Tae-Hwan Lim

Different clinical features of aortic intramural hematoma versus dissection involving the ascending aorta

OBJECTIVES The goal of this study was to test the hypothesis that the absence of direct flow communication through intimal tear in aortic intramural hematoma (AIH) involving the ascending aorta has different clinical impact on clinical course compared with typical aortic dissection (AD). BACKGROUND Although emergent surgical repair has been applied for patients with proximal AIH as if it was typical AD, the natural history of proximal AIH is not known clearly yet. METHODS Direct comparison of the clinical data of 81 patients with proximal AD and 24 patients with AIH was performed retrospectively. RESULTS Patients with AIH were older (67 +/- 10 vs. 50 +/- 13, p = 0.001), and female gender was more predominant in AIH (19/24 vs. 29/81, p = 0.001). The development of mediastinal hemorrhage and pericardial and pleural effusion was more frequent in patients with AIH than it was in patients with AD. Although medical treatment was more frequently selected in the AIH group (75% vs. 15%, p = 0.001) due to old age and other associated medical diseases, the mortality rate with medical treatment was much lower in patients with AIH than it was in patients with AD (6% vs. 58%, p = 0.003). In follow-up imaging studies of 13 patients who survived AIH without surgical repair, seven patients showed complete resolution. Typical AD developed in three patients, and the other three patients showed focal AD only in the descending aorta. The two-year survival rate did not show significant difference (84% +/- 6% in AIH vs. 76% +/- 17% in AD, p = 0.47). CONCLUSIONS Absence of continuous flow communication can explain a more favorable clinical course of AIH than for AD, and medical treatment with frequent imaging follow-up and timed elective surgery in cases with complications can be a rational option for patients with proximal AIH.

Association Between Bicuspid Aortic Valve Phenotype and Patterns of Valvular Dysfunction and Bicuspid Aortopathy: Comprehensive Evaluation Using MDCT and Echocardiography

OBJECTIVES We sought to define the clinical importance of an integrated classification of bicuspid aortic valve (BAV) phenotypes and aortopathy using multidetector computed tomography (MDCT). BACKGROUND An association between BAV phenotypes and the pattern of valvular dysfunction or bicuspid aortopathy has yet to be definitely established. METHODS The study cohort included 167 subjects (116 men, age 54.6 ± 14.4 years) who underwent both MDCT and transthoracic echocardiography from 2003 to 2010. Two BAV phenotypes-fusion of the right and left coronary cusps (BAV-AP) and fusion of the right or left coronary cusp and noncoronary cusp (BAV-RL)-were identified. Forty-five patients showed normal aortic dimensions and were classified as type 0. In the remaining patients, hierarchic cluster analysis showed 3 different types of bicuspid aortopathy according to the pattern of aortic dilation: type 1 (aortic enlargement confined to the sinus of Valsalva [n = 34]), type 2 (aortic enlargement involving the tubular portion of the ascending aorta [n = 49]), and type 3 (aortic enlargement extending to the transverse aortic arch [n = 39]). RESULTS The prevalence of BAV-AP and BAV-RL was 55.7% and 44.3%, respectively. Comparing BAV-AP and BAV-RL, no differences in age or in the prevalence of male sex were determined. However, significant differences in the valvular dysfunction pattern were noted, with moderate-to-severe aortic stenosis predominating in patients with BAV-RL (66.2% vs. 46.2% in BAV-AP; p = 0.01), and moderate-to-severe aortic regurgitation in BAV-AP (32.3% vs. 6.8% in BAV-RL; p < 0.0001). A normal aorta was the most common phenotype in BAV-AP patients (33.3% vs. 18.9% in BAV-RL; p = 0.037), and type 3 aortopathy was the most common phenotype in BAV-RL patients (40.5% vs. 9.7% in BAV-AP; p < 0.0001). CONCLUSIONS The patterns of valvular dysfunction and bicuspid aortopathy differed significantly between the 2 BAV phenotypes, suggesting the possibility of etiologically different entities.

