Position Of Organs Research Articles

Cross-sectional representations of the central nervous system in Pirogov’s “Ice Anatomy”

ABSTRACT Russian surgeon Nikolay Ivanovich Pirogov (Pirogoff; 1810–1881) introduced the teaching of applied topographical anatomy in Russia. Pirogov’s monumental four-part atlas, Anatome topographica sectionibus per corporis humanum congelatum triplici directione ductis illustrate (An Illustrated Topographic Anatomy of Saw Cuts Made in Three Dimensions Across the Frozen Human Body), colloquially known as the “Ice Anatomy,” was published in Latin in folio in the 1850s. Pirogov sought to investigate “the normal and pathological positions of different organs and body parts using sections made in the three principal directions [anatomical planes] … throughout all regions.” To accomplish this, he froze cadavers “to the density of the thickest wood” and then cut them into thin plates with a special mechanical saw. His approach was reportedly inspired by his observations of butchers sawing across frozen pig carcasses at the meat market in St. Petersburg during winter. Pirogov systemically obtained full-size representations of more than 1,000 sections. A painter made a representative copy of the cross-sectional contours of each section, using ruled glass overlain on the sections. The final lithographs were of high artistic quality and execution, resembling modern high-resolution medical imaging (i.e., CT or MRI). Moreover, structures were serially sectioned and systematically illustrated along all three anatomical planes, something that had never previously been attempted. This allowed clinicians and anatomists to scrutinize the spatial relationships of structures from multiple perspectives and at a much more detailed level than was previously possible, although the cost, massiveness, and complexity of the completed work precluded wide dissemination.

Heterostyly, incompatibility system and pollinators in Varronia spinescens Borhidi (L.) (Cordiaceae)

Heterostyly, the reciprocal position of sexual organs between different morphs within a population, is assumed to promote cross-pollination in hermaphroditic plants. Heterostyly is usually linked to an incompatibility system where only the crosses between the different morphs produce fruit. Although heterostyly has been frequently studied in plant species with specialized pollination systems, few studies have investigated this in species with a broad spectrum of floral visitors. Here, we describe the heterostyly of Varronia spinescens and conducted hand-pollination experiments in the field to determine the incompatibility system. We also analysed perianth morphology, morph-ratio, adaptive inaccuracy in reciprocity and pollinator visitation rate in relation to floral morph and number of open flowers. Our results indicate that V. spinescens is a distylous species with a high degree of reciprocity between the sexual organs, presenting a non isoplethic morph ratio with a bias towards the long style (L-) morph. The incompatibility system is heteromorphic and the studied population received visits by a very high number of visitor and pollinator species. Varronia spinescens is thus the heterostylous species of the genus with the second-highest number of registered pollinators. Our results suggest that in a generalist pollination system with little floral morphological restriction to pollinators, the maintenance of sexual polymorphism is likely associated with a high reciprocity between morphs.

Dose Prediction for Cervical Cancer Brachytherapy Using 3-D Deep Convolutional Neural Network

Brachytherapy is a critical modality in treatment of cervix cancer. However, developing a clinically acceptable plan is a time-consuming manual process. In this article, we propose a dose prediction method for cervix cancer brachytherapy using a 3-D deep convolutional neural network (CNN) to guide treatment planning. The method learns the prediction model from a database of historical treatment plans and predicts the 3-D dose distribution with the 3-D organ structures and positions of the inserted applicators as inputs. 110 treatment plans for cervical cancer brachytherapy were used for training the deep CNN to learn a 3-D dose prediction model. Twenty cases were used to evaluate the performance of the proposed method by analyzing the outcomes in terms of mean dose values, derived DVHs from dose distribution, and statistical analysis of sum of absolute residual. Our results show that the predicted mean V100 of the CTV and mean D2cc of organ-at-risks are close to those in the clinical treatment plans. The mean D2cc doses in bladder, rectum and bowel are 5.97, 3.67, and 4.05 Gy, respectively, in comparison to 5.77, 3.42, and 4.16 Gy in clinical plans, indicating a great potential to predict accurate dose distribution and facilitate the brachytherapy treatment planning workflow.

