Prognostic Implications of Initial Focal Contrast Enhancement in Acute Type B Intramural Hematoma

BACKGROUND

The prognostic implication of initial focal contrast enhancement (FCE), including focal intimal disruption (FID) and intramural blood pool (IBP), in acute type B intramural hematoma (IMH) remain unclear.

OBJECTIVES

The purpose of this study was to compare the prognostic implications in IMH with or without FCE.

METHODS

A total of 574 patients were enrolled. FID was defined as an intimal disruption with contrast-filled out-pouching from the aorta lumen with a communicating orifice of >3 mm, and IBP was defined as a localized contrast medium-filled pool inside the IMH.

RESULTS

A total of 207 (36.1%) patients with initial FCE, including 132 (63.8%) FIDs and 75 (36.2%) IBPs, were identified. Patients with FCE accompanying IMH were more likely to have hypertension (P = 0.001), pleural effusion (P = 0.006), fewer aortic segments involved (P < 0.001), more adverse aortic events (AAEs) (P < 0.001), and fewer freedom from intervention (P = 0.002). Pleural effusion (HR: 1.79; 95% CI: 1.25-2.55; P = 0.001) and FCE (HR: 1.51; 95% CI: 1.12-2.02; P = 0.006) were identified to be the independent risk factors of AAEs. In the subgroup analysis, IMH with initial FID were more likely to progress than those with initial IBP (P < 0.001). FIDs located at the proximal descending aorta (HR: 2.95; 95% CI: 1.65-5.29; P < 0.001) were associated with AAEs.

CONCLUSIONS

Patients with FCE accompanying IMH were more likely to progress, especially in those initial FID localized at the proximal descending aorta. (Nature course and predictors of progression of intramural hematoma: A retrospective, multicenter study; ChiCTR2300073829).

Clinical characteristics and outcomes of Stanford type B aortic intramural hematoma: A single centre experience

Objective

To compare the clinical characteristics of Stanford type B aortic intramural hematoma (IMH) and Stanford type B aortic dissection (AD), and to identify the differences between thoracic endovascular aortic repair (TEVAR) and medical management (MM) in the Stanford type B IMH patients.

Methods

A retrospective observational study was conducted in patients treated between January 2015 and December 2016. The clinical characteristics and CT images of patients with type B IMH and type B AD were compared, and the clinical characteristics and CT images of patients in the type B IMH group who were treated with TEVAR and MM were compared.

Results

A total of 176 patients were included in this study, including 62 patients of type B IMH and 114 patients of type B AD. Five patients died in the IMH group and three in the AD group. The proximal hematoma or entry tear in both groups was mainly located in the descending aorta, and the proportion of the iliac artery involved in the AD group was significantly higher than that in the IMH group (31.6% vs. 8.1% P < 0.05). There were 50 MM patients and 12 TEVAR patients in the IMH group. No death occurred in the TEVAR group, while five patients in the MM group died. Seven patients in the MM group had disease progression vs. 12 in the TEVAR group (P < 0.05). The patients in the TEVAR group had more intima lesions than those in the MM group (83.3% vs. 30.0%, P < 0.05). TEVAR group involved more iliac artery hematoma than MM group (33.3% vs. 2.0%, P < 0.05). The maximum thickness of hematoma in TEVAR group was 14.9 ± 3.4 mm, which was significantly larger than that of MM group (10.2 ± 2.8 mm) (P < 0.05).

Conclusion

In the diagnosis of IMH, patients' symptoms and high-risk signs of CTA should be paid attention to. TEVAR therapy should be actively considered on the basis of effective medical management when there are intima lesions (ULP/PAU), increased aortic diameter and hematoma thickness, extensive hematoma involvement, and pleural effusion.

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.

