Demonstration of the common hepatic artery coursing in the lesser omentum by three-dimensional computed tomography.
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Aged↗
Biomedical subjects
Masaaki Akahane
Publications and source records attributed to Masaaki Akahane.
Liver CT image processing: a short introduction of the technical elements.
In this paper, we describe the technical aspects of image analysis for liver diagnosis and treatment, including the state-of-the-art of liver image analysis and its applications. After discussion on modalities for liver image analysis, various technical elements for liver image analysis such as registration, segmentation, modeling, and computer-assisted detection are covered with examples performed with clinical data sets. Perspective in the imaging technologies is also reviewed and discussed.
Humans↗
Assessment of major aortopulmonary collateral arteries with multidetector-row computed tomography.
Multidetector-row computed tomography (MDCT) studies were performed in three adult patients with pulmonary atresia with a ventricular septal defect. In all patients, the native pulmonary arteries were absent, and the pulmonary circulation was totally supplied by major aortopulmonary collateral arteries (MAPCAs). MDCT studies with 1-mm collimation provided detailed information on MAPCAs and bronchial collaterals, such as the numbers and sites of origin, their varying diameters, their courses, and the areas of the lungs they supply. MDCT studies may provide an efficient road map for safe and successful selective catheterization and may substitute for conventional angiography in patients with considerable risks.
Abnormalities, Multiple↗
Magnetic resonance findings of bile duct adenoma with calcification.
Computed tomographic (CT) and magnetic resonance (MR) appearances of bile duct adenoma (BDA in a patient who underwent partial hepatectomy of segment 8 are presented. BDA showed a ring-shaped hyperdense area suggesting calcification and ring enhancement on CT. It appeared hypointense on both T1- and T2-weighted MR images. Preoperatively, the diagnoses considered included metastatic carcinoma, cholangiocarcinoma, tuberculosis, and rare tumors such as epithelioid hemangioendothelioma. The radiological findings were confirmed by pathological investigation.
Adenoma, Bile Duct↗
Bezier surface reformation: an original visualization technique of cervical nerve roots on myelographic CT.
PURPOSE: The aim of this study was to assess the feasibility of an original reformation method of cervical myelographic computed tomography (CT) using the Bezier surface technique. MATERIAL AND METHODS: Presurgical myelographic computed tomography (CT) scans using a multidetector row CT scanner were performed in 25 patients with avulsion injury of the cervical nerve roots. Each volumetric data set was reformatted using Bezier surface technique to depict the individual nerve root in a single image. In the reformatted images, visualization of the dorsal and ventral nerve roots between C4 and T1 on the uninjured side (300 nerves) was rated. RESULTS: Bezier surface reformation (BSR) images depicted the dorsal and the ventral nerve roots between C4 and C8 in 125 (100%) and 125 (100%) of 125 nerves, respectively. The dorsal and the ventral nerve roots of T1 were depicted in 25 (100%) and 22 (88%) in 25 nerves, respectively. CONCLUSION: The BSR technique of cervical myelographic CT enables simultaneous display of multiple cervical nerve roots in one image. BSR is a feasible technique for the assessment of the cervical nerve roots.
Accidents, Traffic↗
Image of the month: left gastric aneurysm.
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Aneurysm↗
Graft-versus-tumor effect against advanced pancreatic cancer after allogeneic reduced-intensity stem cell transplantation.
BACKGROUND: The prognosis of advanced pancreatic cancer is extremely poor and therefore a novel treatment strategy is desired. The authors thus started a prospective study of allogeneic reduced-intensity hematopoietic stem cell transplantation (RIST) for patients with advanced pancreatic cancer to evaluate the feasibility and efficacy of this approach for such patients. METHODS: Only patients with pathologically proven pancreatic cancer that was locally advanced or metastatic and not amenable to curative resection were included. The conditioning regimen consisted of gemcitabine, fludarabine, and busulfan. RESULTS: In the first stage of this study, the authors treated seven patients. Treatment-related mortality before day 100 was observed in one patient. The median survival after RIST was 229 days. An objective response on computed tomographic scan was observed in two patients and another had a tumor marker response. Marked tumor shrinkage was observed in one of the remaining patients after donor lymphocyte infusion. These antitumor effects appeared after the effect of the conditioning regimen had disappeared. In addition, some of these responses were associated with an increase in the serum anticarcinoembryonic antigen antibody level. CONCLUSIONS: Pancreatic cancer appeared to be sensitive to a graft-versus-tumor effect; therefore, a larger clinical study with a refined strategy is warranted.
