Giant-cell arteritis: concordance study between aortic CT angiography and FDG-PET/CT in detection of large-vessel involvement

Purpose

The purpose of our study was to assess the concordance of aortic CT angiography (CTA) and FDG-PET/CT in the detection of large-vessel involvement at diagnosis in patients with giant-cell arteritis (GCA).

Methods

We created a multicenter cohort of patients with GCA diagnosed between 2010 and 2015, and who underwent both FDG-PET/CT and aortic CTA before or in the first ten days following treatment introduction. Eight vascular segments were studied on each procedure. We calculated concordance between both imaging techniques in a per-patient and a per-segment analysis, using Cohen’s kappa concordance index.

Results

We included 28 patients (21/7 women/men, median age 67 [56–82]). Nineteen patients had large-vessel involvement on PET/CT and 18 of these patients also presented positive findings on CTA. In a per-segment analysis, a median of 5 [1–7] and 3 [1–6] vascular territories were involved on positive PET/CT and CTA, respectively (p = 0.03). In qualitative analysis, i.e., positivity of the procedure suggesting a large-vessel involvement, the concordance rate between both procedures was 0.85 [0.64–1]. In quantitative analysis, i.e., per-segment analysis in both procedures, the global concordance rate was 0.64 [0.54–0.75]. Using FDG-PET/CT as a reference, CTA showed excellent sensitivity (95%) and specificity (100%) in a per-patient analysis. In a per-segment analysis, sensitivity and specificity were 61% and 97.9%, respectively.

Conclusions

CTA and FDG-PET/CT were both able to detect large-vessel involvement in GCA with comparable results in a per-patient analysis. However, PET/CT showed higher performance in a per-segment analysis, especially in the detection of inflammation of the aorta’s branches.

     

Congenital anomalies of the left brachiocephalic vein detected in adults on computed tomography

Purpose

Anomalous left brachiocephalic vein (BCV) is a rare and less known systemic venous anomaly. We evaluated congenital anomalies of the left BCV in adults detected during computed tomography (CT) examinations.

Materials and methods

This retrospective study included 81,425 patients without congenital heart disease who underwent chest CT. We reviewed the recorded reports and CT images for congenital anomalies of the left BCV including aberrant and supernumerary BCVs. The associated congenital aortic anomalies were assessed.

Results

Among 73,407 cases at a university hospital, 22 (16 males, 6 females; mean age, 59 years) with aberrant left BCVs were found using keyword research on recorded reports (0.03%). Among 8018 cases at the branch hospital, 5 (4 males, 1 female; mean age, 67 years) with aberrant left BCVs were found using CT image review (0.062%). There were no significant differences in incidences of aberrant left BCV between the two groups. Two cases had double left BCVs. Eleven cases showed high aortic arches. Two cases had the right aortic arch, one case had an incomplete double aortic arch, and one case was associated with coarctation.

Conclusion

Aberrant left BCV on CT examination in adults was extremely rare. Some cases were associated with aortic arch anomalies.

     

Early integration of a bone plug in the femoral tunnel in rectangular tunnel ACL reconstruction with a bone-patellar tendon-bone graft: a prospective computed tomography analysis

Purpose

The purpose of this prospective study was to evaluate how early the bone plug was integrated into the rectangular femoral tunnel after anatomical ACL reconstruction using a bone-patellar tendon-bone (BTB) graft via a rectangular tunnel (RT BTB ACL-R).

Methods

Twenty consecutive patients who had undergone the reconstruction procedure were evaluated by CT scans at 4 and 8 weeks postoperatively. In each scan, 30 slices for multiplanar reconstruction were collected parallel to the long axis of the parallelepiped femoral tunnel and perpendicular to the tendinous plane of the bone plug. Each slice was classified as “complete,” indicating no visible gap between the plug and the tunnel wall or trabecular continuity or “incomplete,” showing a visible gap. Bone plug-tunnel integration was evaluated as “excellent,” “good,” “fair,” or “poor” for >20, 11–20, 5–10, and <4 “complete” slices, respectively.

Results

In this evaluation, 55% of the patients were rated as “excellent” on the first scan, and 80% were “excellent” on the second scan, showing healing over time. The CT values at the anterior interface between the bone plug and the tunnel wall were also measured on both scans. The mean changes in CT value at 8 weeks were significantly lower than those at 4 weeks.

Conclusion

This study shows that bone plug-femoral tunnel integration was almost complete by 8 weeks after surgery using RT BTB ACL-R.

