OBJECTIVE: To demonstrate that human visual illusion can contribute to sub-endocardial dark rim artifact in contrast-enhanced myocardial perfusion magnetic resonance images.MATERIALS AND METHODS: Numerical phantoms were generated to simulate the first-passage of contrast agent in the heart, and rendered in conventional gray scale as well as in color scale with reduced luminance variation. Cardiac perfusion images were acquired from two healthy volunteers, and were displayed by the same gray and color scales used in the numerical study. Before and after k-space windowing, the left ventricle (LV)-myocardium boarders were analyzed visually and quantitatively through intensity profiles perpendicular the boarders.RESULTS: k-space windowing yielded monotonically decreasing signal intensity near the LV-myocardium boarder in the phantom images, as confirmed by negative finite difference values near the board ranging −1.07 to −0.14. However, the dark band still appears, which is perceived by visual illusion. Dark rim is perceived in the in-vivo images after k-space windowing that removed the quantitative signal dip, suggesting that the perceived dark rim is a visual illusion. The perceived dark rim is stronger at peak LV enhancement than the peak myocardial enhancement, due to the larger intensity difference between LV and myocardium. In both numerical phantom and in-vivo images, the illusory dark band is not visible in the color map due to reduced luminance variation.CONCLUSION: Visual illusion is another potential cause of dark rim artifact in contrast-enhanced myocardial perfusion MRI as demonstrated by illusory rim perceived in the absence of quantitative intensity undershoot.

PURPOSE: To develop a two-dimensional (2D) image-based respiratory motion correction technique for free-breathing coronary magnetic resonance angiography (MRA). MATERIALS AND METHODS: The proposed respiratory navigator obtained aliased a 2D sagittal image from under-sampled k-space data and utilized motion correlation between the aliased images. The proposed navigator was incorporated into the conventional coronary MRA sequence including the diaphragm navigator and tested in three healthy subjects. RESULTS: The delineation of major coronary arteries was significantly improved using the proposed 2D motion correction (S/I and A/P) compared to one-dimensional (S/I) correction using the conventional diaphragm navigator. CONCLUSION: The 2D image-based respiratory navigator was proposed for free-breathing coronary angiography and showed the potential for improving respiratory motion correction compared to the conventional 1D correction.
Coronary Angiography ; Coronary Vessels ; Diaphragm ; Healthy Volunteers ; Magnetic Resonance Angiography

Magnetic resonance angiography (MRA) plays an important role in accurate diagnosis and appropriate treatment planning for patients with arterial disease. Contrastenhanced (CE) MRA is fast and robust, offering hemodynamic information of arterial flow, but involves the risk of a side effect called nephrogenic systemic fibrosis. Various non-contrast-enhanced (NCE) MRA techniques have been developed by utilizing the fact that arterial blood is moving fast compared to background tissues.NCE MRA is completely free of any safety issues, but has different drawbacks for various approaches. This review article describes basic principles of CE and NCE MRA techniques with a focus on how to generate angiographic image contrast from a pulse sequence perspective. Advantages, pitfalls, and key applications are also discussed for each MRA method.

Limited data are available about incomplete stent expansion (SE) on platelet deposition (PD). We examined PD following different SE using an extracorporeal porcine arteriovenous shunt model to which a perfusion chamber with four parallel silastic tubes were connected. Blood flow was set at a 20 and 100 mL/min in 1.8 and 3.1 mm diameter tubes, respectively. P154 stents were deployed completely (Group A, n=15) or incompletely (Group B, n=15) in 1.8 mm (n=13) and 3.1 mm (n=17) tubes. 51Cr-labelled platelet autologous blood was injected 1 hr before the perfusion. After 15 min-perfusion, the testing tubes were assessed for radioactivity counts. In-stent cross sectional area was measured by intravascular ultrasound. There was a significant difference in PD between group A and B regardless of channel size (118+/-18.4 vs 261.4+/-52.1 pits x 10(6)/cm2, p<0.05). With adjusted shear rate and similar stenosis, PD was similar in both tubes. In smaller 1.8 mm tubes, a stenosis as subtle as 10% was associated with a significant PD difference (226.1+/-20 vs 112.9+/-20.5 plts x 10(6)/cm2, p<0.005). This model enabled a repetitive, simultaneous comparison of PD following different SE states. It seems that the quality of SE remains crucial in smaller channels.
Animal ; Arteriovenous Shunt, Surgical ; Extracorporeal Circulation ; Male ; Models, Animal ; Perfusion ; Platelet Activation* ; Stents/adverse effects* ; Swine ; Thrombosis/etiology*

