Eijun Sueyoshi

Fate of intramural hematoma of the aorta : CT evaluation

PURPOSE Our goal was to investigate the fate of intramural hematoma of the aorta. METHOD In 32 patients with intramural hematoma of the aorta, we reviewed CT (n = 32) and MR (n = 22) findings. The diagnosis was established by CT, and regular follow-up studies were performed. RESULTS All intramural hematomas decreased in size. Ulcer-like projections (ULPs) were identified at the initial study in 6 patients and during the follow-up period in 14 patients. The ULPs progressed to saccular aneurysm in 12 patients (mean 47.0 days), while fusiform aneurysm developed in 6 patients (mean 347.7 days) without ULP. In two patients, the affected aorta progressed to overt aortic dissection. CONCLUSION Intramural hematoma itself usually decreases in size. However, the affected aorta can progress to aneurysm or overt aortic dissection. Development of saccular aneurysm from ULPs can be considered an early complication. In cases without ULP, fusiform aneurysm may develop as a late complication. All intramural hematomas need to be followed since it seems to be difficult to predict the exact fate of intramural hematoma from the initial imaging findings.

Growth Rate of Affected Aorta in Patients With Type B Partially Closed Aortic Dissection

BACKGROUND Our purpose was to evaluate the growth rate (GR) of the affected aorta and to clarify whether a partially closed false lumen can affect aortic enlargement in patients with type B double-barrelled aortic dissection (AD). METHODS Seventy-one patients (mean age, 64.4 years) who had experienced AD were enrolled in this study. Regular follow-up computed tomography studies (mean, 48.9 months) were performed. During the follow-up period, aortic diameter was measured with computed tomography. The fastest GR was calculated. RESULTS Based on final computed tomography findings, the patients were divided into three groups: those with completely closed false lumens (n = 8), those with partially closed false lumens (n = 20), and those with patent false lumens (n = 43). Among the patients with partially closed false lumens, 3 of 20 (15%) had a sac formation type and 17 (85%) had a non-sac formation type. The mean fastest GRs for groups with a completely closed false lumen, partially closed false lumen, and patent false lumen were -0.2 +/- 0.6, 4.0 +/- 4.3, and 4.9 +/- 4.5 mm/year, respectively. The differences among the three groups were statistically significant (p = 0.0149). In the partially closed false lumen group, the mean fastest GRs of the sac and non-sac formation types were 12.7 +/- 1.1 and 2.6 +/- 2.7 mm/year, respectively; this difference is statistically significant (p = 0.007). CONCLUSIONS Affected aortas with partially closed false lumens do not exhibit the highest GR. The status of a partially closed false lumen is not a significant risk factor for enlargement; however, careful follow-up study is needed whenever the sac formation type of partially closed false lumen is identified.

Tuberculous tenosynovitis of the wrist: MRI findings in three patients

Abstract We report recent MRI findings in patients with tuberculous tenosynovitis of the wrist. Marked synovial thickening around the flexor tendons and fluid in the tendon sheath were clearly shown on MRI. Post-contrast study was useful in distinguishing the thick tenosynovium from the surrounding structures and fluid in the tendon sheath. The well-enhanced tenosynovium was also seen in the carpal tunnel in all cases. On the basis of these findings, we could easily distinguish tenosynovitis from other soft-tissue-mass lesions, such as tumors or infected ganglia. Tuberculous tenosynovitis is often not diagnosed early, and its differentiation from soft tissue tumors may be clinically difficult. MRI, particularly post-contrast study, is useful for early diagnosis of, and planning treatment for, tuberculous tenosynovitis.

Vascular Complications of Hepatic Artery After Transcatheter Arterial Chemoembolization in Patients With Hepatocellular Carcinoma

OBJECTIVE The purpose of this article is to review the angiographic changes, development of collaterals, and possible complications after transcatheter arterial chemoembolization (TACE) in hepatocellular carcinoma (HCC). CONCLUSION Extrahepatic collateral arteries can supply the tumor after repeated TACE. Knowledge of hepatic artery changes can help in repeated TACE procedures and reduce TACE time. Appreciation of the complications and collaterals may improve the outcome of patients with HCC.

Quantification of lung perfusion blood volume (lung PBV) by dual-energy CT in patients with and without pulmonary embolism: preliminary results.

OBJECTIVES Recently, software has been used for quantification of lung PBV, which can be evaluated objectively; however, this technique is yet to be validated. The purpose was to investigate the clinical feasibility of the quantification of lung perfusion blood volume (lung PBV) by dual-energy CT in patients with pulmonary embolism (PE). MATERIALS AND METHODS One hundred thirteen patients with clinical suspicion of PE underwent dual-energy CT angiography with a standard injection protocol. Patients were divided into each two groups with and without PE based on the presence of endoluminal clots on transverse diagnostic scans. We evaluated the quantification of lung PBV using a workstation. Associations between lung PVB and the numbers of pulmonary segments with PE were also evaluated. RESULTS Thirty three of 113 (29%) patients were found to have endoluminal clots in the right and/or left lungs. The remaining 80 patients did not have endoluminal clots. In 33 patients, the mean number of segments with endoluminal clots was 5.2±3.3. For patient (whole lung)-based analysis, in patients with and without PE, mean lung PBVs were 20.8±2.3 and 28.7±6.8 Hounsfield Unit (HU), respectively, with a significant difference between the two groups (p<0.0001). In patients with PE, there was a significant correlation between lung PBV and the numbers of pulmonary segments with PE (R=0.57, p=0.0005). CONCLUSION The findings of this preliminary study suggest that quantification of lung PBV may reflect the pulmonary artery perfusion, which is useful to evaluate pulmonary blood flow in patients with PE.

