Margin Of Lobe Research Articles

Hybrid event bed distribution in a mixed siliciclastic-calcareous turbidite succession: a cross-current perspective from the Bordighera Sandstone, Ligurian Alps, NW Italy

Transitional flow deposits (TFDs) and hybrid event beds (HEBs) form part of the high-density sediment gravity flow spectrum. They record flow characteristics intermediate between fully turbulent and laminar flow states. The transformation from initially frictional into transitional or quasi-laminar cohesive flow behaviour results from enhanced detrital clay concentrations that dampen flow turbulence, triggering the development of an argillaceous sandstone interval that displays characteristics of a cohesive debris flow deposit. Since excess detrital clay proportions reduce primary porosity and permeability, the presence of TFDs and HEBs hinders turbidite sandstone reservoir properties. In applied scenarios, understanding their spatial distribution is crucial for avoiding well misplacement. Spatial distribution models for TFDs and HEBs largely document them as a characteristic feature of distal and lateral outer fan environments. These models are compared with results from facies analysis conducted on a dataset derived from the detailed investigation of three stratigraphic sections, acquired along a cross-current transect of the distal depositional domain of the Bordighera Sandstone (BGS). In its distal domain, the sand-rich Bordighera turbidite system is characterized by direct interbedding with calcareous fine-grained turbidites of the Sanremo Helminthoid Flysch, and features high proportions of HEBs and TFDs. Analysis of spatial trends in facies distribution allows the detailed allocation of intra- bed- to sandbody-scale heterogeneity to different axial and off-axis lobe sub-environments which are determined through quantitative sedimentological parameters. Results reveal that in the Bordighera turbidite system argillaceous sandstone bed types are not limited to lobe-fringe environments, but instead are primarily occurring in more proximal high net-to-gross zones of the largely unconfined terminal lobe domain. They account for more than 60% of stratigraphic thickness in axial zones (net-to-gross ratio = 0.87), whereas their proportions decrease towards off-axis lobe (36%; net-to-gross = 0.58) and marginal lobe to lobe fringe domains (23%; net-to-gross = 0.49).

Deglaciation dynamics of the Scandinavian Ice Sheet in the Salpausselkä zone, southern Finland

Deglaciation patterns of the Scandinavian Ice Sheet in the Salpausselkä zone, southern Finland were studied. Digital elevation models (DEM/LiDAR‐imageries) were used to map and categorize glacifluvial formations of the study area, and evidence for ice re‐advance and retreat phases and their extent across the Younger Dryas Salpausselkä zone was collected. The results suggest that the Finnish Lake District Ice Lobe, located in SE Finland, retreated a minimum of 60 km north of the proximal side of the present First Salpausselkä ridge prior to the Younger Dryas, most probably during the Allerød interstadial (c. 13 900–12 700 years ago). This retreat phase was followed by a re‐advance after which the First Salpausselkä was formed (maximum age 13 300±900 years ago) in front of the Finnish Lake District Ice Lobe’s ice margin. Subsequently, ice retreated further north and the Second Salpausselkä in front of the Finnish Lake District Ice Lobe margin was formed, according to OSL‐age determinations between 11 500 and 12 000 years ago. Previous research indicates that a similar retreat and re‐advance event to that of the Finnish Lake District Ice Lobe did not take place in the area covered by the Baltic Sea Ice Lobe to the southwest. Overall, the results suggest that the ice retreat of the Finnish Lake District Ice Lobe was of the same magnitude as the contemporary Allerød interstadial ice retreat event along the western flank of the Scandinavian Ice Sheet in Norway and minor ice‐sheet oscillations in central Sweden.