Focal Intimal Disruption Size at Multidetector CT and Disease Progression in Type B Aortic Intramural Hematoma

Background Recent imaging techniques show that patients with aortic intramural hematoma (IMH) have various sizes of focal intimal disruptions (FIDs) that may affect clinical outcomes. Purpose To evaluate the relationship between size of FIDs detected at multidetector CT and disease progression in patients with type B IMH. Materials and Methods This retrospective study analyzed consecutive patients with type B IMH who underwent multidetector CT at admission within 24 hours after symptom onset from January 2011 to March 2017. FID was defined as a focal contrast material-filled pouch projecting outside of the aorta lumen with a communicating orifice greater than 3 mm. Large FID was defined as an FID of at least 10 mm in length and width and at least 5 mm in depth. Aorta-related events were defined as a composite of aortic rupture, surgical or endovascular aortic repair, progressive aortic enlargement, and development of aortic dissection. Results Seventy-six patients (mean age, 72 years ± 11 [standard deviation]; 54 men) were evaluated. Fifty patients (66%; 50 of 76) had 91 FIDs. Twenty-eight patients had large FIDs and 22 patients had small FIDs. Aorta-related events occurred in 15 of 28 patients with large FIDs, two of 22 patients with small FIDs, and four of 26 patients with no FID. Patients with large FIDs showed lower aorta-related event-free survival rates than did patients with small FIDs or no FID (small FIDS, 63% ± 10 vs 90% ± 7 at 3 years, respectively [P = .001]; and no FIDS, 63% ± 10 vs 84% ± 7 at 3 years, respectively [P = .005]). Multivariable analysis showed that a maximum aortic diameter of at least 40 mm (hazard ratio, 4.8; 95% CI: 1.8, 12.6; P = .001) and large FID (hazard ratio, 3.2; 95% CI: 1.1, 8.9; P = .03) were the independent predictors of aorta-related events. Conclusion A large portion of patients with B-intramural hematoma (IMH) had focal intimal disruption (FID) detected at CT at admission. Large FIDs were associated with disease progression of IMH. © RSNA, 2021 See also the editorial by Raptis and Braverman in this issue. Online supplemental material is available for this article.

Clinical features and outcomes after endovascular therapy for penetrating aortic ulcer and intramural hematoma

OBJECTIVES

To identify the differences between clinical features and outcomes after endovascular therapy for penetrating aortic ulcer (PAU) and intramural hematoma (IMH).

METHODS

From January 2009 to March 2020, patients who underwent endovascular therapy for PAU and IMH were enrolled. Information on patient demographics, presentation, PAU and IMH morphology, laboratory examination, and clinical follow-up information was collected and analyzed. Univariate analysis was performed to identify the differences between IMH and PAU, and Kaplan-Meier was used to calculate the cumulative survival rate and freedom from reintervention.

RESULTS

A total of 114 patients were enrolled; 80 (70.2%) of them were diagnosed with PAU. Compared with PAU, patients with IMH were younger (p = 0.006), more likely to be admitted emergently (p = 0.001), had longer hospital stay (p = 0.028), and had higher levels of C-reactive protein (p = 0.030). Meanwhile, patients with IMH were more likely to be associated with hypertension (p = 0.020) and pleural effusion (p < 0.001) and less likely to have a history of acute coronary syndrome (p = 0.019) and prior cardiovascular intervention (p = 0.017). The five-year freedom from reintervention and cumulative survival rate were 94.2% (95% confidential interval, 88.9%-99.9%) and 87.8% (95% confidential interval, 79.5%-96.9%) in PAU patients and 89.6% (95% confidential interval, 75.8%-99.9%) and 85.1% (95% confidential interval, 68.0%-99.9%) in IMH patients, respectively. There was no significant difference in freedom from reintervention (p = 0.795) or cumulative survival rate (p = 0.817).

CONCLUSIONS

IMH appeared to occur in younger patients with hypertension and usually had an acute onset, while PAU was more likely to be found incidentally in older patients with atherosclerosis. Endovascular therapy was effective in both IMH and PAU patients with encouraging outcomes.

Differential clinical features and long-term prognosis of acute aortic syndrome according to disease entity

AIMS

To evaluate the acute and long-term prognosis of acute aortic syndrome (AAS) according to the disease entity [intramural haematoma (IMH) vs. aortic dissection (AD)] and the anatomical location (type A vs. B).