Infected abdominal aortic aneurysm: early CT findings

Abstract. We describe computed tomographic (CT) findings at the early stage of infected abdominal aortic aneurysm in three patients. Periaortic mass and increased fat density were the characteristic findings of early aortic infection on CT. Similar findings caused by other diseases may be difficult to differentiate by imaging alone, but these findings should be used to trigger close follow-up for patients with suspected infected abdominal aortic aneurysm.

MRI of Takayasu's arteritis: typical appearances and complications.

OBJECTIVE Although Takayasus arteritis (TA) is more common in Asian countries, it has a worldwide distribution. MRI is widely used for its diagnosis. Our purpose is to present a comprehensive pictorial review of its typical appearances and complications on MRI. CONCLUSION MRI can effectively provide almost all anatomic information in patients with TA. MRI is very useful for accurate diagnosis of TA and its complications. Knowledge of MRI findings is essential for improving patient outcome.

MR Imaging of the Aorta

Recent advances in noninvasive imaging methods, such as CT and MR imaging, have replaced most of invasive angiographic procedures in the diagnosis of acquired aortic disease, decreasing the cost and morbidity of diagnosis. This article reviews and illustrates present MR imaging methods for evaluation of the aorta. Common diseases of the aorta also are discussed with a focus on their unique morphologic and functional features and characteristic MR imaging findings. Knowledge of pathologic conditions of common aortic diseases and proper MR imaging techniques enables accurate and time-efficient aortic evaluation.

Contrast-enhanced myocardial inversion time at the null point for detection of left ventricular myocardial fibrosis in patients with dilated and hypertrophic cardiomyopathy: a pilot study.

OBJECTIVE The purpose of this article is to investigate a noninvasive method for quantifying diffuse myocardial fibrosis with cardiac MRI in patients with dilated cardiomyopathy and hypertrophic cardiomyopathy. MATERIALS AND METHODS We performed cardiac MRI on 35 patients (24 patients with dilated cardiomyopathy and 11 patients with hypertrophic cardiomyopathy) and 10 control subjects, on a clinical 1.5-T cardiac MRI scanner. Delayed hyperenhancement images were obtained 15 minutes after injection of a bolus of gadopentetate dimeglumine (0.2 mmol/kg), to identify fibrosis using an inversion recovery gradient-echo technique (inversion time scout sequence: TR, 20.8 milliseconds; TE, 1.3 milliseconds; inversion time, individually determined to null the myocardial signal [range, 85-800 milliseconds]). An inversion time mapping sequence was used to calculate the contrast-enhanced myocardial inversion time at the null point of a single midventricular slice as an index of diffuse fibrosis. RESULTS The mean contrast-enhanced myocardial inversion time at the null point was significantly shorter in the patient group than the control group (343. 7 +/- 27.9 vs 390.4 +/- 19.3 milliseconds; p < 0.0001). In the patient group, the mean contrast-enhanced myocardial inversion time at the null point was shorter in patients with dilated cardiomyopathy than in patients with hypertrophic cardiomyopathy (337.0 +/- 29.6 vs 358.6 +/- 17.1 milliseconds, p = 0.02). In the dilated cardiomyopathy group, contrast-enhanced myocardial inversion time at the null point was significantly related to the left ventricular ejection fraction (r = 0.52; p = 0.01). However, in the hypertrophic cardiomyopathy group, contrast-enhanced myocardial inversion time at the null point had only a small positive correlation with the left ventricular ejection fraction (r = 0.27; p = 0.41). CONCLUSION Contrast-enhanced myocardial inversion time at the null point is shorter with myocardial fibrosis in patients with dilated cardiomyopathy and hypertrophic cardiomyopathy. In dilated cardiomyopathy, contrast-enhanced myocardial inversion time at the null point is inversely related to the severity of dilated cardiomyopathy.

PET features of aortic diseases.

OBJECTIVE Recently, several reports have highlighted the potential role of (18)F-FDG PET for the assessment of various aortic diseases based on FDG accumulation. In this article, we divided various aortic diseases into the following three groups on the basis of the mechanism of FDG accumulation: atherosclerosis, aortitis or periaortitis, and thrombus. Elucidating the mechanisms and patterns of FDG uptake in various aortic diseases provides valuable information for clinical management. CONCLUSION PET findings can provide additional information for the diagnosis of aortic diseases and valuable information for clinical management. It is essential to understand the characteristics of FDG uptake in various aortic diseases for proper appreciation of PET findings.