CT Angiogram Research Articles

A Challenging Diagnosis - Large Leiomyomas on Rudimentary Uterus in Mayer-Rokitansky-Küster-Hauser (MRKH) Syndrome

A 40-year-old woman diagnosed with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome at 16 years of age presented with a large abdominal mass protruding to the right subcostal margin, equivalent to 30 weeks gestation. She didn’t have comorbidities of hypertension or diabetes. The vitals were normal with BMI 30. She was asymptomatic except for occasional vague abdominal discomfort. Further imaging studies were conducted to assess the extent and nature of the findings. Pelvic and transvaginal ultrasound demonstrated the presence of multiple large fibroids extending beyond the level of the umbilicus. This was corroborated by pelvic MRI, which further confirmed the massively enlarged multi-fibroid uterus. Additionally, intravenous contrast-enhanced imaging revealed large bilateral ovarian collaterals and prominent blood vessels extending to the broad ligament. Triple-phase CT angiogram of the abdomen/pelvis with pre-contrast revealed an 8mm aneurysm on the anterior aspect of the abdominal aorta and unusual vascular anatomy, raising the possibility of an atypical or neoplastic process in the right iliac fossa. In view of these findings, an opinion by an Oncologist was sought, who suspected the possible presence of an abnormal nidus of vessels and a fluid attenuation area in the right iliac fossa. Additionally, the Risk of Ovarian Malignancy Algorithm (ROMA) test was performed, revealing a slightly elevated value. To reach the final diagnosis, the decision for the exploratory laparotomy was undertaken. Intraoperative findings revealed the presence of a rudimentary uterus with normal ovaries (Figure 1 and Figure 2), as well as the presence of bilateral broad fibroids (Figure 3). The broad ligament areas around the uterus were occupied with large circumscribed masses, identified as fibroids. The right-side fibroid measuring 17 x 15cm (Figure 4) and the left-side fibroid measuring 10 x 10cm (Figure 5) were excised, respectively, while preserving the left ovary and rudimentary uterus. Peritoneal fluid samples were obtained to ascertain the nature of malignancy. No evidence of infiltration or adhesions was detected. Postoperatively, the patient experienced no complications. Histological examination of the masses growing from bilateral uterine remnants confirmed the presence of leiomyomas, with no glandular epithelium identified. Peritoneal fluid analysis revealed the absence of malignant cells.

Popliteal Artery Entrapment Syndrome: Updates for Evaluation, Diagnosis, and Treatment.

Popliteal artery entrapment syndrome remains difficult to diagnose. Meanwhile, our limited knowledge and understanding make treatment decisions complex. The list of differential diagnoses for exertional leg pain is broad. Oftentimes, patients exhibit confounding and coexisting diagnoses. However, accurate and rapid diagnosis of popliteal artery entrapment syndrome is essential to reduce potential lasting damage to the popliteal artery. A combination of clinical history, physical examination, ankle-brachial index, along with dynamic and static imaging such as duplex ultrasound, computed tomography angiogram, and magnetic resonance angiography, aids diagnosis. Surgical treatment may be definitive depending on the type of popliteal artery entrapment syndrome, but there have been recent advances in diagnostics with intravascular ultrasound and nonsurgical treatment with botulinum toxin type A. Further research is needed to standardize diagnostic criteria, uncover innovative diagnostic methods, and validate promising nonoperative treatment options.

Early three-dimensional growth in uncomplicated type B aortic dissection is associated with long-term outcomes

