Trunk Level Research Articles

A Young Man With Acute-Onset Bilateral Arm Weakness After Traumatic Sciatic Neuropathy: A Clinical Vignette.

A Young Man With Acute-Onset Bilateral Arm Weakness After Traumatic Sciatic Neuropathy: A Clinical Vignette.

Influence of dilution on arterial-phase artifacts and signal intensity on gadoxetic acid–enhanced liver MRI

ObjectivesTo investigate the effect of saline-diluted gadoxetic acid, done for arterial-phase (AP) artifact reduction, on signal intensity (SI), and hence focal lesion conspicuity on MR imaging.MethodsWe retrospectively examined 112 patients who each had at least two serial gadoxetic acid–enhanced liver MRIs performed at 1 ml/s, first with non-diluted (ND), then with 1:1 saline-diluted (D) contrast. Two blinded readers independently analyzed the artifacts and graded dynamic images using a 5-point scale. The absolute SI of liver parenchyma, focal liver lesions (if present), aorta, and portal vein at the level of the celiac trunk and the SI of the paraspinal muscle were measured in all phases. The signal-to-norm (SINorm) of the vascular structures, hepatic parenchyma and focal lesions, and the contrast-to-norm (CNorm) of focal liver lesions were calculated.ResultsAP artifacts were significantly reduced with dilution. Mean absolute contrast-enhanced liver SI was significantly higher on the D exams compared to the ND exams. Likewise, SINorm of liver parenchyma was significantly higher in all contrast-enhanced phases except transitional phase on the D exams. SINorm values in the AP for the aorta and in the PVP for portal vein were significantly higher on the diluted exams. The CNorm was not significantly different between ND and D exams for lesions in any imaging phase. The interclass correlation coefficient was excellent (0.89).ConclusionGadoxetic acid dilution injected at 1ml/s produces images with significantly fewer AP artifacts but no significant loss in SINorm or CNorm compared to standard non-diluted images.Key Points• Diluted gadoxetic acid at slow injection (1 ml/s) yielded images with higher SINormof the liver parenchyma and preservedCNormfor focal liver lesions.• Gadoxetic acid–enhanced MRI injected at 1 ml/s is associated with arterial-phase (AP) artifacts in 31% of exams, which maydegrade image quality and limits focal liver lesion detection.• Saline dilution of gadoxetic acid 1:1 combined with a slow injection rate of 1 ml/s significantly reduced AP artifacts from 31 to 9% and non-diagnostic AP artifacts from 16 to 1%.

Downstream thoracic endovascular aortic repair following the frozen elephant trunk procedure.

The frozen elephant trunk technique has become a well-established treatment option for patients presenting all thoracic aortic pathologies including acute and chronic dissection, aortic aneurysms and even penetrating aortic ulcers involving the aortic arch and descending aorta. Nevertheless, there is a significant incidence of and risk for distal aortic reinterventions after the frozen elephant trunk. Indications mainly include a planned staged approach, diameter progression of downstream aortic segments and the development of distal stent-graft induced new entries (dSINEs). Endovascular stent-graft extension through conventional thoracic endovascular aortic repair (TEVAR) is a relatively simple and safe method to address any pathologies in the remaining descending thoracic aorta up to the level of the coeliac trunk. In fact, the frozen elephant trunk stent-graft provides an ideal proximal landing zone for any endovascular stent-graft extension. Postoperative outcomes are very promising with very low reported in-hospital mortality and morbidity. In case this 2-staged-approach fails to stabilize the remaining aorta, a 3-step procedure, namely open thoracoabdominal aortic replacement, is simplified because the anastomosis site has moved distally. Follow-up of all patients, following frozen elephant trunk implantation or distal stent-graft extension, is mandatory, ideally in an outpatient clinic dedicated to the aorta in order to identify disease progression or to detect any complications as soon as possible.