     

Three days of high-dose glucocorticoid treatment attenuates large-vessel 18F-FDG uptake in large-vessel giant cell arteritis but with a limited impact on diagnostic accuracy

Purpose

To evaluate the in-treatment diagnostic accuracy of FDG PET/CT in large-vessel giant cell arteritis (LV-GCA) by serial scans before and after a short course of high-dose glucocorticoid treatment.

Methods

Twenty-four glucocorticoid-naïve patients with new-onset PET/CT verified LV-GCA (pre-treatment baseline PET) were prospectively included. Excluded were patients with a previous history of GCA or polymyalgia rheumatica, LV-GCA-mimicking conditions and patients on immunosuppressive therapy. All patients were treated with 60 mg of oral prednisolone daily and assigned for in-treatment FDG PET/CT after either 3 (PET3) or 10 days (PET10). Two experienced nuclear medicine physicians, blinded to patients’ clinical data, reviewed the FDG PET/CT images. A visual semi-quantitative approach was used. Segmental and homogenous FDG uptake in the wall of the aorta and/or supra-aortic branches with higher uptake intensity than liver was considered consistent with vasculitis. Inter-reader reliability was evaluated.

Results

Although glucocorticoid treatment attenuated FDG uptake in large vessels, LV-GCA was accurately diagnosed in 10/10 patients after 3 days of treatment, but only in 5/14 patients after 10 days of treatment (p?<?0.001). Interrater reliability was substantial (agreement 87%, Cohen’s weighted kappa 0.70). No correlation between CRP and FDG uptake was found.

Conclusions

Within 3 days of high-dose glucocorticoid treatment, FDG PET/CT can diagnose LV-GCA with high sensitivity. This window of opportunity ensures that prompt glucocorticoid treatment can be initiated to avoid debilitating GCA complications with a limited effect on diagnostic accuracy. After 10 days of treatment, FDG PET/CT sensitivity decreases significantly.

     

Intra-patient comparison of reduced-dose model-based iterative reconstruction with standard-dose adaptive statistical iterative reconstruction in the CT diagnosis and follow-up of urolithiasis

Objectives

To evaluate the accuracy of reduced-dose CT scans reconstructed using a new generation of model-based iterative reconstruction (MBIR) in the imaging of urinary tract stone disease, compared with a standard-dose CT using 30% adaptive statistical iterative reconstruction.

Methods

This single-institution prospective study recruited 125 patients presenting either with acute renal colic or for follow-up of known urinary tract stones. They underwent two immediately consecutive scans, one at standard dose settings and one at the lowest dose (highest noise index) the scanner would allow. The reduced-dose scans were reconstructed using both ASIR 30% and MBIR algorithms and reviewed independently by two radiologists. Objective and subjective image quality measures as well as diagnostic data were obtained.

Results

The reduced-dose MBIR scan was 100% concordant with the reference standard for the assessment of ureteric stones. It was extremely accurate at identifying calculi of 3 mm and above. The algorithm allowed a dose reduction of 58% without any loss of scan quality.

Conclusions

A reduced-dose CT scan using MBIR is accurate in acute imaging for renal colic symptoms and for urolithiasis follow-up and allows a significant reduction in dose.

Key points

? MBIR allows reduced CT dose with similar diagnostic accuracy ? MBIR outperforms ASIR when used for the reconstruction of reduced-dose scans ? MBIR can be used to accurately assess stones 3 mm and above

     

Clinical impact of computed tomography in the emergency department in nontraumatic chest and abdominal conditions

Aim

To evaluate the clinical impact of CT scan in modifying the clinical management in patients referred to the emergency department.

Methods

We prospectively evaluated 300 patients (177 males, 63?±?18 years old) admitted in the emergency department (ED) of a single institution, who underwent a CT examination for thoracic and/or abdominal complains. Demographic and clinical data were collected. Hypothesized outcome prior to CT scan and final management (i.e., discharge, short observation in the ED, hospitalization, and department of admission) were compared.

Results

After CT examination, a major variation in diagnosis occurred in 37% of cases and clinical management changed in 43%, occurring in 51% of patients who underwent abdominal CT, in 40% of chest CT, and in 29% of chest/abdominal CT (P?=?0.015). Department of hospitalization changed in 26% of cases (P?<?0.001). Clinical impact of CT scan was significantly associated (P?=?0.001) with the color code at admission. In particular, the more severe was the clinical condition, the lower was the variation of management after CT examination.

