Patrice M. Bret

Palliative Treatment of Painful Bone Metastases with MR Imaging–guided Focused Ultrasound

PURPOSE To evaluate the safety and initial efficacy of magnetic resonance (MR) imaging-guided focused ultrasound for the palliation of pain caused by bone metastases in patients in whom standard available treatments had been ineffective or not feasible. MATERIALS AND METHODS Informed consent was obtained in 11 patients (seven women, four men; average age, 58.6 years) with pain related to non-weight-bearing bone metastases who were subsequently treated with MR imaging-guided focused ultrasound in this research and ethics board-approved study. Efficacy was evaluated by changes in visual analog scale (VAS) scores, in pain medication usage, and in quality of life. Safety of the device was evaluated by recording incidence and severity of treatment-related adverse events up to 3 months after treatment at physical examination and follow-up imaging. Follow-up imaging included contrast material-enhanced MR imaging and unenhanced computed tomography (CT) 1 month after treatment and contrast-enhanced MR imaging 3 months after treatment. Imaging studies were assessed for changes in tumor imaging characteristics and any adverse events associated with MR imaging-guided focused ultrasound treatment. RESULTS Twelve lesions were treated in 11 patients. All patients reported progressive decrease in pain in treated regions and reduction in pain medication usage during the 3-month follow-up period. VAS scores averaged 6.0 before treatment and decreased to 0.5 at 3 months (decrease in pain scores, 92%; P < .01). No adverse events were recorded at physical examination or follow-up imaging. The majority of patients with osteolytic metastases had varying degrees of necrosis of the enhancing medullary component of the metastasis at follow-up enhanced MR imaging. Five patients had increased bone density at the site of treated osteolytic metastases at follow-up unenhanced CT at 3 months after MR imaging-guided focused ultrasound. CONCLUSION MR imaging-guided focused ultrasound is a noninvasive technique that allows palliative treatment of bone metastases with little or no morbidity.

Hepatocellular carcinoma: diagnosis by percutaneous fine needle biopsy.

One hundred fifty-nine cases of hepatocellular carcinomas (HCCs) were reviewed from a series of 1060 cases of percutaneous fine needle biopsies of the liver. The biopsies were performed under ultrasonic guidance using a 22-gauge needle with a beveled tip. Specimens were obtained from the lesion and from areas of normal-appearing liver for comparison. Two sets of slides were prepared for Papanicolaou and Giemsa staining. In 147 cases (92%), the diagnosis of malignancy was established. In 134 cases (84%), the specific diagnosis of HCC was made. Fifty-four percent of the HCCs were well differentiated without cytonuclear abnormalities. In these cases, the diagnosis was made by comparison of specimens from the tumor with those obtained from the normal liver. Thirty-seven percent of the HCC were moderately differentiated with cytonuclear abnormalities. Nine percent of the HCCs were poorly differentiated, and in these cases, identification of glycogen on periodate-Schiffs procedure staining permitted differentiation from a metastatic tumor. In 9 cases, the aspirate was inadequate: there was insufficient tissue in 3 cases and the lesion was missed in the 6 other cases. In 3 cases, a biopsy of normal liver was not obtained and the diagnosis of HCC could only be suspected. Significant bleeding after biopsy occurred in 4 of 1060 cases, all with HCC.

Radiotherapy of high bile duct carcinoma using intracatheter iridium 192 wire

The authors developed an original procedure of endocurietherapy of high bile duct carcinoma. An iridium 192 wire is inserted into either a percutaneous transhepatic catheter or a surgically implanted external diversion catheter. The delivered dose varies between 10 and 60 Gy at 1 cm from the wire. Four of the seven patients analyzed also received external irradiation. There were no systemic or local complications. All patients experienced symptomatic relief and four are alive with no evidence of disease. This well‐tolerated procedure permits symptomatic palliation without excessive side effects for the patient. In some cases, a curative effect can be expected.

Hepatic CT enhancement: effect of the rate and volume of contrast medium injection in an animal model

AbstractBackground: To evaluate the relative effect of rate of injection and volume of contrast medium on aortic, portal, and hepatic enhancement during computed tomography (CT). Methods: Thirty-eight nonincremental CT examinations were performed in three mini-pigs by using a combination of three different volumes (1.5, 2, and 3 mL/kg) and five different rates (1.5, 3, 4.5, 6, and 7.5 mL/s) of contrast material injection. Time-density enhancement curves of the aorta, portal vein, and liver were plotted over time for each rate of injection, each volume of contrast, and each volume–rate combination. In addition, aortic, portal, and liver peak enhancements, time-to-peak enhancements, optimal scanning intervals, and contrast enhancement indices were calculated for each volume–rate combination. Results: Higher rates of injection increased peak aortic enhancement but had no effect on peak portal or hepatic enhancement. This result may be explained by the dilution of the bolus of contrast medium in the splanchnic circulation. When the results of a 6-mL/s injection of 1.5 mL/kg of contrast material were compared with a 3-mL/s injection of 2 mL/kg, maximum aortic enhancement increased by 32%, whereas maximum liver enhancement decreased by 35%. Conclusion: An increase in the rate of contrast injection results in an increase of peak aortic enhancement even when the total iodine load is decreased. However, an increase of the rate of contrast injection does not increase maximum liver enhancement, which is related to the total iodine dose injected. Therefore, one cannot compensate a decrease in the iodine load by an increase in injection rate in contrast-enhanced CT of the liver.