Computed Microtomography (Micro-CT) in the Anatomical Study and Identification of Solenogastres (Mollusca)

Solenogastres are vermiform marine molluscs characterised by an aculiferous mantle, a longitudinal ventral pedal groove and a terminal or subterminal pallial cavity. Their classification is based in part on the type of mantle sclerites, but identification to even the family level generally requires the study of internal anatomical characters. Taxonomically important internal characters include those related to radular structure, the type of ventrolateral glandular organs of the pharynx and the reproductive system, among others. In order to study their internal anatomical organisation, according to the classical reconstruction method, serial histological sections of specimens are made, from which the 2D internal anatomy of the specimen can be reconstructed manually. However, this is a time-consuming technique that results in destruction of the specimen. Computed microtomography or micro-CT is a non-destructive technique based on the measurement of the attenuation of X-rays as they pass through a specimen. Micro-CT is faster than histology for studying internal anatomy and it is non-destructive, meaning that specimens may be used for e.g., DNA extraction or retained as intact vouchers. In this paper, the utility of micro-CT for studying taxonomically important internal anatomical structures was assessed. Results of the 3D anatomical study of the soft parts of four specimens of three species using micro-CT are presented: Proneomenia sluiteriHubrecht, 1880, Dorymenia menchuescribanaeGarcía-Álvarez et al., 2000 and Anamenia gorgonophilaKowalevsky, 1880. Micro-CT enabled detailed study of most taxonomically important anatomical characters, precise measurements of structures, and observation of the relative position of organs from a variety of angles. However, it was not possible to observe the radula and some details of the ventral foregut organs could not be discerned. Despite these limitations, results of this study highlight micro-CT as a valuable tool to compliment histology in the study of solenogaster anatomy and in non-destructively identifying animals to the family and even genus-level.

Бестроакарная Timesh-лигатурная кольпопексия у пациенток репродуктивного возраста с опущением передней стенки влагалища

This article presents the results of surgical treatment of 3 patients aged between 35 and 42 years with stage II anterior vaginal wall prolapse who underwent a trocar-less transobturator correction of anterior prolapse with titanium mesh implants of individual sizes according to a newly developed technique using titanium fixators. The efficacy and safety of the new trocar-less surgical technique for correcting stage II anterior vaginal wall prolapse in patients of reproductive age using titanium implants and fixators were demonstrated. Conclusion. The trocar-less fixation of titanium implants of individual sizes using 4 titanium fixators, their combination with non-absorbable ligatures into a single functional unit, and multifocal fixation of implants contribute to the normalization of anatomic position of pelvic organs, relief of anterior prolapse symptoms, lower risk of injuries to obturator vessels and nerves, and lower incidence of mesh-related complications. Key words: pelvic organ prolapse, TiMesh-ligature colpopexy, trocar-less transobturator correction, titanium fixators

Teškoće u usvajanju veština čitanja i pisanja kod dece sa apraksijom govora

Mastering the skills of reading and writing encourages intensive lexical development that enriches the ability to speak and write. The presence of a delay or an identified speech and/or language disorder at an early age affects the outcome of learning these skills. The aim of this paper is to familiarize readers with the characteristics of apraxia of speech and to draw attention to the difficulties these children exhibit in the process of learning to read and write. Apraxia of speech represents a difficulty in planning and programming the position of the speech organs that are required for the production of speech sounds. For a long time it was believed that this was exclusively a motor speech disorder. New findings changed the aspect of observing this disorder where language disorders were also identified in these children. The primary reason for children with apraxia of speech having difficulty acquiring reading and writing is a delay in the development of phonological awareness, which is known to be the basis of the language system for learning academic skills. Research dealing with the characteristics of written language in children with apraxia of speech is scarce, especially in the Serbian language. A review of the available literature found an emphasis on the presence of language barriers that are assumed to hinder the acquisition of these skills, which subsequently results in poorer academic performance.

