Intraluminal calcification and occlusion of the abdominal aorta above the renal arteries.
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Adult↗
Biomedical subjects
C Charnsangavej
Publications and source records attributed to C Charnsangavej.
Segmental renal artery embolization in solitary renal carcinoma.
Segmental renal artery embolization was performed as an alternative method to treat solitary renal carcinoma in 2 patients who were poor surgical candidates. In the first patient, a recurrent renal carcinoma in a solitary kidney was selectively embolized. Tumor aggression was observed eighteen months later. Recanalization of the segmental artery and collateral from the capsular artery required a second embolization. In the second patient with a transitional cell carcinoma involving the lower half of the only functioning kidney, segmental renal artery embolization successfully controlled his persistent gross hematuria.
Adenocarcinoma↗
Displacement of the tail of the pancreas in the absence of the left kidney.
The tail of the pancreas may be displaced posteriorly and medially if the left kidney is small or absent. This variant can ben shown by computed tomography.
Adult↗
Occlusion of the right pulmonary artery by acute dissecting aortic aneurysm.
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Acute Disease↗
A large lumen microcatheter for oncologic intervention.
A newly available Tracker-325 catheter (Target Therapeutics, Fremont, CA, USA), modified from the Tracker-18 catheter, has the same outer diameter but a larger lumen. This catheter was used in 15 patients during a 7-month period for superselective arterial catheterization when conventional catheters could not be placed successfully. Arterial embolization (n = 7), chemoembolization (n = 5), and chemoinfusion (n = 3), were performed. The increased luminal diameter of the Tracker-325 allowed an increased flow rate for diagnostic arteriography, accommodated larger embolic particles, and improved the ability to achieve a super-selective position.
Angiography↗
Hepatic artery infusion and chemoembolization in the management of liver metastases.
Hepatic metastases rather than the primary neoplasm usually dictate the course of the disease and patient's survival. For unresectable disease, intraarterial infusion of chemotherapy, embolization, and chemoembolization are viable alternatives. Intraarterial therapy for hepatic metastases is based on the dual blood supply of the normal liver (portal vein, 75%, and hepatic artery, 25%) and that of the tumors (hepatic artery, 90%). Intraarterial infusion delivers a higher concentration of chemotherapy, whereas chemoembolization adds ischemia and increased contact time with the tumor. Selective vascular occlusion for infusion, redistribution of the blood supply and pulsatile flow enhance the delivery of therapeutic agents to the liver.
Antineoplastic Agents↗
Multidetector-row helical CT and advanced postprocessing techniques for the evaluation of pancreatic neoplasms.
An important feature of multidetector-row helical computed tomography (CT) is the increased speed of scanning that permits routine use of very thin collimation and acquisition of near isometric imaging data of the abdomen within the time span of a single breath-hold. The parallel escalation in the capabilities of workstations makes feasible the practical use of advanced postprocessing techniques to create high quality volumetric imaging. This article highlights the unique contributions of multidetector-row CT and advanced postprocessing techniques to the evaluation of the pancreas and peripancreatic vascular structures and their value in the diagnosis and staging of pancreatic neoplasms.
Adenocarcinoma↗
Use of thin-section, multidetector row helical CT images for coronal oblique reformations for optimal visualization of structures in the hepatoduodenal ligament.
Multidetector row computed tomography (CT) can acquire abdominal images of unprecedented thinness in a single breath-hold. This study investigated whether acquiring source axial images at 1.25 mm as opposed to 2.5 mm would result in a perceptible difference in image quality for coronal oblique reformations. Similarly, the hypothesis that a slice pitch of 3:1 would be superior to 6:1 was evaluated. Twenty-nine CT studies were retrospectively evaluated. The images were divided into four groups: 1.25-mm axial images, pitch 3:1; 2.5-mm axial images, pitch 3:1; 1.25-mm axial images, pitch 6:1; and 2.5-mm axial images, pitch 6:1. Three radiologists evaluated by consensus the coronal oblique reformations for overall image quality and image quality of structures in the hepatoduodenal ligament and of nodal groups. Use of 1.25-mm rather than of 2.5-mm source axial images resulted in statistically significant better scores for overall image quality and visualization of the hepatic artery, portal vein, pancreatic duct, and nodal groups. However, a pitch of 3:1 rather than of 6:1 did not result in significant differences in ratings of image quality. Use of 1.25-mm rather than of 2.5-mm source axial images improves image quality when creating coronal oblique reformations for abdominal anatomy.