METHODS AND RESULTS

A total of 1012 patients [672 with AD and 340 with IMH (33.6%)] were enrolled between 1993 and 2015. Compared with AD patients, IMH patients were older and had higher frequency of female sex and distal aorta involvement. The overall crude in-hospital mortality of AAS was 8.6%; type A AD [15.0%; adjusted hazard ratio (aHR) 30.4; 95% confidence interval (CI) 8.62-107.3; P < 0.001], type A IMH (8.0%; aHR 4.85; 95% CI 1.29-18.2; P = 0.019), type B AD (5.0%; aHR 3.51; 95% CI 1.00-12.4; P = 0.051), and type B IMH [1.5%; aHR 1.00 (reference)]. During a median follow-up duration of 8.5 years (interquartile range: 4.0-13.5 years), AD (aHR 2.78; 95% CI 1.87-4.14; P < 0.001) and type A (aHR 2.28; 95% CI 1.45-3.58; P < 0.001) was associated with a higher risk of aortic death. After 90 days, a risk of aortic death was no longer associated with anatomical location (aHR 0.74; 95% CI 0.40-1.36; P = 0.33), but remained associated with disease entity (aHR 1.83; 95% CI 1.10-3.04; P = 0.02).

CONCLUSION

The clinical features, response to treatment strategy, and outcomes of IMH patients were distinct from those of AD patients. Both early and late survival was better for IMH than for AD. In addition to the anatomical location of AAS, the disease entity is an independent factor associated with both acute and long-term mortality in patients with AAS. Further investigation is necessary to confirm the prognostic implication of disease entity in different patient populations.

Penetrating atherosclerotic ulcer

PURPOSE OF REVIEW

Penetrating aortic ulcer (PAU) is defined as ulceration of an aortic atherosclerotic plaque penetrating through the internal elastic lamina into the media. With the advances in imaging techniques, the differential diagnosis between PAU and other aortic ulcers remains a challenge. This review aims to summarize the latest insight into PAU, based on clinical context and the newest imaging characteristics, to aid treatment decision-making.

RECENT FINDINGS

Most PAUs are asymptomatic and do not require urgent invasive treatment. Nevertheless, when PAU leads to an acute aortic syndrome, emergency invasive therapy is recommended. A differential diagnosis with other lesions, such as ulcerated plaques or intimal disruptions within the context of an aortic intramural hematoma, is required as the risk of complications and management differ. Imaging technique plays a pivotal role in the correct diagnosis of aortic ulcers.

SUMMARY

The differential diagnosis of PAU with other aortic ulcers based on clinical and imaging technique information is mandatory as it may imply different prognosis and management. This diagnosis is particularly important when PAU is the cause of acute aortic syndromes as urgent invasive treatment should be recommended.

Prediction of adverse events in patients with initially medically treated type A intramural hematoma

BACKGROUND

Prior studies provided limited data regarding natural history of initially medically treated type A intramural hematoma (IMH).

OBJECTIVES

To develop predictive models for adverse aorta-related events in patients with type A IMH.

METHODS

We performed a retrospective pooled analysis of individual patient data, including baseline clinical and CT characteristics. All patients enrolled were followed up for adverse aorta-related events, defined as a composite of aortic disease-related death and the presence of aortic complications that required aortic invasive treatment.

RESULTS

A total of 172 patients (52.9% men) were included, with a mean age of 61.1 ± 11.2 years. During a median follow-up time of 770.5 (45.3-1695.8) days, 60 patients (34.9%) experienced adverse aorta-related events. In Cox regression model for predicting adverse aorta-related events, hypertension (HR = 3.78, p = .067), MAD (HR = 1.05, p = .018), presence of ULP (HR = 2.43, p = .002) and pericardial effusion (HR = 1.65, p = .061) were independently associated with adverse aorta-related events. A majority of the adverse aorta-related events (n = 46, 76.7%) occurred within acute and subacute phase (90 days) of IMH. In predictive model for 90 days aortic events, MAD≥50.7 mm (OR = 2.79, p = .006) and presence of ULP (OR = 3.20, p = .002) were independent predictors. C statistic of the predictive model were 0.71 (p < .001).

CONCLUSIONS

Predictive models including baseline clinical and CT characteristics as predictors allow for accurate estimation of risk of adverse aorta-related events in patients with type A IMH. The proposed predictive models are helpful for risk estimates and decision making.

