Subsequent Computed Tomography Angiography Research Articles

Initial screening test for blunt cerebrovascular injury: Validity assessment of whole-body computed tomography

Our whole-body computed tomography protocol (WBCT), used to image patients with polytrauma, consists of a noncontrast head computed tomography (CT) followed by a multidetector computed tomography (40- or 64- slice) that includes an intravenous, contrast-enhanced scan from the face through the pelvis. WBCT is used to screen for blunt cerebrovascular injury (BCVI) during initial CT imaging of the patient with polytrauma and allows for early initiation of therapy with the goal of avoiding stroke. WBCT has not been directly compared with CT angiography (CTA) of the neck as a screening tool for BCVI. We hypothesize that WBCT is a valid modality to diagnose BCVI compared with neck CTA, thus screening patients with polytrauma for BCVI and limiting the need for subsequent CTA. A retrospective review of the trauma registry was conducted for all patients diagnosed with BCVI from June 2009 to June 2013 at our institution. All injuries, identified and graded on initial WBCT, were compared with neck CTA imaging performed within the first 72hours. Sensitivity was calculated for WBCT by the use of CTA as the reference standard. Proportions of agreement also were calculated between the grades of injury for both imaging modalities. A total of 319 injured vessels were identified in 227 patients. On initial WBCT 80 (25%) of the injuries were grade I, 75 (24%) grade II, 45 (14%) grade III, 41 (13%) grade IV, and 58 (18%) were classified as indeterminate: 27 vertebral and 31 carotid lesions. Twenty (6%) of the 319 injuries were not detected on WBCT but identified on subsequent CTA (9 grade I, 7 grade II, 4 grade III); 6 vertebral and 14 carotid. For each vessel type and for all vessels combined, WBCT demonstrated sensitivity rates of over 90% to detect BCVI among the population of patients with at least one vessel injured. There was concordant grading of injuries between WBCT and initial diagnostic CTA in 154 (48% of all injuries). Lower grade injures were more discordant than higher grades (55% vs 13%, respectively; P<.001). Grading was upgraded 8% of the time and downgraded 25%. WBCT holds promise as a rapid screening test for BCVI in the patient with polytrauma to identify injuries in the early stage of the trauma evaluation, thus allowing more rapid initiation of treatment. In addition, in those patients with high risk for BCVI but whose WBCT results are negative for BCVI, neck CTA should be considered to more confidently exclude low-grade injuries.

Number of Entry Tears Is Associated With Aortic Growth in Type B Dissections

Aortic growth rate in acute type B aortic dissection (ABAD) is a significant predictor for aortic complications and death. To improve the overall outcome, radiologic predictors might stratify patients who benefit from successful medical management vs those who require intervention. This study investigated whether the number of identifiable entry tears in ABAD patients is associated with aortic growth. ABAD patients with uncomplicated clinical conditions and therefore treated with medical therapy were evaluated. Those with a computed tomography angiography (CTA) obtained at clinical presentation and a subsequent CTA obtained at least 90 days after medical treatment were included (2005 to 2010). The CTAs were investigated for the number of entry tears between the true and false lumen. Diameters of the dissected aortas were measured at five levels on the baseline and on the last available follow-up CTA, and annual aortic growth rates were calculated. The number of entry tears in these patients and the location in the aorta were compared with the aortic growth rate. Included were 60 patients who presented with 243 dissected segments. Mean growth rates during follow-up (median, 23.2; range, 3 to 132 months) were significantly higher in patients with 1 entry tear (5.6 ± 8.9 mm) than in those with 2 (2.1 ± 1.7 mm; p = 0.001) and 3 entry tears (mean 2.2 ± 4.1; p = 0.010). The distance of the primary entry tear from the left subclavian artery did not have an effect on the aortic growth rate (median, 38; interquartile range, 24 to 137 mm; p = 0.434). The number of entry tears in ABAD patients detected on the first CTA after clinical presentation is a significant predictor for aortic growth. Patients with 1 entry tear at presentation show a higher growth rate than other patients and might benefit from more strict surveillance or early prophylactic intervention.

A Fighter Pilot Case of Pulmonary Sequestration

Pulmonary sequestration is a rare congenital malformation. The diagnosis of pulmonary sequestration is based on the identification of an abnormal arterial supply. Conventional treatment for pulmonary sequestration is surgical removal of the tissue, which may induce serious trauma and requires a long recovery time. Recently, endovascular treatment has become feasible as a safer and less invasive method to treat pulmonary sequestration. To the best of our knowledge, pulmonary sequestration has not been reported in pilots. In this study, we report a fighter pilot case of intralobar pulmonary sequestration detected with the assistance of spiral computed tomography (CT) and digital subtraction angiography. The young fighter pilot had experienced recurrent hemoptysis and pulmonary infections for approximately 10 yr before the pulmonary sequestration was diagnosed. We performed a transcatheter arterial embolization and a subsequent CT angiography confirmed complete infarction of the sequestration. After the treatment, no clinical complications were observed and the patient, with normal lung function restored, was qualified to serve as a fighter pilot again. Compared with conventional removal surgery, endovascular treatment is a superior treatment for pulmonary sequestration in a fighter pilot in maintenance of pilot qualification.