Are We Misrepresenting Superficial Femoral Artery Stenting? High Rates of Restenosis and Limb Loss Are Seen With Long-term Follow-up

Are We Misrepresenting Superficial Femoral Artery Stenting? High Rates of Restenosis and Limb Loss Are Seen With Long-term Follow-up

Vascular anatomical variants found in the VH Dissector Pro software. Descriptive anatomical study

IntroductionWith advances in technology over the past decades, reductions in teaching time,increasing class sizes, and increasing costs of cadaver‐based instruction, computer‐based learning resources are used every increasingly in anatomy curricula to encouragestudent learning, and its use has been found to increase anatomy teaching, enhanceindependent learning, problem solving, and provide flexibility.MethodsUsing the VH Dissector Pro software version 6.0.16, a group of researchers through dissection tools reached the vascular planes of the cadaver in all body regions, in which the presence of some type of arterial vascular variant was searched.ResultsAfter having carried out the search in the VH Dissector Pro software version 6.0.16, it was found that in the upper limbs the deep brachial artery presented its origin at the level of the third portion of the right axillary artery and the left subscapular artery. An accessory renal artery was found bilaterally in the abdominal region. In the pelvic region, an origin was found bilaterally at the level of the posterior trunk of the internal iliac of the obturator artery. All these findings were found after analyzing all the body regions of the cadaver in the arterial vascular plane.ConclusionThe knowledge of normal anatomy and anatomical variants is of great importance for anatomists who teach in different careers in the health area, as well as for clinical professionals who could find this type of variations both in diagnostic processes and surgical. By presenting this knowledge they will be able to transmit and differentiate normality versus the presence of anatomical variants that not only can be in cadavers, in imaging samples but could also be present in virtual anatomy. In addition, this study leaves the concern of analyzing other systems that could also present some other anatomical variant.

Effect of Contrast Agent Dose Reduction on Vascular Enhancement and Image Quality in Thoracoabdominal Dynamic 3-Dimensional Magnetic Resonance Angiography: A Systematic Intraindividual Analysis in Pigs.

High spatial and temporal resolution contrast-enhanced magnetic resonance angiography (MRA) with gadolinium-based contrast agents (GBCAs) at standard dose offers both detailed anatomic information on both arterial and venous vessels and hemodynamic characteristics. Several preclinical and clinical dynamic 3-dimensional (3D) MRA studies that focused on arterial vessels only proposed that high image quality may also be achieved with significantly reduced GBCA doses, calling into question the need to use standard doses. A systematic analysis of GBCA doses and resulting image quality for both arteries and veins has not yet been performed. The purpose of this study was therefore to systematically analyze dose-dependent vascular enhancements in dynamic 3D-MRA of the thoracoabdominal vasculature at 1.5 T in an animal model to determine the optimal contrast agent protocol for optimized vascular assessment. The vascular enhancement in thoracoabdominal dynamic 3D-MRA (time-resolved angiography with interleaved stochastic trajectories, TWIST at 1.5 T) was interindividually and intraindividually compared in 5 anesthetized Göttingen minipigs using gadobutrol at the standard dose (0.1 mmol/kg body weight, ie, 0.1 mL/kg) and at reduced doses (0.08, 0.06, 0.04, 0.02 mmol/kg) in a randomized order. All injections were performed at 2 mL/s followed by 20 mL saline. Images were quantitatively analyzed, measuring signal intensities in 5 regions that covered the passage of the GBCA through the body at different representative stages of circulation (pulmonary, arterial, and venous system). The evaluation of GBCA dose-dependent signal intensity changes in the different vascular regions was performed by linear regression analysis.The qualitative image analysis of dynamic 3D-MRA by 3 independent radiologists included the visibility of 25 arterial and venous vessel segments at different stages of GBCA passage. Possible quality losses were statistically tested by comparing image quality ratings at the reduced dose with that of the standard dose using Friedman test followed by Dunn post hoc test for multiple comparison. Significance was stated at P < 0.05. Quantitative analysis revealed shorter time-to-peak intervals and bolus durations in line with decreasing GBCA dose and volume in all vessels. Although the peak signal was almost independent of the administered GBCA dose at the level of the pulmonary trunk, a linear signal decrease in the abdominal aorta ( r2 = 0.96), the renal arteries ( r2 = 0.99), the inferior vena cava ( r2 = 0.99), and the portal vein ( r2 = 0.97) was observed. Cumulative analysis of arterial segments revealed significantly lower image quality at doses below 40% of the standard dose, whereas in venous segments, significantly lower image quality was observed at doses below 60% of the standard dose. In dynamic 3D-MRA at 1.5 T, dose reduction leads to a signal loss that is most pronounced in the venous system and results in significantly lower image quality according to the dose and vessels of interest. Careful dose reduction is thus required according to the specific diagnostic needs. For dynamic 3D-MRA of the arterial and venous system, GBCA doses of at least 60% of the standard dose up to the full dose are preferable, whereas 40% of the standard dose seems feasible if only the arterial system is to be imaged.

