A low threshold to ECG-gated repeat CTA reduces the risk of false-positive diagnosis of type A dissection in interhospital referrals: a case series study

Pericardial Recesses on Computed Tomography: Implications for the Pulmonologist

The pericardium comprises a double-walled fibrous-serosal sac that encloses the heart. Reflections of the serosal layer form sinuses and recesses. With advances in multidetector computed tomography (CT) technology, pericardial recesses are frequently detected with thin-section CT. Knowledge of pericardial anatomy on imaging is crucial to avoid misinterpretation of fluid-filled pericardial sinuses and recesses as adenopathy/pericardial metastasis or aortic dissection, which can impact patient management and treatment decisions. The authors offer a comprehensive review of pericardial anatomy and its variations observed on CT, potential pitfalls in image interpretation, and implications for the pulmonologist with respect to unnecessary diagnostic procedures or interventions.

Aortic Intimo-intimal Intussusception: A Pooled Analysis of Published Reports

AIM

Aortic intimo-intimal intussusception (AoII) is a rare manifestation of aortic dissection with high mortality. This study aimed to obtain a comprehensive understanding of AoII.

METHODS

Three databases (PubMed, Scopus, Embase) were searched with predefined search terms ["intimal intussusception", "aortic intussusception", "(circumferential) AND (intimal dissection)" and "(circumferential) AND (aortic dissection)"]. Demographics, clinical manifestations, imaging methods, therapies, and follow-up data were recorded and analyzed.

RESULTS

The literature search finally identified 81 papers comprising 87 patients (Mean age: 53.7 ± 14.9 years old; male: n = 63). According to morphologic criteria (orientation of AoII intimal flap), patients were divided into three groups: antegrade (n = 37), retrograde (n = 49) and bidirectional (n = 1) orientation. The most frequent symptoms in antegrade group were chest pain (62.2%), syncope (27%), and unconsciousness (21.6%), while in retrograde group, they were chest pain (71.4%), dyspnea (20.4%), and back pain (16.3%). Regarding applied imaging modalities, 67.5% of patients in antegrade group were diagnosed with≥2 methods, comparing with 87.7% in retrograde group. A total of 21 patients (24.1%) with AoII finally died, among which 13.8% (12/87) died before surgery.

CONCLUSION

AoII is a rare form of aortic dissection with high mortality. Antegrade orientation of the intima flap was more accompanied with neurological disorders and asymmetric blood pressure, while retrograde orientation mostly manifested with aortic regurgitation. Application of multiple imaging examinations may detect this rare entity in time.

Optimal phase analysis of electrocardiogram-gated computed tomography angiography in patients with Stanford type A acute aortic dissection

Objective

To determine the phase that facilitates flap observation of the ascending aorta in Stanford type A acute aortic dissection with perfused false lumen.

Methods

We reconstructed retrospective Electrocardiogram-gated Computed Tomography Angiography images of the ascending aorta of all 20 patients to 20 phases of curved-multiplanar reconstruction in 5% increment. One radiologist created and randomized 10 cross-sectional images of each phase for every patient and two radiologists scored these images on a 5-point scale depending on the degree of flap stoppage. We calculated the average score for each phase of each case and compared them among the three groups.

Results

Image scores were significantly better in the 65 %-100 % R-R interval group than those in the 5%-30 % (p < 2e-16) and 35 %-60 % R-R interval groups(p = 7.2e-10). Similar scores were observed in the Heart Rate > 70 group (p = 0.00039, 2.2e-14). Moreover a similar tendency was observed in the arrhythmia group (p = 0.0035, 0.294). No difference was found in the degree of flap stoppage in the 65 %-100 % R-R interval group between the Heart Rate > 70 and Heart Rate ≤ 70 groups (p = 0.466) and between the arrhythmia and non-arrhythmia groups (p = 0.1240).

Conclusion

In observing the ascending aorta, We obtained a good image at 65 %-100 % R-R interval and similar tendency was observed in the patients with arrhythmia.

Detection of the intimal tear in aortic dissection and ulcer-like projection in intramural hematoma: usefulness of full-phase retrospective ECG-gated CT angiography

PURPOSE

To compare the accuracy of non-electrocardiogram (ECG)-gated CT angiography (CTA), single-diastolic-phase ECG-gated CTA, and full-phase ECG-gated CTA in detecting the intimal tear (IT) in aortic dissection (AD) and ulcer-like projection (ULP) in intramural hematoma (IMH).

MATERIALS AND METHODS

A total of 81 consecutive patients with AD and IMH of the thoracic aorta were included in this single-center retrospective study. Non-ECG-gated CTA, single-diastolic-phase ECG-gated CTA, and full-phase ECG-gated CTA were used to detect the presence of the IT and ULP in thoracic aortic regions including the ascending aorta, aortic arch, and proximal and distal descending aorta.

RESULTS

The accuracy of detecting the IT and ULP was significantly greater using full-phase ECG-gated CTA (88% [95% CI: 100%, 75%]) than non-ECG-gated CTA (72% [95% CI: 90%, 54%], P = 0.001) and single-diastolic-phase ECG-gated CTA (76% [95% CI: 93%, 60%], P = 0.008).

CONCLUSION

Full-phase ECG-gated CTA is more accurate in detecting the IT in AD and ULP in IMH, than non-ECG-gated CTA and single-diastolic-phase ECG-gated CTA.