Conclusions

This work confirms the crucial role of CT examination in the management of nontraumatic patients admitted to the ED, both in terms of better clarifying the diagnosis and in influencing the clinical management.

     

Image fusion between 18F-FDG PET and MRI in cardiac sarcoidosis: A case series

Background

Sarcoidosis is a systemic disorder of unknown etiology. It is distinguished by the presence of noncaseating epithelioid granulomas. This study demonstrates the use of image fusion between (18)F-fluoro-2-deoxy-d-glucose positron emission tomography (18F-FDG PET) and magnetic resonance imaging (MRI) to diagnose patients with cardiac sarcoidosis (CS).

Methods

Seven patients diagnosed with sarcoidosis were retrospectively included. All patients underwent 18F-FDG PET/CT and cardiac MRI.

Results

On the MRI scan, late gadolinium enhancement (LGE) was observed in five patients. T2-weighted images revealed areas with an increased signal consistent with myocardial edema in two patients and with hypointensity suggesting fibrosis in one patient. Increased 18F-FDG uptake was seen in the myocardial wall in three patients, indicating active inflammation.

Conclusion

18F-FDG PET and MRI image fusion allows clinicians to obtain complete morphofunctional cartography in patients with sarcoidosis. Our data show that 18F-FDG PET/MRI image fusion imaging can be useful in the diagnosis of CS.

     

Aortic knob width reflects left ventricular diastolic function assessed by gated myocardial perfusion single photon emission computed tomography in patients with normal myocardial perfusion

Background

Aortic knob width on chest radiography represents the extent of aortic dialation and tortuosity of the aortic arch. We tested the hypothesis that aortic knob width reflected left ventricular (LV) diastolic function assessed by gated myocardial perfusion single photon emission computed tomography (SPECT) in patients with normal myocardial perfusion.

Methods

One hundred and thirty patients with preserved LV ejection fraction and normal myocardial perfusion were enrolled in this study. Aortic knob width was measured along the horizontal line from the point of the lateral edge of the trachea to the left lateral wall of the aortic knob. The peak filling rate (PFR) and the one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters.

Results

There were 114 male and 16 female patients. Age ranged from 43 to 88 years (69.9?±?8.9 years). Aortic knob width ranged from 24.2 to 53.4 mm (37.6?±?5.7 mm). There was a significant correlation between age and aortic knob width (r?=?0.34, p?<?0.001). Aortic knob width was inversely correlated with both PFR (r?=??0.53, p?<?0.001) and 1/3 MFR (r?=??0.42, p?<?0.001). Multivariate linear regression analysis revealed that serum creatinine (β?=??0.16, p?=?0.045) and aortic knob width (β?=??0.45, p?<?0.001) were significant predictors of PFR, and that age (β?=??0.20, p?=?0.02) and aortic knob width (β?=??0.33, p?<?0.001) were significant predictors of 1/3 MFR.

Conclusions

Our data suggested that aortic knob width on chest radiography was a simple marker of LV diastolic function in patients with normal myocardial perfusion.

     

The scab-like sign: A CT finding indicative of haemoptysis in patients with chronic pulmonary aspergillosis?

Objectives

The aim of this study was to assess the CT findings that characterise haemoptysis in patients with chronic pulmonary aspergillosis (CPA).

Methods

We retrospectively identified 120 consecutive patients with CPA (84 men and 36 women, 17–89 years of age, mean age 68.4 years) who had undergone a total of 829 CT examinations between January 2007 and February 2017. In the 11 patients who underwent surgical resection, CT images were compared with the pathological results.

Results

The scab-like sign was seen on 142 of the 829 CT scans, specifically, in 87 of the 90 CT scans for haemoptysis and in 55 of the 739 CT scans obtained during therapy evaluation. In 48 of those 55 patients, haemoptysis occurred within 55 days (mean 12.0 days) after the CT scan. In the 687 CT scans with no scab-like sign, there were only three instances of subsequent haemoptysis in the respective patients over the following 6 months. Patients with and without scab-like sign differed significantly in the frequency of haemoptysis occurring after a CT scan (p<0.0001). Pathologically, the scab-like sign corresponded to a fibrinopurulent mass or blood crust.

Conclusions

The scab-like sign should be considered as a CT finding indicative of haemoptysis.