Choroid plexus tumors are uncommon brain tumors that primarily occur in children. Most of these tumors originate from the intraventricular area, and the most common clinicalpresentation is increased intracranial pressure. Dissemination through the cerebrospinal fluid space is the inevitable natural course of the disease. Here, we present 2 rare cases of adult choroid plexus carcinoma (CPC), each with distinct clinical presentation and progression. The first case was a 40-year-old male who presented with multiple intraventricular masses. After surgical biopsy, radiation and intrathecal chemotherapy failed to elicit any response. The patient progressed with spinal cord dissemination and expired 1 year later. The second case presented with visual disturbance, and brain MRI revealed a large ovoid juxtaventricular mass with peritumoral edema. This 49-year-old female patient underwent craniotomy for what was thought to be a high-grade glioma; however, the mass was connected to the choroid plexus at the operative field. Her pathology specimen was diagnosed as CPC, and adjuvant systemic chemotherapy was administered. She has now been free of recurrence for 10 months. The description of the presentation and progression of these rare adult-onset CPC provides insight for the diagnosis and treatment of other rare instances of choroid plexus tumors.
Adult ; Biopsy ; Brain ; Brain Neoplasms ; Cerebrospinal Fluid ; Child ; Choroid Plexus Neoplasms ; Choroid Plexus ; Choroid ; Craniotomy ; Diagnosis ; Drug Therapy ; Edema ; Female ; Fourth Ventricle ; Glioma ; Humans ; Intracranial Pressure ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Pathology ; Recurrence ; Spinal Cord

BACKGROUND/AIMS: The follow-up strategy after hepatectomy for hepatocellular carcinoma (HCC) usually depends on the experience of physician, resulting in frequent imaging studies, which leads to increased cost. Hence, we investigated the role of monitoring alpha-fetoprotein (AFP) levels after hepatectomy in patients with preoperative high AFP. METHODS: From January 2000 to December 2004, 66 patients who underwent curative hepatectomy due to HCC with preoperative AFP level >400 ng/mL were reviewed. Changes in AFP level after the operation were investigated. The recurrence was suspected in case of two consecutive increase of AFP over cut-off value. Cut-off value was determined by ROC curve. All patients were divided into 2 groups: patients who met the definition (Group S) and those who didn't (Group D). RESULTS: AFP level of 20 ng/ml was proposed as the cut-off value for diagnosis of recurrence by ROC curve. Thirty two patients who didn't have the AFP level decreased below 20 ng/ml after the resection had HCC recurred, whereas 16 out of 34 patients who had AFP decreased had tumor recurrence. The AFP level of patients without recurrence was kept below 20 ng/ml during the follow-up. The AFP level of 44 out of 48 recurred patients increased over 20 ng/ml upon recurrence. By definition, group D were 5 patients. In 4 patients of group D, the AFP level didn't increase above 20 ng/ml upon recurrence. These patients had HCC and they recurred 1 year after the surgery. CONCLUSIONS: In patients with preoperative AFP level >400 ng/ml, the AFP level tended to increase above 20 ng/ml at recurrence mostly within 1 year. Hence, we proposed that these patients could be monitored by only AFP until 1 year after surgery.
Adult ; Aged ; Carcinoma, Hepatocellular/mortality/radiography/*surgery ; Disease-Free Survival ; Female ; Hepatectomy ; Humans ; Liver Neoplasms/mortality/radiography/*surgery ; Male ; Middle Aged ; Neoplasm Recurrence, Local/mortality/radiography/*surgery ; ROC Curve ; alpha-Fetoproteins/*analysis

