Natural history and CT appearances of aortic intramural hematoma

CT angiography of acute aortic syndrome in patients with chronic kidney disease

The term acute aortic syndrome (AAS) refers to a range of different entities, including dissection, intramural haematoma and penetrating atherosclerotic ulcer. Patients with chronic renal disease and particularly those with dominant polycystic kidney disease are susceptible to this pathology, given the underlying renal arteriopathy and hypertension. Imaging plays a crucial role in diagnosing, grading and guiding management of these patients, with computed tomography angiography (CTA) being on the frontline. Albeit of overlapping of imaging findings between these conditions, specific imaging characteristics help discriminate and guide treatment. Given the nephrotoxic contrast agent involved, tailored CTA protocols or alternative imaging modalities such as MRI or US are necessary in this patient population. This review article discusses the main imaging findings of entities found in the spectrum of AAS, as well as the appropriate use and protocol of imaging modalities, focusing on the appropriate use of nephrotoxic contrast agents, the preservation of renal function and maintenance of optimal diagnostic accuracy.

Patients undergoing emergent surgery for type A intramural hematomas or type A aortic dissections have similar outcomes

OBJECTIVE

Despite key differences in pathological processes, both Intramural Hematomas and Aortic Dissections are Acute Aortic Syndromes repaired with similar surgical technique. The objective of this study was to determine differences in surgical outcomes between patients with Intramural Hematoma versus Type A Aortic Dissection undergoing Ascending Aortic Arch repair.

METHODS

This retrospective review of prospectively collected data included all patients with acute Intramural Hematoma or Type A Aortic Dissection who underwent emergent Ascending- or Arch Repair from January 2018 to May 2023 at a single academic institution. Primary outcomes included intraoperative mortality, 30-Day mortality, and postoperative stay. Secondary outcomes included postoperative complications. Outcomes were analyzed using Chi-squared, Fisher's Exact, and t-tests, with significance set at p < 0.05.

RESULTS

A total of 107 patients were included, 27 of whom (25%) had Intramural Hematoma and 80 (75%) had Type A Aortic Dissection. There were no differences in preoperative characteristics such as age, gender, and comorbidities, and no differences in perioperative characteristics such as case length, cardiopulmonary bypass, aortic cross-clamp, and circulatory arrest times. When comparing postoperative outcomes, there was a higher rate of postoperative pericardial effusions requiring pericardial window in the Intramural Hematoma cohort compared to the Aortic Dissection cohort (15% [n = 4] vs. 3% [n = 2]; p = 0.02). There were no differences in other primary outcomes such as intraoperative mortality, 30-Day mortality, and postoperative length of stay. There were also no differences in the rates of postoperative complications such as bleeding requiring reoperation, cerebrovascular accident, atrial fibrillation, pleural effusion requiring thoracentesis, and surgery-related Emergency Department visits.

CONCLUSIONS

Our analysis demonstrates similar outcomes for patients undergoing Ascending Aortic Arch repair between patients with Intramural Hematoma and Type A Aortic Dissection. Despite the higher rate of required postoperative pericardial windows in the Intramural Hematoma cohort, the overall primary outcomes remained comparable. These findings better elucidate the standard of care for patients with acute Intramural Hematoma undergoing Ascending Aortic Arch repair.

A nomogram prediction model for short-term aortic-related adverse events in patients with acute Stanford type B aortic intramural hematoma: development and validation

Background

This study is to examine the factors associated with short-term aortic-related adverse events in patients with acute type B aortic intramural hematoma (IMH). Additionally, we develop a risk prediction nomogram model and evaluate its accuracy.

Methods

This study included 197 patients diagnosed with acute type B IMH. The patients were divided into stable group (n = 125) and exacerbation group (n = 72) based on the occurrence of aortic-related adverse events. Logistic regression and the Least Absolute Shrinkage and Selection Operator (LASSO) method for variables based on baseline assessments with significant differences in clinical and image characteristics were employed to identify independent predictors. A nomogram risk model was constructed based on these independent predictors. The nomogram model was evaluated using various methods such as the receiver operating characteristic curve, calibration curve, decision analysis curve, and clinical impact curve. Internal validation was performed using the Bootstrap method.

Results

A nomogram risk prediction model was established based on four variables: absence of diabetes, anemia, maximum descending aortic diameter (MDAD), and ulcer-like projection (ULP). The model demonstrated a discriminative ability with an area under the curve (AUC) of 0.813. The calibration curve indicated a good agreement between the predicted probabilities and the actual probabilities. The Hosmer-Lemeshow goodness of fit test showed no significant difference (χ 2 = 7.040, P = 0.532). The decision curve analysis (DCA) was employed to further confirm the clinical effectiveness of the nomogram.

Conclusion

This study introduces a nomogram prediction model that integrates four important risk factors: ULP, MDAD, anemia, and absence of diabetes. The model allows for personalized prediction of patients with type B IMH.

Multimodality Imaging of Infective Endocarditis

Infective endocarditis (IE) is a complex multisystemic disease resulting from infection of the endocardium, the prosthetic valves, or an implantable cardiac electronic device. The clinical presentation of patients with IE varies, ranging from acute and rapidly progressive symptoms to a more chronic disease onset. Because of its severe morbidity and mortality rates, it is necessary for radiologists to maintain a high degree of suspicion in evaluation of patients for IE. Modified Duke criteria are used to classify cases as "definite IE," "possible IE," or "rejected IE." However, these criteria are limited in characterizing definite IE in clinical practice. The use of advanced imaging techniques such as cardiac CT and nuclear imaging has increased the accuracy of these criteria and has allowed possible IE to be reclassified as definite IE in up to 90% of cases. Cardiac CT may be the best choice when there is high clinical suspicion for IE that has not been confirmed with other imaging techniques, in cases of IE and perivalvular involvement, and for preoperative treatment planning or excluding concomitant coronary artery disease. Nuclear imaging may have a complementary role in prosthetic IE. The main imaging findings in IE are classified according to the site of involvement as valvular (eg, abnormal growths [ie, "vegetations"], leaflet perforations, or pseudoaneurysms), perivalvular (eg, pseudoaneurysms, abscesses, fistulas, or prosthetic dehiscence), or extracardiac embolic phenomena. The differential diagnosis of IE includes evaluation for thrombus, pannus, nonbacterial thrombotic endocarditis, Lambl excrescences, papillary fibroelastoma, and caseous necrosis of the mitral valve. The location of the lesion relative to the surface of the valve, the presence of a stalk, and calcification or enhancement at contrast-enhanced imaging may offer useful clues for their differentiation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Acute Aortic Syndromes from Diagnosis to Treatment-A Comprehensive Review

This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an "aorta code". Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in "aortic centres" improves long-term outcomes and decreases mortality rates.