Key Points

? Haemoptysis is commonly found in patients with CPA. ? A CT finding indicative of haemoptysis in CPA patients is described. ? Scab-like sign may identify CPA patients at higher risk of haemoptysis.

     

Use of Suture-Mediated Closure Device in Percutaneous Direct Carotid Puncture During Chimney-Thoracic Endovascular Aortic Repair

Background

Insertion of a carotid chimney graft during thoracic endovascular aortic repair (Ch-TEVAR) is a recognized technique to extend the proximal landing zone into the aortic arch in the treatment of thoracic aortic disease. Conventional technique requires surgical exposure of the carotid artery for insertion of the carotid chimney graft.

Methodology

We describe our experience in the use of a suture-mediated closure device in percutaneous Ch-TEVAR in four patients.

Results

Successful hemostasis was achieved in all four patients. No complications related to the carotid puncture were recorded.

Conclusion

We conclude that using suture-mediated closure device for carotid closure appears feasible and deserves further studies as a potential alternative to conventional surgical approach.

     

Pulmonary measles disease: old and new imaging tools

Background

Measles virus can cause lower respiratory tract infection, so that chest radiography is necessary to investigate lung involvement in patients with respiratory distress.

Purpose

To assess measles pneumonia imaging during the measles outbreak occurred in 2016–2017 in Italy.

Material and methods

We retrospectively observed adult patients with a serological diagnosis of measles, who underwent chest-X rays for suspected pneumonia. If a normal radiography resulted, the patient underwent unenhanced CT. A CT post processing software package was used for an additional quantitative lung and airway involvement analysis.

Results

Among 290 patients affected by measles, 150 underwent chest-X ray. Traditional imaging allowed the pneumonia diagnosis in 114 patients (76%). The most frequent abnormality at chest X-rays was bronchial wall thickening, observed in 88.5% of the cases; radiological findings are faint in the 25% of the cases (29/114 patients). In nine subjects with a normal chest X-ray, unenhanced CT with a quantitative analysis was performed, and depicted features consistent with constrictive bronchiolitis.

Conclusion

Measles may produce bronchiolitis and pneumonia. In the cases in which involvement of pulmonary parenchyma is not sufficient to result in radiological abnormalities, CT used with a dedicated postprocessing software package, provides an accurate lungs and airways analysis, also determining the percentage of lung involvement.

     

Image classification for Die-punch fracture of intermediate column of the distal radius

Objective

The aim of the study was to analyze the imaging findings of Die-punch fracture of intermediate column of the distal radius, and to explore the clinical application value of image classification.

Methods

The clinical data of 45 patients who were admitted to our hospital from May 2010 to October 2016 were analyzed retrospectively. All patients met the inclusion criteria for Die-punch fracture. X-ray and CT scan were performed to examine the fracture, and the results were assessed by two doctors in a double blind method. Finally, the image classification of Die-punch fracture was formulated.

Results

According to the imaging features of Die-punch fracture, it was divided into four types: type I (dorsal type, 15 cases), type II (volar type, 8 cases), type III (splitting type, 10 cases), type IV (collapsed type, 12 cases). The accuracy rate of CT was 100% (45/45). The misclassification rate of X-ray was 15.6% (7/45) and the missed diagnosis rate was 11.1% (5/45).

Conclusions

CT examination could accurately diagnose Die-punch fracture and perform preoperative image classification.

     

Cardiac computed tomography as a viable alternative to echocardiography to detect vegetations and perivalvular complications in patients with infective endocarditis

Purpose

We considered cardiac computed tomography (CT) as a possible alternative modality to echocardiography in the assessment of infective endocarditis (IE). We evaluated the diagnostic capability of preoperative CT.

Materials and methods

We retrospectively evaluated the depiction of vegetations and perivalvular complications in preoperative cardiac CT images of 14 patients diagnosed with IE who required surgical intervention, who were seen at our institution from May 30, 2008 to February 3, 2017. We compared the CT findings with those of TTE and TEE assessments, and intraoperative findings.

Results

Cardiac CT correctly identified intraoperatively proven vegetations in 12 out of 13 (92.3%) patients and demonstrated 100% sensitivity and positive predictive value in depicting vegetations in the aortic valve and 100% sensitivity, specificity, positive predictive value, and negative predictive value in depicting pseudoaneurysm as perivalvular complications. CT offered superior identification of pseudoaneurysm to that with echocardiography and detected vegetations as small as 6 mm in maximal length. Vegetation size correlated well between TEE and CT.