Adult↗
Delayed enhancement of pelvic lymphangiomyoma associated with lymphangioleiomyomatosis on MR imaging (2005: 9b).
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Adult↗
Crohn's disease with life-threatening hemorrhage from terminal ileum: successful control by superselective arterial embolization.
A case of life-threatening lower gastrointestinal hemorrhage from Crohn's disease is reported. Several promising studies have recently been published that describe superselective embolization for the treatment of massive lower gastrointestinal hemorrhage in patients with bleeding colonic diverticular disease and angiodysplasia, and success rates of 74%-93% have been reported. But in patients with Crohn's disease, successful superselective embolization has rarely been reported. This is a report of successful superselective embolization in a patient with Crohn's disease; this should be the initial treatment of choice in Crohn's disease in an attempt to avoid surgical resection, because repeated resections predispose patients to the development of short-bowel syndrome.
Crohn Disease↗
Detection of common bile duct stones: comparison between endoscopic ultrasonography, magnetic resonance cholangiography, and helical-computed-tomographic cholangiography.
OBJECTIVES: New modalities, namely, endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), and helical computed-tomographic cholangiography (HCT-C), have been introduced recently for the detection of common bile duct (CBD) stones and shown improved detectability compared to conventional ultrasound or computed tomography. We conducted this study to compare the diagnostic ability of EUS, MRCP, and HCT-C in patients with suspected choledocholithiasis. METHODS: Twenty-eight patients clinically suspected of having CBD stones were enrolled, excluding those with cholangitis or a definite history of choledocholithiasis. Each patient underwent EUS, MRCP, and HCT-C prior to endoscopic retrograde cholangio-pancreatography (ERCP), the result of which served as the diagnostic gold standard. RESULTS: CBD stones were detected in 24 (86%) of 28 patients by ERCP/IDUS. The sensitivity of EUS, MRCP, and HCT-C was 100%, 88%, and 88%, respectively. False negative cases for MRCP and HCT-C had a CBD stone smaller than 5mm in diameter. No serious complications occurred while one patient complained of itching in the eyelids after the infusion of contrast agent on HCT-C. CONCLUSIONS: When examination can be scheduled, MRCP or HCT-C will be the first choice because they were less invasive than EUS. MRCP and HCT-C had similar detectability but the former may be preferable considering the possibility of allergic reaction in the latter. When MRCP is negative, EUS is recommended to check for small CBD stones.
Adult↗
Sciatic endometriosis diagnosed by computerized tomography-guided biopsy and CD10 immunohistochemical staining.
OBJECTIVE: To report a case of sciatic endometriosis diagnosed by computerized tomography (CT)-guided biopsy in combination with CD10 immunohistochemical staining. DESIGN: Case report. SETTING: University hospital. PATIENT(S): A 33-year-old Japanese woman complaining of right-sided sciatica. INTERVENTION(S): Transgluteal computerized tomography (CT)-guided needle biopsy of a mass in the course of the right sciatic nerve was conducted for a histologic diagnosis. MAIN OUTCOME MEASURE(S): Histologic study with hematoxylin and eosin staining and CD10 immunohistochemical staining was performed. RESULT(S): Computerized tomography-guided biopsy was performed without any complication. CD10 staining distinguished endometrial stromal cells. CONCLUSION(S): Computerized tomography-guided biopsy followed by CD10 immunohistochemical staining is a minimally invasive procedure for accurate diagnosis of sciatic endometriosis.
Adult↗
Pancreas duct abnormalities in patients with ulcerative colitis: a magnetic resonance pancreatography study.
