Endovascular treatment of visceral aneurysms and pseudoaneurysms.

Visceral artery aneurysm (VAA) is a rare and potentially life-threatening condition, defined as true artery aneurysms and pseudoaneurysms of splanchnic circulation and renal artery. This study reports our experience in the diagnosis and endovascular treatment of visceral artery aneurysms (VAAs) over a 10-year period. Between 2008 and 2018, a total of 24 VAAs in 21 patients were diagnosed by clinical symptoms and a combination of imaging techniques, such as Doppler ultrasound, computed tomography angiogram, and catheter angiogram. All patients underwent endovascular treatment to exclude aneurysms. Oral antiplatelet medicine was administered, and imaging examination was performed during follow-up. Technical success was achieved in all 21 patients, and no periprocedural complications occurred. Endovascular coiling alone was employed in 10 aneurysms. Coiling was combined with gelfoam in 2 aneurysms. Coiling was assisted by stent in 4 aneurysms. Covered stents were deployed in 8 aneurysms individually. Clinical symptoms disappeared or highly improved in all patients after treatment. None of the patients showed recurrent symptoms after discharge. However, two cases with new aneurysms after 6 and 8 months, respectively, and one case with in-stent thrombosis after 12 months were reported during follow-up. This study may justify the efficacy of percutaneous endovascular coil embolization and stent deployment. It also provides beneficial experience about how to choose appropriate various endovascular strategies based on both clinical symptoms and aneurysm anatomy condition.

Primo Bundles Identified by Microcomputed Tomography in Primo Vascular Tissue on the Surface of Rat Abdominal Organs.

BACKGROUND: The primo vascular system (PVS) is a novel network composed of primo nodes (PNs) and primo vessels (PVs). Currently, its anatomy is not fully understood. OBJECTIVES: The aim of this study was to elucidate the three-dimensional PN-PV structure. METHODS: Organ-surface PVS tissue was isolated from healthy and anemic rats. The tissues were analyzed by X-ray microcomputed tomography (CT), hematoxylin and eosin staining, and scanning electron microscopy. RESULTS: From CT images, we identified one or more bundles in a PV. In the PN, the bundles were enlarged and existed in isolation and/or in anastomosis. The transverse CT images revealed four areas of distinct intensities: zero, low, intermediate, and high. The first two were considered to be the sinuses and the subvessels of the PVS and were identified in the hematoxylin and eosin-stained PN sections. The enlargement of the PN from anemic rats was associated with an increase in the intermediate-intensity area. The high-intensity area demarcated the bundle and was overlapped with the mesothelial cells. In scanning electron microscopy, the PV bundles branched out, tapering down to a single bundle at some distance from the PN. Each bundle was composed of several subvessels (∼5 µm). Clustered round microcells (1-25 µm), scattered flat oval cells (∼15 µm), and amorphous extracellular matrix were observed on the surface of the PVS tissue. CONCLUSIONS: The results newly showed that the primo bundle is a structural unit of both PVs and PNs. A bundle was demarcated by high CT intensity and mesothelial cells and consisted of multiple subvessels. The PN bundles contained also sinuses.

Bellymount enables longitudinal, intravital imaging of abdominal organs and the gut microbiota in adult Drosophila.

Cell- and tissue-level processes often occur across days or weeks, but few imaging methods can capture such long timescales. Here, we describe Bellymount, a simple, noninvasive method for longitudinal imaging of the Drosophila abdomen at subcellular resolution. Bellymounted animals remain live and intact, so the same individual can be imaged serially to yield vivid time series of multiday processes. This feature opens the door to longitudinal studies of Drosophila internal organs in their native context. Exploiting Bellymount's capabilities, we track intestinal stem cell lineages and gut microbial colonization in single animals, revealing spatiotemporal dynamics undetectable by previously available methods.

The German Evidence-Based Child Protection Guideline - Imaging in Suspected Child Abuse. / Die deutsche S3-Kinderschutzleitlinie ­ Bildgebung bei Verdacht auf Kindesmisshandlung.