Acute type A aortic intramural hematoma and type A aortic dissection: correlation between the intimal tear features and pathogenesis

Background

To determine the prevalence, clinical and imaging features of intimal tear detected by ECG-gated multidetector computed tomography (MDCT) and confirmed by surgery in patients with acute type A intramural hematoma (ATAIMH) and acute type A aortic dissection (AAAD).

Methods

This retrospective study involved analysis of the intimal tear characteristics in 72 consecutive patients with ATAIMH and 209 with AAAD who were diagnosed by MDCT. The size and location of the intimal tear were measured and compared between these two groups of patients. The findings were also compared with those from 28 patients with ATAIMH who underwent surgical treatment to determine the intimal tear features as observed on CT angiography (CTA).

Results

Patients in the ATAIMH group were significantly older than those in the AAAD group (58.6±11.3 vs. 49.4±12.8 years, P<0.001), and females were predominant in the former category (ATAIMH vs. AAAD: 44.4% vs. 27.8%, P<0.01). Marfan syndrome and pregnancy were associated with most of the occurrences of AAAD. Sixty-four patients (88.9%) with ATAIMH were recognized as having intimal tear in the CTA images. The number of aortic segments in the ATAIMH patients was smaller than that in the AAAD patients (4.45±1.56 vs. 5.04±1.72 segments, P<0.01). The distribution of the intimal tear did not show any difference between the two groups. During the surgery, pericardial hemorrhage was observed in a higher proportion of patients in the ATAIMH than in the AAAD group (60.7% vs. 22.1%; P<0.01). In the former category, all of the intimal tears detected using CTA were confirmed during the operation, and the size was significantly larger than measured on the CTA images (6.95±5.12 vs. 19.59±6.51 mm, P<0.001). Six ATAIMH patients progressed to classical aortic dissection (AD) at surgery.

Conclusions

Patients with ATAIMH have a high prevalence of intimal tear, which is significantly smaller than that measured in patients with classic AAAD. Just like AD, ATAIMH may also be triggered by intimal tear. Hence, timely surgical repair is needed.

Beyond the term penetrating aortic ulcer: A morphologic descriptor covering a constellation of entities with different prognoses

Penetrating aortic ulcer (AU) is defined as localized disruption of the intimal layer of the aortic wall, resulting in a crater-like lesion outpouching from the vessel contour. AU is a generic term which encompasses a constellation of entities with different etiologies and prognoses and may be a complication of infective, inflammatory, traumatic, iatrogenic, atherosclerotic processes or intramural hematoma. One of the most challenging scenarios of AU for a differential diagnosis, but also for treatment implications, is when they are associated with acute aortic syndrome. Despite advances in the field of aortic disease, lack of consensus defining these lesions and the significant semantic confusion in the medical literature of the acronym PAU (for penetrating aortic ulcer but also for penetrating atherosclerotic ulcer) have given rise to controversy in guidelines and expert consensus, leading to the same treatment being recommended for entities with different etiology and prognosis. Moreover, in the medical literature, most diagnoses were mainly based on imaging techniques which identified AU regardless of clinical symptoms, surrounding imaging findings or dynamic morphologic changes. In this Review, we provide the latest insight into the differential diagnosis between AU, also called penetrating aortic ulcers, based on clinical context and the newest imaging characteristics to aid treatment decision-making.

Intramural hematoma and penetrating ulcer in the descending aorta: differences and similarities

Acute aortic syndromes include a variety of overlapping clinical and anatomic diseases. Intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU), and aortic dissection can occur as isolated processes or can be found in association. All these entities are potentially life threatening, so prompt diagnosis and treatment is of paramount importance. IMH and PAU affect patients with atherosclerotic risk factors and are located in the descending aorta in 60-70% of cases. IMH diagnosis can be correctly made in most cases. Aortic ulcer is a morphologic entity which comprises several entities-the differential diagnosis includes PAU, focal intimal disruptions (FID) in the context of IMH evolution and ulcerated atherosclerotic plaque. The pathophysiologic mechanism, evolution and prognosis differ somewhat between these entities. However, most PAU are diagnosed incidentally outside the acute phase. Persistent pain despite medical treatment, hemodynamic instability, maximum aortic diameter (MAD) >55 mm, significant periaortic hemorrhage and FID in acute phase of IMH are predictors of acute-phase mortality. In these cases, TEVAR or open surgery should be considered. In non-complicated IMH or PAU, without significant aortic enlargement, strict control of cardiovascular risk factors and frequent follow-up imaging appears to be a safe management strategy.