To name but a few: descriptions of five new species of Terebellides (Annelida, Trichobranchidae) from the North East Atlantic

The number of described species of the genus Terebellides Sars, 1835 (Annelida, Trichobranchidae) has greatly increased in the last years, particularly in the North East Atlantic. In this context, this paper deals with several putative species recently delineated by molecular means within a well delimited clade of Terebellides. Species are characterised here by a combination of morphological characters, and a complementary nucleotide diagnostic approach. Three species were identified as the nominal species T. stroemii Sars, 1835, T. bigeniculatus Parapar, Moreira & Helgason, 2011 and T. europaeaLavesque et al., 2019. Five species are described as new: T. bakkenisp. nov., T. kongsrudisp. nov., T. norvegicasp. nov., T. ronningaesp. nov. and T. scoticasp. nov. The distinctive morphological characters refer to the branchial shape, absence or presence of papillae on lamellae of anterior margin of branchial dorsal lobes, absence or presence of ciliated papillae dorsal to thoracic notopodia, geniculate chaetae in one or two chaetigers, and the morphology of thoracic and abdominal uncini teeth. Furthermore, the description of T. bigeniculatus is revised and complemented after examination of type specimens. An updated identification key to all species of the genus in NE Atlantic and a proposal of a classification of different types of abdominal uncini to be used in taxonomy are also included.

Structural and histochemical characterization of the osmophores in corollas of Asteraceae (tribes Onoserideae and Famatinantheae)

Osmophores are engaged in scent production and differ from other secretory structures by their product, site, duration, and anatomical structure. Whereas osmophores have been well-documented in flowers of several families, they are barely mentioned in the Asteraceae. The aims of this study are to: 1) determine the occurrence of osmophores in corollas of 39 species of the tribe Onoserideae and the only species of Famatinantheae with histochemical methods; and 2) analyze the morphology and structure of osmophores in these groups. Histochemical and histological techniques revealed osmophores in the marginal and in the central corollas of Famatinanthus Ariza & S.E. Freire and Plazia Ruiz & Pav. at the apex and margin of the corolla lobes, and at the sinuses. Osmophores were confirmed following positive staining reactions for TIOFH and TIOFH3 (Neutral Red, Oil Red O, and Iodine-Potassium-Iodide); the samples reacted negatively for Benedict's test for detecting reducing sugars. The osmophores found in this study are constituted uniquely by a papillose or non-papillose epidermis, or they extend into the mesophyll forming scent glands. In both cases, they are associated to stomata and starch grains. The corollas of the other species of Onoserideae did not react positively for osmophores.

Biometrical analysis and thallus morphology characteristics of Placopsis antarctica from King George Island, Antarctica ( Short Communication )

Placopsis antarctica is an ornithocoprophilous lichen that has been for a long time confused with P. contortuplicata I. M. Lamb. In our study, we focused on morphological characteristics of P. antarctica thalli. We report biometrical data on dominant morphological structures of P. antarctica thallus: cephalodia, marginal lobes, sorediate pits and soralia. Thalli of P. antarctica were collected at the King George Island, Antarctica and analyzed in a laboratory using a digital microscopy approach. Central cephalodium was found rather elliptic then round-shaped. Mean length/width was found 2.424/1.720 mm. Marginal lobes were found wider at the apex (1.415 mm) than basal part (0.495 mm). Side cephalodia were smaller, their mean length/width was found 1.034/0.610 mm.

A new species of freshwater crab genusFrediusPretzmann, 1967 (Crustacea: Brachyura: Pseudothelphusidae) from a naturally isolated orographic forest enclave within the semiarid Caatinga in Ceará, northeastern Brazil

