Mesenteric vasculature-guided small bowel segmentation on high-resolution 3D CT angiography scans

The aim was to describe the small bowel morphology with conventional B-mode and elastography and additionally to evaluate dynamic effects of COVID-19 associated small bowel microvascularization using CEUS with color coded perfusion parameters.Thirteen patients with severe COVID-19 acute respiratory distress syndrome (ARDS) were investigated. 13 patients required intensive care treatment with mechanical ventilation. Five patients required extracorporeal membrane oxygenation (ECMO). Contrast-enhanced ultrasound (CEUS) was performed by an experienced investigator as a bolus injection of up to 2.4 ml sulfur hexafluoride microbubbles via a central venous catheter. In the parametric analysis of CEUS, the flare of microbubbles over time is visualized with colors. This is the first work using parametric analysis of CEUS to detect perfusion differences in the small bowel.Parametric analysis of CEUS in the intestinal phase was carried out, using DICOM loops for 20 seconds. In 5 patients, parametric analysis revealed intraindividual differences in contrast agent behavior in the small bowel region. Analogous to the computed tomography (CT) images parametric analysis showed regions of simultaneous hyper- and hypoperfusion of the small intestine in a subgroup of patients. In 5 patients, the parametric image of transmural global contrast enhancement was visualized.Our results using CEUS to investigate small bowel affection in COVID-19 suggest that in severe COVID-19 ARDS systemic inflammation and concomitant micro embolisms may lead to disruption of the epithelial barrier of the small intestine.This is the first study using parametric analysis of CEUS to evaluate the extent of small bowel involvement in severe COVID-19 disease and to detect microemboli. In summary, we show that in COVID-19 the small bowel may also be an important interaction site. This is in line with the fact that enterocytes have been shown to a plenitude of angiotensin converting enzyme (ACE)-2 receptors as entry sites of the virus.

Aims: With the development of spiral scanning, computed tomography angiography (CTA) is preferred over conventional angiography in many vascular applications. Reduced respiratory and motion artifacts and ability to catch arterial phase during one inspiration are the advantages of spiral CTA. Our aim in this study is to evaluate the value of spiral CTA in demonstrating stent integrity, stent patency, and renal artery/stent relationship after renal artery stenting. Methods: 15 patients (12 male and 3 female) who had renal artery metallic stents were included in this study. Systolic and diastolic blood pressure and creatinine values of the patients were measured before and after the stent. Patients were examined by CTA after renal artery stenting. In renal artery segments with renal artery stenosis and stenting on CTA; stent diameter, stent length, integrity, luminal contrast enhancement and intraluminal calcification were evaluated with 1 mm axial reconstructed images and "post-process" techniques multiplanar reformat (MPR), maximum intensity projection (MIP), shaded surface display (SSD), and virtual intravascular endoscopy (VIE). Results: Of the stenosis in which stents were placed, 1 was located in the proximal renal artery, 4 were in the mid-renal artery, and 10 were ostial. The whole stent was visualized in 8 cases. Among the MPR images, the axial plane was the best to depict the lumen in 13 cases. The stent lumen was best visualized on oblique MPR images in the axial plane. The visibility of the stent lumen decreased in MIP images with increased slice thickness. In cases where stenosis was considered due to intimal hyperplasia within the stent, no stenotic appearance was observed on MPR and MIP images. In all patients, stent and wall calcifications were observed separately from the contrast medium on MPR and MIP images. On SSD images, the stent could not be distinguished from contrast material and vascular wall calcifications in all patients. In VIE images, the renal artery ostium and the stent were viewed from the aortic lumen in all patients. The stent was observed as patent in 14 cases. In one case, occlusion was demonstrated proximal to the stent. Conclusion: Spiral CTA is a noninvasive procedure in evaluating the integrity of the stent, stent patency and renal artery/stent relationship after renal artery stenting.