Acute type B aortic intramural hematoma: the added prognostic value of a follow-up CT

OBJECTIVES

To investigate prognostic significance of follow-up CT findings for initially medically treated type B aortic intramural hematoma (IMH).

METHODS

We performed a retrospective pooled analysis of individual patient data, including baseline and follow-up CT characteristics. All enrolled patients were followed up for adverse aorta-related events, defined as a composite of aortic disease-related death and surgical or endovascular aortic repair.

RESULTS

A total of 238 patients (73.9% men) were included, with a mean age of 58.1 ± 9.8 years. During follow-up, 83 patients (34.9%) experienced adverse aorta-related events, most of the events (83.1%) occurred within 1 month after follow-up CT imaging (n = 69). In the Cox regression model for predicting adverse aorta-related events, baseline maximal aortic diameter (MAD) (HR = 1.05, p = 0.008), ulcer-like projection (ULP) (HR = 2.47, p < 0.001), changes of maximal hematoma thickness (MHT) (HR = 1.22, p < 0.001), newly developed ULP (HR = 4.44, p < 0.001), and newly developed pleural effusion (HR = 2.46, p = 0.002) were powerful independent predictors. In combined predictive model for 1-month aortic events, baseline MHT ≥ 11.8 mm (OR = 4.39, p = 0.001), ULP (OR = 3.98, p < 0.001), changes of MHT (OR = 1.46, p < 0.001), newly developed ULP (OR = 9.27, p = 0.002), and newly developed pleural effusion (OR = 3.45, p = 0.015) were independent predictors. Besides, in patients with pleural effusion at baseline, resorption of pleural effusion was associated with adverse aorta-related events (HR = 0.36, p = 0.027) and 1-month aortic events (OR = 0.23, p = 0.026).

CONCLUSIONS

Follow-up CT findings provide strong and incremental prognostic information for initially medically treated type B IMH, which are helpful for risk estimates and decisions-making.

KEY POINTS

• Follow-up CT provides strong and incremental prognostic information for initially medically treated type B aortic intramural hematoma. • Follow-up CT is highly recommended for type B intramural hematoma in patients who did not receive urgent invasive therapy. • Follow-up CT is helpful for risk estimates and decisions-making.

Intimal disruption in type B aortic intramural hematoma. Does size matter? A systematic review and meta-analysis

BACKGROUND

Type B intramural hematoma (IMH) is considered a low-risk entity for aortic complications if aortic dilation, containing rupture or clinical instability are absent. However, the development of intimal disruptions (ID), present in >40% of cases, poses an unknown risk.

OBJECTIVES

To establish which ID characteristics imply a higher risk of aortic complications and, therefore, merit invasive treatment.

METHODS

A systematic review and a meta-analysis were made following a search in EMBASE, MEDLINE and PsycINFO for articles published between January 1995 and December 2017. The combined endpoint was defined as aortic mortality, invasive treatment for aortic disease and/or increase in maximum aortic diameter ≥55 mm. Lesions with communicating orifice ≤3 mm were defined as tiny ID (TID) and those with >3 mm as focal ID (FID).

RESULTS

Six studies with 564 participants diagnosed of type B IMH were included. Incidence of ID was 54.3% (306 individuals): 27.7% (156 individuals) initially met TID criteria; however, 13.9% of these (21 of 151 with morphologic evolution) evolved to FID within the first 6 months. Ninety-two cases suffered clinical aorta-related events (16.3%; mean follow-up range: 15-85 months; median: 52 months). Patients with TID had a similar risk of aorta-related events to those without ID (RR = 0.904; 95% CI, 0.335-2.440; P = 0.842; I² = 42.5%), but lower than those with FID (RR = 0.299; 95% CI, 0.094-0.952; P = 0.041; I² = 26.9%).

CONCLUSIONS

Tiny intimal disruption in type B IMH evolution is not related to an increased risk of complications and should not be considered an indication for invasive treatment. However, since 14% of TID evolve to FID within the first 6 months, close follow-up with imaging techniques is advisable.