A new species of freshwater crab, Fredius ibiapaba, is described and illustrated from a mid-altitude forested patch in Ipú (Ibiapaba plateau, Ceará, northeastern Brazil), between 635 to 782 m. The new species can be separated from its congeners by the morphology of its first gonopod: proximal half remarkably swollen, sloping abruptly downwards distally to a nearly right-angular shoulder; mesial lobe much smaller than cephalic spine; cephalic lobe moderately developed; auxiliary lobe lip, delimiting field of apical spines, protruded all the way to distal margin of auxiliary lobe. Comparative 16S rDNA sequencing used to infer the phylogenetic placement of Fredius ibiapaba n. sp. revealed that it is the sister taxon of F. reflexifrons, a species which occurs allopatrically in the Amazon and Atlantic basin’s lowlands (<100 m). Fredius ibiapaba n. sp. and F. reflexifrons are highly dependent upon humidity and most probably were once part of an ancestral population living in a wide humid territory. Shrinking humid forests during several dry periods of the Tertiary and Quaternary likely have resulted in the fragmentation of the ancestral humid area and hence of the ancestral crab population. Fredius reflexifrons evolved and spread in a lowland, humid river basin (Amazon and Atlantic basins), whilst F. ibiapaba n. sp. evolved isolated on the top of a humid plateau. The two species are now separated by a vast intervening area occupied by the semiarid Caatinga

Phylogenetic position, complete larval development and larval sexual dimorphism in a rhizocephalan barnacle, Lernaeodiscus rybakovi sp. nov. (Cirripedia: Rhizocephala: Peltogastridae), parasitizing the crab Pachycheles stevensii Stimpson, 1858 (Decapoda: Anomura: Porcellanidae)

Molecular and morphological methods are used to describe Lernaeodiscus rybakovi, a new rhizocephalan species parasitizing the porcellanid crab Pachycheles stevensii Stimpson, 1858, collected in Russian waters of the Sea of Japan. Molecular analysis of three species, including the new one, confirms the monophyly of the genus Lernaeodicus Müller, 1862 and its recent transfer to the family Peltogastridae. The main morphological features of the new species are also common with characters of the other species of the genus Lernaeodiscus Müller, 1862. Externa of L. rybakovi differs from the well studied Lernaeodiscus porcellanae from the E. Pacific by molecular markers, color and the absence of pronounced marginal lobes. Retinacula on the internal cuticle of L. rybakovi are found in the genus Lernaeodiscus for the first time. Some of the female hosts with adult externae were unusual in also carrying their own eggs on the pleopods, a rare situation among rhizocephalans. The complete larval development in the genus Lernaeodiscus is described here for the first time and includes five naupliar and one cypris instar. The main morphological features of Lernaeodiscus nauplii (the presence of flotation collar, morphology of the frontolateral horns and furcal spines, and the arrangement of dorsal setae on the shield head) are common with those of other known peltogastrid larvae, but also resemble nauplii of Peltogasterella in the presence of naupliar eyes and thin structure of the flotation collar. The sizes of male and female cyprids of L. rybakovi overlap slightly. In summer months, larval sex ratio is male-biased. We briefly review important larval characters in the Rhizocephala.

Two new species of the genus Notacanthurus from China (Ephemeroptera: Heptageniidae, Ecdyonurinae).

Previously, only three of seven species in the Asian genus Notacanthurus were reported both nymphs and imagoes, and no Chinese species was found. Here two new species collected from China, which are named as Notacanthurus maculatus sp. n. and N. lamellosus sp. n. respectively, are described and pictured in detail. The nymph of N. maculatus sp. n. has following combined characters: posterior margin of sternum IX straight, claws with two subapical denticles, and gills V-VI with arrow-like accessory lobes. The male imago has unspecialized anterior margin of head and Electrogena-like penis lobes. The second species N. lamellosus sp. n. is more distinguishable. Its nymph has pale dots on head, median dorsal ridges on abdominal terga I-IX, claws with five subapical denticles, and dorsal lamellae of gills II-IV divided into two portions. Anterior margin of male imago is not protruding either, forewings have less pigmented crossveins between Sc and R1, and penis lobes have apical and ventral sclerites. A key to all known nymphs of the genus is provided.