Ultrasound-Based Navigation for Open Liver Surgery with Active Tumor Tracking and Deformation Compensation: Preliminary Results

Introduction: Intraoperative ultrasound (US) localization of lesions after neoadjuvant chemotherapy is challenging because their size may decrease beyond the ultrasound resolution. To improve their localization, we introduce an ultrasound-based electromagnetic (EM) navigation system which maps the preoperative image with the intraoperative ultrasound, thus highlighting their location. Methods: Based on MRI or CT, a 3D model of the liver, lesions, hepatic and portal vein was generated and matched with the intraoperative organ position either by 1) identifying common landmarks between the pre- and intraoperative image or 2) automatically using deformable modeling of hepatic and portal vasculature extracted from 3DUS using deep learning. Accuracy was assessed as Euclidean distance between the lesion imaged in the preoperative image and the one identified in intraoperative 3DUS. Results: From March 2019 to May 2021, 45 navigated procedures were safely performed. Navigation provided additional localization features by overlaying preoperative 3D models of liver lesions, vasculature and biliary anatomy onto the intraoperative ultrasound. Accuracy, calculated in 36 patients, was 8.5 ± 4.2 mm for the landmark method (n=20), and 5.7 ± 3.6 mm for automatic generation of the vasculature (n=16) (p=0.043). Surgical navigation was available on average after 13.4 minutes. Conclusion: The proposed navigation system allows to accurately localize liver lesions and is improved by automatic vasculature detection in the US image and compensation of respiratory motion and liver manipulation.

ULTRASOUND IMAGING OF THE SPLEEN, STOMACH, LIVER, KIDNEYS, BLADDER, AND PROSTATE IN PIGLETS (Sus scrofa domestica)

This study aims to describe ultrasonographic imaging of the spleen, stomach, liver, kidney, bladder, and prostate in piglets (Sus scrofa domestica). Ultrasonography was performed on six male piglets aged 1 month with a body weight of 4-8 kg. Ultrasonography of the spleen, stomach, liver, urinary bladder, and prostate was observed in the dorsal-recumbency position, and the kidney was observed in the lateral-recumbency position. The ultrasound examination used the Chison EBit 60, which is a linear type transducer with a frequency of 9 MHz, transverse and sagittal positions, and a gain of about 55-80. Ultrasonography of the spleen showed that the shape of the spleen head varied in each individual. The results of gastric ultrasonography showed the gastric lining clearly and the similarity of the position, shape, structure, echogenicity, and size of the stomach. The results of liver ultrasonography showed that the echogenicity of the liver tended to be hyperechoic, the kidneys were hyperechoic, and the bladder was hypoechoic due to the use of improper gain. The average length of the right kidney was 4.73±0.50 cm and the left kidney was 4.08±0.26 cm. The bladder wall thickness was 1.3±0.31 mm. Imaging of the bladder showed changes in wall size and echogenicity. Prostate ultrasound results obtained an average length of 2.68±0.45 cm, width 1.69±0.35 cm. The results of this study can be used as a reference for normal data on organ position, organ structure, and organ echogenicity of the spleen, stomach, liver, kidney, bladder, and prostate in piglets.

Incidental finding of situs inversus totalis in a patient of carcinoma ovary

Situs inversus totalis is a very rare congenital defect with incidence rate of about 1:10,000 live births [1]. It is characterised by transposition of abdominal and thoracic organs, viscera and vasculature. It results from rotation inopposite direction of viscera and organs during organogenesis [2]. It is an autosomal recessive condition and sometimes it can be X linked and also found in identical twins [3]. Our patient was a 45 year old female who was diagnosed to have carcinoma ovary and underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy. CT scan abdomen revealed this condition. Images show that her organs are simply transposition in sagittal plane. The heart is located on right side of thorax (dextrocardia) with right sided aortic arch. The left sided lung has three lobes and right sided lung has two lobes (Image 1). The stomach, spleen are located on right side of abdomen, whereas liver and gall bladder are on left side (Image 2a & 2b). Blood vessels, lymphatics and intestines are also transpositioned. Uterus and ovaries can be seen absent. Patient was unaware of the condition throughout her life and it was incidentally diagnosed. This condition causes confusion for clinician as all the signs and symptoms will be on the other side of normal anatomical position of organ. It also complicates organ transplantation as donor organs will certainly come from situs solitus donors.

Different molecular changes underlie the same phenotypic transition: Origins and consequences of independent shifts to homostyly within species.