Application and significance of precise computed tomography angiography (CTA) scanning technology in the assessment of lower extremity arterial diseases.

Generating computed tomography (CT) angiography (CTA) 3-dimensional (3D) volume-rendered (3DVR) images can be time consuming without specialized technical staff or artificial intelligence solutions. However, their role in aneurysm detection in patients with subarachnoid hemorrhage is not known. Our aim was to assess the diagnostic utility of 64-detector row CTA with 3DVR (CTA+3DVR) vs without 3DVR (CTA-3DVR) in intracranial aneurysm detection. A retrospective analysis of patients presenting with spontaneous subarachnoid hemorrhage (regardless of location) who underwent 64-detector row CTA and subsequent digital subtraction angiography (DSA) between 2013 and 2020 was performed. DSA was the reference standard. Almost all DSAs were performed with 3D rotational angiography. Two neuroradiologists blinded to the DSA results separately reviewed CTA source and maximum intensity projection images without 3DVR images (CTA-3DVR) and then immediately followed by the 3DVR images (CTA + 3DVR). Disagreements were resolved by consensus review. Aneurysm size was measured on DSA. In total, 200 patients were included in the study. 140 aneurysms in 114 patients were detected on DSA. CTA-3DVR detected 135 of 140 aneurysms (96.4%), and CTA+3DVR detected 136 of 140 aneurysms (97.1%). All missed aneurysms measured 2-4 mm. Three of four missed aneurysms were associated with multiple aneurysms, and 1 was a singly occurring, 2-mm M3 segment aneurysm. The 1 additional aneurysm detected by CTA + 3DVR was a 3-mm left A3 segment aneurysm. No false positives occurred with or without 3DVR. CTA+3DVR detected 1 additional distal A3 aneurysm vs CTA-VR. 3DVR does not seem to substantially improve the detection of aneurysms but may be useful in the emergent setting for aneurysm morphology characterization.

The current status of multidetector row CT and three-dimensional imaging of the small bowel

Fenestrated endovascular aortic aneurysm repair (FEVAR) is used in pararenal abdominal aortic aneurysms to achieve a durable proximal seal. This study investigated the mid-term course of the proximal fenestrated stent graft (FSG) sealing zone on the first and latest available post-FEVAR computed tomographic angiography (CTA) scan in a single-center series. In 61 elective FEVAR patients, the shortest length of circumferential apposition between the FSG and the aortic wall (shortest apposition length [SAL]) was retrospectively assessed on the first and last available postoperative CTA scans. Patient records were reviewed for FEVAR-related procedural details, complications, and reinterventions. The median (interquartile range) time between the FEVAR procedure and the first and last CTA scan was 35 (30-48) days and 2.6 (1.2-4.3) years, respectively. The median (interquartile range) SAL was 38 (29-48) mm, and 44 (34-59) mm on the first and last CTA scans, respectively. During follow-up, the SAL increased >5 mm in 32 patients (52%), and decreased >5 mm in six patients (10%). Reintervention was performed for a type 1a endoleak in one patient. Twelve other patients needed 17 reinterventions for other FEVAR-related complications. Good mid-term apposition of the FSG in the pararenal aorta was achieved post-FEVAR, and the occurrence of type 1a endoleaks was low. The number of reinterventions was substantial, however, but for reasons other than loss of proximal seal.

1993). The initial management of NET comprises surgical excision of the primary tumour (aimed at reducing as much as possible of the tumour mass); additionally, in patients who are not cured by surgery alone, medical therapy is used for the control of symptoms and humoral syndromes with agents such as somatostatin analogues and/or a-interferon. Specific therapy with radiopharmaceuticals using radio-labelled substances such as meta-iodobenzylguanidine (MIBG) or somatostatin analogues appears promising for some tumours which show diagnostic uptake, and is the first-line systemic management for sensitive cases. Hepatic artery ligation and/or chemoembolization is also used in patients with excessive hepatic tumour load and uncontrollable symptoms. The control of tumour growth with chemotherapeutic agents is currently mainly reserved for patients with recurrent and/or progressive disease and where other therapeutic modalities have failed. Chemotherapy may be particularly helpful for selected cases of advanced NET, especially pancreatic or poorly differentiated NET. This review deals with the general role of chemotherapy in the management of malignant NET, its integration with other modes of therapy, and the specific protocols which have been used. Histological classification and differentiation of NET