Diffuse Large B-Cell Lymphoma Mimicking Intramural Hematoma of the Thoracic Aorta

Diffuse large B-cell lymphoma (DLBCL) is an aggressive lymphoma that is fatal if left untreated. Few cases have been reported of involvement of the aorta. Here we present a case of DLBCL that was diagnosed by periaortic computed tomography-guided biopsy. (Level of Difficulty: Intermediate.).

Spinal cord infarction resulting from intramural haematoma of the thoracic aorta

We present the case of a female patient in her 60s with multiple medical comorbidities who presented to the emergency department with sudden-onset tearing chest, back and abdominal pain in the setting of a hypertensive emergency. Initial CT-angiography demonstrated mild-diffuse thickening of thoracic and abdominal aorta without signs of intramural haematoma or dissection. The patient was subsequently admitted and medically managed. In the days following admission, the patient developed a small bowel obstruction and neurological deficits. Repeat imaging demonstrated an intramural haematoma extending from left subclavian artery to the diaphragm resulting in foci of spinal cord infarction. Instances of spinal cord infarction secondary to aortic intramural haematoma are rare, with a minority of cases reported as of 2020. This case report highlights a non-classic patient presentation of an intramural haematoma, shedding light onto possible clinical outcomes, treatment options and important risk factors.

Efficacy of endovascular repair in the treatment of retrograde ascending aortic intramural haematoma

BACKGROUND

The current treatment for retrograde ascending aortic intramural hematoma (RAIMH) remains challenging. This study aims to summarize the short-term results of endovascular repair in the treatment of retrograde ascending aortic intramural hematoma.

METHODS

Between June 2019 and June 2021, 21 patients (16 males and 5 females) with a retrograde ascending aortic intramural hematoma, aged 53 ± 14years, received an endovascular repair in our hospital. All cases involved an ascending aortic or aortic arch intramural hematoma. 15 patients had an ulcer on the descending aorta combined with an intramural hematoma in the ascending aorta and 6 patients had typical dissection changes on the descending aorta combined with an intramural hematoma in the ascending aorta. All patients had a successful endovascular stent-graft repair, with 10 cases operated on in the acute phase (<14 days) and 11 cases in the chronic phase (14-35 days).

RESULTS

A single-branched aortic stent graft system was implanted in 10 cases, a straight stent in 2 cases, and a fenestrated stent in 9 cases. All surgeries were technically successful. One of the patients developed a new rupture 2 weeks after surgery and was converted to a total arch replacement. No perioperative stroke, paraplegia, stent fracture or displacement, limb or abdominal organ ischemia occurred. The intramural hematomas started being absorbed on CT angiography images before discharge. There was no incidence of postoperative 30-day mortality, and the intramural hematomas in the ascending aorta and aortic arch were fully or partly absorbed.

CONCLUSION

Endovascular repair of retrograde ascending aortic intramural hematoma was shown to be safe and effective, and correlated with favorable short-term results.

The Role of Multimodality Imaging Approach in Acute Aortic Syndromes: Diagnosis, Complications, and Clinical Management

Acute aortic syndromes are life-threatening conditions with high morbidity and mortality. The principal pathological feature is acute wall damage with possible evolution towards aortic rupture. Accurate and timely diagnosis is mandatory to avoid catastrophic consequences. Indeed, misdiagnosis with other conditions mimicking acute aortic syndromes is associated with premature death. In this view, cardiovascular imaging is necessary for the correct diagnosis and management. Echocardiography, computed tomography, magnetic resonance imaging, and aortography allow for diagnosis, guarantee immediate treatment, and detect associated complications. Multimodality imaging is essential in the diagnostic work-up to confirm or rule out acute aortic syndromes. The aim of this review is to highlight the contemporary evidence on the role of single cardiovascular imaging techniques and multimodality imaging in the diagnosis and management of acute aortic syndromes.

Endovascular treatment of traumatic renal artery pseudoaneurysm with a Stanford type A intramural haematoma: A case report

BACKGROUND

Aortic intramural hematoma (IMH) associated with aortic branch tear and intramurally located pseudoaneurysm after blunt trauma has not been reported. Here, we report a case of progressive type A aortic IMH associated with a pseudoaneurysm arising from the injured proximal renal artery after blunt trauma.

CASE SUMMARY

During logging operations, a 66-year-old man experienced blunt force trauma after being injured by a fallen tree. He arrived at our trauma center with a left flank pain complaint. Computed tomography (CT) revealed a pseudoaneurysm arising from the proximal renal artery (localized within the aortic media) and Stanford type A IMH. A covered stent was deployed along the left main renal artery, bridging the pseudoaneurysm and covering the parent artery, successfully excluding the pseudoaneurysm as confirmed using aortography. However, although the degree of the pseudoaneurysm decreased, follow-up CT revealed remnant pseudoaneurysm, likely caused by an endoleak. Subsequently, a covered stent was additionally installed through the previously deployed covered stent. Successful exclusion of the pseudoaneurysm was confirmed using final aortography. In the 7-mo follow-up CT scan, the IMH and pseudoaneurysm completely disappeared with no evidence of stent-related complications.