Percutaneous fine-needle aspiration biopsy of the pancreas resulting in death

Percutaneous fine-needle aspiration biopsy of the pancreas presents a slightly higher risk of complications than does biopsy of other abdominal organs, occasionally leading to death. In the case we discuss, computed tomographic (CT)-guided percutaneous fine-needle aspiration biopsy of a pseudolesion of the uncinate process resulting in hemorrhagic pancreatitis and the death of the patient within 1 week of the procedure.

Enhancement patterns of renal masses during multiphase helical CT acquisitions

AbstractBackground: To describe the appearance of renal masses during multiphase helical computed tomography (CT) acquisition and evaluate the impact of a cortical nephrographic phase on diagnosis. Methods: The CT examinations of 33 patients with 37 lesions [18 renal cell carcinomas (RCC), nine solid tumors, 10 cystic lesions] were reviewed to characterize renal masses during four phases of CT scanning: plain, cortical nephrographic, tubular nephrographic, and pyelographic. Two reviewers analyzed all lesions on the complete data set, and a third reviewer analyzed three combinations of images separately: (1) plain and tubular nephrographic phases, (2) plain and cortical nephrographic phases, and (3) three phases combined. Receiver operating characteristics (ROC) curves were generated to determine the respective value of each combination in lesion characterization. Results: During the cortical nephrographic phase, hyperdensity of solid renal masses was 100% specific and 22% sensitive for RCC, whereas combining hyperdense and isoattenuating heterogeneous masses was 91% specific and 56% sensitive. ROC curves demonstrated a sensitivity of 85%, 90%, 100% for the three combinations, respectively, with a constant specificity of 88% for diagnosing RCC. Conclusion: The cortical nephrographic phase is useful to characterize renal masses and should be included in the routine helical CT protocol.

Incidence of portal vein thrombosis complicating liver metastasis as detected by duplex ultrasound.

In a prospective study of 100 patients with liver metastasis using real‐time ultrasound, 8 patients (8%) were found to have portal vein thrombosis (PVT). Sixty seven of these patients, which included all with PVT, also underwent duplex examination. Pulsed Doppler showed absent flow in 4 of 8 patients, indicating complete obstruction. The other 4 showed different degrees of flow suggesting incomplete obstruction or collateral formation. We conclude that PVT complicating liver metastasis is not a rare finding.

Obstructive jaundice by a dissecting aneurysm of celiac axis and hepatic artery

SummaryWe report a case of dissecting aneurysm of the celiac axis and hepatic artery resulting in obstructive jaundice. The aneurysm was demonstrated both by ultrasound and by angiography, but the associated aortic dissection was apparent only on CT scan. The patient was treated with percutaneous transhepatic biliary drainage, surgical exclusion of the aneurysm by ligation, and progressive dearterialization of the hepatic artery.

Design and implementation of World Wide Web-based tools for image management in computed tomography, magnetic resonance imaging, and ultrasonography.

This article describes our experience in developing and using several web-based tools to facilitate access to and management of images from inside and outside of our department. Having recently eliminated film in ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), a simple method was required to access imaging from computers already existing throughout the hospital. The success of the World Wide Web (WWW), the familiarity of endusers with web browsers, and the relative ease of developing user interfaces virtually dictated that such an approach be pursued in our case. The resulting web-based tools allow validated users to search our Digital Imaging and Communications in Medicine (DICOM)-compliant archive servers for specific exams; to download image data from a remote site; to request the retrieval of data from long-term storage; to view images, and to perform certain DICOM routing operations. The existing infrastructure of the Internet has allowed us to develop a low-cost system capable of being used for teleradiology. Since low-level, machine-specific interface programming was avoided, these tools were developed rapidly and are easily adapted. The familiarity of browser-based interfaces has facilitated user acceptance, and the benefit of platform independence minimizes software portability concerns.

Risks Associated with Intestinal Perforation during Experimental Percutaneous Drainage

RATIONALE AND OBJECTIVES The authors evaluated the complication rate of transgressing small or large bowel during intraperitoneal percutaneous catheter placement in an animal model. METHODS Twenty-four 8-F catheters were percutaneously placed through the small and large bowel of 12 pigs. In six animals, the catheters were left in place until autopsy, whereas in the remaining six animals, the catheters were withdrawn 5 days after insertion. Computed tomographic (CT) scans were performed on days 1 and 8 after catheter placement in pigs in which catheters were in place at time of autopsy, and on days 1, 5, and 8 in pigs in which catheters were removed. RESULTS CT results showed no abscess or peritoneal effusion, but a pneumoperitoneum was present in four animals whose signs resolved on subsequent studies. Autopsy was performed in all animals 9 days after catheter placement. No clinical complication occurred, and no significant biochemical changes were observed. At autopsy, no bowel leakage, peritonitis, or abscess was visible. Bowel and peritoneal adhesions were found around the catheter tract. There was no difference between the animals with catheters in place at the time of autopsy and the animals without catheters. There also was no difference between the group of animals with small or large bowel transgression. CONCLUSION This study suggests that traversing the intestine during percutaneous placement of an intra-abdominal catheter should not be considered an absolute contraindication when no other approach is available.