INTRODUCTION: Metastatic neuroendocrine neoplasms (NENs) are prevalent at initial prognosis. Surgery with the aim to cure is the current recommended guideline. However, there is not data in supporting therapy for complications from surgery. We successfully treated anastomotic stricture using endoscopic dilation, a modality recommended for treating of Crohn’s Disease stricture. CASE DESCRIPTION/METHODS: 69-year-old female with a history of HTN, hypothyroidism and metastatic Small Bowel Carcinoid Tumor s/p small bowel resection complicated by post-op ileus and now high grade small bowel obstruction (SBO). Initially diagnosed with carcinoid with imaging showing 2.2 × 1.4 cm nodularity in small bowel and mesenteric nodal involvement with elevated chromogranin and 5-HIAA. PET scan showed ileocolic mesenteric adenopathy with no hypermetabolic activity noted. Pathology from small bowel resection revealed high grade carcinoid tumor, for which octreotide therapy was initiated. Patient later developed a high grade SBO at the anastomotic site. She underwent colonoscopy and anastomotic stricture with severe stenosis of 3 mm was noted 10 cm from the ileocecal valve. A Visiglide wire was successfully passed through the stricture under fluoroscopic guidance. She was then serially dilated to 12 mm using a pyloric balloon dilator. Improvement in luminal narrowing was noted after dilation. Output from nasogastric tube began to decrease and her abdominal pain slowly improved. A few days later she began moving her bowels and nasogastric tube was removed. She was advanced from liquid to soft diet and was discharged in stable condition. DISCUSSION: Metastatic intestinal and pancreatic NENs represent 40–50% at initial diagnosis. Besides systemic therapies, current consensus guideline for metastatic NENs recommends for surgical resection with locoregional or ablative therapies. One complication of surgical resection is the development of anastomotic strictures. Strictures in the small bowel are commonly seen in Crohn's Disease. Literature has shown great success with endoscopic balloon dilation for the management of Crohn’s associated strictures. However, small bowel strictures as a complication of surgical resection of carcinoid tumors is not well documented. Our case illustrates how using an endoscopic technique known to manage Crohn’s complications can be novel to cases with similar pathophysiology but different etiology.