Multislice spiral CT angiography for evaluation of acute aortic syndrome

OBJECTIVE

To discuss the diagnostic value of multislice CT angiography (MSCTA) in acute aortic syndrome (AAS).

MATERIALS AND METHODS

The clinical and imaging data of 36 cases diagnosed as AAS by MSCTA were collected. The manifestations of the MSCTA images were reviewed retrospectively, and the average x-ray dose was calculated.

RESULTS

Among 36 AAS cases, 16 cases had aortic dissection (AD), 8 cases had penetrating atherosclerotic ulcer (PAU), 7 cases had intramural hematoma (IMH), and 5 cases had unstable thoracic aneurysm (UTA). Of 16 cases with AD, type A and type B accounted for 43.7% (7/16) and 56.3% (9/16), respectively. Of 7 cases with IMH, type A and type B accounted for 42.9% (3/7) and 57.1% (4/7), respectively.

CONCLUSION

In spite of the x-ray radiation, MSCTA proves to be a rapid and noninvasive imaging technique for the diagnosis of AAS.

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.

Advances in the diagnosis of acute aortic syndromes: Role of imaging techniques

Aortic diseases include a wide range of pathological conditions: aortic aneurysms, pseudoaneurysms, acute aortic syndromes, atherosclerotic and inflammatory conditions, genetic diseases and congenital anomalies. Acute aortic syndromes have acute onset and may be life-threatening. They include aortic dissection, intramural haematoma, penetrating aortic ulcer and traumatic aortic injury. Pain is the common denominator to all acute aortic syndromes. Pain occurs regardless of age, gender and other associated clinical conditions. In this review, we deal with the main findings in the clinical setting and the most recent indications for diagnostic imaging, which are aimed to start an appropriate treatment and improve the short- and long-term prognosis of these patients.

Update in acute aortic syndrome: intramural hematoma and incomplete dissection as new disease entities

Acute aortic syndrome is a relatively recent clinical entity. Non-invasive imaging methods, such as computed tomography and transesophageal echocardiography, have contributed significantly to the diagnosis of variant forms of classic aortic dissection, which have become important disease entities in acute aortic syndrome. Imaging findings may result in risk stratification and application of different treatment options, providing a rational approach to achieve a better outcome of this syndrome. This review will focus on the imaging characteristics of two important variant forms of classic aortic dissection, intramural hematoma and incomplete dissection, and the role of imaging methods in the evaluation of differences in the hemodynamic status of false lumens that contributes to patient prognosis.

Detection of Intimal Defect by 64-Row Multidetector Computed Tomography in Patients With Acute Aortic Intramural Hematoma

Background—

Previous pathological and clinical studies demonstrated an intimal defect in patients with acute aortic intramural hematoma (IMH). The purpose of this study was to investigate the prevalence and clinical outcome of intimal defect detected by multidetector computed tomography (MDCT) in patients with IMH.

Methods and Results—

We retrospectively analyzed 38 consecutive patients with IMH in whom 64-row MDCT was performed during the acute phase (median, 5 days from the onset). Intimal defect was defined as continuity disruption of the inner layer of thrombosed false lumen, which could be detected by 1-mm axial and longitudinal interactive multiplanar reformation images. Clinical outcome of intimal defect was assessed in patients with type B IMH (n=32). A total of 48 lesions in 27 (71%) patients were recognized as intimal defects. The incidence of intimal defect was not affected by the timing of MDCT examination (1 to 3 days, 79%; 4 to 7 days, 58%; 8 to 14 days, 75%; P =0.56). In type B IMH, 16 (76%) of 21 patients with intimal defect showed progression (enlargement or progression to aortic aneurysm) in the chronic phase. In contrast, all 11 patients without intimal defect had complete resorption of hematoma. In lesion-based analysis, a depth of intimal defect of ≥5 mm predicted progression with sensitivity, specificity, and positive and negative predictive values of 84%, 95%, 94%, and 86%, respectively.

Conclusions—

A considerable portion of patients with IMH showed intimal defect detected by MDCT even in the very early stage, and defects frequently enlarged. Patients with intimal defect should be carefully followed up with serial imaging.