Cranioplasty after Two Giant Intraosseous Angiolipomas of the Cranium: Case Report and Literature Review.

Angiolipomas are rare, benign tumors resulting from the proliferation of adipose tissue and blood vessels, most frequently encountered subcutaneously at the upper limbs and trunk level. Due to their rarity, few cases of intraosseous angiolipomas are presented in the literature. The paper reports a 50-year-old female case with intracranial hypertension syndrome, frontal and parietal headache, nausea, and vomiting symptoms increasing in intensity. A CT exam revealed two hypodense expansive intraosseous formations/lesions. The first one was located in the projection of the frontal bone and the second one was placed on the left parietal bone. After further investigations, a two-stage procedure was considered. A frontal craniotomy with excision of the intraosseous tumor was performed in the first stage. In the second stage, a left parietal craniotomy was done with excision of the intraosseous tumor combined with a cranioplasty procedure. The patient had a favorable postoperative evolution with no symptoms or neurological deficits. This is among the few reported cases of intraosseous angiolipoma located at the cranium level and the first case report of two intraosseous angiolipomas situated on the same site. The medical recommendation was a complete surgical excision of the lesion followed by cranioplasty.

Involvement of the BDNF-TrkB-KCC2 pathway in neuropathic pain after brachial plexus avulsion.

IntroductionBrachial plexus avulsion significantly increased brain‐derived neurotrophic factor (BDNF) release in the spinal cord. Here we investigated the involvement of the BDNF–TrkB–KCC2 pathway in neuropathic pain caused by BPA injury. We hypothesized that activation of BDNF–TrkB may inhibit neuronal excitability by downregulating KCC2 to maintain a high intracellular Cl‐concentration. We established a neuropathic pain rat model by avulsion of the lower trunk brachial plexus, and investigated the effects of the TrkB‐specific antibody K‐252a on the expression of BDNF, TrkB, and KCC2.MethodsWe randomly divided 40 male SD rats into four groups. In the brachial plexus avulsion group, C8‐T1 roots were avulsed from the spinal cord at the lower trunk level. In the K252a group, 5uL K252a was applied intrathecally daily for three days after avulsion. In the sham surgery group, expose only and without damage. The control group did not undergo any treatment. Mechanical hyperalgesia and cold allodynia were analyzed by electronic pain measuring instrument and acetone spray method at different time points on days 1, 3, 7, 10, 14, and 21 after surgery. At 21 days after surgery, the expression of BDNF and TrkB in dorsal horn neurons and GFAP in astrocytes were detected by immunohistochemistry at the C5‐T1 segment of the spinal cord. The expression levels of BDNF, TrkB, and KCC2 in the C5‐T1 spinal cord were measured by Western Blot at 7 and 21 days.ResultsMechanical hyperalgesia and cold allodynia were significantly reduced in the K252a group compared with the brachial plexus avulsion group. Compared with the BPA group, BDNF, TrkB and GFAP were significantly decreased in the K252a group at 21 days after treatment by immunohistochemical test. In the WB test, the expressions of BDNF and TrkB in the K252a group were quantitatively detected to be decreased, while the expression of KCC2 was increased, which was obvious at 7 and 21 days.ConclusionBDNF‐TrkB‐KCC2 pathway can significantly relieve neuropathic pain after BPA, and is a potential target for the treatment of neuropathic pain.

Effect of superior trunk block on diaphragm function and respiratory parameters after shoulder surgery

BackgroundThe interscalene brachial plexus block has been used effectively for intraoperative and postoperative analgesia in patients undergoing shoulder surgery, but it is associated with high rates of diaphragmatic dysfunction. Performing...