ObjectiveLate adverse events (LAEs) are common among initially uncomplicated type B aortic dissection (uTBAD); however, identifying those patients at highest risk of LAEs remains a significant challenge. Early false lumen (FL) growth has been suggested to increase risk, but confident determination of growth is often hampered by error in two-dimensional clinical measurements. Semi-automated three-dimensional (3D) mapping of aortic growth, such as by vascular deformation mapping (VDM), can potentially overcome this limitation using computed tomography angiograms (CTA). We hypothesized that FL growth in the early pre-dissection phase by VDM can accurately predict LAEs. MethodsWe performed a two-center retrospective study of patients with uTBAD, with paired CTAs in the acute (1-14 days) and subacute/early chronic (1-6 months) periods. VDM analysis was used to map 3D growth. Standard clinical CT measures (ie, aortic diameters, tear characteristics) were also collected. Multivariate analysis was conducted using a decision tree and Cox proportional hazards model. LAEs were defined as aneurysmal FL (>55 mm); rapid growth (>5 mm within 6 months); aorta-specific mortality, rupture, or re-dissection. ResultsA total of 107 (69% male) patients with uTBAD initially met inclusion criteria with a median follow-up of 7.3 years (interquartile range [IQR], 4.7-9.9 years). LAEs occurred in 72 patients (67%) at 2.5 years (IQR, 0.7-4.8 years) after the initial event. A multivariate decision tree model identified VDM growth (>2.1 mm) and baseline diameter (>42.7 mm) as optimal predictors of LAEs (area under the receiver operating characteristic curve = 0.94), achieving an 87% accuracy (sensitivity of 93%, specificity of 76%) after leave-one-out validation. Guideline reported high-risk features were not significantly different between groups. ConclusionsEarly growth of the FL in uTBAD was the best tested indicator for LAEs and improves upon the current gold-standard of baseline diameter in selecting patients for early prophylactic thoracic endovascular aortic repair.

Transorbital Approach Clipping of Middle Cerebral Artery Aneurysm: A Virtual Reality Morphometric Anatomic Study

The transorbital approach (TOA) has a unique advantage to the more common lateral approaches as it provides direct access to the anterior middle fossa and medial sylvian fissure (SF) without significant dissection or retraction. However, when to use the TOA for surgical treatment of MCA aneurysms remains unclear. This study details the feasibility of clipping unruptured middle cerebral artery (MCA) aneurysms via the TOA by highlighting the anatomic features that either facilitate or hinder the approach. Virtual reality (VR) models of 25 MCA aneurysms from CT angiograms of actual patients were rendered with the relevant anatomic structures, including the neighboring temporal lobe and SF. TOA was performed on the models in VR and the globe was translated medially and inferiorly, replicating retraction used intraoperatively. Anatomic data, including the area of surgical freedom (AOF) at the aneurysm, were recorded. Trials of aneurysm clipping were conducted in VR and each aneurysm was classified as "possible" or "impossible" candidates for clipping via TOA. Separately, the relationship between surgical view and SF visualized was analyzed. Sixteen aneurysms were eliminated as candidates for TOA treatment either through VR clip trial and/or because the SF was inaccessible. The remaining 9 (36%) were candidates for TOA. Comparing the details of these two aneurysm categories with Mann Whitney U tests, there was a statistically significant difference in the AOF of the TOA approach and the width of the aneurysm dome. A clinical case report is also provided highlighting the VR rehearsal similarity with surgery. Given the minimally-invasive, technically-challenging approach, the feasibility and safety of TOA for MCA aneurysms must be evaluated before wide clinical adoption. This study identified AOF, aneurysm width, and SF accessibility as three features that may significantly impact the possibility of clipping MCA aneurysms via TOA.

366. MINIMALLY INVASIVE MANAGEMENT OF AORTO-OESOPHAGEAL FISTULA: THORACIC ENDOVASCULAR AORTIC REPAIR AND THORACOSCOPIC ASSISTED OESOPHAGECTOMY WITH DELAYED GASTRIC CONDUIT RECONSTRUCTION