Heterostemma cucphuongense (Apocynaceae, Asclepiadoideae), a new species from Vietnam

Heterostemma cucphuongense (Apocynaceae, Asclepiadoideae), a new species from Vietnam is described, illustrated and compared with the similar species Heterostemma succosum Kerr. Heterostemma cucphuongense differs from H. succosum by the morphology of the rachis of the inflorescence, the margins of the corolla lobes and the colour of the adaxial surface of the corolla.

Chronology of advance and recession dynamics of the southern Green Bay Lobe of the Laurentide Ice Sheet, south-central Wisconsin, USA

AbstractWe used a combination of accelerator mass spectrometry (AMS) radiocarbon dating, optically stimulated luminescence (OSL) age estimates, and stratigraphic data from cores collected along the southern margin of the Green Bay Lobe (GBL) of the Laurentide Ice Sheet to provide new information on the timing and dynamics of the end of advance of the GBL and the dynamics of the ice sheet while very near its maximum position. Coring at multiple sites along the margin of the GBL indicate that ice had reached a stable position near its maximum extent by 24.7 ka; that ice advanced several kilometers to the Marine Isotope Stage 2 maximum position sometime shortly after 21.2 ka; and that ice remained at or beyond that position through the time interval represented by an OSL age estimate of 19.2 ± 3.2 ka. The timeline developed from these chronological data is internally consistent with, and further refines, AMS radiocarbon ages and OSL age estimates previously published for the southern margin of the GBL. It also provides new chronological control on the expansion of the GBL from its late Marine Isotope Stage (MIS) 3 extent to its MIS 2 maximum.

First Report of Colletotrichum musicola Causing Soybean Anthracnose in Brazil

Soybean (Glycine max L.) is one of the most important crops worldwide as a source of protein-rich foods and animal feeds. Anthracnose, one of the major limiting factors to soybean production (Dias et al. 2016), is caused by species such as Colletotrichum truncatum, C. sojae, and C. plurivorum (Damm et al. 2009, 2019). In December 2016 and 2017, soybean plants of cultivars Monsoy 8768 and Pioneer y-70 with typical symptoms of anthracnose (necrotic and irregular brown lesions on stems, leaves, and pods) were collected in Mato Grosso, Brazil. Commercial fields sampled showed 10 to 15% incidence of anthracnose in 1 ha in each sampled area. In total, 10 different geographic locations were sampled. Colletotrichum strains were isolated and cultured on potato dextrose agar at 25°C with a 12-h light photoperiod from surface-disinfected (70% alcohol followed by 0.5% sodium hypochlorite) plant tissues. Among others, three single-spore isolates (LFN0048 from Sinop, LFN0074 and LFN0090 from Lucas do Rio Verde) showed different morphology; isolates LFN0048 and LFN0074 were selected for further characterization. Total DNA was extracted and partial glyceraldehyde 3-phosphate dehydrogenase (GAPDH), histone H3 (HIS3), and β-tubulin (TUB2) genes were amplified and sequenced. The sequences were deposited in GenBank (accession numbers MN604249 and MK163893 for HIS3, MN604248 and MK142674 for GAPDH, and MN604250 and MK142675 for TUB) and were compared with most similar reference sequences of Colletotrichum (Damm et al. 2019). Both isolates clustered with Colletotrichum musicola epitype (CBS 132885), showing 100 and 98.5% similarity in GAPDH, 99.5 and 98.9% in HIS3, and 99.2% in TUB2. On PDA, colonies showed dark-gray aerial mycelium with entire margins, reverse violaceous-black. Conidia and ascospore size and shape match those previously described by Damm et al. (2019): 12.12 to 15.86 × 4.93 to 6.95 µm and 15.5 to 19.34 × 5 to 7.84 µm, respectively (n = 100). Appressoria (n = 50) were single or in loose groups, violaceous-black with predominant obovoid, truncated, and cylindrical shapes, with smooth, undulate, or lobate margin, and 9.25 to 29.79 × 7.22 to 21.06 µm. Perithecia, paraphyses; and unitunicate eight-spored asci were also observed. Asci were cylindrical to clavate, smooth-walled, and 48.12 to 68.78 × 9.59 to 14.47 µm (n = 50). Soybean anthracnose is seed-borne (Dias et al. 2018; Rogerio et al. 2017); therefore, pathogenicity tests were carried out on pregerminated seeds. Five seeds of Brasmax 8579 cultivar were inoculated with 10 µl of a conidial suspension (10⁶ conidia/ml) that was placed in the emerging radicle, and five mock-inoculated seeds were used as a control. Seedlings were planted in vermiculite and incubated at 25°C with a 12-h photoperiod. After 7 days, inoculated plants showed necrotic lesions on the cotyledons, leaflets, and hypocotyl, whereas control plants remained asymptomatic. The experiment was repeated three times. C. musicola was reisolated from the symptomatic tissues, and the identity was confirmed by morphology and multilocus phylogeny. Until now, C. musicola has been reported to be associated with Musa sp. (Damm et al. 2019) and Colocasia esculenta (Vasquez-Lopez et al. 2019) in Mexico, and with Phaseolus lunatus in Brazil (Cavalcante et al. 2018). To our knowledge, this is the first report of C. musicola joining a group of new and emergent species of Colletotrichum causing anthracnose in soybean-producing regions around the world.

