predisposition to keloid scarring. Finally, intellectual disability is present in a small number of subjects with AD-FMD but has not been described in association with X-linked FMD.

Safety and efficacy of minimally invasive surgery plus alteplase in intracerebral haemorrhage evacuation (MISTIE): a randomised, controlled, open-label, phase 2 trial.

BACKGROUND: Craniotomy, according to the results from trials, does not improve functional outcome after intracerebral haemorrhage. Whether minimally invasive catheter evacuation followed by thrombolysis for clot removal is safe and can achieve a good functional outcome is not known. We investigated the safety and efficacy of alteplase, a recombinant tissue plasminogen activator, in combination with minimally invasive surgery (MIS) in patients with intracerebral haemorrhage. METHODS: MISTIE was an open-label, phase 2 trial that was done in 26 hospitals in the USA, Canada, the UK, and Germany. We used a computer-generated allocation sequence with a block size of four to centrally randomise patients aged 18-80 years with a non-traumatic (spontaneous) intracerebral haemorrhage of 20 mL or higher to standard medical care or image-guided MIS plus alteplase (0·3 mg or 1·0 mg every 8 h for up to nine doses) to remove clots using surgical aspiration followed by alteplase clot irrigation. Primary outcomes were all safety outcomes: 30 day mortality, 7 day procedure-related mortality, 72 h symptomatic bleeding, and 30 day brain infections. This trial is registered with ClinicalTrials.gov, number NCT00224770. FINDINGS: Between Feb 2, 2006, and April 8, 2013, 96 patients were randomly allocated and completed follow-up: 54 (56%) in the MIS plus alteplase group and 42 (44%) in the standard medical care group. The primary outcomes did not differ between the standard medical care and MIS plus alteplase groups: 30 day mortality (four [9·5%, 95% CI 2·7-22.6] vs eight [14·8%, 6·6-27·1], p=0·542), 7 day mortality (zero [0%, 0-8·4] vs one [1·9%, 0·1-9·9], p=0·562), symptomatic bleeding (one [2·4%, 0·1-12·6] vs five [9·3%, 3·1-20·3], p=0·226), and brain bacterial infections (one [2·4%, 0·1-12·6] vs zero [0%, 0-6·6], p=0·438). Asymptomatic haemorrhages were more common in the MIS plus alteplase group than in the standard medical care group (12 [22·2%; 95% CI 12·0-35·6] vs three [7·1%; 1·5-19·5]; p=0·051). INTERPRETATION: MIS plus alteplase seems to be safe in patients with intracerebral haemorrhage, but increased asymptomatic bleeding is a major cautionary finding. These results, if replicable, could lead to the addition of surgical management as a therapeutic strategy for intracerebral haemorrhage. FUNDING: National Institute of Neurological Disorders and Stroke, Genentech, and Codman.

Biallelic mutations in CYP26B1: A differential diagnosis for Pfeiffer and Antley-Bixler syndromes.

Recently, a newly identified autosomal recessive skeletal dysplasia was described characterized by calvarial abnormalities (including cranium bifidum, coronal, and lambdoid synostosis), oligodactyly, femoral bowing, narrow thorax, small pelvic bones, and radiohumeral synostosis. In the two families described, a more severe phenotype led to in utero lethality in three siblings while in a single patient in a second family the phenotype was sufficiently mild to allow survival to 5 months of age. The disorder is caused by biallelic missense mutations in CYP26B1, which encodes for a cytochrome P450 enzyme responsible for the catabolism of retinoic acid in a temporally and spatially restricted fashion during embryonic development. Here, we provide the third family affected by the disorder and the first affected individual to survive beyond infancy. This woman homozygous for c.1303G>A; p.(Gly435Ser) in CYP26B1, which was associated with multisutural synostosis, radiohumeral synostosis, normal bone mineral density, and apparent intellectual disability, a phenotype with significant similarities to Antley-Bixler and Pfeiffer syndromes. © 2016 Wiley Periodicals, Inc.

Mutations in MAP3K7 that Alter the Activity of the TAK1 Signaling Complex Cause Frontometaphyseal Dysplasia.

Frontometaphyseal dysplasia (FMD) is a progressive sclerosing skeletal dysplasia affecting the long bones and skull. The cause of FMD in some individuals is gain-of-function mutations in FLNA, although how these mutations result in a hyperostotic phenotype remains unknown. Approximately one half of individuals with FMD have no identified mutation in FLNA and are phenotypically very similar to individuals with FLNA mutations, except for an increased tendency to form keloid scars. Using whole-exome sequencing and targeted Sanger sequencing in 19 FMD-affected individuals with no identifiable FLNA mutation, we identified mutations in two genes-MAP3K7, encoding transforming growth factor ß (TGF-ß)-activated kinase (TAK1), and TAB2, encoding TAK1-associated binding protein 2 (TAB2). Four mutations were found in MAP3K7, including one highly recurrent (n = 15) de novo mutation (c.1454C>T [ p.Pro485Leu]) proximal to the coiled-coil domain of TAK1 and three missense mutations affecting the kinase domain (c.208G>C [p.Glu70Gln], c.299T>A [p.Val100Glu], and c.502G>C [p.Gly168Arg]). Notably, the subjects with the latter three mutations had a milder FMD phenotype. An additional de novo mutation was found in TAB2 (c.1705G>A, p.Glu569Lys). The recurrent mutation does not destabilize TAK1, or impair its ability to homodimerize or bind TAB2, but it does increase TAK1 autophosphorylation and alter the activity of more than one signaling pathway regulated by the TAK1 kinase complex. These findings show that dysregulation of the TAK1 complex produces a close phenocopy of FMD caused by FLNA mutations. Furthermore, they suggest that the pathogenesis of some of the filaminopathies caused by FLNA mutations might be mediated by misregulation of signaling coordinated through the TAK1 signaling complex.