CONCLUSION

Endovascular treatment such as stent-graft placement can be an effective and safe treatment for traumatic renal artery injury.

Intramural Hematoma in Vertebrobasilar Dolichoectasia-Related Stroke: A Retrospective Analysis of Six Consecutive Patients

BACKGROUND

The pathophysiology underlying vertebrobasilar dolichoectasia (VBD) is largely unknown. However, a few reports have demonstrated that acute intramural hematoma (IMH) in VBD is associated with stroke. We aimed to investigate the clinical and radiological features of IMH in VBD and the role of IMH in predicting rupture and patient outcomes.

METHODS

We retrospectively reviewed the medical records of patients treated in 2 stroke centers between January 2012 and December 2021. Patients presenting with VBD and stroke were eligible for study inclusion. We excluded patients with stroke caused by arterial dissection or artery-to-artery embolism. IMH was defined as a crescent-shaped area of high signal density in the vessel wall on axial computed tomography in the absence of an intimal flap, double lumen, and pearl-and-string sign.

RESULTS

Six patients were analyzed. All presented with symptoms of brainstem/cerebellar infarction without headache. Interobserver agreement for the presence or absence of IMH was excellent (100%). IMH was detected in 5 patients. The positive predictive value of IMH for rupture was 80% (95% confidence interval, 28%-99.5%). The median time from symptom onset to rupture was 2.5 days (range, 1.5-4). Median computed tomography values were significantly higher within the IMH than those in the lumen of the basilar artery (70 vs. 44.5 Hounsfield units; P = 0.008). The modified Rankin scale score on day 30 after onset was 5 in 1 patient and 6 in the remaining 5.

CONCLUSIONS

IMH in patients with VBD presenting with brainstem/cerebellar infarction should be regarded as a sign associated with a high risk of rupture.

Enhancing the Interpretation of Unenhanced Abdominopelvic CT

Unenhanced abdominopelvic CT is frequently performed in patients who are critically ill or have contraindications to intravenous contrast. These cases can be challenging to interpret for the radiologist. Attention to CT physics and care in optimizing image viewing through techniques such as windowing can maximize diagnostic yield. In this case-based review, we will discuss the CT physics concepts of attenuation, common indications and reasons for unenhanced abdominopelvic CT, and review its utility through a series of illustrative cases.

Emergent Magnetic Resonance Angiography for Evaluation of the Thoracoabdominal and Peripheral Vasculature

Thoracoabdominal and peripheral vasculature pathologies include a variety of severe and life threatening conditions that may be encountered in the emergent setting. Computed tomography angiography (CTA) is the first-line modality for imaging of the vasculature in this context, but magnetic resonance angiography (MRA) also plays an important and emerging role in the evaluation of carefully selected patients. Intravenous (IV) iodinated contrast is necessary for CTA, although MRA is most useful in patients who cannot receive IV iodinated contrast for reasons including prior severe allergic-like reaction to iodinated contrast, poor IV access, or severe renal insufficiency. Gadolinium-based contrast agents are administered for MRA when possible, as they generally improve the diagnostic quality and shorten the duration of the exam. In most clinical situations, however, noncontrast MRA is sufficient to obtain a diagnostic evaluation. In this review, we discuss the key strengths and limitations of MRA performed in the emergent setting, highlighting the role of MRA in the diagnosis of acute aortic syndromes, aortitis, aortic aneurysm, pulmonary embolism, and peripheral vascular disease.

Management of penetrating aortic ulcer and intramural hematoma in the thoracic aorta

Acute aortic syndrome is a broad clinical entity that encompasses several pathologies. Aortic dissection is a well-studied disorder, but the other most prominent disorders within the scope of acute aortic syndrome, penetrating aortic ulcer and intramural hematoma, are more nebulous in terms of their pathophysiology and treatment strategies. While patient risk factors, presenting symptoms, and medical and surgical management strategies are similar to those of aortic dissection, there are indeed nuanced differences unique to penetrating aortic ulcer and intramural hematoma that surgeons and acute care providers must consider while managing patients with these diagnoses. The aim of this review is to summarize patient demographics, pathophysiology, workup, and treatment strategies that are unique to penetrating aortic ulcer and intramural hematoma.

Intramural Hematoma of the Thoracic Aorta: A Single Institution 12 Year Experience

OBJECTIVE

The natural history and management of intramural hematoma (IMH) varies significantly worldwide. In this retrospective analysis of our institutional database, we report long-term results from medical and surgical management of types A and B IMH.

METHODS

CT scan reports completed at our tertiary care hospital from July 2007 to July 2020 were used to identify patients with IMH with thickness >7mm. Those with IMH directly related to trauma, previous aortic surgery, penetrating atheromatous ulcer, dissection flap, iatrogenic source, or who never received any treatment for IMH at the time of presentation were excluded.

RESULTS

A total of 54 patients with IMH met inclusion and exclusion criteria. Twenty-four presented with Stanford type A: 10 were initially managed surgically and 14 were initially managed medically. Two patients in the medical group crossed over to surgery. Thirty patients presented with type B IMH and were initially managed medically, with three eventually receiving surgical intervention. In-hospital survival was 90% for type A IMH treated surgically, 93% for type A IMH treated medically, and 97% for type B IMH treated medically. At last follow-up imaging of medically managed patients, 36% of type A IMH and 31% of type B IMH patients had complete resolution of IMH at 3.7 and 31.5 months respectively, without operative intervention. Development of aortic aneurysm at the site of previous IMH was seen in 18% (2/11) and 12% (3/26) for the type A medical and type B medical cohorts; the overall rate of aortic aneurysm formation in the region of IMH or in another segment was 50%. There was no difference in long-term survival between the three cohorts at a mean follow up of 22.8 months.

