Yoichiro Suetomi

Transient portal vein thrombosis caused by radiofrequency ablation for hepatocellular carcinoma

branch of the left portal vein. Dynamic CT showed the lesion to be an inhomogeneous enhancement during the arterial phase, with slightly hyperto low-attenuation during the portal venous phase and delayed phase, respectively, with no invasion into the portal vein (Fig. 1). Contrast-enhanced harmonic US with intravenous administration of Levovist (SHU-508, Schering, Germany) and hepatic angiography all demonstrated a hypervascular mass with dense tumor stain. A diagnosis of HCC was made on the basis of the clinical data and imaging findings. Because of his advanced age and liver dysfunction, the patient underwent US-guided percutaneous RFA. The treatment was performed by using an RF generator (RTC 2000; Radiotherapeutic, Sunny Vale, CA, USA) and a LeVeen (Radiotherapeutic, Sunny Vale, CA, USA) needle (15-gauge, 25-cm-long insulated cannula, containing ten individual hook-shaped electrode tines with an array diameter of 3.5 cm). The needle was inserted first into the deep and then into the middle and superficial parts of the tumor under the guidance of real-time US. The initial emission power was set at 50 W, and then gradually increased to 90W and lasted until the tissue impedance value was up to 100%. Dynamic CT scan performed 6 days later showed a complete response, with a coagulation area about 5cm in diameter. In addition, there was a small hypodense area within the first branch of the left portal vein during the portal venous phase (Fig. 2), suggesting the formation of portal vein thrombosis. Considering that the patient appeared to have no symptoms after treatment, no special medical treatment was given to the patient. On a follow-up CT scan performed 3 months after RFA, the portal vein thrombosis had disappeared spontaneously (Fig. 3). The patient is doing well. Portal vein thrombosis is usually a complication of pre-existing cirrhosis, abdominal malignancy, or abdominal inflammation.3 It was also reported as a complication following splenectomy, which might be caused by Radiofrequency ablation (RFA) is an effective and safe treatment option for patients with focal liver tumors. Procedure-related complications were minimal1 and mild. Pleural effusion, subcapsular and subcutaneous hematoma, and perihepatic abscess have been reported as complications of RFA.1,2 However, portal vein thrombosis caused by RFA is rarely reported, because heat injury to the vessel is believed to have a minimal risk due to the cooling effect of RFA. Herein, we present details of a patient with transient portal vein thrombosis that followed RFA treatment for hepatocellular carcinoma (HCC) and disappeared spontaneously. A 78-year-old man was admitted to our hospital for further examination and treatment of a liver mass detected by follow-up abdominal computed tomography (CT) scan for hepatitis C-related cirrhosis in October 2000. There were no special abnormal findings on physical examination. Laboratory tests showed leukopenia (white blood cell count, 2100/μl), with mild anemia (red blood cell count, 3.47 106/μl; hemoglobin, 11.8 g/dl) and decreased platelet count (5.9 104/μl); and a low level of serum total protein (5.8 g/dl) with mild elevation of serum total bilirubin (1.7mg/dl) and γ-glutamyl transpeptidase (γ GTP; 126IU/l). Coagulation test results were normal. Serum levels of protein induced by vitamin K absence (PIVKA-II) were elevated (2390 mAU/ml; normal range, 40 mAU/ml). Values of alpha-fetoprotein (AFP) and lens culinaris agglutinin AFP (AFP-L3) were within normal ranges. Serum antibodies for hepatitis C were positive. The patient had had a history of hepatitis C-related cirrhosis for about 10 years. Abdominal ultrasonography (US) revealed a hypoechoic lesion 3 cm in diameter in the medial segment of the left liver lobe (segment 4) near the first

Contrast advanced dynamic flow imaging and contrast pulse subtraction imaging: Preliminary results in hepatic tumors