Menkes disease: importance of diagnosis with molecular analysis in the neonatal period.

Menkes disease is a congenital disorder caused by changes in copper metabolism derived from mutations in the ATP7A gene. It is characterized by physical and neurological alterations. In the neonatal period, these alterations can be nonspecific, which makes early diagnosis a challenge. Diagnosis can be suspected when there are low levels of ceruloplasmin and serum copper. Molecular analysis confirms the diagnosis. Treatment is parenteral administration of copper histidine. We report a familial case with molecular confirmation. The proband had clinical and biochemical suspicious. Treatment with copper histidine was indicated, but initiated at the age of 2 months and 27 days only. He did not present improvements and died at 6 months. The mother became pregnant again, a male fetus was identified and copper histidine was manufactured during pregnancy. He was born healthy, biochemical markers were reduced and treatment was indicated. Molecular analysis was performed confirming mutation in both the mother and the proband, while the other son did not have mutation, so treatment was discontinued. We support the clinical relevance of molecular confirmation for the correct diagnosis and genetic counseling, once clinical findings in the neonatal period are nonspecific and early treatment with parenteral copper histidine must be indicated.

Menkes disease: importance of diagnosis with molecular analysis in the neonatal period / Doença de Menkes: importância do diagnóstico com análise molecular no período neonatal

Summary Menkes disease is a congenital disorder caused by changes in copper metabolism derived from mutations in the ATP7A gene. It is characterized by physical and neurological alterations. In the neonatal period, these alterations can be nonspecific, which makes early diagnosis a challenge. Diagnosis can be suspected when there are low levels of ceruloplasmin and serum copper. Molecular analysis confirms the diagnosis. Treatment is parenteral administration of copper histidine. We report a familial case with molecular confirmation. The proband had clinical and biochemical suspicious. Treatment with copper histidine was indicated, but initiated at the age of 2 months and 27 days only. He did not present improvements and died at 6 months. The mother became pregnant again, a male fetus was identified and copper histidine was manufactured during pregnancy. He was born healthy, biochemical markers were reduced and treatment was indicated. Molecular analysis was performed confirming mutation in both the mother and the proband, while the other son did not have mutation, so treatment was discontinued. We support the clinical relevance of molecular confirmation for the correct diagnosis and genetic counseling, once clinical findings in the neonatal period are nonspecific and early treatment with parenteral copper histidine must be indicated.

Resumo A doença de Menkes é causada por uma alteração genética no metabolismo do cobre, por mutações no gene ATP7A. Caracteriza-se por alterações neurológicas e no exame físico. No período neonatal, essas alterações podem ser inespecíficas, o que torna o diagnóstico precoce um desafio. O diagnóstico pode ser suspeitado quando há baixos níveis séricos de cobre e ceruloplasmina. A análise molecular confirma o diagnóstico, e o tratamento deve ser feito com histidina de cobre. Nós relatamos um caso familial de doença de Menkes. O probando apresentava quadro clínico e alterações bioquímicas compatíveis com a doença de Menkes, em consulta com 1 mês de vida. O tratamento foi indicado, mas apenas iniciado com 2 meses e 27 dias. Ele não apresentou melhora clínica e veio a óbito com 6 meses. A mãe teve uma nova gestação, foi identificado um feto do sexo masculino e foi solicitada a manipulação da histidina de cobre ainda durante a gestação. O bebê nasceu saudável, os marcadores bioquímicos estavam diminuídos e o tratamento com histidina de cobre foi indicado. Realizamos a análise molecular, que confirmou mutação no gene ATP7A na mãe e no probando; porém, o outro filho não apresentava mutação e o tratamento foi interrompido. Nós defendemos a importância clínica da confirmação molecular para o correto diagnóstico e o aconselhamento genético da doença de Menkes, uma vez que os achados clínicos e as alterações bioquímicas no período neonatal são inespecíficos, e o tratamento com histidina de cobre parenteral deve ser rapidamente instituído.

Accuracy of the ABC/2 Score for Intracerebral Hemorrhage: Systematic Review and Analysis of MISTIE, CLEAR-IVH, and CLEAR III.