Transplant renal artery false aneurysm.

The transplant renal artery false aneurysm is a rare event but can be fatal. We report the case of a patient with a false aneurysm, which appeared 6 years after transplantation. The clinical presentation was an increase of the creatinine value and de novo graft hydronephrosis. The first ultrasound performed showed no aneurysm, leaving doubt whether this would not have been caused iatrogenically with the nephrostomy catheter placement. On the other hand, the resolution of hydronephrosis with aneurysmectomy leads us to believe that the aneurysm had existed previously. We consider this an interesting case by the manner of presentation and the success of the approach. A 44-year-old male patient received a first kidney transplant from a cadaveric donor in August 2005. Active bleeding was detected in the early post-operative period. He was reoperated and an arterial anastomotic dehiscence needing a vascular reconstruction was found. The remaining post-transplant period was unremarkable with a baseline serum creatinine of 2.0 mg/dL. In October 2011, he had an asymptomatic increase in serum creatinine to 2.7 mg/dL and urine analysis was completely normal. Ultrasonography showed a de novo hydronephrosis. Provisional diagnosis of obstruction was contemplated and a percutaneous nephrostomy was placed. Renal function did not improve. Ultrasonography was repeated showing a hypoechoic mass with a pulsatile flow pattern by colour Doppler scanning and maintained hydronephrosis. Subsequent computed tomography angiography confirmed a 4 × 4 cm false aneurysm at the anastomosis of the transplanted renal artery with the right external iliac extern (Figure 1). Digitally subtracted angiography was done prior to surgery (Figure 2). The resection of the false aneurysm was performed and the transplanted renal artery was anastomosed to the external iliac artery. Post-operatively, creatinine improved to basal value and ultrasonography showed no hydronephrosis. Fig. 1. Three dimensional computed tomography angiography reconstruction view showing the false aneurysm and the nephrostomy catheter. Fig. 2. Digitally subtracted angiography showing the false aneurysm at the junction of the transplanted renal artery with the right external iliac artery. False aneurysms following kidney transplantation are rare, but can be potentially devasting and cause functional impairment and even loss of the graft due to the risk of rupture [1]. Patients are usually asymptomatic and they are diagnosed incidentally. They can be managed conservatively with regular monitoring if the false aneurysms are small. When they cause clinical signs or risk rupture, interventional treatment is required.

Computed tomography detection of carotid calcium and subclinical carotid atherosclerosis

Computed tomography (CT) detection of coronary calcium has become a popular technique for assessing coronary atherosclerosis. Whether CT detection of carotid calcium could similarly assess carotid atherosclerosis is unknown. We thus performed a study evaluating the feasibility of carotid calcium scoring by CT. We also looked for an association between carotid calcium and subclinical carotid atherosclerosis. Subjects (n = 876) underwent non-contrast CT scanning of their carotid arteries. Carotid calcium was quantified by the Agatston method. Stenoses were detected by subsequent CT angiography. Significant subclinical atherosclerosis was defined by the presence of a ≥30% carotid stenosis. The frequency of a ≥30% carotid stenosis was then analyzed as a function of carotid calcium scores and various cardiovascular risk factors. CT detection of carotid calcium was feasible, robust, and reliable. Significant univariate associations for a ≥30% carotid stenosis included age (P < 0.001), diabetes (P = 0.02), hypertension (P = 0.01), and the carotid calcium score (P < 0.001). Those with a ≥30% carotid stenosis exhibited a median (25th, 75th percentile) carotid calcium score of 153 (19, 489), while those without a ≥30% carotid stenosis had a median (25th, 75th percentile) carotid calcium score of 0 (0, 89). Conversely, when no carotid calcium was detected, there was a low (1%) frequency of significant carotid atherosclerosis. The frequency of a ≥30% carotid stenosis increased as the carotid calcium score increased (P < 0.001 for trend). This association remained significant after adjustment for age, hypertension, diabetes, hyperlipidemia, and tobacco use. CT detection of carotid calcium can assess the burden of carotid atherosclerosis.

Intravenous Thrombolysis in an Elderly Patient With Acute Ischemic Stroke Masking Aortic Dissection

Before thrombolytic treatment for acute ischemic stroke is undertaken, conditions associated with increased risk of hemorrhagic complications, such as an acute aortic dissection (AAD), should be excluded. We report an 80-year-old woman with acute ischemic stroke as the sole clinical manifestation of AAD who was treated with intravenous (IV) tissue plasminogen activator (tPA). She had no history of hypertension or any signs or symptoms suggestive of AAD. After IV tPA infusion was started, carotid color-coded duplex sonography demonstrated proximal left common carotid artery dissection suggestive of AAD. Infusion of tPA was stopped, and subsequent computed tomography angiography confirmed Stanford type A aortic dissection. In this case, prompt neurosonologic evaluation helped us make an appropriate diagnosis and avoid complications related to treatment. Neurosonologic evaluation should be considered as soon as possible in all patients with acute ischemic stroke, especially when thrombolytic treatment is being considered.