<b>Objective:</b> To explore the preoperative whole perforator evaluation and intraoperative eccentric design of anterolateral thigh flap (ALTF) based on superficial fascial perforators by modified computed tomography angiography (CTA), and the clinical effects were observed. <b>Methods:</b> A prospective observational study was adopted. Twelve patients with oral and maxillofacial tumors and 10 patients with open injury of the upper limb with large soft tissue defects were hospitalized in the Department of Hand & Microsurgery and Department of Oral & Maxillofacial Surgery of Affiliated Hospital of Binzhou Medical University from January 2021 to July 2022, with 12 males and 10 females, aged from 33 to 75 years, an average age of 56.6 years. The wounds of the patients with oral and maxillofacial tumors were reconstructed by ALTF after the extensive tumor resection and radical cervical lymph node dissection in the same stage; the wounds of the patients with skin and soft tissue defect on the upper limb were covered by ALTF in stage Ⅱ after debridement in stage Ⅰ. After debridement, the area of wound was 3.5 cm×3.5 cm-25.0 cm×10.0 cm and the area of the required flap area was 4.0 cm×4.0 cm-23.0 cm×13.0 cm. Modified CTA scan was performed on the donor site of ALTF before the operation, with the parameters of modified CTA being set to mainly reduce the tube voltage and tube current, and increase the contrast dose and the dual phase scan. The acquired image data were sent to GE AW 4.7 workstation and adopted the volume reconstruction function for visual reconstruction and evaluation of the whole perforator. The information of perforator and source artery was marked on the body surface before operation according to the above evaluation. During the operation, an eccentric flap centered on the visible superficial fascia whole perforator was designed and cut according to the desired flap area and shape. The donor sites of the flap were repaired by direct sutures or full-thickness skin grafts. The total radiation dose was compared between the modified CTA scan and the traditional CTA scan. The distribution of outlet point of perforator of double thighs, the length and direction of superficial fascia perforators based modified CTA were recorded. The type, number, and origin of the target perforator, distribution of of outlet point of perforator, and the diameter, course, and branch of the source artery observed before the operation were compared with those observed during the operation. The healing of donor site wound and the survival of flaps in recipient site were observed after operation. The texture and appearance of flap, oral and upper limb functions, and the functions of femoral donor sites were followed up. <b>Results:</b> The total radiation dose of modified CTA scan was lower than that of the traditional CTA scan. A total of 48 perforators of double thighs were observed, among which, 31 (64.6%) perforators went outward and downward, 9 (18.8%) perforators went inward and downward, 6 (12.5%) perforators went outward and upward, and 2 (4.2%) perforators went inward and upward, and the average length of superficial fascia perforators was 19.94 mm. The preoperative observed type, number, and source of the perforator, the distribution of the outlet point of the perforator, diameter, course, and branches of the source artery were basically consistent with the intraoperative exploration. The types of 15 septocutaneous (including musculoseptocutaneous) perforators and 10 musculocutaneous perforators observed before the operation was consistent with intraoperative exploration. The distance between the mark of the surface perforator point and the actual exit point of the perforator during operation was (0.38±0.11) mm. All flaps survived without vascular crisis. The donor site wounds of 5 cases of skin grafting and 17 cases of direct suturing wounds healed well. The postoperative follow-up was 2 months to 1 year, with an average of 8.2 months, the flaps were soft and slightly bloated; the function of diet and mouth closing was accessible in patients with oral and maxillofacial tumors, the speech function was mildly impaired in patients with tongue cancer, but they could complete basic oral communication; the wrist and elbow joints and forearm rotation function were not significantly limited in patients with upper limb soft tissue injuries; there was no obvious tightness in the donor sites, and the function of the hip and knee joints was not limited. <b>Conclusions:</b> The whole perforator and even the subcutaneous perforator of the donor site of ALTF can be evaluated by modified CTA, and the flap can be used in oral or maxillofacial reconstruction and repair of skin and soft tissue defects of upper limbs to achieve good results. By clarifying the type, number, and source of the perforator, the distribution of the outlet point of the perforator, diameter, course, and branches of the source artery before the operation, the eccentric design of the ALTF based on the superficial fascia perforator was realized. This study has strong guiding value.

The aorta is the largest vessel of the human body and its pathological degenerations, such as dissections and aneurysms, can be life threatening. An automatic and fast segmentation of the aorta can therefore be a helpful tool to quickly identify an abnormal anatomy. The segmentation of the aortic vessel tree (AVT) typically requires extensive manual labor, but, in recent years, progress in deep learning techniques made the automation of this process viable. For this purpose, we tested different deep learning networks to segment the aortic vessel tree from computed tomography angiography (CTA) scans with a deep neural network consisting of an encoder-decoder architecture with skip connections and an optional self-attention block. The networks were trained on a dataset of 56 CTA scans from three different sources and resulted in Dice score similarities between 0.043−0.897. Generally, the classical U-Nets performed better than the ones containing a self-attention block, indicating that they might diminish performance for AVT segmentation. The quality of the resulting segmentations was highly dependent on the CTA image quality, especially on the contrast between the aorta and the surrounding tissues. However, the trained deep neural network can segment CTA scans well with limited computational resources and training data.