PurposeTo investigate the usefulness of contrast advanced dynamic flow imaging and contrast pulse subtraction imaging in the intranodular hemodynamics of hepatic tumors.Materials and MethodsTen patients underwent contrast advanced dynamic flow imaging and contrast pulse subtraction imaging using Levovist®, a microbubble contrast agent. Fourteen hepatic tumor nodules were studied: 9 were hepatocellular carcinoma, 1 metastasis, 1 hemangioma, 1 adenomatous hyperplasia, and 2 metastatic lymph nodes of hepatocellular carcinoma. Real-time scanning of contrast advanced dynamic flow imaging and intermittent interval-delay scanning of contrast pulse subtraction imaging were carried out in the early arterial phase, the late vascular phase, and the postvascular phase. The results obtained from contrast advanced dynamic flow imaging and contrast pulse subtraction imaging were compared with those obtained by precontrast power Doppler imaging and three-phase dynamic CT, respectively.ResultsThe rate of detection of intranodular vascularity by contrast advanced dynamic flow imaging (93%) or contrast pulse subtraction imaging (93%) was significantly higher than that of precontrast power Doppler imaging (29%) and was as high as that of dynamic CT. Characteristic intranodular hemodynamics were detected in hepatocellular carcinoma, metastasis, hemangioma, and adenomatous hyperplasia with typical appearance of an intranodular blood vessel image in the early arterial phase, a parenchymal stain image in the late vascular phase, and a perfusion defect image in the post-vascular phase.ConclusionContrast advanced dynamic flow imaging and contrast pulse subtraction imaging clearly show the intranodular hemodynamics in hepatic tumors.

Detection of tumor vascularity in hepatocellular carcinoma with contrast-enhanced Dynamic Flow imaging: Comparison with contrast-enhanced power Doppler imaging

Objective: To compare the effectiveness of contrast-enhanced Dynamic Flow imaging and contrast-enhanced power Doppler imaging using Levovist® as a microbubble contrast agent in evaluating intratumoral vascularity in hepatocellular carcinoma (HCC).Materials and Methods: Twenty-nine patients with 54 hepatocellular carcinoma nodules (before treatment, 31; after treatment, 23) were studied with both Dynamic Flow and power Doppler imaging with intravenous injection of Levovist®. Tumor vascularity was categorized as 0, no blood flow signals within the tumor; 1, dotlike blood flow signals within the tumor; 2, moderate blood flow signals within the tumor; and 3, abundant blood flow signals within the tumor. Detectability of intratumoral vascularity of hepatocellular carcinoma in three groups based on tumor depth, blooming and noise artifacts on contrast-enhanced Dynamic Flow and contrast-enhanced power Doppler imaging were also compared with results obtained using dynamic CT as a the gold standard. The effectiveness of contrast-enhanced Dynamic Flow and contrast-enhanced power Doppler imaging in assessing therapeutic effect were compared at the same time.Results: The ability of contrast-enhanced Dynamic Flow Doppler imaging to detect tumor vascularity in the superficial and intermediate hepatocellular carcinoma groups was close to that of contrast-enhanced power Doppler imaging (p>0.05). However, contrast-enhanced Dynamic Flow imaging demonstrated tumor parenchymal stain in 28 hepatocellular carcinoma nodules (61%), which was not detected by contrast-enhanced power Doppler imaging. Further, significantly fewer artifacts appeared in contrast-enhanced Dynamic Flow imaging than in contrast-enhanced power Doppler imaging (p<0.001). In assessing therapeutic response, the sensitivity of contrast-enhanced Dynamic Flow imaging was similar to that of dynamic CT. In deep areas, however, those more than 6 cm below the surface of the body, contrast-enhanced Dynamic Flow imaging was less sensitivity than contrast-enhanced power Doppler imaging (p=0.005).Conclusion: Contrast-enhanced Dynamic Flow imaging provides an effective approach to assessing intratumoral vascularity and therapeutic response in HCC lesions situated less than 6 cm from the surface of the body. It is superior to contrast-enhanced power Doppler imaging in its ability to detect tumor parenchymal stain and production of fewer artifacts.