&lt;p&gt;&lt;strong&gt;&lt;em&gt;Salvia huastecana &lt;/em&gt;(Lamiaceae), a new species from San Luis Potosí, Mexico&lt;/strong&gt;&lt;/p&gt;

Salvia huastecana is described and illustrated as a new species. It is known from the municipality of Xilitla, San Luis Potosí, Mexico. This taxon belongs to Salvia sect. Angulatae, is similar to S. albiflora and S. roscida but it can be distinguished by a higher number of flowers per verticillaster (9−12), longer caducous bracts with long caudate apex, hirsute calyx with erect trichomes and white corolla, sometimes with the upper lip and margins of the lateral lobes of the lower lip light blue stained. Photographs of living plants and the illustration of the new species are provided.

Aspicilia stalagmitica (Megasporaceae) – новый вид лишайника с изидиевидными выростами таллома

Aspicilia stalagmitica Paukov et Davydov from the Altai Mts, a species with isidia-like outgrowths on areoles, is described as new to science. From other species of the genus Aspicilia stalagmitica differs by the following set of characters: short narrow marginal lobes, conidiomata in the isidia-like outgrowths, appressed to almost substipitate apothecia, long picnoconidia, and stictic acid as a main secondary metabolite. A phylogenetic analysis of Aspicilia stalagmitica (ITS) showing its relationships within Aspicilia is presented.

Is phenotypic plasticity determined by temperature and fluid regime in filter-feeding gelatinous organisms?

Some organisms can compensate for changes in the fluid environment (Re), through behavioral or morphological responses, but it is not known whether their filtering structures could respond to such changes. Among filter-feeding organisms, scyphomedusae have a feeding mechanism based on vortices produced by bell pulsations, which carry fluids toward post-bell structures (tentacles and oral arms) where food particles are retained. To understand if variations in the physical environment (temperature and viscosity) could determine functional shapes or dimensions of feeding structures to compensate for these variations, we cultivated two scyphomedusae species, Lychnorhiza lucerna and Cassiopea andromeda, in different temperatures. Bell and oral-arm filtering structures (digitata) were measured and compared among treatments. Temperature influenced the bell and digitata development (p < 0.001). Ephyrae at lower temperatures filled the umbrella margin more slowly, and developed smaller bells and longer, more spaced and thicker digitata. At lower temperatures, the thickness of the boundary layer around the digitata and the bell marginal lobes increases as the viscosity of the fluid environment increases (i.e., Reynolds number, Re). Therefore, neighboring structures can operate as a continuous structure due to the overlap of their surrounding boundary layers. On the oral arms, the potential overlap of the boundary layers around adjacent digitata could reduce or obstruct the flow between these structures and hinder particle filtration. However, the morphology of the digitata developed differently at the different temperatures, which may compensate for potential boundary-layer overlapping effects. Scyphomedusae proved to be resilient to different developmental temperatures and exhibited different growth patterns that maintained the functionality of the swimming and feeding structures. This phenotypic plasticity suggests the existence of a survival mechanism for filter-feeding jellyfish in a wide range of temperatures. Therefore, we consider whether characteristics of the physical environment (e.g., temperature and viscosity) could determine, to some extent, the functional shapes and dimensions of the feeding structures of filter-feeding gelatinous organisms.