A 1.5-month-old girl, weighing 4.7 Kg, presented with vomiting, blood tinged stool and jaundice. We performed living donor liver transplantation(LDLT) for the management of fulminant hepatic failure with worsening encephalopathy. The donor was her father, 30 years old, weighing 51 kg. During the pre-operative donor evaluation, a computed tomography volumetry was 170 mL for left lateral section of the liver, which was 3.61% of the graft-recipient weight ratio(GRWR). In donor operation, the reduction of the left lateral section was made just after parenchyma resection of left lateral section was completed, and before clamping of the vessels. The segment II was resected from the left lateral section in situ. The transection plane between segment II and III was identified with the use of intraoperative ultrasonography and clamping of Glisson of segment II. The segment III graft weighed 135 g, which was 2.87 % GRWR. The operation time was 6 hours 15 minutes and transfusion was not needed. Recipient operation was performed in conventional manner of pediatric LDLT using left lateral section with primary closure of abdominal wall without tension. The operation time was 7 hours 35 minutes and cold ischemic time was 1 hour 33 minutes. She recovered well without any significant complications. She discharged on the post operative 24th day. Total bilirubin, aspartic acid transaminase and alanine aminotransferase was 0.6 mg/dL, 26 IU/L and 37 IU/L respectively at the point of discharge. LDLT with monosegment seems to be a feasible option for neonates and small infants requiring liver transplantation.
Abdominal Wall ; Alanine Transaminase ; Aspartic Acid ; Bilirubin ; Cold Ischemia ; Constriction ; Fathers ; Humans ; Infant ; Infant, Newborn ; Jaundice ; Liver ; Liver Failure, Acute ; Liver Transplantation ; Living Donors ; Tissue Donors ; Tolnaftate ; Transplants ; Vomiting

Coronary stenting for long complex lesion is effective but associated with complication. We compared the results of stenting between with multiple conventional stenting group (group A) and with single long stenting group (group B). Fifty patients were prospectively and randomly enrolled: 25 patients for each group. Each group showed no significant differences of clinical characteristics. One patient died of heart failure in each group, not associated with the procedure itself. One patients had cerebrovascular accident in each group. Five patients had major bleeding (2, group A; 3, group B). Angiographic success rate was 100% in each group and procedural success rate was 96% and 100% in group A and B, respectively. Angiographic and clinical restenosis rate at 6 months follow-up were 60%, 36% in group A and 65%, 44% in group B, respectively (p=S). Multivariate analysis showed that several factors affected the angiographic restenosis rate as follows; a) male gender (M:F=76.9%:25.0%, P<0.001), b) AMI (AMI:stable angina pectoris=72.7%:66.7%, P<0.001), c) lesion length d) residual stenosis. In conclusion, there were no statistical differences of restenosis and complication rate between the two groups. Our data support single long stenting is acceptable and economically more favorable for long diffuse lesion, compared to multiple conventional stenting.
Constriction, Pathologic ; Coronary Stenosis* ; Coronary Vessels* ; Follow-Up Studies ; Heart Failure ; Hemorrhage ; Humans ; Male ; Multivariate Analysis ; Prospective Studies ; Stents* ; Stroke