The repeated transition from outcrossing to selfing is a key topic in evolutionary biology. However, the molecular basis of such shifts has been rarely examined due to lack of knowledge of the genes controlling these transitions. A classic example of mating system transition is the repeated shift from heterostyly to homostyly. Occurring in 28 angiosperm families, heterostyly is characterized by the reciprocal position of male and female sexual organs in two (or three) distinct, usually self-incompatible floral morphs. Conversely, homostyly is characterized by a single, self-compatible floral morph with reduced separation of male and female organs, facilitating selfing. Here, we investigate the origins of homostyly in Primula vulgaris and its microevolutionary consequences by integrating surveys of the frequency of homostyles in natural populations, DNA sequence analyses of the gene controlling the position of female sexual organs (CYPᵀ), and microsatellite genotyping of both progeny arrays and natural populations characterized by varying frequencies of homostyles. As expected, we found that homostyles displace short-styled individuals, but long-style morphs are maintained at low frequencies within populations. We also demonstrated that homostyles repeatedly evolved from short-styled individuals in association with different types of loss-of-function mutations in CYPᵀ. Additionally, homostyly triggers a shift to selfing, promoting increased inbreeding within and genetic differentiation among populations. Our results elucidate the causes and consequences of repeated transitions to homostyly within species, and the putative mechanisms precluding its fixation in P.vulgaris. This study represents a benchmark for future analyses of losses of heterostyly in other angiosperms.

Magnetic resonance linear accelerator technology and adaptive radiation therapy: An overview for clinicians.

Radiation therapy (RT) continues to play an important role in the treatment of cancer. Adaptive RT (ART) is a novel method through which RT treatments are evolving. With the ART approach, computed tomography or magnetic resonance (MR) images are obtained as part of the treatment delivery process. This enables the adaptation of the irradiated volume to account for changes in organ and/or tumor position, movement, size, or shape that may occur over the course of treatment. The advantages and challenges of ART maybe somewhat abstract to oncologists and clinicians outside of the specialty of radiation oncology. ART is positioned to affect many different types of cancer. There is a wide spectrum of hypothesized benefits, from small toxicity improvements to meaningful gains in overall survival. The use and application of this novel technology should be understood by the oncologic community at large, such that it can be appropriately contextualized within the landscape of cancer therapies. Likewise, the need to test these advances is pressing. MR-guided ART (MRgART) is an emerging, extended modality of ART that expands upon and further advances the capabilities of ART. MRgART presents unique opportunities to iteratively improve adaptive image guidance. However, although the MRgART adaptive process advances ART to previously unattained levels, it can be more expensive, time-consuming, and complex. In this review, the authors present an overview for clinicians describing the process of ART and specifically MRgART.

Persistent cloaca in the gynecologist's practice (a literature review)

Introduction. Cloacal abnormalities are rare congenital malformations having the most severe and complex forms of anorectal and urogenital malformations. Patients - always females who are born with the persistent cloaca - at the stage of embryogenesis had a merging of lower urethra, vagina and rectum into a single canal or cavity which is opened posterior to the clitoris. The persistent cloaca remains a challenging reconstructive problem for pediatric gynecologists, urologists and surgeons. Doctors must have skills in surgical urology, proctology and in all types of plastic surgery on the vagina and cervix.Material and methods. Data searches were conducted in PubMed and Google Scholar. The following keywords were used: “Cloacal abnormalities” and “Persistent cloaca”.Conclusion. Regardless of a technique, goals for cloaca management remain the same. The primary surgical procedure is aimed to restore normal anatomical positioning of pelvic organs and to form the urethra, vagina and rectum as well as to achieve control over bowel function, urination and reproductive potential of the patient. A surgical correction of persistent cloaca should be performed in specialized medical institutions by specialists having experience in treating children with anorectal anomalies.