Adult↗
Vascular involvement in pancreatic adenocarcinoma: reassessment by thin-section CT.
We defined computed tomographic (CT) criteria of vascular involvement by pancreatic carcinoma and used these criteria to assess vascular involvement in 56 patients with pancreatic adenocarcinoma. CT of the pancreas was performed at 1.5-mm section thickness and 5-mm section intervals during a bolus phase of intravenous contrast enhancement. The type of vascular involvement was correlated with surgical and pathologic findings. When there was fat-plane (type A) or normal pancreatic parenchyma (type B) separating the tumor from adjacent vessels, the tumor could be resected without venous resection in 21 of 22 patients (95%). When the tumor was inseparable from the vessels but the points of contact formed a convexity against the vessel (type C), CT was not reliable in predicting whether or not the tumor was fixed against the vessel. When the tumor was partially encircling (type D) the vessel, the tumor was fixed against the vessels in most cases. The resectable rate was 47%, but resection would also require venous resection. When the tumor was completely encircling (type E) or occluding (type F) the vessel, all tumors were not resectable with a negative margin. Thin-section CT with bolus intravenous contrast enhancement improved the ability to assess vascular involvement in pancreatic adenocarcinoma.
Adenocarcinoma↗
Magnetic resonance imaging and computed tomography appearance of asymptomatic paravaginal cysts.
The magnetic resonance imaging (MRI) and computed tomography (CT) appearance of 18 paravaginal cysts was reviewed. On MRI, serious cysts were hypointense on T1-weighted and hyperintense on T2-weighted images. Cysts presumed to contain proteinaceous material were hyperintense on T1-weighted and T2-weighted sequences while hemorrhagic cysts exhibited varying stages of hemorrhage. On CT, a high attenuation cyst was presumed to contain proteinaceous material or hemorrhage. MRI and CT examination may reveal paravaginal cysts; their varied appearance must be recognized to avoid confusion with other lesions.
Adult↗
Intraperitoneal catheters: percutaneous placement with fluoroscopic guidance.
PURPOSE: The authors reviewed their experience with percutaneous placement of catheters into the peritoneal cavity for the administration of intraperitoneal chemotherapy to determine if their approach resulted in a lower complication rate than the reported 12%-16% rate and to demonstrate the technical advantages over surgically placed catheters. PATIENTS AND METHODS: Seventy-six patients with gastrointestinal or gynecologic malignancies underwent 152 procedures during a 20-month period. The catheters were used to deliver antineoplastic agents and, in some patients, to drain ascites. Catheter insertion was performed with local anesthesia and a modified Seldinger technique. A 5-F catheter was used in 89% of procedures; in the remainder, the catheter was of a larger caliber. RESULTS: The procedure was successful in 145 (95%) instances and failed in seven (5%) attempts because of peritoneal adhesions. The catheters remained in place for less than 2 days in 56%, 2-10 days in 25%, and more than 10 days in 19% of patients. One catheter remained in place for 15 weeks. Complications occurred in seven procedures (5%). Four cases of mild peritonitis responded to a brief course of intravenously administered antibiotics, and severe pain in two patients required premature catheter removal. A single case of inadvertent transcolonic catheter placement occurred without adverse sequelae to the patient. CONCLUSIONS: Intraperitoneal catheterization can be performed with local anesthesia by using a simple technique with a very low complication rate. The catheters can remain in place for prolonged periods without significant risks.
Adult↗
Preliminary experimental evaluation of temporary segmental hepatic venous occlusion: angiographic, pathologic, and scintigraphic findings.