CONCLUSION

There appears to be a role for medical treatment with anti-impulse therapy in appropriately selected patients with type A IMH. These patients must be followed closely clinically and radiographically for signs of deterioration in the short- and long-term phases of their care. They can achieve similar long-term survival compared with surgically treated type A IMH and medically treated type B IMH patients using this algorithm but may require late surgical intervention, especially for aneurysmal disease.

MDCT Imaging of Non-Traumatic Thoracic Aortic Emergencies and Its Impact on Diagnosis and Management—A Reappraisal

Non-traumatic thoracic aorta emergencies are associated with significant morbidity and mortality. Diseases of the intimomedial layers (aortic dissection and variants) have been grouped under the common term of acute aortic syndrome because they are life-threatening conditions clinically indistinguishable on presentation. Patients with aortic dissection may present with a wide variety of symptoms secondary to the pattern of dissection and end organ malperfusion. Other conditions may be seen in patients with acute symptoms, including ruptured and unstable thoracic aortic aneurysm, iatrogenic or infective pseudoaneurysms, aortic fistula, acute aortic thrombus/occlusive disease, and vasculitis. Imaging plays a pivotal role in the patient’s management and care. In the emergency room, chest X-ray is the initial imaging test offering a screening evaluation for alternative common differential diagnoses and a preliminary assessment of the mediastinal dimensions. State-of-the-art multidetector computed tomography angiography (CTA) provides a widely available, rapid, replicable, noninvasive diagnostic imaging with sensitivity approaching 100%. It is an impressive tool in decision-making process with a deep impact on treatment including endovascular or open surgical or conservative treatment. Radiologists must be familiar with the spectrum of these entities to help triage patients appropriately and efficiently. Understanding the imaging findings and proper measurement techniques allow the radiologist to suggest the most appropriate next management step.

Management of spontaneous isolated intramural hematoma of the superior mesenteric artery: a single-center experience

PURPOSE

To investigate the clinical course and optimal management for spontaneous isolated intramural hematoma of the superior mesenteric artery (SIHSMA).

METHODS

From January 2015 to October 2020, a total of 31 consecutive patients with SIHSMA were included in this study. The demographics, clinical features, treatment details, imaging information, and outcomes were reviewed.

RESULTS

There were 24 males and 7 females, with a mean age of 54.9 years (SD 6.9 years). Seven patients (7/31, 23%) were associated with ulcer-like projection (ULP), one patient (1/31, 3%) with intramural blood pool (IBP), and the remaining twenty-three patients (23/31, 74%) had no ULP or IBP. All patients were initially managed conservatively and underwent a median follow-up of 25.5 months (IQR 14.5, 39.9), which showed 3 patients (3/31, 10%) subsequently underwent stenting (2 within 7 days and 1 after 1.5 months), 1 patient (1/31, 3%) progressed to a localized dissection 7 months later but remained stable and asymptomatic until the time of writing, and the remaining patients (27/31, 87%) had no progression. In the present cohort, the overall survival was 100% (31/31). The free-from progression and stenting rate under conservative treatment was 87% (27/31). The invasive intervention rate was 10% (3/31). The natural complete regression rate of IMH in patients without ULP was higher than those with ULP (91% [21/23] vs. 29% [2/7], p = .003).

CONCLUSION

The majority of patients with SIHSMA can be managed conservatively. Patients with ULP seemed to have a lower IMH regression rate than those without ULP.

Acute Aortic Syndrome Revisited: JACC State-of-the-Art Review

The purpose of this paper is to describe all available evidence on the distinctive features of a group of 4 life-threatening acute aortic pathologies gathered under the name of acute aortic syndrome (AAS). The epidemiology, diagnostic strategy, and management of these patients has been updated. The authors propose a new and simple diagnostic algorithm to support clinical decision making in cases of suspected AAS, thereby minimizing diagnostic delays, misdiagnoses, and unnecessary advanced imaging. AAS-related entities are reviewed, and a guideline to avoid imaging misinterpretation is provided. Centralization of patients with AAS in high-volume centers with high-volume surgeons is key to improving clinical outcomes. Thus, the role of multidisciplinary teams, an "aorta code" (streamlined emergent care pathway), and aortic centers in the management of these patients is boosted. A tailored patient treatment approach for each of these acute aortic entities is needed, and as such has been summarized. Finally, a set of prevention measures against AAS is discussed.

The Hyperattenuating Crescent Sign Is Not Necessarily a Sign of Impending Aortic Aneurysm Rupture

BACKGROUND

The "crescent sign" is a hyperattenuating crescent-shaped region on CT within the mural thrombus or wall of an aortic aneurysm. Although it has previously been associated with aneurysm instability or impending rupture, the literature is largely based on retrospective analyses of urgently repaired aneurysms. We strove to more rigorously assess the association between an isolated "crescent sign" and risk of impending aortic rupture.

METHODS

Patients were identified by querying a single health system PACS database for radiology reports noting a crescent sign. Adult patients with a CT demonstrating a descending thoracic, thoracoabdominal, or abdominal aortic aneurysm and "crescent sign" between 2004 and 2019 were included, with exclusion of those showing definitive signs of aortic rupture on imaging.

RESULTS

A total of 82 patients were identified. Aneurysm size was 7.1 ± 2.0 cm. Thirty patients had emergent or urgent repairs during their index admission (37%), 19 had elective repairs at a later date (23%), and 33 patients had no intervention due to either patient choice or prohibitive medical comorbidities (40%). Patients without intervention had a median follow up of 275 days before death or loss to follow up. In patients undergoing elective intervention, 6,968 patient-days elapsed between presentation and repair, with zero episodes of acute rupture (median 105 days). Patients undergoing elective repair had smaller aneurysms compared to those who underwent emergent/urgent repair (6.2 ± 1.3 vs. 7.7 ± 2.1 cm, P = 0.008). No surgical candidate with an aneurysm smaller than 8 cm ruptured. There were 31 patients with previous axial imaging within 2 years prior to presentation with a "crescent sign," with mean aneurysm growth rate of 0.85 ± 0.62 cm per 6 months [median 0.65, range 0-2.6]. Those with aneurysms sized below 5.5 cm displayed decreased aneurysm growth compared to patients with aneurysm's sized 5.5-6.5 cm or patients with aneurysms greater than 6.5 cm (0.12 vs. 0.64 vs. 1.16 cm per 6 months, P= 0.002).