BACKGROUND: The presumed etiology and prevalence of pancreatic abnormalities in patients with ulcerative colitis (UC) have been controversial. We conducted a controlled (cross-sectional) study of patients with UC compared with non-UC controls to determine the prevalence of pancreatic duct abnormalities in patients with UC and to determine if these are specific to UC using magnetic resonance cholangiopancreatography. METHODS: Magnetic resonance cholangiopancreatography was performed on 79 unselected patients with UC and 45 non-UC controls, without a history of pancreatitis attack, between February 2000 and May 2003. RESULTS: Among patients with UC, the prevalence of pancreatic duct abnormalities was 16.4% (95% confidence interval, 8.3%-24.6%): coexisting dilatation and narrowing of the main pancreatic duct were found in 5; diffuse narrowing of pancreatic ducts in 5; and dilatation of pancreatic ductal branches in 3. These abnormalities were compatible with chronic pancreatitis. Among the controls, no pancreatic duct abnormality was found. CONCLUSIONS: Changes in the pancreatic duct were found in approximately one-sixth of patients with UC, none of whom had a history of overt pancreatitis. These pancreatic duct abnormalities are likely to be specific to patients with UC.
Adolescent↗
Complications of percutaneous radiofrequency ablation for hepato-cellular carcinoma: imaging spectrum and management.
Percutaneous radiofrequency (RF) ablation is feasible for the treatment of unresectable hepatocellular carcinoma, and experience at the authors' institution during 5 years indicates that percutaneous RF ablation can be performed safely in most cases. However, early or late complications related to mechanical or thermal damage may be observed at follow-up examination. Complications may be classified in three groups: vascular (eg, portal vein thrombosis, hepatic vein thrombosis with partial hepatic congestion, hepatic infarction, and subcapsular hematoma), biliary (eg, bile duct stenosis and biloma, abscess, and hemobilia), and extrahepatic (eg, injury to the gastrointestinal tract, injury to the gallbladder, pneumothorax and hemothorax, and tumor seeding). Most complications can be managed with conservative treatment, percutaneous or endoscopic drainage, or surgical repair. Because an early and accurate diagnosis is necessary for proper management, radiologists should be familiar with the imaging features of each type of complication.
Aged↗
Administration of iodized oil resulted in impaired liver function due to enhanced portosystemic shunting.
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Aged↗
Contrast-enhanced MR angiography in rats with hepatobiliary contrast agents.
The aim of this animal study was to evaluate the feasibility of contrast-enhanced magnetic resonance (MR) angiography with two hepatobiliary contrast agents, Gd-DTPA-DeA and Gd-EOB-DTPA. Coronal images of the rat abdomen were acquired using a three-dimensional spoiled gradient recalled sequence before and after the administration of Gd-DTPA-DeA, Gd-EOB-DTPA, or Gd-DTPA. Four sets of postcontrast images were collected every 90 s. Contrast ratios were calculated for the abdominal aorta on the source images, and the retention index was defined as the ratio of the contrast ratio on the last imaging to that on the first postcontrast imaging. Partial minimum intensity projection (MIP) images covering the abdominal aorta were generated from the first and second postcontrast imagings, and the image quality was visually evaluated. The contrast ratio on the first postcontrast imaging was the highest for Gd-DTPA-DeA, followed by Gd-EOB-DTPA and Gd-DTPA. Retention indices were higher with Gd-DTPA-DeA than with Gd-EOB-DTPA and Gd-DTPA, implying a prolonged contrast effect with Gd-DTPA-DeA. On the MIP image from the first postcontrast imaging, delineation of the abdominal aorta tended to be better with Gd-DTPA-DeA and Gd-EOB-DTPA than with Gd-DTPA, and the difference was evident at low injection doses. Image quality for the second postcontrast imaging was higher with Gd-DTPA-DeA than with the other two agents, suggesting a longer imaging window for Gd-DTPA-DeA. In conclusion, Gd-DTPA-DeA and Gd-EOB-DTPA showed stronger contrast enhancement for the rat abdominal aorta and provided MR angiograms of higher image quality when compared with Gd-DTPA at the same injection dose. These hepatobiliary agents may make it possible to perform contrast-enhanced MR angiography even at a low injection dose.
Animals↗
Prolonged renal parenchymal retention of 99mTc mercaptoacetyltriglycine after nephron-sparing surgery.