BACKGROUND AND PURPOSE: The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography-based planimetry (CTP). METHODS: In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. RESULTS: In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC (r(2)=0.93) than with site-ABC (r(2)=0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm(3); CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P<0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots. CONCLUSIONS: ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.

A new acro-osteolysis syndrome caused by duplications including PTHLH.

Parathyroid hormone-like hormone (PTHLH, MIM 168470) is a humoral factor, structurally and functionally related to parathyroid hormone, which mediates multiple effects on chondrocyte, osteoblast and osteoclast function. Mutations and copy number imbalances of the PTHLH locus and in the gene encoding its receptor, PTHR1, result in a variety of skeletal dysplasias including brachydactyly type E, Eiken syndrome, Jansen metaphyseal chondrodysplasia and Blomstrand type chondrodysplasia. Here we describe three individuals with duplications of the PTHLH locus, including two who are mosaic for these imbalances, leading to a hitherto unrecognized syndrome characterized by acro-osteolysis, cortical irregularity of long bones and metadiaphyseal enchondromata.

Mutations in genes encoding the cadherin receptor-ligand pair DCHS1 and FAT4 disrupt cerebral cortical development.

The regulated proliferation and differentiation of neural stem cells before the generation and migration of neurons in the cerebral cortex are central aspects of mammalian development. Periventricular neuronal heterotopia, a specific form of mislocalization of cortical neurons, can arise from neuronal progenitors that fail to negotiate aspects of these developmental processes. Here we show that mutations in genes encoding the receptor-ligand cadherin pair DCHS1 and FAT4 lead to a recessive syndrome in humans that includes periventricular neuronal heterotopia. Reducing the expression of Dchs1 or Fat4 within mouse embryonic neuroepithelium increased progenitor cell numbers and reduced their differentiation into neurons, resulting in the heterotopic accumulation of cells below the neuronal layers in the neocortex, reminiscent of the human phenotype. These effects were countered by concurrent knockdown of Yap, a transcriptional effector of the Hippo signaling pathway. These findings implicate Dchs1 and Fat4 upstream of Yap as key regulators of mammalian neurogenesis.

Analysis of koi herpesvirus latency in wild common carp and ornamental koi in Oregon, USA.

Koi herpesvirus (KHV) infection is associated with high mortalities in both common carp (Cyprinus carpio carpio) and koi carp (Cyprinus carpio koi) worldwide. Although acute infection has been reported in both domestic and wild common carp, the status of KHV latent infection is largely unknown in wild common carp. To investigate whether KHV latency is present in wild common carp, the distribution of KHV latent infection was investigated in two geographically distinct populations of wild common carp in Oregon, as well as in koi from an Oregon-based commercial supplier. Latent KHV infection was demonstrated in white blood cells from each of these populations. Although KHV isolated from acute infections has two distinct genetic groups, Asian and European, KHV detected in wild carp has not been genetically characterized. DNA sequences from ORF 25 to 26 that are unique between Asian and European were investigated in this study. KHV from captive koi and some wild common carp were found to have ORF-25-26 sequences similar to KHV-J (Asian), while the majority of KHV DNA detected in wild common carp has similarity to KHV-U/-I (European). In addition, DNA sequences from IL-10, and TNFR were sequenced and compared with no differences found, which suggests immune suppressor genes of KHV are conserved between KHV in wild common carp and koi, and is consistent with KHV-U, -I, -J.

Segmentation and quantification of intra-ventricular/cerebral hemorrhage in CT scans by modified distance regularized level set evolution technique.

PURPOSE: An automatic, accurate and fast segmentation of hemorrhage in brain Computed Tomography (CT) images is necessary for quantification and treatment planning when assessing a large number of data sets. Though manual segmentation is accurate, it is time consuming and tedious. Semi-automatic methods need user interactions and might introduce variability in results. Our study proposes a modified distance regularized level set evolution (MDRLSE) algorithm for hemorrhage segmentation. METHODS: Study data set (from the ongoing CLEAR-IVH phase III clinical trial) is comprised of 200 sequential CT scans of 40 patients collected at 10 different hospitals using different machines/vendors. Data set contained both constant and variable slice thickness scans. Our study included pre-processing (filtering and skull removal), segmentation (MDRLSE which is a two-stage method with shrinking and expansion) with modified parameters for faster convergence and higher accuracy and post-processing (reduction in false positives and false negatives). RESULTS: Results are validated against the gold standard marked manually by a trained CT reader and neurologist. Data sets are grouped as small, medium and large based on the volume of blood. Statistical analysis is performed for both training and test data sets in each group. The median Dice statistical indices (DSI) for the 3 groups are 0.8971, 0.8580 and 0.9173 respectively. Pre- and post-processing enhanced the DSI by 8 and 4% respectively. CONCLUSIONS: The MDRLSE improved the accuracy and speed for segmentation and calculation of the hemorrhage volume compared to the original DRLSE method. The method generates quantitative information, which is useful for specific decision making and reduces the time needed for the clinicians to localize and segment the hemorrhagic regions.