Abstract Background Development of aorto-oesophageal fistula (AOF) within the context of thoracic aortic aneurysm is rare and carries a high mortality rate. Here we present two cases detailing the successful management of AOF. Methods A 58 year old male presented with haematemesis. CT angiogram demonstrated fistulation between a mycotic aneurysmal thoracic aorta and the oesophagus. He underwent Thoracic Endovascular Aneurysm Repair (TEVAR). This was followed by thoracoscopic assisted oesophagectomy (TAO) and delayed gastric conduit reconstruction. A 49 year old female presented with massive haematemesis. CT angiogram demonstrated a calcified thoracic aneurysmal sac. This was managed with TEVAR. Subsequent investigations revealed mediastinitis, stent graft infection and AOF. This was managed with TAO and delayed gastric conduit reconstruction. Results Gastric conduit reconstruction achieved an excellent functional result in both patients. Ongoing Aortic CT surveillance has revealed satisfactory appearances with no current plans for further vascular intervention. Both patients have returned to full employment. Conclusions TEVAR should be used as the initial bridging intervention to stabilise haemodynamically unstable patients with AOF. Subsequent oesophageal resection can be safely performed using a minimally invasive approach with subsequent retro-sternal reconstruction using a gastric conduit. CT follow up demonstrate no ongoing issues with the implanted aortic stents

Computational fluid dynamics; a new diagnostic tool in giant intracerebral aneurysm treatment

Giant intracerebral aneurysms (GIA) comprise up to 5 % of all intracranial aneurysms. The indirect surgical strategy, which leaves the GIA untouched but reverses the blood flow by performing a bypass in combination with proximal parent artery occlusion is a useful method to achieve spontaneous aneurysm occlusion. The goal of this study was to assess the utility of computational fluid dynamics (CFD) in preoperative GIA treatment planning. We hypothesise that CFD simulations will predict treatment results.A fluid-structure interaction (FSI) CFD investigation was performed for the entire arterial brain circulation. The analyses were performed in three patient-specific CT angiogram models. The first served as the reference geometry with a C6 internal carotid artery (ICA) GIA, the second a proximal parent artery occlusion (PAO) and virtual bypass to the frontal M2 branch of the middle cerebral artery (MCA), and the third a proximal PAO in combination with a temporal M2 branch bypass. The volume of “old blood”, flow residence time (FRT), dynamic viscosity and haemodynamic changes were also analysed.The “old blood” within the aneurysm in the bypass models reached 41 % after 20 cardiac cycles while in the reference model it was fully washed out. In Bypass 2 “old blood” was also observed in the main trunk of the MCA after 20 cardiac cycles. Extrapolation of the results yielded a duration of 4 years required to replace the “old blood” inside the aneurysm after bypass revascularization. In both bypass models a 7-fold increase in mean blood viscosity in the aneurysm region was noted.Bypass revascularization combined with proximal PAO favours thrombosis. Areas prone to thrombus formation, and subsequently the treatment outcomes, were accurately identified in the preoperative model. Virtual surgical operations can give a remarkable insight into haemodynamics that could support operative decision-making.

Critical Lower-Limb Ischemia and Arterial Thrombosis Following Intraarticular Corticosteroid Injection of the Knee.

We present a case of acute lower-limb arterial thrombosis following intra-articular steroid injection into the knee of a previously fit and active 41-year-old man. Symptoms of acute limb ischemia developed within 24 hours of treatment. Objective assessment with ultrasound arterial duplex and CT angiogram of the lower limb confirmed acute thrombosis of the popliteal artery in the treated leg. Although there is documented evidence of the association between steroid therapy and venous thromboembolic phenomena, there are no cases of arterial thrombosis in the literature. The temporal series of events that we report strongly suggest an association between the corticosteroid injection and the acute thrombotic event, the mechanism of which remains unclear. The patient underwent successful revascularization. It is important to document and disseminate this seemingly rare complication of a commonly associated procedure to increase awareness, invoke caution, and invite others to share similar cases.