OBJECTIVE: Nephron-sparing surgery is a treatment in which a part of a diseased kidney is resected and some parenchyma of the kidney is spared. Impairment of spared renal parenchyma after the surgery may cause prolonged prarenchymal retention in renal scintigraphy with Tc mercaptoacetyltriglycine (Tc-MAG3). The aim of this study was to determine whether or not parenchymal retention of Tc-MAG3 is prolonged after nephron-sparing surgery. METHODS: Twenty-two patients underwent a total of 29 Tc-MAG3 studies within 1 year after nephron-sparing surgery. In 17 patients (23 examinations) who had bilateral kidneys, the presence of diffuse prolongation of parenchymal retention was determined for the operated kidney. In all patients, the presence of regional prolongation around the surgical margin was assessed. RESULTS: Diffuse prolongation was observed in four of 10 examinations performed within 1 month after surgery and in none of 13 examinations performed later than 1 month after surgery. Regional prolongation was shown in 10 of 14 examinations performed within 1 month after surgery and in three of 15 examinations performed later than 1 month after surgery. In five patients who were studied both prior to and later than 1 month after surgery, regional prolongation was noted on the first study. On the second study, regional prolongation was improved and initial renal uptake around the surgical margin was intensified. CONCLUSIONS: Renal parenchymal retention of Tc-MAG3 is frequently prolonged in the early period after nephron-sparing surgery. Renal scintigraphy with Tc-MAG3 may aid in characterizing acute renal damage after nephron-sparing surgery.
Adolescent↗
Biliary motor function in gallstone patients evaluated by fatty-meal MR cholangiography.
PURPOSE: To investigate the possibility of evaluating biliary motor function with magnetic resonance cholangiography (MRC). MATERIALS AND METHODS: Twenty patients with gallstones and 30 control subjects were studied using fatty-meal MRC. After baseline MRC, they were encouraged to drink 250 mL of milk and underwent postprandial MRC every 10 minutes for 60 minutes. Postprandial changes in gallbladder volume and the diameter of the common duct were assessed as indicators of gallbladder contractility and biliary obstruction, respectively. Postprandial dilatation at 60 minutes was considered indicative of persistent biliary obstruction. RESULTS: Gallbladder ejection fraction was calculated at 66.0% +/- 12.2% (range, 40.3%-88.6%) in the controls. Gallbladder volume expressed as a percentage of the baseline value was significantly larger at 20-60 minutes in the gallstone patients than in the controls. Gallbladder ejection fraction varied widely (mean, 46.4% +/- 24.4%; range, 2.8%-81.5%) and was significantly reduced in comparison with that of the controls (P < 0.01). In two gallstone patients with co-existing ductal stones, transient postprandial dilatation associated with ampullary impaction was observed. Persistent biliary obstruction was not indicated in any subjects. CONCLUSION: The results of this study suggest the feasibility of fatty-meal MRC, as well as its potential for evaluating biliary motor function.
Adult↗
Phantom and animal studies of a new hepatobiliary agent for MR imaging: comparison of Gd-DTPA-DeA with Gd-EOB-DTPA.
PURPOSE: To investigate the characteristics of Gd-DTPA-DeA as a hepatobiliary contrast agent for MR imaging in comparison with those of Gd-EOB-DTPA. MATERIALS AND METHODS: We undertook phantom experiments to assess T1 relaxivity for Gd-DTPA-DeA, Gd-EOB-DTPA, and Gd-DTPA in human plasma. For Gd-DTPA-DeA and Gd-EOB-DTPA, we evaluated the contrast effect in rats using an SPGR sequence. The contrast ratios of liver and abdominal aorta were measured up to 21 minutes after intravenous administration of the agents. Visualization of the bile duct and renal pelvis was also assessed. RESULTS: In human plasma, T1 relaxivity was similar for Gd-DTPA-DeA and Gd-EOB-DTPA, and higher than those for Gd-DTPA. Whereas the contrast ratio of liver peaked about five minutes after the injection of Gd-EOB-DTPA and was followed by a subsequent decline, a continuous rise was shown for Gd-DTPA-DeA, resulting in a larger maximal contrast effect. Contrast ratios of the abdominal aorta were larger for Gd-DTPA-DeA. Biliary excretion was observed for both agents but occurred earlier with Gd-EOB-DTPA. While renal excretion was shown for all rats three minutes after the injection of Gd-EOB-DTPA, it was not observed for Gd-DTPA-DeA. CONCLUSION: Gd-DTPA-DeA may be used as a hepatobiliary contrast agent and shows different pharmacokinetics from Gd-EOB-DTPA.
Animals↗