Conclusion

Favorable comparison of CT and echocardiography in detecting vegetations and perivalvular complications in patients diagnosed with IE suggested potential for expansion in the use of CT for evaluating organic lesions in patients suspected or diagnosed with IE.

     

Variation in emergency department use of computed tomography for investigation of acute aortic dissection

Introduction

Acute aortic dissection (AAD) is a life-threatening condition making early diagnosis critical. Although 90% present with acute pain, the myriad of associated symptoms can make diagnosis a challenge. Our objective was to assess how we are using computed tomography to rule out acute aortic dissection specifically rate of ordering, diagnostic yield, and variation in practice.

Methods

We included consecutive adult patients presenting to two tertiary academic care emergency departments over one calendar year presenting with non-traumatic chest, back, abdominal, or flank pain. Primary outcome was rate of CT thorax/abdomen ordered to rule out AAD. Secondary outcome was variation in CT ordering, measured comparing number of CTs ordered per physician. Sample size of 12 per group was calculated based on an expected delta in mean CT ordered of 5 and a within group SD of 3.

Results

Thirty-one thousand two hundred one patients presented with truncal pain during the study period, 22,729 were included (mean 47 years, SD 18.5 years, 56.2% female); prevalence of AAD (N?=?4) was 0.02%. CT was ordered to rule out AAD in 175 (0.7%) patients (mean 62 years, SD 16.5, 50.6% female). Significant variation between physicians ordering was found, with individual physicians ordering varying from 0.6 to 12%.

Conclusions

Current rate of imaging for acute aortic dissection is low and potentially inefficient, with a large variation in practice. These findings suggest potential for more standardized and efficient use of CT for the diagnosis of acute aortic dissection.

     

Awareness of radiation risks from CT scans among patients and providers and obstacles for informed decision-making

Introduction

Using the study design from a prominent 2004 study, we aimed to reassess patient, provider, and radiologist awareness of CT radiation more than a decade later.

Methods

Adults presenting to the emergency department of a tertiary care center over a 2-week period with mild to moderate pain requiring an abdominopelvic CT scan were surveyed. Patients were asked if anyone had discussed the risks/benefits of the CT scan including radiation dose and were asked to estimate their dose compared to a chest X-ray. Emergency providers and radiologists were given similar surveys and were asked about potential obstacles to discussing CT radiation with patients.

Results

A total of 101 patients, 570 emergency providers, and 161 radiologists were surveyed. Twenty-three percent (14/61) of patients, 39% (219/568) of emergency providers, and 48% (77/161) of radiologists correctly selected the radiation dose range of an abdominopelvic CT. Seventy-eight percent (441/567) of emergency providers reported routinely discussing radiation dose with patients, while 20% (20/98) of patients reported that their emergency provider discussed radiation dose with them. Time limitation and concern of dissuading the patient from CT were the most commonly reported obstacles for discussing risks.

Conclusions

Patients and providers in 2015 appear to be more aware of radiation dose from CT than they were in 2004. Discussion of CT scan radiation exposure and associated risks only occurs sometimes and may actually occur less frequently than perceived by emergency providers.

     

A review of split-bolus single-pass CT in the assessment of trauma patients

Purpose

The purpose of this study was to review and compare the image quality and radiation dose of split-bolus single-pass computed tomography(CT) in the assessment of trauma patients in comparison to standard multi-phase CT techniques.

Methods

An online electronic database was searched using the MESH terms “split-bolus,” “dual phase,” and “single pass.” Inclusion criteria required the research article to compare a split contrast bolus protocol in a single-pass scan in the assessment of trauma patients. Studies using split-bolus CT technique in non-traumatic injury assessment were excluded. Six articles met the inclusion criteria.

Conclusions

Parenchymal and vascular image qualities, as well as subjective image quality assessments, were equal or superior in comparison to non-split-bolus multi-phase trauma CT protocols. Split-bolus single-pass CT decreased radiation exposure in all studies. Further research is required to determine the superior split-bolus protocol and the specificity and sensitivity of detecting blunt cerebrovascular injury screening, splenic parenchymal vascular lesions, and characterization of pelvic vascular extravasation.

     

MR imaging of carotid webs

Purpose

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging.

Methods

Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web.

Results

Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients.

Conclusion

Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE).