3D spatial priors for semi-supervised organ segmentation with deep convolutional neural networks

Fully Convolutional neural Networks (FCNs) are the most popular models for medical image segmentation. However, they do not explicitly integrate spatial organ positions, which can be crucial for proper labeling in challenging contexts. In this work, we propose a method that combines a model representing prior probabilities of an organ position in 3D with visual FCN predictions by means of a generalized prior-driven prediction function. The prior is also used in a self-labeling process to handle low-data regimes, in order to improve the quality of the pseudo-label selection. Experiments carried out on CT scans from the public TCIA pancreas segmentation dataset reveal that the resulting STIPPLE model can significantly increase performances compared to the FCN baseline, especially with few training images. We also show that STIPPLE outperforms state-of-the-art semi-supervised segmentation methods by leveraging the spatial prior information. STIPPLE provides a segmentation method effective with few labeled examples, which is crucial in the medical domain. It offers an intuitive way to incorporate absolute position information by mimicking expert annotators.

Visually guided respiratory motion management for Ethos adaptive radiotherapy.

PurposeEthos adaptive radiotherapy (ART) is emerging with AI‐enhanced adaptive planning and high‐quality cone‐beam computed tomography (CBCT). Although a respiratory motion management solution is critical for reducing motion artifacts on abdominothoracic CBCT and improving tumor motion control during beam delivery, our institutional Ethos system has not incorporated a commercial solution. Here we developed an institutional visually guided respiratory motion management system to coach patients in regular breathing or breath hold during intrafractional CBCT scans and beam delivery with Ethos ART.MethodsThe institutional visual‐guidance respiratory motion management system has three components: (1) a respiratory motion detection system, (2) an in‐room display system, and (3) a respiratory motion trace management software. Each component has been developed and implemented in the clinical Ethos ART workflow. The applicability of the solution was demonstrated in installation, routine QA, and clinical workflow.ResultsAn air pressure sensor has been utilized to detect patient respiratory motion in real time. Either a commercial or in‐house software handled respiratory motion trace display, collection and visualization for operators, and visual guidance for patients. An extended screen and a projector on an adjustable stand were installed as the in‐room visual guidance solution for the closed‐bore ring gantry medical linear accelerator utilized by Ethos. Consistent respiratory motion traces and organ positions on intrafractional CBCTs demonstrated the clinical suitability of the proposed solution in Ethos ART.ConclusionThe study demonstrated the utilization of an institutional visually guided respiratory motion management system for Ethos ART. The proposed solution can be easily applied for Ethos ART and adapted for use with any closed bore‐type system, such as computed tomography and magnetic resonance imaging, through incorporation with appropriate respiratory motion sensors.

Quantification and Dosimetric Impact of Normal Organ Motion During Adaptive Radiation Therapy Plan Verification Using a 1.5 Tesla Magnetic Resonance Equipped Linear Accelerator (MR LINAC)

<h3>Purpose/Objective(s)</h3> Patients receiving adaptive radiation therapy (RT) undergo contour and plan modification prior to treatment delivery. This process takes time to complete, ranging from 15 to 60 minutes or longer. We hypothesize that during the time required to create an adapted RT plan, normal organ movement will result in unanticipated doses delivered to local organs at risk. This study quantifies the dosimetric impact of abdominal organ motion during the time required to create an adaptive RT plan. <h3>Materials/Methods</h3> Patients receiving 5-fraction treatments with MR guided adaptive RT using a 1.5 Tesla MR LINAC were prospectively enrolled in an ongoing imaging study (NCT03500081). Two sets of MRIs were acquired: the first (pre-beam MRI) used to contour organs at the start of treatment, and the second (verification MRI) used to verify organ position immediately before beam-on. Both MRIs were collected in commercially available software. Each normal organ within 1cm of radiation targets was contoured on the verification MRI. The differences in organ position between the two MRIs represents the normal organ movement during the time required for plan adaptation. Max dose (Dmax), volumetric 0.5 cubic centimeter (cc) dose (D0.5cc), volumetric 3000cGy (V30), and volumetric 2000cGy (V20) were calculated. Mixed model tests analyzing differences between the MRI sets were performed using a data management and decision management software. <h3>Results</h3> Thirty adapt-to-shape patients were included. Recontoured normal organs included colon, duodenum, small bowel, and stomach, for a total of 120 new individually created contour volumes. The table below summarizes the mean differences of Dmax in the normal organs between the MRI sets for various organs at risk. Note that only small bowel demonstrated a statistically significant difference in Dmax doses. The D0.5cc, and V30 were also statistically significant for small bowel. <h3>Conclusion</h3> Statistically significant differences in small bowel doses are demonstrated when doses are calculated using the verification MRI. This is likely due to the small bowel's increased mobility compared to other organs analyzed. There is an absence of statistically significant differences in all other abdominal organ doses between these scans. These results reflect that highly mobile structures, such as small bowel, benefit from acquisition of a verification MRI following daily adaptive plan generation. Future research should focus on methods to shorten the adaption duration and/or account for these unanticipated doses, as they represent a significant limitation of adaptive MR guidance.