PURPOSE: Pigs were used to evaluate temporary segmental hepatic venous occlusion as a means of improving the selective delivery of therapeutic agents within the liver. MATERIALS AND METHODS: Hepatic angiography and scintigraphy were performed alone and in combination with hepatic venous occlusion. RESULTS: Arteriograms obtained during venous obstruction demonstrated a greater number of peripheral arterial branches in the occluded area compared with the nonoccluded areas. A prolonged hepatogram showing hepatofugal opacification of the portal branches was observed in the occluded area. Microscopically, mild congestion of the sinusoids and central veins was seen immediately after 60-minute occlusion, but these changes were not evident 2 hours after balloon deflation. Severe congestion and focal hemorrhage were found in the occluded segment of the liver 2 hours after 90-minute venous occlusion. When the right or left hepatic vein was occluded during hepatic arterial infusion of technetium-99m macroaggregated albumin, there was a significant (P < or = .05) increase in the amount of radioactivity measured in the obstructed segment and a significant (P < or = .05) decrease in that found in the nonoccluded regions. CONCLUSION: These results indicate that temporary segmental hepatic vein occlusion is safe for up to 60 minutes and may be clinically applicable as a means of improving the therapeutic index of agents within the liver when they are administered via concomitant hepatic arterial infusion.
Angiography↗
Major vascular resection as part of pancreaticoduodenectomy for cancer: radiologic, intraoperative, and pathologic analysis.
Intraoperative assessment is inaccurate in defining the relationship of a pancreatic head neoplasm to adjacent vascular structures. We evaluated the ability of preoperative contrast-enhanced CT to predict the need for vascular resection during pancreaticoduodenectomy and examined the resected vessels for histologic evidence of tumor invasion. During a 7-year period, 63 patients underwent pancreaticoduodenectomy with en bloc resection of adjacent vascular structures for a presumed pancreatic head malignancy. Clinical, radiologic, operative, and pathologic data were reviewed and analyzed. Fifty-six patients underwent resection of the superior mesenteric-portal vein confluence, three patients required inferior vena cava resection, and the hepatic artery was resected and reconstructed in eight patients. The operative mortality rate was 1.6%, and the overall complication rate was 22%. CT predicted the need for resection of the superior mesenteric or portal veins in 84% of patients. Pathologic analysis revealed tumor invasion of the vein wall in 71% of resected specimens. Tumor invasion of vascular structures adjacent to the pancreas can be predicted with preoperative CT and should alert the surgeon that vascular resection may be required. Histologic evidence of tumor cell infiltration of vessel walls was present in the majority of the resected specimens.
Adenocarcinoma↗
Poly(ethylene glycol)-conjugated anti-EGF receptor antibody C225 with radiometal chelator attached to the termini of polymer chains.
Several biological barriers, including significant liver uptake, limit the clinical application of radiolabeled antibodies in radioimmunoscintigraphy. Here, a general approach is described for radiolabeling of monoclonal antibodies conjugated with poly(ethylene glycol) (PEG). This strategy is demonstrated with C225, a monoclonal antibody directed against epidermal growth factor (EGF) receptor. We synthesized a heterofunctional PEG with one end attached to a radiometal chelator, diethylenetriaminepentaacetic acid (DTPA), and the other end to a protected thiol group, S-acetylthioacetate. After a deprotection step, the resulting DTPA-PEG-SH was conjugated to maleimide-activated C225 to yield DTPA-PEG-C225 conjugate. Characterization of DTPA-PEG-C225 with immunoprecipitation and Western blot analysis revealed that the conjugate was biologically active in binding to the EGF receptor in A431 cells. Competitive EGF receptor binding assay in MDA-MB-468 cells showed that DTPA-PEG-C225, with up to 60% of the amino groups in C225 substituted, retained 66% of C225's binding affinity. Moreover, DTPA-PEG-C225 with increasing degrees of NH(2) substitution from 20% to 70% retained the activity of C225 to induce apoptosis in DiFi cells. More importantly, DTPA-PEG-C225 demonstrated less nonspecific interaction than DTPA-C225. Pharmacokinetic analysis using (111)In-labeled compounds revealed narrower steady-state distribution of (111)In-DTPA-PEG-C225 than (111)In-DTPA-C225, probably due to reduced nonspecific binding of PEG-modified antibody to tissues. The terminal half-life (t(1/2,)(gamma)) of (111)In-DTPA-PEG-C225, 21.1 h, was shorter than that of (111)In-DTPA-C225, 52.9 h. These data suggest that (111)In-DTPA-PEG-C225 may provide better imaging characteristics than (111)In-DTPA-C225, and that using PEG as a linker between the monoclonal antibody and DTPA may be a promising strategy in optimizing the imaging characteristics of immunoscintigraphic agents.