The iliac and femoral arteries: Dimensions and tortuosity in a South African radiological sample

BackgroundArterial morphology varies and changes with increasing age. This may challenge the success of endovascular procedures and influence candidate selection. The study aimed to determine the mean dimensions, tortuosity severity, and tortuosity phenotype of the iliofemoral pathway of adult males and females from a South African sample. Furthermore, the relationship between increased age and changes in vessel morphology was investigated. DesignA retrospective cross-sectional study was conducted using a sample of 224 (117 males and 107 females) computed tomography angiograms of patients hospitalized due to traumatic injuries (aged 18–80 years), accessed from Tygerberg Hospital, Cape Town, South Africa. MethodsThe arterial lengths and lumen diameters of the common iliac (CIA), external iliac (EIA), and femoral arteries (FA) were measured. Tortuosity severity was described by visual estimation and quantified using the tortuosity index (TI) and inflection count metric (ICM). The data were compared between right and left sides of the body, the sexes, and age categories. ResultsOn average, the common iliac artery was the widest (9.50 ± 1.53 mm), while the external iliac artery was the longest (110.89 ± 16.04 mm). Bilateral asymmetries were observed. Arterial diameters were larger in males. Regression analysis revealed a strong positive relationship between arterial tortuosity and increasing age, particularly in females. Tortuosity was most frequently observed in the external iliac artery. However, the c-shaped curving tortuosity phenotype was observed in all three arteries investigated. ConclusionThe morphology of the iliofemoral arterial pathway varied bilaterally, between the sexes, and with increased age. These findings align with previous studies, noting the variable morphology of the iliofemoral pathway, in countries outside of Sub-Saharan Africa. Sex- and age-specific descriptions of arterial anatomy may enhance the safety of endovascular procedures and interventions. These descriptions contribute towards the development of a reference database of typical arterial anatomy in South Africa, ultimately assisting with patient selection and the identification of vascular pathologies.

Spontaneous Renal Artery Dissection in Active Duty Male.

Spontaneous renal artery dissection is a rare condition with nonspecific symptoms that can be challenging to diagnose. We present the case of a 25-year-old male presenting with left flank pain, mild leukocytosis, and a benign urinalysis found to have renal artery dissection on computed tomography angiogram. The patient's condition improved following conservative management with anticoagulants. This case demonstrates that Spontaneous renal artery dissection may be a potential cause of renal artery infarction in young, previously healthy patients.

A Prevalence Anatomic-Imaging Study of the Posterior Inferior Cerebellar Artery's Origin.

Background and Objectives: Typically, the vertebral arteries (VAs) enter the posterior fossa through dural rings and further unite, forming the basilar artery. The posterior inferior cerebellar artery (PICA) is usually a branch of the V4 segment of the VA (intradural origin). It may also leave the V3 suboccipital segment of the VA (extradural origin). The transdural origin of the PICA within the VA's dural ring has been consistently overlooked. A study was designed to determine the topographical patterns of the PICA's origin. Materials and Methods: Determinations were performed in a retrospective sample of 225 computed tomography angiograms. Four types of PICA origin were documented: type 0, absent PICA; type 1, the extradural origin of the PICA from the V3 segment of the VA; type 2, the transdural origin of the PICA within the dural ring; and type 3, the intradural origin of the PICA from the V4 segment of the VA. The bilateral symmetry of types was also investigated. Results: Out of 450 VAs, type 0 (absent PICA) was found in 36%, type 1 (extradural) in 0.44%, type 2 (transdural) in 5.56%, and typical type 3 in just 58%. In types 1 and 2, the PICA entered the posterior fossa through the dural ring and the marginal sinus. In the overall group (N = 225), the type combinations 1_1, 1_2 and 1_3 were not found. Bilaterally absent PICAs occurred in 18.67%. The bilateral combinations 0_1/0_2/0_3/2_2/2_3/3_3 were found, respectively, in 0.89%/3.11%/30.67%/1.78%/4.44%/40.44%. Four of the seventy-eight PICAs opposite to an absent one, three intradural and one transdural, were true bihemispheric PICAs. Conclusions: The PICAs with extradural or transdural origins are facultative contents of the dural ring and are at risk during neurosurgical approaches in the foramen magnum. Rare bihemispheric PICAs could originate either intradurally or within the dural ring.

Traumatic occipital artery pseudoaneurysm: Case report, anatomical considerations, and literature review.