AIM: Development of a fully evidence-based guideline including all aspects of child abuse. METHODS: In a case-based procedure, 144 primary PICO questions were generated from 476 presented cases of child abuse. Literature research was performed in 5 databases (Pubmed, CINHAL, Embase, PsycInfo, Eric) and in the Cochrane Library. The literature was evaluated according to SIGN and AGREE II. RESULTS: 137 recommendations were developed. Those related to imaging procedures are presented and discussed in this article. CONCLUSION: The first fully evidence-based German guideline concerning all aspects of child abuse has been established. For imaging, several relevant new approaches have been proposed. KEY POINTS: · The average radiation exposure is significantly reduced for the whole group of examined children.. · The pelvic view and lateral spine are no longer basic views of the skeletal survey but are only performed additionally in the case of a positive survey.. · Oblique views and a follow-up survey are performed in the case of a negative skeletal survey and ongoing suspicion of child abuse.. CITATION FORMAT: · Born M, Schwier F, Stoever B et al. The German Evidence-Based Child Protection Guideline - Imaging in Suspected Child Abuse. Fortschr Röntgenstr 2020; 192: 343 - 348.

'Squeeze & excite' guided few-shot segmentation of volumetric images.

Deep neural networks enable highly accurate image segmentation, but require large amounts of manually annotated data for supervised training. Few-shot learning aims to address this shortcoming by learning a new class from a few annotated support examples. We introduce, a novel few-shot framework, for the segmentation of volumetric medical images with only a few annotated slices. Compared to other related works in computer vision, the major challenges are the absence of pre-trained networks and the volumetric nature of medical scans. We address these challenges by proposing a new architecture for few-shot segmentation that incorporates 'squeeze & excite' blocks. Our two-armed architecture consists of a conditioner arm, which processes the annotated support input and generates a task-specific representation. This representation is passed on to the segmenter arm that uses this information to segment the new query image. To facilitate efficient interaction between the conditioner and the segmenter arm, we propose to use 'channel squeeze & spatial excitation' blocks - a light-weight computational module - that enables heavy interaction between both the arms with negligible increase in model complexity. This contribution allows us to perform image segmentation without relying on a pre-trained model, which generally is unavailable for medical scans. Furthermore, we propose an efficient strategy for volumetric segmentation by optimally pairing a few slices of the support volume to all the slices of the query volume. We perform experiments for organ segmentation on whole-body contrast-enhanced CT scans from the Visceral Dataset. Our proposed model outperforms multiple baselines and existing approaches with respect to the segmentation accuracy by a significant margin. The source code is available at https://github.com/abhi4ssj/few-shot-segmentation.

The validity of the viscero-abdominal disproportion ratio for type of surgical closure in all fetuses with an omphalocele.

OBJECTIVE: To determine the predictive value of the fetal omphalocele circumference/abdominal circumference (OC/AC) ratio for type of surgical closure and survival and to describe the trajectory of OC/AC ratio throughout gestation. METHODS: This cohort study included all live-born infants prenatally diagnosed with an omphalocele in our tertiary centre (2000-2017) with an intention to treat. The OC/AC ratio and liver position were determined using 2D ultrasound at three periods during gestation (11-16, 17-26, and/or 30-38 weeks). Primary outcome was type of closure; secondary outcome was survival. In the secondary analyses, the predictive value of the OC/AC-ratio trend for type of closure and survival was assessed. RESULTS: Primary closure was performed in 37/63 (59%) infants, and 54/63 (86%) survived. The OC/AC ratio was predictive for type of closure and survival in all periods. Optimal cut-off values for predicting closure decreased throughout gestation from 0.69 (11-16 weeks) to 0.63 (30-38 weeks). Repeated OC/AC-ratio measurements were available in 33 (73%) fetuses. The trend of the OC/AC ratio throughout gestation was not significantly associated with type of closure. All infants without liver herniation underwent primary closure. CONCLUSION: Type of omphalocele surgical closure and survival can be predicted prenatally on the basis of the OC/AC ratio and liver herniation independent of associated anomalies. LEARNING OBJECTIVE: The reader will be able to use the OC/AC ratio throughout gestation in all omphalocele cases for prediction of type of closure and survival and thus patient counselling.

Deciphering normal and anomalous viscero-atrial situs on multidetector CT angiography.

Viscero-atrial situs encompasses the laterality, relative position and configuration of the abdominal viscera, the atria of the heart and the tracheobronchial tree. Determining the situs and cardiac position is the first step in the commonly used sequential, segmental approach to the imaging evaluation of congenital heart defects (CHD). Abnormalities of visceroatrial situs and cardiac position are frequently associated with the presence of complex CHDs and accurate assessment of situs abnormalities can help predict the probability and type of the defect. Multidetector CT (MDCT) angiography, with its multiplanar reformatting and volume rendering techniques, offers accurate information about the morphology and three-dimensional relationships of the various cardiac and extra cardiac structures. In this pictorial essay, we present the MDCT imaging findings of the spectrum of abnormalities of visceroatrial situs and cardiac position, using a third generation dual source CT scanner.