CONCLUSIONS

The finding of an isolated radiographic "crescent sign" without other signs of definitive aortic rupture (i.e., hemothorax, aortic wall disruption, retroperitoneal bleeding) is not necessarily an indicator of impending aortic rupture, but may be found in the setting of rapid aneurysm growth. Many factors, including other associated radiographic findings, aneurysm size and growth rate, and patient symptomatology, should guide aneurysm management in these patients. We found that patients with minimal symptoms, aneurysm sizes below 6.5 cm, and no further imaging findings of aneurysm instability, such as periaortic fat stranding, can be successfully managed with elective intervention after optimization of comorbid factors with no evidence of adverse outcomes.

Thoracic Endovascular Aortic Repair for Retrograde Type A Aortic Intramural Hematoma

Objectives: To evaluate the effects of thoracic endovascular aortic repair (TEVAR) in descending aorta for retrograde type A aortic intramural hematoma (re-TAIMH).

Methods: From January 2013 to September 2019, 65 consecutive patients diagnosed with re-TAIMH and treated by TEVAR were enrolled in this retrospective cohort study, of whom 44 patients presented with entry tear in descending aorta (Group A) and 21 with penetrating atherosclerotic ulcer (Group B). The clinical data, including baseline characteristics, adverse events, aortic remolding, and overall survival were reviewed.

Results: The mean age of all the patients was 52.0 ± 8.3 years, and 54 (83.1%) patients were men. The mean maximal ascending aortic diameter (MAAD) was 43.1 ± 5.4 mm, and the mean maximal ascending aortic hematoma thickness (MAAHT) was 9.6 ± 4.7 mm. TEVAR was performed under general anesthesia in 53 (81.5%) patients, while 12 (18.5%) patients were treated under local anesthesia. There were two deaths during hospitalization (one with rupture and another with multiple organ dysfunction syndrome), and overall survival at 1, 4, and 7 years for all 65 patients was 93.8, 92.0, and 87.4%, respectively. The MAAD and MAATH decreased significantly after TEVAR (p < 0.05) in the two groups, so did the mean descending aortic diameter at the pulmonary bifurcation level. Type I endoleak, dialysis, progression to type A aortic dissection, and enlargement in MAAHT and MAAD were more common complications, which occurred in four, three, two, and two patients, respectively.

Conclusion: Patients with retrograde TAIMH treated by TEVAR had a favorable prognosis including late survival and aortic remolding. However, some post-intervention complications were not negligible.

Role of MRI in the Evaluation of Thoracoabdominal Emergencies

Thoracic and abdominal pathology are common in the emergency setting. Although computed tomography is preferred in many clinical situations, magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) have emerged as powerful techniques that often play a complementary role to computed tomography or may have a primary role in selected patient populations in which radiation is of specific concern or intravenous iodinated contrast is contraindicated. This review will highlight the role of MRI and MRA in the emergent imaging of thoracoabdominal pathology, specifically covering acute aortic pathology (acute aortic syndrome, aortic aneurysm, and aortitis), pulmonary embolism, gastrointestinal conditions such as appendicitis and Crohn disease, pancreatic and hepatobiliary disease (pancreatitis, choledocholithiasis, cholecystitis, and liver abscess), and genitourinary pathology (urolithiasis and pyelonephritis). In each section, we will highlight the specific role for MRI, discuss basic imaging protocols, and illustrate the MRI features of commonly encountered thoracoabdominal pathology.

Computed Tomography Angiography Assessment of Acute Aortic Syndromes: Classification, Differentiating Imaging Features, and Imaging Interpretation Pitfalls

An acute aortic syndrome (AAS) is an important life-threatening condition that requires early detection and management. Acute intramural hematoma (IMH), aortic dissection (AD) and penetrating atherosclerotic ulcer (PAU) are included in AAS. ADs can be classified using the well-known Stanford or DeBakey classification systems. However, these classification systems omit description of arch dissections, anatomic variants, and morphologic features that impact outcome. The Society for Vascular Surgery and Society of Thoracic Surgeons (SVS-STS) have recently introduced a classification system that classifies ADs according to the location of the entry tear (primary intimomedial tear, PIT) and the proximal and distal extent of involvement, but does not include description of all morphologic features that may have diagnostic and prognostic significance. This review describes these classification systems for ADs and other AAS entities as well as their limitations. Typical computed tomography angiography (CTA) imaging appearance and differentiating features of ADs, limited intimal tears (LITs), IMHs, intramural blood pools (IBPs), ulcer-like projections (ULPs), and PAUs will be discussed. Furthermore, this review highlights common imaging interpretation pitfalls, what should be included in a comprehensive CTA report, and provides a brief overview of current management options.

Systemic vasculitides and the role of multitechnique imaging in the diagnosis

Vasculitis, a systemic disease characterised by inflammation of the blood vessels, remains challenging to diagnose and manage. Vessel size has been the basis for classifying systemic vasculitides. Imaging plays a vital role in diagnosing this challenging disease. This review article aims (a) to summarise up-to-date literature in this field, as well as include classification updates and (b) to review available imaging techniques, recent advances, and emphasis on imaging findings to diagnose large vessel vasculitides.