Introduction: Guidelines for ascending thoracic aortic aneurysm (ATAA) repair use ATAA diameter, with repair recommended at ≥5.5cm, but ATAA biomechanics may better predict acute type A dissection (ATAD) risk. However, little is known regarding changes in wall stresses among clinically followed patients with &lt;5.5cm ATAA over time. This information is important for patient risk stratification. Hypothesis: We hypothesized that peak ATAA wall stresses would change over time in a patient-specific fashion alongside diameter. Methods: 31 nonsurgical ATAA patients (&lt;5.5cm and growth &lt;0.5cm/year) with computed tomography angiography (CTA) scans taken 3 to 5 years apart were identified. Images were used to construct patient specific three-dimensional ATAA models. Peak diastolic circumferential stresses were determined along the ascending aorta (AA), sinotubular junction (STJ), and aortic sinuses using finite element analysis. Diameters at both time points were measured from CTA scans by a single radiologist blinded to stress results. Stress and diameter distributions were compared using paired t-tests. Results: In the overall population, ATAA diameter increased over time (4.39±0.4 cm vs. 4.43±0.4 cm, p=0.02), while diastolic circumferential stresses along the aorta did not significantly change. However, we found two distinct patient groups: one where wall stresses increased and one where stresses decreased over time. Separate analysis of these groups showed significant changes in circumferential stress in all three aortic regions (488 ± 120 vs. 340 ± 63 kPa for the sinuses, 472 ± 127 vs 345 ± 76 kPa for the STJ and 337 ± 54 vs 277 ± 28 kPa for AA, p&lt;0.001), and significant increase in diameter in the group with increasing stresses (p=0.02). Conclusions: In this nonsurgical group, there is no statically significant change of peak ATAA wall stresses at diastole over 3-5 years. The patients with increased stress were found to be associated with increases in diameter during the corresponding time period. More patient specific data is required to investigate the interaction between wall biomechanics and aortic remodeling. Our results lay the foundation for developing patient-specific ATAD risk predictors for ATAD using patient-specific wall stress changes.

Sclerosing mesenteritis is associated with a spectrum of diseases which include mesenteric lipodystrophy and mesenteric panniculitis. This inflammatory and fibrosing disorder can affect the small and large bowel wall and mesenteric vessels by exerting a mass effect. The following case highlights the difficulties with diagnosing and managing this unusual disease. A 64-year-old man presented with acute central abdominal pain, radiating to his back, and profuse vomiting. He was diagnosed clinically with small bowel obstruction. He had had an episode of small bowel obstruction 6 years earlier. At this time, he underwent an exploratory laparotomy, and a mass was identified in the small bowel mesentery. The features were thought to be in keeping with sclerosing mesenteritis. He had a dramatically favourable response to the initiation of prednisolone. He continued to be well and asymptomatic for a further 5 years on long-term maintenance low-dose steroids and 6-mercaptopurine. He re-presented in 2009 (six years after initial presentation) with very severe acute abdominal pain and vomiting. He had no recent change in weight or appetite, and had not had time off work. He underwent a second laparotomy and the tissue diagnosis was of metastatic carcinoid tumour involving the small bowel mesentery. This is the first case to our knowledge where sclerosing mesenteritis has been confirmed histologically on biopsy and then subsequently diagnosed with histologically proven carcinoid tumour. For this particular reason it must be always remembered that sclerosing mesenteritis is a ‘pathological’ and not a radiological diagnosis and that a large proportion of cases are associated with neoplasia.