Segmental arterial mediolysis in splanchnic arteries: an uncommon cause of abdominal pain.

Segmental arterial mediolysis is an uncommon arterial disease that primarily involves splanchnic arteries; abdominal pain is the most common clinical manifestation. We report the case of a 53-year-old male with postprandial diffuse abdominal pain of one month's standing. Physical examination was uneventful, and laboratory tests revealed no abnormal findings. Abdominopelvic CT/Angio-CT showed an increased caliber of the superior mesenteric artery resulting from eccentric circumferential wall thickening. The patent lumen had a segment with fusiform aneurysmal dilatation, 7 x 26 mm long. These vascular changes extended along a number of distal jejunal branches, which also presented complete lumen obliteration. Abdominal arteries were free from signs of arteriosclerotic disease. Findings were consistent with segmental arterial mediolysis.

Visceral artery aneurysms: evolving interdisciplinary management and future role of the abdominal surgeon.

BACKGROUND: Visceral artery aneurysms (VAA) are rare vascular lesions. Clinically silent VAA are increasingly detected by cross-sectional imaging but some lesions are at risk for rupture with severe bleeding. The aim of the present study was to evaluate the trends in the interdisciplinary management at a tertiary center. METHODS: Patients who underwent treatment for VAA at University Hospital of Bonn between 2005 and 2018 were enrolled in this retrospective study. Demographic, clinical, VAA-specific data as well as information on therapy, early and long-term outcome were collected and statistically analyzed. RESULTS: Forty-two consecutive patients, 19 females and 23 males with a median age of 59 years (range 30-91 years), were diagnosed with 56 VAA. The majority were true aneurysms (N = 32; 57%), whereas 43% (N = 24) were pseudoaneurysms. The most common localization was the splenic artery (N = 18; 32%) and the average diameter was 3 cm (range 1-5 cm). Twenty-five patients (59.5%) had VAA-related symptoms such as chronic abdominal pain and hemorrhage at primary diagnosis, while the diagnosis was incidental in 17 patients (40.5%). Eleven patients (26%) underwent open surgery whereas 29 patients (69%) received an endovascular treatment. Patients with pseudoaneurysms were significantly older (P = 0.003), suffered more often from associated symptoms (P < 0.001) and required more emergency interventions (P < 0.0001) compared to those with true VAA. In the last years, the number and proportion of true VAA increased significantly (P < 0.001) while a significantly larger proportion could be managed interventionally (P = 0.017). CONCLUSIONS: VAA are increasingly detected on imaging with lesions presenting very heterogeneously. Due to the risk of lethal rupture and in the absence of reliable prognostic markers, all the patients with VAA should be offered definite treatment. Localization, anatomy and the end-organ perfusion after intervention or operation are the most important aspects to consider when planning a treatment for VAA. For this reason, a multidisciplinary evaluation of every individual patient is necessary for an optimized outcome.

OBELISK-Net: Fewer layers to solve 3D multi-organ segmentation with sparse deformable convolutions.

Deep networks have set the state-of-the-art in most image analysis tasks by replacing handcrafted features with learned convolution filters within end-to-end trainable architectures. Still, the specifications of a convolutional network are subject to much manual design - the shape and size of the receptive field for convolutional operations is a very sensitive part that has to be tuned for different image analysis applications. 3D fully-convolutional multi-scale architectures with skip-connection that excel at semantic segmentation and landmark localisation have huge memory requirements and rely on large annotated datasets - an important limitation for wider adaptation in medical image analysis. We propose a novel and effective method based on trainable 3D convolution kernels that learns both filter coefficients and spatial filter offsets in a continuous space based on the principle of differentiable image interpolation first introduced for spatial transformer network. A deep network that incorporates this one binary extremely large and inflecting sparse kernel (OBELISK) filter requires fewer trainable parameters and less memory while achieving high quality results compared to fully-convolutional U-Net architectures on two challenging 3D CT multi-organ segmentation tasks. Extensive validation experiments indicate that the performance of sparse deformable convolutions is due to their ability to capture large spatial context with few expressive filter parameters and that network depth is not always necessary to learn complex shape and appearance features. A combination with conventional CNNs further improves the delineation of small organs with large shape variations and the fast inference time using flexible image sampling may offer new potential use cases for deep networks in computer-assisted, image-guided interventions.

Abdomen agudo por actinomicosis / Acute abdomen caused by actinomycosis

No disponible

Increased visceral tissue perfusion with heated, humidified carbon dioxide insufflation during open abdominal surgery in a rodent model.