Cardiac computed tomography in the contemporary evaluation of infective endocarditis

Increasing data have accumulated on the role of Cardiac Computed Tomography (CCT) in infective endocarditis (IE) with high accuracy for large vegetations, perivalvular complications and for exclusion of coronary artery disease to avoid invasive angiography. CCT can further help to clarify the etiology of infective prosthetic valve dysfunction (e.g. malposition, abscess, leak, vegetation or mass). Structural interventions have increased the relevance of CCT in valvular heart disease and have amplified its use. CCT may be ideally integrated into a multimodality approach that incorporates a central role of transesophageal echocardiography (TEE) with 18-FDG PET and/or cardiac magnetic resonance in individually selected cases, guided by the Heart Team. The coronavirus-19 (COVID-19) pandemic has resulted in renewed attention to CCT as a safe alternative or adjunct to TEE in selected patients. This review article provides a comprehensive, contemporary review on CCT in IE to include scan optimization, characteristics of common IE findings on CCT, published data on the diagnostic accuracy of CCT, multimodality imaging comparison, limitations and future technical advancements.

Hemopericardium in the acute clinical setting: Are we ready for a tailored management approach on the basis of MDCT findings?

The clinical spectrum of pericardial effusions varies from innocuous serous fluid to life-threatening hemopericardium. A misdiagnosis may be made by similar clinical presentation of acute chest pain/hypotension. Echocardiography is the first-line test for diagnosis of pericardial effusion and its etiology, but sometimes there are different drawbacks to the correct cardiovascular ultrasound diagnosis. Radiologists are reporting an increasing amount of thoracic Multidetector CT examinations at the emergency department. Multidetector CT has now become an established and complementary method for cardiac imaging, and diseases of the pericardium can now be quickly identified with increasing certainty. The aim of this review is to discuss the hemopericardium key Multidetector CT features in acute clinical setting which indicate the need to proceed with predominantly medical or surgical treatment, however, being able to identify forms of bleeding pericardial effusion for which only "a watch and wait strategy" and/or deferred treatment is indicated. In the emergency care setting, radiologists must be aware of different findings of hemopericardium in order to address a tailored and timely management approach.

Diagnosing Aortic Intramural Hematoma: Current Perspectives

Aortic intramural hematoma (AIH) is an entity within the acute aortic syndrome. Combination of a priori probability, clinical history, laboratory blood test and imaging techniques are the basis for diagnosis of AIH. This review is focused on all aspects related to diagnosis of patients with AIH, from clinical to imaging and analytical.

Broken-crescent sign at CT indicates impending aortic rupture in patients with acute aortic intramural hematoma

Background

This retrospective study evaluated the computed tomography (CT) features and clinical implications of a novel broken-crescent sign in patients with acute aortic intramural hematoma (IMH).

Methods

Out of 104 patients with aortic IMH encountered in our institution between 2003 and 2018, nine patients exhibited a positive broken-crescent sign, which was defined as a focal defect within the hyper-attenuating crescentic IMH on unenhanced CT, corresponding to a smooth out-bulging of the aortic lumen on enhanced study. The clinical findings, CT features, and outcomes of these nine patients were analyzed.

Results

Of five males and four females (age range 48–84 years, mean 69.7 years), six had type A and three had type B IMH. Five patients who had medical treatment and stable status for 1 to 3 days suffered sudden death, two of whom showed ascending aortic rupture with hemopericardium in one and adventitial tear with outward spillage of IMH in another at follow-up CT. The other four patients had early surgical or endovascular management survived; two demonstrated ascending aorta ecchymosis with adventitial tear and intact intima at surgery. Our results support the supposition that aortic IMH complicated with adventitial tear and partial outward seepage of IMH may generate a broken-crescent sign in CT. Despite initially stable clinical status, the residual intact inner aortic wall carries a high risk of sudden aortic rupture.

Conclusions

In patients with acute aortic IMH, identification of a broken-crescent sign in CT is highly suggestive of impending aortic rupture, and early aggressive treatment is mandatory.

Endovascular repair of type A aortic intramural hematoma accompanied by aberrant right subclavian artery and Kommerell's diverticulum: a case report

Background

The lesions of aberrant right subclavian artery, Kommerell’s diverticulum and type A aortic intramural hematoma are rare, and we usually treat them with open surgery. In some cases patients have increased risk to undergo surgery, the experiences of endovascular or medical treatment are limited.

Case presentation

Here we reported a case of a 53-year-old man with these three entities present with chest and back ache and attempted a novel approach, thoracic endovascular aortic repair, in the absence of surgical treatment. The patient lived over 5 years and this case provides initial experience and lesson about the endovascular and medical management of the uncommon and dangerous disease- type A aortic intramural hematoma with aortic congenital malformation.

Conclusion

Thoracic endovascular aortic repair with medical treatment may be a potential alternative approach for type A aortic intramural hematoma.

Non-contrast computed tomography of type A acute aortic dissection in patients with out-of-hospital cardiopulmonary arrest: a case series

Background

The prognosis of patients admitted for acute aortic dissection (AAD) has remarkably improved. However, we must also consider out-of-hospital cardiopulmonary arrest (OHCPA) patients while assessing the prognosis. In recent years, autopsy imaging has become more common as an alternative to conventional autopsy. Therefore, we reviewed our OHCPA patients with type A AAD using acute phase non-contrast computed tomography (CT).

Case summary

Here, we report a case series of three patients who developed OHCPA and were diagnosed with type A AAD using non-contrast CT. Although the direct causes of death varied in each case, we could easily determine the direct causes of death from clinical course of the condition and from non-contrast CT.

Discussion

Although non-contrast CT does not completely replace autopsy, if its convenience and non-invasiveness make it possible for more patients to undergo the procedure, the real prognosis (including morbidity and mortality) may be better understood. Therefore, we considered it significant to use non-contrast CT for investigating the cause of sudden death.