Usefulness of an Image-Based Noise-Reduction Technique in Cone Beam Computed Tomography for Adaptive Radiotherapy

Cone-beam computed tomography (CBCT) plays an important role in adaptive radiation therapy and can be used to observe changes in body shape, tumor size, and organ position during the treatment period. This technique can also be used to generate an image for replanning. However, performing CBCT during every image guided radiotherapy (IGRT) process increases the radiation dose. Therefore, in this study, we investigated the reduction of the CBCT exposure dose using an image-based edge-preserving noise-reduction technique. A three-dimensional cross-directional bilateral filter (3D-CDBF) which was recently developed by one of the coauthors and reported to provide a noise reduction performance better than a mode-based iterative reconstruction.Catphan was used to evaluate the performance of 3D-CDBF in CBCT. The baseline scan parameters were 120 kV, 40 mA, 40 ms, and 660 frames/360° rotation. The tube current was changed to 32, 20, and 10 mA to reduce the exposure dose. The CBCT images were reconstructed with the filtered back projection (FBP). The 3D-CDBF images were obtained by processing the FBP images. Task-based spatial resolution (task-based transfer function: TTF) and noise power spectrum (NPS) were used to evaluate image quality. Visual evaluation of the image quality was also performed by two experienced radiation oncologists and five radiologists using clinical pelvic images of two patients undergoing radiotherapy for prostate cancer. Additionally, the accuracy of the dose calculation when replanning with 3D-CDBF images was evaluated.The 50%/10% TTFs were 0.364/0.646 mm-1 using FBP and 0.362/0.645 mm-1 using 3D-CDBF, suggesting the excellent edge preservation ability of 3D-CDBF. The noise power of 3D-CDBF compared to FBP were 25.4% at 0.2 mm-1 and 17.0% at 0.5 mm-1. 3D-CDBF notably reduced noise power over the entire frequency range. Therefore, the NPS level of 10 mA became similar to that of 40 mA. The visual evaluation allowed by the 3D-CDBF images was considerably higher than that realized with other images. Additionally, dose evaluation by gamma analysis showed that 3D-CDBF had no effect on the accuracy of the dose calculation.Compared with conventional FBP, the 3D-CDBF yielded significant improvements in quantitative and qualitative image qualities. The results indicated a possible 75% dose reduction of this method, while preserving the accuracy of the dose calculation.

Polymorphism in the symmetries of gastric pouch arrangements in the sea anemone D. lineata

Symmetry in the arrangement of body parts is a distinctive phylogenetic feature of animals. Cnidarians show both bilateral and radial symmetries in their internal organs, such as gastric pouches and muscles. However, how different symmetries appear during the developmental process remains unknown. Here, we report intraspecific variations in the symmetric arrangement of gastric pouches, muscles, and siphonoglyphs, the Anthozoan-specific organ that drives water into the organism, in D. lineata (Diadumenidae, Actiniaria). We found that the positional arrangement of the internal organs was apparently constrained to either biradial or bilateral symmetries depending on the number of siphonoglyphs. Based on the morphological observations, a mathematical model of internal organ positioning was employed to predict the developmental backgrounds responsible for the biradial and bilateral symmetries. In the model, we assumed that the specification of gastric pouches is orchestrated by lateral inhibition and activation, which results in different symmetries depending on the number of siphonoglyphs. Thus, we propose that a common developmental program can generate either bilateral or biradial symmetries depending on the number of siphonoglyphs formed in the early developmental stages.