Tissue perfusion during surgery is important in reducing surgical site infections and promoting healing. This study aimed to determine if insufflation of the open abdomen with heated, humidified (HH) carbon dioxide (CO2) increased visceral tissue perfusion and core body temperature during open abdominal surgery in a rodent model. Using two different rodent models of open abdominal surgery, visceral perfusion and core temperature were measured. Visceral perfusion was investigated using a repeated measures crossover experiment with rodents receiving the same sequence of two alternating treatments: exposure to ambient air (no insufflation) and insufflation with HH CO2. Core body temperature was measured using an independent experimental design with three treatment groups: ambient air, HH CO2 and cold, dry (CD) CO2. Visceral perfusion was measured by laser speckle contrast analysis (LASCA) and core body temperature was measured with a rectal thermometer. Insufflation with HH CO2 into a rodent open abdominal cavity significantly increased visceral tissue perfusion (2.4 perfusion units (PU)/min (95% CI 1.23-3.58); p<0.0001) compared with ambient air, which significantly reduced visceral blood flow (-5.20 PU/min (95% CI -6.83- -3.58); p<0.0001). Insufflation of HH CO2 into the open abdominal cavity significantly increased core body temperature (+1.15 ± 0.14°C) compared with open cavities exposed to ambient air (-0.65 ± 0.52°C; p = 0.037), or cavities insufflated with CD CO2 (-0.73 ± 0.33°C; p = 0.006). Abdominal visceral temperatures also increased with HH CO2 insufflation compared with ambient air or CD CO2, as shown by infrared thermography. This study reports for the first time the use of LASCA to measure visceral perfusion in open abdominal surgery and shows that insufflation of open abdominal cavities with HH CO2 significantly increases visceral tissue perfusion and core body temperature.

Multiparametric Whole-body MRI with Diffusion-weighted Imaging and ADC Mapping for the Identification of Visceral and Osseous Metastases From Solid Tumors.

RATIONALE AND OBJECTIVES: The purpose of this study was to investigate the use of multiparametric, whole-body, diffusion-weighted imaging (WB-DWI) and apparent diffusion coefficient (ADC) maps with T2-weighted magnetic resonance imaging (MRI) at 3T for the detection and monitoring of metastatic disease in patients. MATERIALS AND METHODS: Fifty-four participants (32 healthy subjects and 22 patients) were scanned with WB-DWI methods using a 3T MRI scanner. Axial, sagittal, or coronal fat-suppressed T2-weighted (T2WI), T1-weighted (T1WI), and DWI images were acquired. Total MRI acquisition and set-up time was approximately 45 minutes. Metastatic disease on MRI was confirmed based on T2WI characteristics. The number of lesions was established on computed tomography (CT) or positron emission tomography (PET-CT). Whole-body ADC maps and T2WI were constructed, and region-of-interests were drawn in normal and abnormal-appearing tissue for quantitative analysis. Statistical analysis was performed using a paired t tests and P < .05 was considered statistically significant. RESULTS: There were 91 metastatic lesions detected from the CT or PET-CT with a missed recurrent lesion in the prostate. Multiparametric WB-MRI had excellent sensitivity (96%) for detection of metastatic lesions compared to CT. ADC map values and the ADC ratio in metastatic bone lesions were significantly increased (P < .05) compared to normal bone. In soft tissue, ADC map values and ratios in metastatic lesions were decreased compared to normal soft tissue. CONCLUSION: We have demonstrated that multiparametric WB-MRI is feasible for oncologic staging to identify bony and visceral metastasis in breast, prostate, pancreatic, and colorectal cancers. WB-MRI can be tailored to fit the patient, such that an "individualized patient sequence" can be developed for a comprehensive evaluation for staging and response during treatment.

The hourglass sign.

The Hourglass sign is a useful imaging clue for diagnosing diaphragmatic ruptures with viscera herniation on multidetector CT, with a sensitivity ranging from 16% to 63% and a specificity around 98%-100%. This sign is also commonly found in the literature under the name "Collar sign," first described in 1995 by Worthy et al. It refers to the waistlike constriction of the herniated structure at the site of the diaphragmatic rupture.

The effect of tissue-segmented attenuation maps on PET quantification with a special focus on large arteries. / Efecto de la segmentación por tejidos en los mapas de atenuación sobre la cuantificación PET con especial hincapié en grandes arterias.