Computed Tomography Imaging Findings of Acute Aortic Pathologies

Acute aortic syndromes (AAS) encompass a spectrum of life-threatening conditions characterized by acute aortic pain. AAS include acute aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, and aneurysm rupture. The prognosis of AAS is clearly related to prompt diagnosis and appropriate management. The different types of AAS cannot be reliably differentiated solely based on clinical presentation since the clinical features are indistinguishable. Multidetector-row computed tomography (MDCT) with electrocardiographic gating (ECG-gated MDCT) has been used in the acute emergency setting as a powerful clinical tool, which enables rapid and specific diagnosis of aortic pathologies. ECG-gated MDCT significantly reduces motion artifact and avoids potential pitfalls in the diagnosis of AAS. The aim of this review is to evaluate the role of MDCT imaging in the assessment of AAS and to discuss the differentiation of this spectrum of aortic diseases with reference to the key imaging findings.

CT imaging of complications of aortic intramural hematoma: a pictorial essay

Aortic intramural hematoma (IMH) is a pathologic process with a clinical presentation identical to aortic dissection and associated with significant morbidity and mortality. Radiologists must be familiar with the imaging appearances of IMH as computed tomography (CT) plays a critical role in both diagnosis and patient management. The course of IMH is variable and the process may regress, remain stable, or progress in extent and therefore imaging findings associated with a negative prognosis must be recognized and included in the formal radiology report. Potentially life-threatening complications and findings associated with IMH include hemopericardium and cardiac tamponade, coexisting aortic dissection, ulcer-like projection, intramural blood pool, and extension of hematoma along the pulmonary or coronary arteries, which are identifiable with aortic protocol CT. The purpose of this pictorial review is to provide the reader with an image-based review of the diagnostic criteria, related complications, and associated critical prognostic features in patients presenting with aortic IMH.

Significance of an additional unenhanced scan in computed tomography angiography of patients with suspected acute aortic syndrome

AIM

To assess potential benefits of an additional unenhanced acquisition in computed tomography angiography (CTA) in patients with suspected acute aortic syndrome (AAS).

METHODS

A total of 103 aortic CTA (non-electrocardiography-gated, 128 slices) performed due to suspected AAS were retrospectively evaluated for acute aortic dissection (AAD), intramural hematoma (IMH), or penetrating aortic ulcer (PAU). Spiral CTA protocol consisted of an unenhanced acquisition and an arterial phase. If AAS was detected, a venous phase (delay, 90 s) was added. Images were evaluated for the presence and extent of AAD, IMH, PAU, and related complications. The diagnostic benefit of the unenhanced acquisition was evaluated concerning detection of IMH.

RESULTS

Fifty-six (30% women; mean age, 67 years; median, 68 years) of the screened individuals had AAD or IMH. A triphasic CT scan was conducted in 76.8% (n = 43). 56% of the detected AAD were classified as Stanford type A, 44% as Stanford type B. 53.8% of the detected IMH were classified as Stanford type A, 46.2% as Stanford type B. There was no significant difference in the involvement of the ascending aorta between AAD and IMH (P = 1.0) or in the average age between AAD and IMH (P = 0.548), between Stanford type A and Stanford type B in general (P = 0.650) and between Stanford type A and Stanford type B within the entities of AAD and IMH (AAD: P = 0.785; IMH: P = 0.146). Only the unenhanced acquisitions showed a significant density difference between the adjacent lumen and the IMH (P = 0.035). Subadventitial hematoma involving the pulmonary trunk was present in 5 patients (16%) with Stanford A AAD. The difference between the median radiation exposure of a triphasic (2737 mGy*cm) compared to a biphasic CT scan (2135 mGy*cm) was not significant (P = 0.135).

CONCLUSION

IMH is a common and difficult to detect entity of AAS. An additional unenhanced acquisition within an aortic CTA protocol facilitates the detection of IMH.

Renal artery involvement in acute aortic dissection: Prevalence and impact on renal atrophy in non-interventional treatment patients

BACKGROUND

To evaluate the frequency of renal artery dissection (RAD) and renal hypoperfusion in aortic dissection (AD) and its effect on subsequent renal atrophy in patients who did not undergo therapeutic intervention.

METHODS

Initial CT data of 155 patients with acute AD (Stanford type A = 88, B = 67) were retrospectively analyzed. The false lumen statuses were patent (n = 94), partially thrombosed (n = 25), and completely thrombosed (n = 36) (also called as intramural hematoma (IMH)). Follow-up CT images of the surviving 122 patients (6-62.6 months, median, 28.9 months) were reviewed for analysis of sequential changes in renal volume. A regional decrease of ≧20 Hounsfield units in the renal cortex was defined as a renal hypo-enhancement sign (RHS). Simplified CT estimations of renal volume and estimated glomerular filtration rates (eGFR) were calculated. The generalized estimating equations (GEE) method was used to predict renal atrophy.

RESULTS

Fifty of the 122 patients presented with 59 RAD in the current study, and a positive RHS was noted in 33.9% (20/59) of these involved kidneys. GEE analysis showed hypertension, surgical treatment for AD, presence of RAD, and positive RHS as significant risk factors for renal atrophy. Patients with RHS had the most severe form of renal atrophy. The severity of renal atrophy was mildly correlated with GFR change (γ2 = 0.044, p < 0.001).

CONCLUSION

Renal atrophy in AD was predicted by the CT findings of RAD and RHS. The severity of renal atrophy was weakly reflected by eGFR.

Acute non-traumatic disease of the abdominal aorta

Acute pathology in the abdominal aorta is associated with significant morbidity and mortality. The most feared complication of abdominal aortic disease is acute rupture in the setting of atherosclerotic abdominal aortic aneurysm. Although frank rupture often is easily diagnosed on CT, other findings such as a hyperattenuating crescent, discontinuous intimal calcium, and draping of the aorta are subtle signs of aneurysm instability. A true aneurysm should be distinguished from a rapidly growing, saccular pseudoaneurysm in the setting of infectious aortitis, as treatment strategy differs. Acute aortic syndrome involving the abdominal aorta, such as dissection and intramural hematoma, often is an extension of thoracic aortic disease, whereas penetrating atherosclerotic ulcers occasionally involve only the abdominal aorta. The goal of treating acute aortic pathology is to repair and prevent rupture, as well as restore and maintain perfusion of the lower extremities, kidneys, and mesentery. However, both open and endovascular repair of the abdominal aorta may become acutely complicated, resulting in compromise of these goals. Examples include aortoenteric fistula, endoleak, anastomotic pseudoaneurysm, graft infection, and thrombosis or kinking of a stent graft resulting in ischemia of the limbs and mesentery.