Common Hepatic Artery Approach in Difficult Laparoscopic Distal Splenopancreatectomy

Introduction: Laparoscopic distal pancreatectomy is the gold standard nowadays. The infiltration of splenic artery near to its origin as well as engagement of splenic vein near to its confluence with superior mesenteric vein could be a reason for technical difficulties. In such cases the most easily accessible major landmark is the common hepatic artery. Transection of the pancreatic neck and splenic vein is essential to reach the dorsal aspect of the splenic artery at the level of the celiac trunk. The aim of this study is to present our approach to retroperitoneal access of the splenic artery. Methods: We present two cases of laparoscopic distal splenopancreatectomy, one of them for cancer of the pancreatic body, and the other one with pseudocyst of the pancreatic body. Mean age of the two patients was 59.5. Results: Totally laparoscopic splenopancreatectomy with hepatoduodenal and celiac lymph node dissection was performed. Peripancreatic invasion near to the origin of the splenic artery was observed. Stepwise pancreatic transection at the neck, followed by transection of splenic vein were done in both cases. In the second one major venous bleeding occured and was managed by clipping and division of the splenic vein. The mean operative time was 240min with insignificant blood loss. The patients had uneventful hospital stay and were discharged on the 7.5th postoperative day. Conclusions: Laparoscopic distal pancreatectomy can be technically difficult and should be performed only by surgeons with sufficient experience in both open pancreatic surgery and advanced laparoscopic gastrointestinal surgery.

Trunk and head displacements stabilized to perform both horizontal and vertical saccadic eye movements.

Vision is crucial for humans to interact with their surrounding environment, and postural sway is reduced to allow short eye movements. However, the extent of subtle changes in postural control for horizontal and vertical eye movements remains unclear. The goal of this study was to investigate the effects of vertical and horizontal eye movements on head and trunk control in young adults. Fifteen healthy adults (23.4 ± 4.7years) stood upright in three conditions for 60s: fixation, horizontal, and vertical guided eye movements. In fixation, participants had to fixate on a stationary target. In both the horizontal and vertical eye movements, the target was presented with a frequency of 0.5Hz and a visual angle of 11°. Eye displacement was monitored using a SMI eye tracker (ETG2.0) and trunk and head sway were monitored using infrared markers (Optotrak 3020, NDI). The mean sway amplitude was lower in both directions for eye movements and lowest in the vertical direction compared to the fixation condition. The sway area was also lower in vertical eye movement than in the fixation condition. We also found that the sway reduction was greater at head than at trunk level. The median frequency sway in the anterior-posterior direction was higher in both eye movements than in fixation. Based upon these results, we suggest that to perform short eye movements, postural sway is more strongly controlled at the head level than at the trunk and in vertical eye movements than in horizontal movements.

1527 A Rare Case of Facial Skin Necrosis Following Subdermal Poly-L-Lactic Acid Injection

Abstract Introduction Non-surgical / minimally invasive aesthetic procedures are a growing trend in the UK. A range of devices are available for soft tissue augmentation, including injectable Poly-L-Lactic acid (PLLA). PLLA is used for soft tissue augmentation and is thought effective for the correction of contour deficiencies, facial wrinkles and in restoring subcutaneous volume in patients with HIV-associated lipoatrophy. Method In this case report, we present a rare but serious complication of subdermal injection of Poly-L-Lactic acid. A 45-year-old lady presented to our service approximately 24 hours after administration of self-sourced poly-L-Lactic acid. Results A 4cm ovaloid patch of full thickness skin necrosis over the zygomatic region was evident on presentation, with reactive/inflammatory changes in the adjacent skin. Vascular compromise is deemed the most likely cause, with loss of the transverse facial artery mapping to the area of necrosis. This patient was managed conservatively, with dressings and a prophylactic course of antibiotics. Conclusions Vascular compromise is a recognised and rare complication of subdermal injectable devices for facial soft tissue augmentation. The transverse facial artery branches from the superficial temporal artery within the substance of the parotid gland. Cadaveric and imaging studies alike demonstrate that the most common anatomical variant is a single TFA (70%), originating at the level of the temporofacial trunk of the facial nerve. It typically has a 5cm course, giving off on average 1.9 cutaneous perforators. This case highlights the importance of a detailed understanding of facial anatomy to ensure safe and effective placement of dermal fillers/devices.