Focus Issue: Frontiers in Heart Valve ImagingOriginal ResearchAssociation Between Bicuspid Aortic Valve Phenotype and Patterns of Valvular Dysfunction and Bicuspid Aortopathy: Comprehensive Evaluation Using MDCT and Echocardiography

OBJECTIVES We sought to define the clinical importance of an integrated classification of bicuspid aortic valve (BAV) phenotypes and aortopathy using multidetector computed tomography (MDCT). BACKGROUND An association between BAV phenotypes and the pattern of valvular dysfunction or bicuspid aortopathy has yet to be definitely established. METHODS The study cohort included 167 subjects (116 men, age 54.6 ± 14.4 years) who underwent both MDCT and transthoracic echocardiography from 2003 to 2010. Two BAV phenotypes-fusion of the right and left coronary cusps (BAV-AP) and fusion of the right or left coronary cusp and noncoronary cusp (BAV-RL)-were identified. Forty-five patients showed normal aortic dimensions and were classified as type 0. In the remaining patients, hierarchic cluster analysis showed 3 different types of bicuspid aortopathy according to the pattern of aortic dilation: type 1 (aortic enlargement confined to the sinus of Valsalva [n = 34]), type 2 (aortic enlargement involving the tubular portion of the ascending aorta [n = 49]), and type 3 (aortic enlargement extending to the transverse aortic arch [n = 39]). RESULTS The prevalence of BAV-AP and BAV-RL was 55.7% and 44.3%, respectively. Comparing BAV-AP and BAV-RL, no differences in age or in the prevalence of male sex were determined. However, significant differences in the valvular dysfunction pattern were noted, with moderate-to-severe aortic stenosis predominating in patients with BAV-RL (66.2% vs. 46.2% in BAV-AP; p = 0.01), and moderate-to-severe aortic regurgitation in BAV-AP (32.3% vs. 6.8% in BAV-RL; p < 0.0001). A normal aorta was the most common phenotype in BAV-AP patients (33.3% vs. 18.9% in BAV-RL; p = 0.037), and type 3 aortopathy was the most common phenotype in BAV-RL patients (40.5% vs. 9.7% in BAV-AP; p < 0.0001). CONCLUSIONS The patterns of valvular dysfunction and bicuspid aortopathy differed significantly between the 2 BAV phenotypes, suggesting the possibility of etiologically different entities.

Outcomes of Patients With Acute Type A Aortic Intramural Hematoma

Background— The proper treatment option for patients with type A intramural hematoma (IMH), a variant form of classic aortic dissection (AD), remains controversial. We assessed the outcome of our institutional policy of urgent surgery for unstable patients and initial medical treatment for stable patients with surgery in cases with complications. Methods and Results— Among 357 consecutive patients with type A acute aortic syndrome, 101 (28.3%) had IMH and 256 had AD. Urgent operations were performed in 224 patients with AD (87.5%) and 16 with unstable IMH (15.8%; P<0.001). The remaining 85 stable IMH patients received initial medical treatment, and adverse clinical events developed in 31 patients (36.5%) within 6 months, which included development of AD (n=25), delayed surgery (n=25), or death (n=6). Initial aorta diameter and hematoma thickness were independent predictors for development of these events, and the best cutoff values were 55 and 16 mm, respectively. The overall hospital mortality was lower in IMH patients than in AD patients (7.9% [8/101] versus 17.2% [44/256]; P=0.0296) and was comparable to that of surgically treated AD patients (7.9% versus 10.7% [24/224]; P=0.56). The 1-, 2-, and 3-year survival rates of IMH patients were 87.6±3.6%, 84.9±3.7%, and 83.1±4.1%, respectively. There was no statistical difference of overall survival rates between patients with IMH and surgically treated AD patients (P=0.787). Conclusions— The clinical outcome of IMH patients receiving treatment by our policy was comparable to that of surgically treated AD patients. However, adverse clinical events were not uncommon with medical treatment alone, and initial aorta diameter and hematoma thickness may identify patients who might benefit from urgent surgery.

Radiologic and clinical findings of Behçet disease: comprehensive review of multisystemic involvement.