We describe a case of a 22-year-old man with a traumatic occipital artery pseudoaneurysm revealed by a painful expanding neck hematoma after a penetrating knife injury. A neuroendovascular consultation was requested after a computed tomography angiogram showed active pseudoaneurysm bleeding. Anatomical considerations of the upper cervical region including dangerous anastomosis between the vertebral and internal carotid artery are discussed, illustrating how this impacted our treatment strategy. We also discuss other treatment modalities after a thorough literature review of traumatic occipital artery pseudoaneurysms.

Reproducibility of a single-volume dynamic CT myocardial blood flow measurement technique: validation in a swine model

BackgroundWe prospectively assessed the reproducibility of a novel low-dose single-volume dynamic computed tomography (CT) myocardial blood flow measurement technique.MethodsThirty-four pairs of measurements were made under rest and stress conditions in 13 swine (54.3 ± 12.3 kg). One or two acquisition pairs were acquired in each animal with a 10-min delay between each pair. Contrast (370 mgI/mL; 0.5 mL/kg) and a diluted contrast/saline chaser (0.5 mL/kg; 30:70 contrast/saline) were injected peripherally at 5 mL/s, followed by bolus tracking and acquisition of a single volume scan (100 kVp; 200 mA) with a 320-slice CT scanner. Bolus tracking and single volume scan data were used to derive perfusion in mL/min/g using a first-pass analysis model; the coronary perfusion territories of the left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA) were automatically assigned using a previously validated minimum-cost path technique. The reproducibility of CT myocardial perfusion measurement within the LAD, LCx, RCA, and the whole myocardium was assessed via regression analysis. The average CT dose index (CTDI) of perfusion measurement was recorded.ResultsThe repeated first (Pmyo1) and second (Pmyo2) single-volume CT perfusion measurements were related by Pmyo2 = 1.01Pmyo1 − 0.03(ρ = 0.96; RMSE = 0.08 mL/min/g; RMSE = 0.07 mL/min/g) for the whole myocardium, and by Preg2 = 0.86Preg1 + 0.13(ρ = 0.87; RMSE = 0.31 mL/min/g; RMSE = 0.29 mL/min/g) for the LAD, LCx, and RCA perfusion territories. The average CTDI of the single-volume CT perfusion measurement was 10.5 mGy.ConclusionThe single-volume CT blood flow measurement technique provides reproducible low-dose myocardial perfusion measurement using only bolus tracking data and a single whole-heart volume scan.Relevance statementThe single-volume CT blood flow measurement technique is a noninvasive tool that reproducibly measures myocardial perfusion and provides coronary CT angiograms, allowing for simultaneous anatomic-physiologic assessment of myocardial ischemia.Key PointsA low-dose single-volume dynamic CT myocardial blood flow measurement technique is reproducible.Motion misregistration artifacts are eliminated using a single-volume CT perfusion technique.This technique enables combined anatomic-physiologic assessment of coronary artery disease.Graphical

Abstract Tu010: Matrix metallopeptidase 9 contributes to the beginning of plaque and is a potential biomarker for the early identification of atherosclerosis in asymptomatic patients with diabetes

Aims: To determine the roles of matrix metallopeptidase-9 (MMP9) on human coronary artery smooth muscle cells (HCASMCs) in vitro , early beginning of atherosclerosis in vivo in diabetic mice, and patients with diabetes. Methods: Active hMMP9 ( act-hMMP9) was added to HCASMCs and markers of inflammation were measured. Act-hMMP9 (n=16) or placebo (n=15) was administered to d i abetic KK.Cg- A y /J (KK) mice. Carotid artery inflammation and atherosclerosis measurements were made at 2 and 10 weeks after treatment. An observational study of newly diagnosed drug naïve patients with type 2 diabetes mellitus (T2DM n=234) and healthy matched controls (n=41) was performed and patients had ultrasound of carotid arteries and some had coronary computed tomography angiogram for the assessment of atherosclerosis. Serum MMP9 was measured and its correlation with carotid artery or coronary artery plaques were determined. Results: Act-hMMP9 induced inflammatory response in HCASMCs in vitro , including increased gene and protein expressions of MCP-1, ICAM-1, VCAM-1, and enhanced macrophage adhesion. Exogenous act-hMMP9 increased inflammation and initiated atherosclerosis in KK mice at 2 and 10 weeks: increased vessel wall thickness, lipid accumulation, and Galectin-3+ macrophage infiltration into the carotid arteries. In newly diagnosed T2DM patients, serum MMP9 correlated with carotid artery plaque size with a possible threshold cutoff point. In addition, serum MMP9 correlated with number of mixed plaques and grade of lumen stenosis in coronary arteries of patients with drug naïve T2DM. Conclusions: MMP9 contributes to the initiation of atherosclerosis and may be a potential biomarker for the early identification of atherosclerosis in patients with diabetes