Visible and Thermal Image-Based Trunk Detection with Deep Learning for Forestry Mobile Robotics.

Mobile robotics in forests is currently a hugely important topic due to the recurring appearance of forest wildfires. Thus, in-site management of forest inventory and biomass is required. To tackle this issue, this work presents a study on detection at the ground level of forest tree trunks in visible and thermal images using deep learning-based object detection methods. For this purpose, a forestry dataset composed of 2895 images was built and made publicly available. Using this dataset, five models were trained and benchmarked to detect the tree trunks. The selected models were SSD MobileNetV2, SSD Inception-v2, SSD ResNet50, SSDLite MobileDet and YOLOv4 Tiny. Promising results were obtained; for instance, YOLOv4 Tiny was the best model that achieved the highest AP (90%) and F1 score (89%). The inference time was also evaluated, for these models, on CPU and GPU. The results showed that YOLOv4 Tiny was the fastest detector running on GPU (8 ms). This work will enhance the development of vision perception systems for smarter forestry robots.

Retrospective analysis of factors associated with aortic remodeling in patients with Stanford type B aortic dissection after thoracic endovascular aortic repair

ObjectiveAcute aortic dissection is a life-threatening condition. Thoracic endovascular aortic repair (TEVAR), together with optimized medical treatment, is currently the first line treatment for acute Stanford type B aortic dissection. TEVAR can close the entry tear and reduce mortality. Aortic remodeling after TEVAR can directly affect the patient’s long-term prognosis. The factors that influence aortic remodeling have, however, received insufficient clinical attention and remain unclear. It is very important to identify these factors.MethodsA total of 100 patients were continuously enrolled from 2011 to 2018 in 2 centers. Relevant data, including time from hospital admission to surgery, medicine use and aortic computed tomography angiography images obtained before and 6 months after surgery were collected. Patients were divided into favorable and adverse aortic remodeling groups, according to the degree of aortic remodeling. Analysis of variance and the chi-square test were performed using SPSS software to compare differences between groups and to determine the factors that influence postoperative aortic remodeling.ResultsThe proportion of single-stent implantations was higher in the favorable remodeling group than in the adverse remodeling group (79.5% vs. 53.8% in distal end of stent-graft level and 81.3% vs. 56.4% in diaphragm level, respectively, p < 0.05). The earlier the TEVAR procedure was performed, the better the aortic remodeling (3.4 days vs. 4.8 days in distal stent graft levels, and 3.6 days vs. 4.9 days in diaphragm level, respectively, p < 0.05), the presence of residual distal entry tears in the abdominal aorta also improved aortic remodeling after TEVAR (85.7% vs. 55.1% in the celiac trunk level, and 92.0% vs. 48.9% in the right renal artery level, respectively, p < 0.05).ConclusionSingle stent-graft implantation and early surgery were associated with favorable aortic remodeling. Distal entry tears were also conducive to aortic remodeling after surgery for aortic dissection.

Sox14 is essential for initiation of neuronal differentiation in the chick spinal cord.

The neural tube comprises several different types of progenitors and postmitotic neurons that co-ordinately act with each other to play integrated functions. Its development consists of two phases: proliferation of progenitor cells and differentiation into postmitotic neurons. How progenitor cells differentiate into each corresponding neuron is an important question for understanding the mechanisms of neuronal development. Here we introduce one of the Sox transcription factors, Sox14, which plays an essential role in the promotion of neuronal differentiation. Sox14 belongs to the SoxB2 subclass and its expression starts in the progenitor regions before neuronal differentiation is initiated at the trunk level of the neural tube. After neuronal differentiation is initiated, Sox14 expression gradually becomes confined to the V2a region of the neural tube, where Chx10 is co-expressed. Overexpression of Sox14 restricts progenitor cell proliferation. Conversely, the blockade of Sox14 expression by the RNAi strategy inhibits V2a neuron differentiation and causes expansion of the progenitor domain. We further found that Sox14 acted as a transcriptional activator. Sox14 acts as a modulator of cell proliferation and is essential for initiation of neuronal differentiation in the chick neural tube.