Clinical characteristics and long-term follow-up of seven cases of anti-GABABR encephalitis in patients of Han Chinese descent

ObjectiveTo improve the diagnosis and treatment of anti-GABAB receptor (anti-GABABR) encephalitis and prevent misdiagnosis or non-diagnosis.MethodsWe retrospectively examined the chief clinical manifestations, auxiliary examination results, treatment strategies, treatment efficacy, and long-term follow-up results of seven consecutive patients with anti-GABABR encephalitis.ResultsEpileptic seizures were the first symptom in 100% of the patients; 85.7% had memory deficit in the hospital, 42.8% had residual symptoms of cognitive impairment at discharge, and 28.6% had cognitive impairment at the end of follow-up; 71.4% of the patients had psychosis in the hospital, 57.1% had residual symptoms of psychosis at discharge, and 14.3% still had psychosis at the end of follow-up. However, the clinical symptoms (psychiatric disorders, cognitive decline) and signs (consciousness disturbance) at onset and after follow-up were not significantly different (P > 0.05). In 71.4% of the patients, anti-GABABR antibody serum levels were higher than those in the cerebrospinal fluid (especially in patients with lung cancer). Magnetic resonance imaging in 71.4% of patients indicated that the marginal lobe demonstrated encephalitis lesions. The average modified Rankin Scale score (2.0 ± 2.31) at follow-up was significantly better than that (3.86 ± 0.90) at the time of admission (P < 0.05).ConclusionThe clinical characteristics of anti-GABABR encephalitis were refractory epilepsy, psychiatric disorders, and cognitive impairment. Multiple antiepileptic drugs are crucial for the treatment of intractable epilepsy. Clinicians should eliminate the possibility of small-cell lung cancer in patients with high anti-GABABR antibody levels. Early active immunotherapy is effective, and the long-term prognosis is good for patients without tumors.

Establishing a new species group of Pseudopoda Jäger, 2000 with the description of two new species (Araneae, Sparassidae).

The huntsman spider genus Pseudopoda Jäger, 2000 contains 140 species worldwide, of which 61 have been described from China. In this paper, this knowledge is increased by the description of two new species from Yunnan Province in China. These new species, P. physematosasp. nov. (♀) and P. semilunatasp. nov. (♂♀), are treated with five previously described ones, P. bibulba Xu & Yin, 2000 (♂♀), P. signata Jäger, 2001 (♂♀), P. wu Jäger, Li & Krehenwinkel, 2015 (♂♀), P. yinae Jäger & Vedel, 2007 (♂), and P. yunnanensis Yang & Hu, 2001 (♂♀), as the newly defined Pseudopoda signata species group. The P. signata group can be distinguished from other groups within Pseudopoda by the male palps with long, slightly broad, S-shaped embolus, small but distinct tegular apophysis, pronounced dRTA and reduced vRTA, and by the female with V-shaped or W-shaped anterior margins of lateral lobes, membranous and wide first winding, long and strongly curved SIDS (sclerotised internal duct system), the latter mostly covered by the first winding. The monophyly of this group is also supported by molecular phylogenetic results mainly based on Chinese Pseudopoda species. In addition, photographs of P. bibulba (♂♀), P. signata (♂♀), and P. yunnanensis (♂♀) are provided. P. bibulba is newly recorded from Guizhou Province and P. signata is newly recorded from Yunnan Province.