OBJECTIVES: Accuracy on quantitative PET image analysis relies on the correct application of attenuation correction which is one of the major challenges for PET/MRI that remains to be solved. The purpose of this study is to evaluate the effect of MRI-based attenuation maps and the use of flexible coils on the quantitative accuracy of PET images with a special focus on large arteries. MATERIALS AND METHODS: PET/CT data from eight oncologic patients was used. PET data was reconstructed using attenuation maps with different level of detail emulating several approaches available on current PET/MRI scanners. PET images obtained with CT-based and MRI-based attenuation maps were compared to evaluate the quantitative biases obtained. The quantitative effect produced by flexible MRI receiver coils on the attenuation maps was also studied. RESULTS: The use of simpler attenuation maps produced increased biases between PET data reconstructed with CT-based and MRI-based attenuation maps for fat, non-fat soft-tissues and bone. Biases in lung were very high due to the large heterogeneity and inter-patient variability of the lung. The quantification on large arteries had small deviations except for the case when flexible coils were used. The TBR provided smaller biases in all cases as it cancelled out the similar deviations obtained for arteries and reference veins. CONCLUSIONS: Simplified attenuation maps used on PET/MRI significantly increase the quantitative variability of PET images especially on lungs and bones. The quantification of PET images acquired with PET/MRI scanners applied to studies of atherosclerosis has small deviations, especially when the TBR is considered.

Computed tomography study of the fetal development of the dairy cow stomach complex.

In the fetal development of animals, critical physiological and anatomical events influence the long-term health and performance of the offspring. To identify the critical growth phases of the fetal bovine stomach, we used computed tomography imaging on 30 German Holstein fetuses to examine the fetal bovine stomach in situ. Computed tomography allows the study of diverse parameters such as the volume of the stomach chambers in situ without the need for sophisticated filling preparation techniques. The absolute volume, relative volume, and monthly volume increase of each stomach chamber were determined. Computed tomography was a reliable method for in situ examination of the fetal bovine stomach complex from the third month of gestation onward. It was able to detect an abnormal position of the abomasum in 2 fetuses. The crown-rump length of the fetuses studied ranged from 9.5 to 89 cm (from 2.2 to 8.3 mo of gestation). Over this timeline, the changes in the relative volumes of the ruminoreticulum and abomasum were inversely related. Until mo 5 of gestation, the relative volume of the ruminoreticulum increased steadily, whereas that of the abomasum decreased. Thereafter, the relative volume of the ruminoreticulum became gradually smaller, and that of the abomasum became larger; by mo 8, the abomasum was larger than the ruminoreticulum. All stomach chambers had large increases in volume over the gestation period and we observed differences in development patterns and volume changes of the individual stomach chambers over this period. The largest monthly volume increase of the stomach complex was between mo 4 and 5 of gestation. In this period, the volume of the ruminoreticulum increased 43.8 times, that of the omasum 38.9 times, and that of the abomasum 30.03 times. Between mo 5 and 6 of gestation, the abomasum had another growth spurt, with a monthly volume increase of 10.4 times. These 2 time points in the gestation period may be critical phases of fetal development that should be considered in the management of pregnant cattle.

Postoperative Visceral Tissue Edema Assessed by Computed Tomography Is a Predictor for Severe Complications After Pancreaticoduodenectomy.

BACKGROUND/AIMS: In pancreatoduodenectomy (PD), the adverse impact of tissue edema owing to intraoperative fluid overload remains unclear. This study aims to evaluate how visceral tissue edema due to fluid overload affects severe postoperative complications after PD. It aims to clarify the usefulness of assessment by computed tomography (CT) of postoperative tissue edema. METHODS: We classified 200 patients who underwent PD as either liberal fluid management (LFM) group (n = 100) or goal-directed fluid therapy (GDFT) group (n = 100), based on intraoperative fluid management. We assessed postoperative tissue edema by cross section of the body trunk area using pre- and postoperative CT. RESULTS: Severe complication (Clavien-Dindo more than grade III) rate was significantly higher in LFM group than GDFT group (37 vs. 17%, P = 0.001). Independent risk factors of severe complications after PD included diameter of main pancreatic duct ≤ 3 mm at the cut surface (P = 0.041; OR 2.274; 95% CI 1.034-5.001), LFM (P = 0.005; OR 2.720; 95% CI 1.355-5.462), and increased rate of body trunk area ≥ 20% (P < 0.001; OR 3.448; 95% CI 1.723-5.462). In subgroup analysis of patients with no transfusion, LFM and increased rate of body trunk area ≥ 20% were independent risk factors of severe postoperative complications. CONCLUSIONS: Visceral tissue edema evaluation is a valuable method to predict severe complications after PD.