Technical aspects in difficult laparoscopic distal splenopancreatectomy

Laparoscopic distal pancreatectomy is the gold standard nowadays. The infiltration of splenic artery near to its origin as well as engagement of splenic vein near to its confluence with superior mesenteric vein could be a reason for technical difficulties. In such cases the most easily accessible major landmark is the common hepatic artery. Transection of the pancreatic neck and splenic vein is essential to reach the dorsal aspect of the splenic artery at the level of the celiac trunk. The aim of this video is to present our approach to retroperitoneal access of the splenic artery. We present two cases of laparoscopic distal splenopancreatectomy, one of them for cancer of the pancreatic body, and the other one with pseudocyst of the pancreatic body. Mean age of the two patients was 59.5. Totally laparoscopic splenopancreatectomy with hepatoduodenal and celiac lymph node dissection was performed. Peripancreatic invasion near to the origin of the splenic artery was observed. Stepwise pancreatic transection at the neck, followed by transection of splenic vein were done in both cases. In the second one major venous bleeding occured and was managed by clipping and division of the splenic vein. The mean operative time was 240 minutes with insignificant blood loss. The patients had uneventful hospital stay and were discharged on the 7.5th postoperative day. Laparoscopic distal pancreatectomy can be technically difficult and should be performed only by surgeons with sufficient experience in both open pancreatic surgery and advanced laparoscopic gastrointestinal surgery.

Estimation of 3D Body Center of Mass Acceleration and Instantaneous Velocity from a Wearable Inertial Sensor Network in Transfemoral Amputee Gait: A Case Study.

The analysis of the body center of mass (BCoM) 3D kinematics provides insights on crucial aspects of locomotion, especially in populations with gait impairment such as people with amputation. In this paper, a wearable framework based on the use of different magneto-inertial measurement unit (MIMU) networks is proposed to obtain both BCoM acceleration and velocity. The proposed framework was validated as a proof of concept in one transfemoral amputee against data from force plates (acceleration) and an optoelectronic system (acceleration and velocity). The impact in terms of estimation accuracy when using a sensor network rather than a single MIMU at trunk level was also investigated. The estimated velocity and acceleration reached a strong agreement (ρ > 0.89) and good accuracy compared to reference data (normalized root mean square error (NRMSE) < 13.7%) in the anteroposterior and vertical directions when using three MIMUs on the trunk and both shanks and in all three directions when adding MIMUs on both thighs (ρ > 0.89, NRMSE ≤ 14.0% in the mediolateral direction). Conversely, only the vertical component of the BCoM kinematics was accurately captured when considering a single MIMU. These results suggest that inertial sensor networks may represent a valid alternative to laboratory-based instruments for 3D BCoM kinematics quantification in lower-limb amputees.

Notch signaling is a critical initiator of roof plate formation as revealed by the use of RNA profiling of the dorsal neural tube

BackgroundThe dorsal domain of the neural tube is an excellent model to investigate the generation of complexity during embryonic development. It is a highly dynamic and multifaceted region being first transiently populated by prospective neural crest (NC) cells that sequentially emigrate to generate most of the peripheral nervous system. Subsequently, it becomes the definitive roof plate (RP) of the central nervous system. The RP, in turn, constitutes a patterning center for dorsal interneuron development. The factors underlying establishment of the definitive RP and its segregation from NC and dorsal interneurons are currently unknown.ResultsWe performed a transcriptome analysis at trunk levels of quail embryos comparing the dorsal neural tube at premigratory NC and RP stages. This unraveled molecular heterogeneity between NC and RP stages, and within the RP itself. By implementing these genes, we asked whether Notch signaling is involved in RP development. First, we observed that Notch is active at the RP-interneuron interface. Furthermore, gain and loss of Notch function in quail and mouse embryos, respectively, revealed no effect on early NC behavior. Constitutive Notch activation caused a local downregulation of RP markers with a concomitant development of dI1 interneurons, as well as an ectopic upregulation of RP markers in the interneuron domain. Reciprocally, in mice lacking Notch activity, both the RP and dI1 interneurons failed to form and this was associated with expansion of the dI2 population.ConclusionsCollectively, our results offer a new resource for defining specific cell types, and provide evidence that Notch is required to establish the definitive RP, and to determine the choice between RP and interneuron fates, but not the segregation of RP from NC.