PANCREATIC DUCTAL DRAINAGE BY ENDOSCOPIC ULTRASOUND‐ASSISTED RENDEZVOUS TECHNIQUE FOR PAIN CAUSED BY DUCTAL STRICTURE WITH CHRONIC PANCREATITIS

With the advances in echoendoscopes, the frontier of therapeutic endoscopic ultrasonography (EUS) is expanding. A 50‐year‐old male presented to us with unrelenting pain following an episode of alcoholic pancreatitis. Imaging studies revealed evidence of pancreatic ductal hypertension with a pseudocyst in the head of the pancreas. Following unsuccessful attempts at drainage of the pancreatic duct (PD) via the minor or major papilla at endoscopic retrograde cholangiopancreatography, he underwent endoscopic ductal drainage with the EUS‐assisted rendezvous technique. The PD was punctured under the guidance of EUS. A guidewire was then introduced into the PD and was guided into the duodenal lumen through the minor papilla. The tip of the guidewire was grasped with forceps coming out of a duodenoscope introduced instead of the echoendoscope. A pancreatic stent was inserted over the guidewire across the minor papilla. After the endoscopic pancreatic stenting, the patient achieved symptomatic relief.

Contrast-enhanced agent detection imaging: Early experience in hepatocellular carcinoma

Purpose: To investigate the usefulness of contrast-enhanced Agent Detection Imaging in assessing intratumoral vasculature in hepatocellular carcinoma.Materials and Methods: Fourteen hepatocellular carcinoma nodules in 11 patients were studied with contrast-enhanced Agent Detection Imaging, a wide-band color Doppler imaging method, employing, Levovist®, a microbubble contrast agent. High acoustic power was used with contrast-enhanced Agent Detection Imaging. Intermittent transmission of Agent Detection Imaging was performed at intervals of 200, 500, and 350 milliseconds in the early arterial phase (10 to 40 seconds), late vascular phase (1 to 3 minutes) and postvascular phase (5 to 7 minutes), respectively. The results were compared with those of three-phase dynamic CT.Results: Intratumoral blood vessels in the early arterial phase and tumor parenchymal stain in the late vascular phase were depicted in 12 (88%) of the 14 hepatocellular carcinoma nodules, while all nodules were demonstrated as perfusion defect in the postvascular phase on contrast-enhanced Agent Detection Imaging. The results of Agent Detection Imaging, that were compared with those of dynamic CT, were all 100% : diagnostic sensitivity (12/12), specificity (2/2), and accurary (14/14).Conclusion: Contrast-enhanced Agent Detection Imaging is a promising method for depicting intratumoral vascularity in hepatocellular carcinoma.

Value of new contrast harmonic technique for detecting tumor vascularity in hepatocellular carcinoma: Preliminary results.

Purpose: To investigate the value of a new wide-band contrast harmonic imaging method in depicting intratumoral vascularity in hepatocellular carcinoma.Materials and Methods: Twenty-two patients with 28 hepatocellular carcinoma nodules evaluated with Contrast Harmonic Echo, a new wide-band harmonic imaging method, using Levovist® as a contrast-enhancing agent. Intermittent imaging was carried out in the early arterial phase for 10 to 40 seconds, in the late vascular phase for 1 to 2 minutes, and in the postvascular phase for 5 to 7 minutes. Subtraction images were obtained using the multishot method during the late vascular phase. The ability of Contrast Harmonic Echo imaging to detect vascularity in hepatocellular carcinoma was compared to that of unenhanced color Doppler imaging by analzing results obtained using dynamic CT as a gold standard.Results: Contrast harmonic Echo imaging detected intratumoral vessels, tumor parenchymal stain, and perfusion defect in the early arterial phase, the late vascular phase, and the postvascular phase, respectively. In the late vascular phase, the subtraction image clearly delineated the tumor parenchymal strain. Intratumoral vascularity was detected in 25 (89%) of the hepatocellular carcinoma nodules by Contrast Harmonic Echo, compared with 15 (54%) when color Doppler imaging was used (p<0.05). The diagnostic sensitivity, specificity, and accuracy of Contrast Harmonic Echo were 96.1%, 100% and 96.4%, respectively, corresponding to results obtained using dynamic CT.Conclusion: Contrast Harmonic Echo imaging is superior to unenhanced color Doppler imaging in depicting intratumoral vessels and parenchymal stain, and agrees closely with results obtained with three-phase dynamic CT.