Microsurgical clipping of large MCA aneurysm in a 2-month-old child.

Cerebral aneurysms in children have a low incidence and accounts for less than 4% of all cerebral aneurysms. These aneurysms have been linked to various factors. Severe headache, seizures, and motor-sensory deficits are common presentations. We describe the case of a 2-month-old male patient who presented with generalized tonic-clonic seizures for 4days. At the hospital, he was stabilized with ventilatory support, sedation, and antiepileptic drugs. A NCCT (Head) showed intraparenchymal hemorrhage in the left fronto-parieto-temporal lobe and subarachnoid hemorrhage. Subsequently a CT angiogram revealed an aneurysm of the left M3 segment of MCA. Successfully, the patient underwent microsurgical clipping of aneurysm and evacuation of hematoma. Pediatric cerebral aneurysms differ from their adult counterparts, mainly in their etiology and evolution. As per literature, aneurysmal clipping and neurological endovascular therapy have shown similar results.

Quantitative Computed Tomography Angiography for the Evaluation of Valvular Fibrocalcific Volume in Aortic Stenosis

BackgroundAortic stenosis (AS) is characterized by calcification and fibrosis. The ability to quantify these processes simultaneously has been limited with previous imaging methods. ObjectivesThe purpose of this study was to evaluate the aortic valve fibrocalcific volume by computed tomography (CT) angiography in patients with AS, in particular, to assess its reproducibility, association with histology and disease severity, and ability to predict/track progression. MethodsIn 136 patients with AS, fibrocalcific volume was calculated on CT angiograms at baseline and after 1 year. CT attenuation distributions were analyzed using Gaussian-mixture-modeling to derive thresholds for tissue types enabling the quantification of calcific, noncalcific, and fibrocalcific volumes. Scan-rescan reproducibility was assessed and validation provided against histology and in an external cohort. ResultsFibrocalcific volume measurements took 5.8 ± 1.0 min/scan, demonstrating good correlation with ex vivo valve weight (r = 0.51; P < 0.001) and excellent scan-rescan reproducibility (mean difference −1%, limits of agreement −4.5% to 2.8%). Baseline fibrocalcific volumes correlated with mean gradient on echocardiography in both male and female participants (rho = 0.64 and 0.69, respectively; both P < 0.001) and in the external validation cohort (n = 66, rho = 0.58; P < 0.001). The relationship was driven principally by calcific volume in men and fibrotic volume in women. After 1 year, fibrocalcific volume increased by 17% and correlated with progression in mean gradient (rho = 0.32; P = 0.003). Baseline fibrocalcific volume was the strongest predictor of subsequent mean gradient progression, with a particularly strong association in female patients (rho = 0.75; P < 0.001). ConclusionsThe aortic valve fibrocalcific volume provides an anatomic assessment of AS severity that can track disease progression precisely. It correlates with disease severity and hemodynamic progression in both male and female patients.