Comparison of pre- and post-contrast-enhanced attenuation correction using a CAIPI-accelerated T1-weighted Dixon 3D-VIBE sequence in 68Ga-DOTATOC PET/MRI

ObjectivesTo investigate the influence of contrast agent administration on attenuation correction (AC) based on a CAIPIRINHA (CAIPI)-accelerated T1-weighted Dixon 3D-VIBE sequence in 68Ga-DOTATOC PET/MRI. Material and methodsFifty-one patients with neuroendocrine tumors underwent whole-body 68Ga-DOTATOC PET/MRI for tumor staging. Two PET reconstructions were performed using AC-maps that were created using a high-resolution CAIPI-accelerated Dixon-VIBE sequence with an additional bone atlas and truncation correction using the HUGE (B0 homogenization using gradient enhancement) method before and after application of Gadolinium (Gd)-based contrast agent. Standardized uptake values (SUVs) of 21 volumes of interest (VOIs) were compared between in both PET data sets per patient. A student’s t-test for paired samples was performed to test for potential differences between both AC-maps and both reconstructed PET data sets. Bonferroni correction was performed to prevent α-error accumulation, p < 0.0024 was considered to indicate statistical significance. ResultsSignificant quantitative differences between SUVmax were found in the perirenal fat (19.65 ± 48.03 %, p < 0.0001), in the axillary fat (17.46 ± 63.67 %, p < 0.0001) and in the dorsal subcutaneous fat on level of lumbar vertebral body L4 (10.26 ± 25.29 %, p < 0.0001). Significant differences were also evident in the lungs apical (5.80 ± 10.53 %, p < 0.0001), dorsal at the level of the pulmonary trunk (15.04 ± 19.09 %, p < 0.0001) and dorsal in the basal lung (51.27 ± 147.61 %, p < 0.0001). ConclusionThe administration of (Gd)-contrast agents in this study has shown a considerable influence on the AC-maps in PET/MRI and, consequently impacted quantification in the reconstructed PET data. Therefore, dedicated PET/MRI staging protocols have to be adjusted so that AC-map acquisition is performed prior to contrast agent administration.

Visceral malperfusion after Frozen Elephant Trunk in chronic aortic dissection: post-operative predictors and outcomes

BackgroundThe aims of this study were to analyse the incidence of visceral malperfusion syndrome (MPS) following Frozen Elephant trunk operations in patients affected by chronic aortic dissection and the associated risk factors. MethodsBetween January 2007 and February 2019, 165 patients underwent surgery with FET for chronic aortic dissection. Post-operative computer tomography angiogram parameters (diameters, early post-operative false lumen enhancement and involving of aortic branches by the dissection) were collected and analysed to evaluate their impact on the occurrence of visceral malperfusion. ResultsVisceral (renal and mesenteric) MPS (with both clinical and radiological signs of MPS) was detected in 10 cases (6.1%). Post-operative visceral malperfusion was strongly related with in hospital mortality. The involvement of the visceral branches in the dissection was not a risk factor for visceral malperfusion occurrence, while a larger post-operative total aortic diameter at level of the coeliac trunk increased the risk of visceral MPS (OR 1.05; CI 1.002–1.102, p-value = 0.04). Furthermore, visceral MPS was associated to a complete thrombosis of the false lumen at level of the distal descending thoracic aorta. ConclusionsThe development of post-operative MPS in frozen elephant trunk is strongly related to in-hospital mortality. The involvement of aortic branches by the dissection does not represent a real predictive risk factor for MPS, while early larger aortic diameters and false lumen thrombosis represent independent risk factors for MPS and in-hospital mortality.