Antibodies, Monoclonal↗
Computed tomography of choledochocele.
One case of choledochocele is reported, and the findings on CT, endoscopic retrograde cholangiopancreatography, and surgery are described. At surgery, in addition to choledochocele, a large choledochal cyst in the proximal common bile duct was discovered. Choledochocele can be diagnosed by CT and can be recognized by the finding of a cystic mass contiguous with the distal common bile duct that invaginates into the contrast-filled duodenum.
Adult↗
Metastatic adnexal trophoblastic neoplasm: contribution of MR imaging.
We report a case of pathologically proven metastatic trophoblastic neoplasm involving the adnexa which occurred after dilatation and curettage and chemotherapy. Duplex doppler ultrasound demonstrated increased vascularity in the adnexa. Angiography was sensitive but did not decisively distinguish between tumor in the adnexa and arteriovenous fistula in the uterus. In addition to abnormal vascularity, magnetic resonance also showed foci of abnormal signal in the adnexa not seen in the uterus and correctly suggested the presence of tumor.
Adnexal Diseases↗
MRI of extraskeletal osteosarcoma.
We report four cases of extraskeletal osteosarcoma of the thigh to illustrate MRI findings of this rare neoplasm. Calcifications or osteoid material were not discernible in these tumors on MRI or conventional radiography. Three tumors were well demarcated on MRI and corresponded to pseudoencapsulation on radiologic-pathologic correlation. These three tumors were heterogeneous in appearance and were hyperintense to muscle on T1-weighted imaging and demonstrated high signal intensity on T2-weighted imaging. In the fourth tumor, which occupied almost the entire thigh, MRI before and after intravenous gadopentetate dimeglumine administration revealed cystic, hemorrhagic, and solid components. Pathological examination revealed a cystic hemorrhagic cavity containing necrotic and viable tumor and a large solid tumor component. The MRI findings in extraskeletal osteosarcoma are non-specific. However, in the appropriate age group the differential diagnosis of a soft-tissue mass in the thigh should include extraskeletal osteosarcoma, even in the absence of radiographically discernible calcifications or osteoid material within the soft-tissue mass.
Aged↗
Spectrum of CT findings in nonmalignant disease of the adrenal gland.
Computed tomography (CT) plays a leading role in the evaluation of nonmalignant disease of the adrenal gland. CT is highly accurate in the localization of adrenal masses in patients with diseases associated with hyperfunctioning adrenal glands such as Cushing syndrome and Cushing disease, Conn syndrome, adrenal tumors leading to virilization or feminization, and pheochromocytomas. CT permits a specific diagnosis of acute or subacute adrenal hematoma and myelolipoma. Hematomas are round to oval and have increased attenuation (50-90 HU) that decreases on follow-up CT scans. Myelolipomas typically manifest as a well-defined suprarenal mass with an attenuation of-30 to -115 HU. Adrenal cysts are usually round to oval and manifest as a hypoattenuating mass with a smooth, thin wall. CT is useful in the evaluation of patients with Addison disease, particularly the subacute form secondary to tuberculosis or disseminated histoplasmosis. Findings typically include bilateral adrenal enlargement with a central necrotic area of hypoattenuation and peripheral enhancement. Thin-section unenhanced CT permits accurate measurement of attenuation and can be used to differentiate adrenal adenoma from metastasis in a cancer patient with an indeterminate mass: Attenuation of 10 HU or less usually indicates adenoma rather than cancer. If the mass is found incidentally at contrast material-enhanced CT, delayed scans obtained as early as 5-15 minutes after intravenous administration of contrast material appear to have comparable accuracy.
Addison Disease↗