Dual origin of the left vertebral artery: Extracranial MRA and CTA findings

A 48-year-old man presented with a posterior circulation stroke secondary to left lateral medullary infarction. Contrast-enhanced magnetic resonance angiography (CEMRA) revealed 40–45% intracranial left vertebral artery stenosis, likely atherosclerotic in nature. CEMRA and subsequent computed tomography angiography also identified a duplicate origin of the left vertebral artery. The importance of recognition of this rare anatomical variant, its potential contribution to stroke aetiology, and the advantage of non-invasive vascular imaging prior to catheter angiography is emphasised.

Disappearing Flapping Plaque in the Internal Carotid Artery

Mobile atheromatous plaque at the origin of the internal carotid artery (ICA) is a rare finding at the carotid ultrasound examination. Acute thrombosis is unusually seen. Either may be secondary to plaque hemmorhage, plaque ulceration, carotid dissection, or proximal embolus. We report an 89-year-old male suffering from an acute neurologic event who on ultrasound had a flapping heterogeneous atheromatous plaque at the right ICA origin. This mobile atheromatous plaque is distinguished from acute thrombus by its echogenicity, narrow pedicle of attachment, and absence of underlying intima. Subsequent computed tomography angiography and repeat ultrasound within 24 hr demonstrated the disappearance of this plaque. Only three small intimal flaps remained. In the intervening period, the patient's symptoms significantly worsened. While conservative management of thrombus with intravenous thrombolysis has been shown in some settings to be appropriate, the diagnosis and management of mobile atheroma are unclear. This case suggests that differentiation between atheroma and thrombus may be valuable in determining management strategies.

The Usefulness of Super-Selective Computed Tomography Angiography (CTA) for Diagnosing and Localizing a Small Insulinoma

Localization of insulinomas by preoperative imaging is critical for successful surgical resection. However, the visualization and localization of small insulinomas by recent imaging modalities still remains a challenge. Here, we report a 77-year-old woman with a small insulinoma successfully localized by performing arterial stimulation and venous sampling (ASVS), and subsequent super-selective CTA (SSCTA). It was not visualized by routine non-invasive imaging tests such as digital subtraction angiography (DSA). The small size (1.0 cm) of the surgically removed tumor supports the usefulness of SSCTA for localizing very small insulinomas.

Long-term results of balloon-expandable LifePath endografts in abdominal aortic aneurysm: A single-center experience

This retrospective single-center study analyzed long-term results after LifePath (Edwards Lifesciences LLC, Irvine, Calif) endoprosthesis implantation for abdominal aortic aneurysm (AAA), primarily focusing on the wire form fracture issue and consecutive endoleak rate. Between 1999 and 2004, all consecutive patients with LifePath AAA devices in our institution were included in the retrospective analysis. All patients had computed tomography angiography (CTA) imaging preoperatively and image postprocessing. The follow-up using CTA imaging specifically addressed material fatigue (wire form fractures) resulting in migrations and type I endoleaks. During the 6-year study period, which included the 1-year withdrawal and redesign of the device, 51 patients were treated with LifePath AAA endografts. The 30-day mortality was 0%. The perioperative 30-day morbidity was 9.8%. One patient required a primary conversion due to misdeployment of the iliac limbs within the graft main body. The primary endoleak rate was 20.56% (type I, 2%; type II, 19.6%). During the mean follow-up of 40.7 months, 12 patients died, six were lost to follow-up, and 32 underwent subsequent CTA imaging. Eight patients (25%) demonstrated a proximal type I endoleak, seven (22%) had a type II endoleak, and three had a type III endoleak (9%). In nine patients (28.1%), wire form fractures could be detected at image postprocessing. Four patients required a secondary conversion due to endoleak and aneurysm growth (2 type I endoleaks and 2 type III endoleaks). Wire form fracture is the major structural problem in the LifePath balloon-expandable endograft device, resulting in a significant endoleak rate. We must caution those patients with a LifePath device in-situ that careful follow-up must be performed due to material fatigue and they should consider secondary conversion.

Subarachnoid hemorrhage and diffuse vasculopathy in an adult infected with HIV

This 34-year-old man with a 10-year history of HIV infection presented with an acute onset of severe headache, fever, nausea, vomiting, and left-sided weakness. Computed tomography (CT) scanning demonstrated diffuse subarachnoid hemorrhage (SAH), and subsequent CT angiography revealed multiple large and giant intracranial aneurysms with diffuse vasculopathy. The patient's CD4-positive cell count was low, although he had been receiving combination antiretroviral therapy and his viral load was undetectable. The preponderance of the literature on HIV-infected patients with intracranial vascular involvement has concerned children in whom there is a high viral load. In such children, appropriate antiretroviral therapy may result in the complete resolution of these vascular abnormalities. In the present study, the authors report on the unique case of an HIV-infected adult patient who presented with SAH, diffuse intracranial vasculopathy, and multiple giant and fusiform aneurysms, despite having received adequate antiretroviral treatment and demonstrating an undetectable viral load. Intracranial vascular involvement in these patients may become increasingly common as the management of HIV infection continues to improve and afflicted patients survive for longer periods.