Assessment of image quality of contrast-enhanced power doppler imaging in hepatocellular carcinoma with the personal ultrasound imager: Comparison with the conventional machine.

ObjectiveTo evaluate the usefulness of contrast-enhanced power Doppler imaging with the personal ultrasound imager in depicting intratumoral vascularity in hepatocellular carcinoma.Materials and MethodsContrast-enhanced power Doppler imaging was used to examine 52 hepatocellular carcinoma nodules in 29 patients, using both the personal ultrasound imager and the conventional ultrasound machine in combination with intravenous injection of Levovist®. Results obtained using dynamic CT were used as the gold standard. The ability of the personal ultrasound imager to detect intratumoral vascularity was compared with that of the conventional ultrasound machine, and the usefulness of the personal ultrasound imager in assessing therapeutic effect after nonsurgical treatment was compared with that of dynamic CT at the same time.ResultsThe personal ultrasound imager and the conventional ultrasound machine, using the fundamental power Doppler imaging mode (p=0.13) and contrast-enhanced power Doppler imaging mode (p=0.41), did not differ significantly in depicting the vascularity of the 52 hepatocellular carcinomas. The sensitivity, specificity, and accuracy of contrast-enhanced power Doppler imaging on the personal ultrasound imager were 95.5%, 87.5%, and 94.2%, respectively, in close agreement with results obtained using dynamic CT. After the 22 hepatocellular carcinomas were treated, the personal ultrasound imager provided diagnostic accuracy of 90.9% on residual tumors when compared with results obtained by dynamic CT, and results obtained using the conventional ultrasound machine were similar.ConclusionThe highly portable personal ultrasound imager using Levovist®-enhanced power Doppler imaging can clearly depict the intratumoral vascularity of hepatocellular carcinoma nodules before and after treatment, achieving results very close to those obtained using the conventional diagnostic ultrasound machine. The personal ultrasound imager is an alternative to the conventional ultrasound machine for depicting tumor vascularity.

Evaluation of Image Quality of Personal Ultrasound Imager: Comparison with the Conventional Machine

ObjectiveTo determine if the image quality of a personal ultrasound imager (PUI) is as good as that of a conventional machine (CM).Materials and MethodsNinety patients were studied by the same operator using both the PUI and CM. The quality of the B-mode images obtained from these patients was scored 0, 1 or 2, defined as poor, fair, or good, respectively. Liver-tumor vascularity depicted by power Doppler imaging (PDI) and directional PDI (DPDI) was classified as 0, no blood signal; 1, dot-like blood signal within the tumor; 2, mild blood-flow signal within the tumor; and 3, abundant blood-flow signal within the tumor.ResultsThe mean score of PUI and CM B-mode image quality was 7.47±0.92 and 7.54±0.99 (mean±SD), respectively (p=0.531). On PDI, grade of vascularity of the liver tumors determined with the PUI was 4.44 and 4.68 in those determined with the CM (p=0.78). On DPDI, tumor vascularity was 3.12 when scored by the PUI and 4.29 when scored with the CM (p=0.03). The qualities of images acquired by the PUI and CM were significantly correlated.ConclusionThe quality of B-mode images acquired using the PUI and CM are statistically the same, and they share a similar ability to detect intratumoral blood-flow signals on PDI. Because of its extreme portability, the PUI is expected to become a valuable diagnostic tool in the clinic.