     

Quantitative 3D analysis of bone in hip osteoarthritis using clinical computed tomography

Objective

To assess the relationship between proximal femoral cortical bone thickness and radiological hip osteoarthritis using quantitative 3D analysis of clinical computed tomography (CT) data.

Methods

Image analysis was performed on clinical CT imaging data from 203 female volunteers with a technique called cortical bone mapping (CBM). Colour thickness maps were created for each proximal femur. Statistical parametric mapping was performed to identify statistically significant differences in cortical bone thickness that corresponded with the severity of radiological hip osteoarthritis. Kellgren and Lawrence (K&L) grade, minimum joint space width (JSW) and a novel CT-based osteophyte score were also blindly assessed from the CT data.

Results

For each increase in K&L grade, cortical thickness increased by up to 25 % in distinct areas of the superolateral femoral head–neck junction and superior subchondral bone plate. For increasing severity of CT osteophytes, the increase in cortical thickness was more circumferential, involving a wider portion of the head–neck junction, with up to a 7 % increase in cortical thickness per increment in score. Results were not significant for minimum JSW.

Conclusions

These findings indicate that quantitative 3D analysis of the proximal femur can identify changes in cortical bone thickness relevant to structural hip osteoarthritis.

Key Points

? CT is being increasingly used to assess bony involvement in osteoarthritis ? CBM provides accurate and reliable quantitative analysis of cortical bone thickness ? Cortical bone is thicker at the superior femoral head–neck with worse osteoarthritis ? Regions of increased thickness co-locate with impingement and osteophyte formation ? Quantitative 3D bone analysis could enable clinical disease prediction and therapy development

     

Computer-aided detection of pulmonary nodules: a comparative study using the public LIDC/IDRI database

Objectives

To benchmark the performance of state-of-the-art computer-aided detection (CAD) of pulmonary nodules using the largest publicly available annotated CT database (LIDC/IDRI), and to show that CAD finds lesions not identified by the LIDC’s four-fold double reading process.

Methods

The LIDC/IDRI database contains 888 thoracic CT scans with a section thickness of 2.5 mm or lower. We report performance of two commercial and one academic CAD system. The influence of presence of contrast, section thickness, and reconstruction kernel on CAD performance was assessed. Four radiologists independently analyzed the false positive CAD marks of the best CAD system.

Results

The updated commercial CAD system showed the best performance with a sensitivity of 82 % at an average of 3.1 false positive detections per scan. Forty-five false positive CAD marks were scored as nodules by all four radiologists in our study.

Conclusions

On the largest publicly available reference database for lung nodule detection in chest CT, the updated commercial CAD system locates the vast majority of pulmonary nodules at a low false positive rate. Potential for CAD is substantiated by the fact that it identifies pulmonary nodules that were not marked during the extensive four-fold LIDC annotation process.

Key Points

? CAD systems should be validated on public, heterogeneous databases. ? The LIDC/IDRI database is an excellent database for benchmarking nodule CAD. ? CAD can identify the majority of pulmonary nodules at a low false positive rate. ? CAD can identify nodules missed by an extensive two-stage annotation process.

     

Acquired peripheral pulmonary artery aneurysms: morphological spectrum of disease and multidetector computed tomography angiography findings—cases series and literature review

Background

Acquired peripheral or intraparenchymal pulmonary artery aneurysms (PPAA) are rare entities but are important to recognize because of the associated morbidity. Hemoptysis is their principal complication and is a potentially fatal condition.

Purpose

To illustrate the causes, multidetector CT angiography (MDCTA) findings and differential diagnosis of acquired PPAA.

Materials and methods

The institutional review boards approved this study. We conducted a retrospective review of the demographic data and the results of clinical and laboratory examinations, and imaging studies of patients managed between January 2012 and January 2017 in two institutions.

Results

A total of 19 patients had acquired PPAA that were detected at MDCTA, 9 patients with normal pulmonary artery pressures and 10 with pulmonary hypertension. Nine patients developed PPAA-related acute symptoms. MDCTA features of PPAA include: a lobulated vascular mass, an indistinct irregular arterial wall, aneurysmal thrombosis or wall calcification, findings of impending rupture including perianeurysmal edema, gas or a soft tissue mass.

Conclusion

PPAA are rare. In our series, endocarditis and pulmonary hypertension are the PPAA leading causes. The treatment modality preferred is embolization, especially as surgery poses a very high risk for patients with severe pulmonary hypertension. Further clarification of the natural history of these rare arterial aneurysms is needed.