Behçet disease is a chronic, relapsing, systemic disorder of unknown etiology, characterized by recurrent oral and genital ulcers, uveitis, and other clinical manifestations in multiple organ systems. Although the diagnosis is made on the basis of the combination of typical clinical symptoms, radiologic findings of Behçet disease show characteristic features of its involvement in the gastrointestinal, neurologic, cardiovascular, and thoracic organ systems. In the gastrointestinal tract, Behçet disease may produce various types of ulcers in the esophagus, stomach, and small and large intestines, as well as deeply penetrating ulcerations in the ileocecal region, with frequently accompanying enteric fistulas. Neurologic involvement includes typical and atypical parenchymal neurobehcet disease, dural sinus thrombosis, cerebral arterial aneurysm, occlusion, dissection, and meningitis. Vascular involvement is divided into three subsets including venous occlusion, arterial occlusion, and arterial aneurysm. Cardiac manifestations include intracardiac thrombus, endomyocardial fibrosis, periaortic pseudoaneurysm, and rupture of the sinus of Valsalva. Manifestations of Behçet disease in the thorax include pulmonary arterial aneurysm, pulmonary arterial thromboembolism, thrombosis in the superior vena cava, pulmonary infarction, hemorrhage, and vasculitis of the pleura and pericardium. These various manifestations of Behçet disease respond to steroid treatment; however, one of the characteristics of Behçet disease is the high rate of complications and recurrence after surgery. Familiarity with its various radiologic and clinical characteristics is essential in making an accurate early diagnosis and for prompt treatment of patients with Behçet disease.

Clinical and Echocardiographic Outcomes of Aortic Intramural Hemorrhage Compared With Acute Aortic Dissection

Aortic intramural hemorrhage (IMH), which presents clinical manifestations identical to those of acute aortic dissection, is different from aortic dissection in terms of the absence of intimal tear and communication of blood flow between the true and false lumen. This study was conducted for the purpose of diagnosing IMH by transesophageal echocardiography (TEE) prospectively and comparing the clinical and echocardiographic outcome of IMH with aortic dissection. Between August 1991 and November 1996, 27 IMHs and 73 acute aortic dissections were diagnosed using TEE in 202 consecutive patients with suspected aortic dissections. The TEE diagnoses of IMH and aortic dissection were initially compared with computed tomography and magnetic resonance imaging and later confirmed by operative findings (n = 37) or follow-up changes (n = 12). In the 49 patients whose diagnosis was confirmed by operation or follow-up changes, the sensitivity and specificity of TEE for the diagnosis of IMH were 27 of 27 (100%) and 20 of 22 (91%), respectively. There were 11 deaths in 73 patients (15%) from acute aortic dissection and 1 death in 27 patients (4%) from IMH during a follow-up of 1.7+/-1.5 years (p = NS). Stanford classification and types of treatment were not related to death in both groups. Complications developed less often in patients with IMH (3 of 27) than in those with acute aortic dissection (24 of 73), and no death occurred in patients with uncomplicated IMH who were medically treated. A follow-up imaging study of 12 IMH patients showed complete resolution in 8, regression in 3, and progression in 1 patient. TEE is accurate in the diagnosis of IMH and IMH has a lower incidence of complications than aortic dissection because of the absence of intimal tear and communication of blood flow in the false lumen.

Usefulness of the Initial Noninvasive Imaging Study to Predict the Adverse Outcomes in the Medical Treatment of Acute Type A Aortic Intramural Hematoma