A new limulid (Chelicerata, Xiphosurida) from the Late Cretaceous (Cenomanian–Turonian) of Gara Sbaa, southeast Morocco

Two specimens of a new species of horseshoe crab, Mesolimulus tafraoutensis sp. nov., are described from the Late Cretaceous (Cenomanian–Turonian) Gara Sbaa Lagerstätte of southeast Morocco. These most likely represent juveniles, as suggested by their small size and possession of a number of characteristics, such as short genal spines, that are characteristic of modern juvenile horseshoe crabs. Despite this, the development of the prosomal keel into a broader cardiac ridge and the scalloped lateral margins of the cardiac lobe clearly place these specimens within Mesolimulus. A further characteristic, the occurrence of only two tubercles on the thoracetron pleural ridges, marks Mesolimulus tafraoutensis sp. nov. as a distinct species. As Mesolimulus resolves phylogenetically as a total group limulid outside of the crown group, the new discovery indicates that stem-lineage limulids persisted into the Cretaceous and co-existed with crown-limulids as they underwent their major radiation.

Oreocharisodontopetala, a new species of Gesneriaceae from Guizhou, China.

A new species, Oreocharisodontopetala Q.Fu & Y.Q.Wang from Guizhou Province in southwest China, is described and illustrated, based on morphological comparison with existing species. It is morphologically most similar to O.elegantissima, but can be easily distinguished by its adaxially bullate leaf blade, abaxially conspicuous reticulate veinlets, brown-purple peduncles, triangular adaxial corolla lobes and abaxial corolla lobe margins bearing 4–10 long teeth, glabrous style and shorter stamens with confluent thecae at the apex, as well as leaf epidermal characters.

Upretia squamulosa, a new lichen species from the arid valley of Jinsha-jiang River, China

Upretia squamulosa is described as new to science from the arid valley of Jinsha-jiang River, China. It is characterized by a squamulose thallus, greyish green to brown upper surface, lecanorine apothecia, and by containing gyrophoric and lecanoric acids. The other species in the genus, U. amarkantakana, differs from the new species by the crustose to subsquamulose thallus with lobate margin and the absence of gyrophoric and lecanoric acids. A phylogenetic tree based on nrITS for Upretia and related genera in the subfamily Caloplacoideae is established to assess the affinities of the new species.

Can we delineate preoperatively the right and ventral margins of caudate lobe of the liver?

PurposeComplete removal of the caudate lobe, which is sometimes necessary, is accomplished via isolated caudate lobectomy or hepatectomy that includes the caudate lobe. It is impossible, however, to confirm the right and ventral margins of the caudate lobe by preoperative imaging. This study was undertaken to determine whether we could identify the right and ventral margins of the caudate lobe preoperatively using Synapse 3D visualization software.MethodsNinety-four preoperative 3-dimensional (3D) computed tomographic images (1-mm slices) of the liver from candidate donors were examined. The images of the caudate lobe were subjected to a counter-staining method according to Synapse 3D to delineate their dimensions. We first examined whether the right margin of the caudate lobe exceeded the plane formed by the root of the right hepatic vein (RHV) and the right side of the inferior vena cava (IVC). Second, we determined whether the ventral margin of the caudate lobe exceeded the plane formed by the root of the middle hepatic vein (MHV) and the root of the RHV.ResultsFor the right margin, 17 cases (18%) exceeded the RHV-IVC plane by a mean of 10.2 mm (range, 2.4–27.2 mm). For the ventral margin, 28 cases (30%) exceeded the MHV-RHV plane by a mean of 17.4 mm (range, 1.2–49.1 mm).ConclusionEvaluating the anatomy of caudate lobe using Synapse 3D preoperatively could be helpful for more precise anatomical resection of the caudate lobe.