Purpose: Carcinoid tumors are a heterogeneous group. Midgut carcinoid accounts for approximately 50% of all carcinoid tumors in adults, the majority of which arise in the ileum. Since the clinical symptoms are often vague and unrecognized until disease becomes advanced, a majority of patients have metastatic disease at time of diagnosis. It is important to determine the location of the primary since, to a considerable degree, it directs management and predicts outcome. The aim of this study was to assess the utility of wireless video capsule endoscopy in identifying a suspected intestinal primary in patients with demonstrated metastatic carcinoid and no detectable primary on standard investigation. Methods: A retrospective chart review was performed and 24 patients with metastatic carcinoid of unknown primary origin were encountered. Patients' baseline characteristics, clinical presentations, radiological evaluations, chemistries, and therapies were all recorded. All patients underwent wireless video capsule endoscopy in search of a primary lesion after having negative localizing or nonspecific findings on EGD/Colonoscopy, Small Bowel Series, CT scan and OctreoScan®. Results: Of the 24 patients, 8 (33.3%) had positive findings on capsule examination, suggesting a primary carcinoid tumor. All had previously diagnosed metastatic carcinoid on needle biopsy. 5 of these (62.5%) had an ileal primary, 1 (12.5%) had a jejeunal primary, and 2 (25%) were simply classified as a mid small bowel primary. In all cases this positive finding changed management. 7 of the 8 patients (87.5%) underwent surgery and had confirmed small bowel carcinoid tumors. 1 patient who had very advanced disease and was not operated upon had a change in his chemotherapy regimen after the positive capsule finding. Of the 16 patients who had negative capsule studies, 6 had metastatic carcinoid diagnosed by liver biopsy, 1 had an orbit biopsy, 1 had a mesenteric mass biopsy, 1 had a lymph node biopsy, and 3 had significantly abnormal chemical markers (urine 5-HIAA, chromogranin A, and serotonin) strongly indicating carcinoid. No primary was found in 12 of the 16 patients, whereas in 4 patients the primary was proven by biopsy to be in the pancreas. Conclusions: We conclude that wireless video capsule endoscopy is useful in detecting carcinoid tumors originating in the small bowel and not detected by any other conventional method. This localization is significantly important in directing treatment and management of these patients.

To analyze population-based incidence, anatomic distribution and patient characteristics of gastrointestinal carcinoid tumours. Neuroendocrine carcinomas (NE, carcinoid tumours) arise from neuroendocrine cells and are most commonly found in gastrointestinal tract and lungs. Previous studies on carcinoids report varying incidence rates, location of tumours and patient survival rates. Retrospective study. 88 patients were diagnosed with carcinoids located in the gastrointestinal tract in the period 1983-2003 in the Norwegian counties Hordaland and Sogn og Fjordane. Patient and tumour characteristics, treatment and survival were analyzed in a sub-group of 51 patients treated at Haukeland University Hospital. Incidence of carcinoids was 0.8 when analyzed from the counties Hordaland and Sogn og Fjordane as well as when analyzed from Haukeland University Hospital. There were 26 men and 25 women. Median age at surgery was 61 years (range 17-87 years). The tumours were located in the small bowel in 53%, appendix 18%, colon 4%, rectum 4%, stomach 8% and duodenum 10%. Five-year survival rate was 50% in stomach, 80% in duodenum, 43% in the small bowel, 100% for tumours in appendix, 40% in colon and 100% in rectum. Carcinoid tumours are relatively uncommon neoplasms and most of them are found in the small bowel. Carcinoids in the ileum tend to be more aggressive and carry a poorer prognosis than carcinoids at other locations. Tumours in the appendix are found at lower age and in an early stage. They rarely metastasize and have an excellent prognosis.

We introduce a cascade classification algorithm for bifurcation detection in Computed Tomography Angiography (CTA) scans of blood vessels. The proposed algorithm analyzes the vessel surrounding by a trained classifier first, followed by an accurate segmentation of the vessel outer wall by Morphological Active Contour Without Edges and finally extracts the boundary features of the segmented object and classifies its shape by Approximate K-nearest Neighbour classifier. The algorithm shows encouraging and competitive results for blood vessels from various parts of a human body including head, neck and legs.