PURPOSE: Liver transplantation (LT) has been advocated as a good management option for patients with hepatocellular carcinoma (HCC). The rate of HCC recurrence after LT is about 20%. Although the median survival time of patients with HCC recurrence is 7~9 months, the role of surgical treatment for metastatic tumors has been reported on. In this study, we evaluated the role of metastasectomy for treating patients with pulmonary metastasis from HCC after LT. METHODS: We retrospectively analyzed 10 patients with pulmonary metastasis after LT and who were treated between April 2005 and October 2007. The underlying liver disease was cirrhosis caused by chronic viral hepatitis. The surveillance protocol for HCC recurrence was as follows: assessing the serum alpha-fetoprotein level every 1 month, chest and abdomen-pelvic computed tomography every 3 months and a bone scan every 1 year or when bone metastasis was suspected. The patients with less than 3 metastatic lesions were recommended to undergo metastasectomy (Group S, n=6) and the patients with more 4 lesions were recommended nonsurgical management, including chemotherapy (Group N, n=4). RESULTS: All the metastatic lesions were detected on the protocol chest CT scans. The median recurrence time was 7.4 months (0.8~18.2) after LT; this was 11.0 (4.8~18.2) months for Group S and 2.0 (0.8~3.3) months for Group N. One patient had a single lesion and the others had multiple lesions on multilobes. The median survival times of Group S were 29.3 (18.5~41.3) months after pulmonary metastasis and 40.3 (23.3~48.0) months after transplantation; 5 patients had no recorded evidence of their disease status. The median survival time of Group N was 4.3 (4.0~6.3) months after metastasis and 6.2 (5.3~7.1) months after transplantation; all the patients have since died. CONCLUSION: The survival outcome seemed to be good for the patients who underwent pulmonary metastasectomy for HCC, if it was detected earlier and it was resectable (< or =3 lesions). However, further study is required for validating the survival benefit of pulmonary metastasectomy.
alpha-Fetoproteins ; Carcinoma, Hepatocellular ; Fibrosis ; Hepatitis ; Humans ; Liver ; Liver Diseases ; Liver Transplantation ; Metastasectomy ; Neoplasm Metastasis ; Recurrence ; Retrospective Studies ; Thorax

PURPOSE: Liver transplantation (LT) has been advocated as a good management option for patients with hepatocellular carcinoma (HCC). The rate of HCC recurrence after LT is about 20%. Although the median survival time of patients with HCC recurrence is 7~9 months, the role of surgical treatment for metastatic tumors has been reported on. In this study, we evaluated the role of metastasectomy for treating patients with pulmonary metastasis from HCC after LT. METHODS: We retrospectively analyzed 10 patients with pulmonary metastasis after LT and who were treated between April 2005 and October 2007. The underlying liver disease was cirrhosis caused by chronic viral hepatitis. The surveillance protocol for HCC recurrence was as follows: assessing the serum alpha-fetoprotein level every 1 month, chest and abdomen-pelvic computed tomography every 3 months and a bone scan every 1 year or when bone metastasis was suspected. The patients with less than 3 metastatic lesions were recommended to undergo metastasectomy (Group S, n=6) and the patients with more 4 lesions were recommended nonsurgical management, including chemotherapy (Group N, n=4). RESULTS: All the metastatic lesions were detected on the protocol chest CT scans. The median recurrence time was 7.4 months (0.8~18.2) after LT; this was 11.0 (4.8~18.2) months for Group S and 2.0 (0.8~3.3) months for Group N. One patient had a single lesion and the others had multiple lesions on multilobes. The median survival times of Group S were 29.3 (18.5~41.3) months after pulmonary metastasis and 40.3 (23.3~48.0) months after transplantation; 5 patients had no recorded evidence of their disease status. The median survival time of Group N was 4.3 (4.0~6.3) months after metastasis and 6.2 (5.3~7.1) months after transplantation; all the patients have since died. CONCLUSION: The survival outcome seemed to be good for the patients who underwent pulmonary metastasectomy for HCC, if it was detected earlier and it was resectable (< or =3 lesions). However, further study is required for validating the survival benefit of pulmonary metastasectomy.
alpha-Fetoproteins ; Carcinoma, Hepatocellular ; Fibrosis ; Hepatitis ; Humans ; Liver ; Liver Diseases ; Liver Transplantation ; Metastasectomy ; Neoplasm Metastasis ; Recurrence ; Retrospective Studies ; Thorax