Comparison of preoperative aortic valve imaging techniques for patients with aortic insufficiency undergoing aortic valve repair surgery

ObjectiveTo report the accuracy of preoperative 4-dimensinal cardiac computed tomography angiogram (CTA), real-time 3-dimensional transesophageal echocardiography (TEE) and intraoperative techniques in aortic valve (AV) measurement and phenotype determination in patients undergoing surgery for aortic insufficiency and/or root aneurysm. MethodsThis is a prospective, observational study of preoperative AV imaging for AV repair surgery. Twenty-two patients were accrued over 12 months. Preoperative TEE and CTA were obtained and measurements provided by dedicated imaging cardiologists. Intraoperative measurements were obtained from the arrested heart and reported by the surgeon before repair. Intraoperative assessment was considered the gold standard of height measurements, with CTA being the standard assessment for commissural orientation. Correlation coefficients were used to describe agreement of measurements. ResultsBaseline characteristics and assessment of phenotype and measurement of commissural orientation, geometric height and commissural heights are reported. TEE (κ = 0.833; P < .01) and CTA (κ = 0.729; P < .01) both agreed with intraoperative assessment of AV phenotype. TEE appeared more accurate than intraoperative measurement at predicting commissural orientation (rs = 0.79; P < .01 vs rs = 0.58; P = .01). CTA and TEE were unlikely to predict and measured shorter than intraoperative geometric height measurement. Measurements of commissural heights by CTA did not agree with and were shorter than intraoperative measurement. ConclusionsTEE and CTA both appear accurate in predicting the AV phenotype identified intraoperatively. CTA and TEE predicted shorter heights than intraoperative measurement.

Safety and efficacy of covered stent grafts in the treatment of emergent access related complications

BackgroundLarge bore percutaneous access is becoming increasingly common. Parallel to this, we observe an increase in vascular access site complications such as bleeding, dissection, thrombosis or pseudo-aneurysms. This study was aimed to evaluate safety and efficacy of covered stent grafts for fixing large bore vascular access injuries. MethodsA total of 147 Viabahn or Viabahn VBX (WL Gore) stent grafts which were placed across the inguinal ligament in emergent settings in 136 patients, were retrospectively analyzed. The two endpoints were the technical success rate, defined by complete arterial repair, and long-term stent graft patency. We also looked at the need for open conversion, wound infections, and in hospital and 30-day mortality. We followed the patients using duplex ultrasound and computed tomography angiogram to assess for arterial patency, freedom from intervention, stent kinking and clinical symptoms. Results30 Viabahn and 117 Viabahn VBX (WL Gore) stent grafts were placed in the distal external iliac artery and into the proximal common femoral artery of 136 patients. Indications for intervention were bleeding in 92 patients (68 %), flow limiting dissection in 41 patients (30 %) and symptomatic AVF in 3 patients (2 %). Primary technical success rate was 100 %. Limited 3-year follow up (101/136 patients) showed 99 % patency with no evidence of stent fracture, stenosis or kinking except in one patient who needed target lesion revascularization due to neointimal hyperplasia. ConclusionsCovered stent grafts can be placed safely, efficiently, and effectively in the distal external iliac and common femoral arteries across the inguinal ligament. These stent grafts can be used as an alternative therapeutic option to open surgery in patients with large bore vascular access injuries.

In vitro and in vivo optimized reconstruction for low-keV virtual monoenergetic photon-counting detector CT angiography of lower legs