Clues to vascular disorders at non-contrast CT of the chest, abdomen, and pelvis

Non-contrast chest CT scans are commonly performed while CT scans of the abdomen and pelvis are performed in a select subset of patients; those with limited renal function, an allergy to iodinated contrast, in the setting of suspected renal calculus, retroperitoneal hematoma, common duct calculus, abdominal aortic aneurysm with or without rupture, and in patients undergoing a PET-CT scan. In the absence of intravenous contrast, vascular structures may prove challenging to evaluate, yet their assessment is an important component of every non-contrast CT examination. We describe the key imaging features of both arterial and venous pathology, and review clues and common associated non-vascular findings, which can help the radiologist identify vascular disorders at non-contrast CT. Briefly, alternative imaging options are discussed.

Aortic intramural hemorrhage: A distinct disease entity with mystery

Aortic intramural hemorrhage (IMH) is one of the disease processes that comprise the spectrum of acute aortic syndrome (AAS) with clinical manifestations and a mortality rate similar to those of classic aortic dissection (AD). However, IMH should be considered as a distinct disease entity rather than a precursor to classic dissection because of differences in their pathology, etiology, natural history, and imaging findings. Multidetector computed tomography (CT) is recommended as the first-line diagnostic imaging modality for IMH, but transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) are also helpful. There is still debate over the appropriate treatment of IMH. Medical treatment of type B IMH appears effective and safe, while surgical treatment is recommended for type A IMH. Thoracic endovascular aortic repair (TEVAR) is a promising treatment for selected patients, and more clinical evidence needs to be assembled.

CT of suspected thoracic acute aortic injury in the emergency department: is routine abdominopelvic imaging worth the additional collective radiation dose?

This study aimed to determine the incidence of non-traumatic acute aortic injury (AAI) extending from the chest into the abdomen or pelvis in emergency department (ED) patients with acute aortic syndrome (AAS), to estimate the effective dose of the abdominopelvic portion of these CT exams, and to compare the number needed to screen (NNS) with the collective population radiation dose of imaging those stations. All patients (n = 238) presenting to the ED with AAS between March 2014 and June 2015 who were imaged per CT AAI protocol (noncontrast and contrast-enhanced CT angiography of the chest, abdomen, and pelvis) were retrospectively identified in this IRB-approved HIPAA-compliant study. The Stanford classification for positive cases of AAI was further subclassified based on chest, abdominal, or pelvic involvement. The dose length product (DLP) of each exam was used to estimate the dose of the abdominal and pelvic stations and the collective effective dose for the population. There were five cases of aortic dissection (AD) and two of intramural hematoma (IMH), with an AAI incidence of 2.9/100. Three cases of AAI were confined to the chest. Two cases of AAI were confined to the chest and abdomen, and two cases involved the chest, abdomen, and pelvis. There was only one case of AAI involving the ascending aorta that extended into the abdomen or pelvis. The number needed to screen to identify (a) AAI extending from the chest into the abdomen or pelvis was 59.5 and (b) Stanford A AAI extending into the abdomen or pelvis was 238. The estimated mean effective dose for the abdominopelvic stations were unenhanced abdomen 2.3 mSv, unenhanced pelvis 3.3 mSv, abdominal CTA 2.5 mSv, and pelvic CTA 3.6 mSv. The collective effective doses to the abdomen and pelvis with unenhanced CT and CTA in 59.5 patients and 238 patients were 761.6 and 3046.4 mSv, respectively. While the estimated mean effective dose for imaging of the abdominopelvic stations are low, the collective effective dose should also be considered. It may be beneficial to modify or omit routine unenhanced CT and/or CTA of the abdomen/pelvis in this patient population in the absence of abdominal symptoms, and image the abdomen and pelvis in positive thoracic cases only.

Differential aspects of ascending thoracic aortic dissection and its treatment: the North American experience

Acute type A aortic dissection is a deadly disease with significant morbidity and mortality. We describe the differential aspects of the disease and the North American experience with its treatment.

Aortic arch pathologies - incidence and natural history

Endovascular interventions have made significant progress and are moving towards treating diseases of the aortic arch. Aortic arch pathologies incur substantial morbidity as well as short and long-term mortality but the progression is not well understood. This article reviews the current evidence on the natural history of aortic arch aneurysms and acute aortic syndromes, including penetrating ulcers, intramural hematomas, acute and chronic type B dissections. Risk factors for disease progression and mortality are also identified with special reference to vascular surgeons.

The Acute Abdominal Aorta

Acute disorders of the abdominal aorta are potentially lethal conditions that require prompt evaluation and treatment. Computed tomography (CT) is the primary imaging method for evaluating these conditions because of its availability and speed. Volumetric CT acquisition with multiplanar reconstruction and three-dimensional analysis is now the standard technique for evaluating the aorta. MR imaging may be useful for select applications in stable patients in whom rupture has been excluded. Imaging is indispensable for diagnosis and treatment planning, because management has shifted toward endoluminal repair. Acute abdominal aortic conditions most commonly are complications of aneurysms and atherosclerosis.

Intramural hematoma or aortic dissection - a diagnostic and therapeutic problem. A case report

The authors present a case report of a 60-year-old patient with an ascending aortic aneurysm along with the associated diagnostic and therapeutic problems. The choice of therapy in patients with aortic intramural hematoma is difficult and should be based on comprehensive evaluation of the patient's status as well as on the experience of the radiologist and surgeon.