Volumetric prediction of breathing and slow drifting motion in the abdomen using radial MRI and multi-temporal resolution modeling

Abdominal organ motions introduce geometric uncertainties to radiotherapy. This study investigates a multi-temporal resolution 3D motion prediction scheme that accounts for both breathing and slow drifting motion in the abdomen in support of MRI-guided radiotherapy. Ten-minute MRI scans were acquired for 8 patients using a volumetric golden-angle stack-of-stars sequence. The first five-minutes was used for patient-specific motion modeling. Fast breathing motion was modeled from high temporal resolution radial k-space samples, which served as a navigator signal to sort k-space data into different bins for high spatial resolution reconstruction of breathing motion states. Slow drifting motion was modeled from a lower temporal resolution image time series which was reconstructed by sequentially combining a large number of breathing-corrected k-space samples. Principal components analysis (PCA) was performed on deformation fields between different motion states. Gaussian kernel regression and linear extrapolation were used to predict PCA coefficients of future motion states for breathing motion (340 ms ahead of acquisition) and slow drifting motion (8.5 s ahead of acquisition) respectively. k-space data from the remaining five-minutes was used to compare ground truth motions states obtained from retrospective reconstruction/deformation with predictions. Median distances between predicted and ground truth centroid positions of gross tumor volume (GTV) and organs at risk (OARs) were less than 1 mm on average. 95- percentile Hausdorff distances between predicted and ground truth GTV contours of various breathing motions states were 2 mm on average, which was smaller than the imaging resolution and 95-percentile Hausdorff distances between predicted and ground truth OAR contours of different slow drifting motion states were less than 0.2 mm. These results suggest that multi-temporal resolution motion models are capable of volumetric predictions of breathing and slow drifting motion with sufficient accuracy and temporal resolution for MRI-based tracking, and thus have potential for supporting MRI-guided abdominal radiotherapy.

Standing open magnetic resonance imaging improves detection and staging of pelvic organ prolapse.

The role of imaging in pelvic organ prolapse (POP) assessment is unclear. Open magnetic resonance imaging (MRI) systems have a configuration that allows for imaging women with POP in different positions. Herein, we use a 0.5 Tesla open MRI to obtain supine, seated, and standing images. We then compare these images to evaluate the impact of posture on detection and staging of POP. Women presenting with symptoms of POP at a tertiary care university hospital were asked to participate in this prospective cohort study. Symptom scores, POP-Q staging and three-position MRI imaging of the pelvis data were collected. The pubococcygeal line (PCL) was used to quantify within-patient changes in pelvic organ position as defined by: no displacement, &lt;1 cm inferior to the PCL, mild (1-3 cm), moderate (3.1-6 cm), and severe (&gt;6 cm) in the axial and sagittal T2-weighted images. Statistical analysis was completed (T-test; p&lt;0.05 significant). A total of 42 women, age range 40-78 years, participated. There was a significant difference in the mean values associated with anterior prolapse in the supine (0.7±1.8), seated (2.4±3.4), and upright (4.2±1.6) positions (p=0.015). There was a significant difference in the mean values associated with apical prolapse in the supine (0.5±1.5), seated (1.5±1.4), and upright (2.1±1.5) positions (p=0.036). Our findings suggest that POP is more readily detected and upstaged with standing MRI images as compared to supine and seated positions. The developed two-minute standing MRI protocol may enable clinicians to better assess the extent of POP.

The development and structure of the mesentery

The position of abdominal organs, and mechanisms by which these are centrally connected, are currently described in peritoneal terms. As part of the peritoneal model of abdominal anatomy, there are multiple mesenteries. Recent findings point to an alternative model in which digestive organs are connected to a single mesentery. Given that direct evidence of this is currently lacking, we investigated the development and shape of the entire mesentery. Here we confirm that, within the abdomen, there is one mesentery in which all abdominal digestive organs develop and remain connected to. We show that all abdominopelvic organs are organised into two, discrete anatomical domains, the mesenteric and non-mesenteric domain. A similar organisation occurs across a range of animal species. The findings clarify the anatomical foundation of the abdomen; at the foundation level, the abdomen comprises a visceral (i.e. mesenteric) and somatic (i.e. musculoskeletal) frame. The organisation at that level is a fundamental order that explains the positional anatomy of all abdominopelvic organs, vasculature and peritoneum. Collectively, the findings provide a novel start point from which to systemically characterise the abdomen and its contents.