Background—There have been contradictory reports about the outcomes of medically treated patients with type A aortic intramural hematoma (AIH), and it is not certain if the initial noninvasive imaging studies can provide any useful predictors for the adverse outcomes. Methods and Results—Imaging studies and clinical outcomes of 25 consecutive patients with type A AIH who initially received medical treatment were analyzed retrospectively. Adverse outcomes (death, surgery, and development of dissection) occurred in 9 patients (group A), whereas the other 16 patients showed an uneventful course (group B). The hematoma thickness (14±4 versus 8±4 mm, P <0.005) and hematoma area (988±316 versus 555±352 mm2, P <0.01) in the imaging study performed ≤48 hours after onset of initial symptoms were significantly larger in group A; maximal aortic diameter (53±6 versus 48±8 mm, P =0.10) and aortic cross-sectional area (2247±501 versus 1809±626 mm2, P =0.09) were also somewhat larger in group A. The hematoma thickness was the only independent predictor for the adverse outcomes by stepwise multiple logistic regression analysis (odds ratio 1.41, 95% confidence interval 1.07 to 1.86, P <0.05). Hematoma thickness ≥11 mm predicted the adverse outcomes with sensitivity 89% and specificity 69%. No one with hemodynamically stable initial condition and the hematoma thickness <11 mm experienced the adverse outcomes. Conclusion—Noninvasive imaging study provides important prognostic information in the medical treatment of acute type A AIH, and initial hematoma thickness seems to be the best index for predicting adverse clinical outcome.

Application of breath-hold T2-weighted, first-pass perfusion and gadolinium-enhanced T1-weighted MR imaging for assessment of myocardial viability in a pig model.

The purpose of this study was to correlate the abnormal signal area on various magnetic resonance (MR) images to the infarct area on pathologic examination and to assess the myocardial viability on the basis of MR images. T2‐weighted, first‐pass perfusion, and delayed gadolinium‐enhanced T1‐weighted images were used as “one‐stop examinations” in a pig model of reperfused myocardial infarction. The results of each MR image were compared with those of 2,3,5‐triphenyltetrazolium chloride (TTC) staining. The abnormal signal areas on T2‐weighted and Gd‐enhanced T1‐weighted images were larger than the infarct areas on TTC staining (34.7% and 32.3% vs. 28.3%; P < 0.05), whereas the nonperfused areas on perfusion images were correlated (25.6% vs, 28.3%; P = 0.139). Electron microscopic examination showed severely distorted ultrastructures in the infarct areas and mildly damaged ultrastructures in the peri‐infarct areas. Perfusion images probably reflected the infarct areas, whereas T2‐weighted and Gd‐enhanced T1‐weighted images seemed to include peri‐infarct as well as infarct areas. J. Magn. Reson. Imaging 2000;11:476–480.

Localized Amyloidosis of the Respiratory System: Ct Features

PURPOSE Amyloidosis includes a spectrum of diseases associated with an abnormal extracellular deposition of amyloid. The respiratory system is involved in approximately 50% of patients with amyloidosis. The purpose of this review is to present the CT findings of localized amyloidosis of the respiratory system. METHODS We reviewed the CT findings of localized amyloidosis of the respiratory system from the previous reports and our experiences. RESULTS Three patterns of involvement in respiratory system are presented: tracheobronchial nodular and diffuse parenchymal. CT demonstrates nodules, plaques, or diffuse thickening of the airways with calcification. Postobstructive collapse is associated in case of diffuse airway involvement. Parenchymal nodules have sharp and lobulated margins with peripheral or subpleural locations. High-resolution CT shows reticular opacities, interlobular septal thickening, and small, well-defined nodules of 2 to 4-mm in diameter predominantly in the subpleural regions. CONCLUSION Amyloidosis of respiratory system has variable findings and CT scans clearly depict extent and distribution of the disease, its postobstructive pulmonary complication, and other associated findings such as calcification and lymphadenopathy.

Cardiac Perforation Caused by Acrylic Cement: A Rare Complication of Percutaneous Vertebroplasty

1All authors: Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap-2dong, Songpa-gu, Seoul 138-736, South Korea. Address correspondence to J. B. Seo (seojb@amc.seoul.kr). ercutaneous vertebroplasty is a minimally invasive procedure consisting of the injection of polymethyl methacrylate (PMMA) into a vertebral body under radiologic guidance [1]. The principal indications for percutaneous vertebroplasty are management of pain associated with benign compression fractures, vertebral metastatic lesions, multiple myelomas, lymphomas, and vertebral hemangiomas [2]. The risk of cement extravasation into the venous system and spinal canal represents the major hazard of this technique. There have been several case reports of pulmonary or systemic embolism caused by PMMA [3–6]. We report a case of cardiac perforation and pulmonary embolism caused by cement leakage during vertebroplasty.