BackgroundLower extremity peripheral artery disease frequently presents with calcifications which reduces the accuracy of computed tomography (CT) angiography, especially below-the-knee. Photon-counting detector (PCD)-CT offers improved spatial resolution and less calcium blooming. We aimed to identify the optimal reconstruction parameters for PCD-CT angiography of the lower legs.MethodsTubes with different diameters (1–5 mm) were filled with different iodine concentrations and scanned in a water container. Images were reconstructed with 0.4 mm isotropic resolution using a quantitative kernel at all available sharpness levels (Qr36 to Qr76) and using different levels of quantum iterative reconstruction (QIR-2–4). Noise and image sharpness were determined for all reconstructions. Additionally, CT angiograms of 20 patients, reconstructed with a medium (Qr44), sharp (Qr60), and ultrasharp (Qr72) kernel at QIR-2-4, were evaluated by three readers assessing noise, delineation of plaques and vessel walls, and overall quality.ResultsIn the phantom study, increased kernel sharpness led to higher image noise (e.g., 16, 38, 77 HU for Qr44, Qr60, Qr72, and QIR-3). Image sharpness increased with increasing kernel sharpness, reaching a plateau at the medium-high level 60. Higher QIR levels decreased image noise (e.g., 51, 38, 25 HU at QIR-2–4 and Qr60) without reducing vessel sharpness. The qualitative in vivo results confirmed these findings: the sharp kernel (Qr60) with the highest QIR yielded the best overall quality.ConclusionThe combination of a sharpness level optimized reconstruction kernel (Qr60) and the highest QIR level yield the best image quality for PCD-CT angiography of the lower legs when reconstructed at 0.4-mm resolution.Relevance statementUsing high-resolution PCD-CT angiography with optimized reconstruction parameters might improve diagnostic accuracy and confidence in peripheral artery disease of the lower legs.Key PointsEffective exploitation of the potential of PCD-CT angiography requires optimized reconstruction parameters.Too soft or too sharp reconstruction kernels reduce image quality.The highest level of quantum iterative reconstruction provides the best image quality.Graphical

The central neck in 3 dimensions: a digital model derived from radiology, peer-reviewed literature, and medical illustration

This project aims to create a 3-dimensional (3D) digital model of central neck anatomy, including muscles, neurovasculature, and viscera. The neck was segmented from a CT angiogram of a healthy 29-year-old female, and then transferred into 3D illustration software after removing imaging artifact. To enhance anatomical accuracy, details not captured by imaging or unclear from the study were added and refined with relevant peer-reviewed literature. These structures were later incorporated into the head and neck model. Following segmentation, the 3D models was refined in 3D CAD software. Structures not identified by segmentation were designed by a medical illustrator and all structures were refined from peer-reviewed anatomic literature. Where discrepancies were found in the literature, the size, source, and methodology of the studies were considered to determine the most common variants of each structure. Finally, the 3D model was uploaded to MedReality for online viewing. Technological progress in illustration software, patient specific anatomic modeling, and precise 3D CAD modeling has allowed the most accurate 3D surgical anatomy model to be created when combined with existing literature. The associated 3D model and manuscript will serve as a helpful tool for medical professionals regardless of academic level. To our knowledge, this literature-based model of the central neck combined with 3D anatomic modeling from real patient data is unprecedented and should aid in surgical anatomy education.

The lateral neck in 3 dimensions: A digital model derived from radiology, peer-reviewed literature, and medical illustration

ObjectivesTo develop an anatomically accurate 3-dimensional (3D) digital model of the lateral neck anatomy, including musculature, neurovasculature, and other associated structures such as lymphatics Materials and MethodsLateral neck anatomy, emphasizing level 1-4 structures, were segmented from a CT angiogram of a healthy 29-year-old female which was later transferred into a 3D illustration software after removal of imaging artifacts. To enhance anatomical accuracy, details not captured by imaging or unclear from the study were refined with relevant peer-reviewed literature. These structures were incorporated into the head and neck model. ResultsFollowing segmentation, the 3D models was refined in 3D CAD software. Structures not identified by segmentation, including vagus and phrenic nerves and lymphatics beyond the scan resolution, were designed by a medical illustrator and all structures were refined from peer-reviewed anatomic literature. Where discrepancies were found in the literature, the sample size, source, and methodology of the studies were considered to determine the most common variant of each structure. Finally, the 3D model was uploaded to MedReality® for online viewing. ConclusionThis study demonstrates the critical anatomic structures, landmarks, and surgical relationships relevant to the lateral neck. The associated 3D model and manuscript will serve as a helpful tool for a broad range of clinicians and trainees in search of a detailed 3D anatomic description of the lateral neck. This literature-based model of the central neck combined with 3D anatomic modeling from real patient data should aid in surgical anatomy education.