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P C Freeny

Publications and source records attributed to P C Freeny.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Utility of bolus dynamic CT for the detection of hypervascular malignant hepatic tumors: mainly referring to the comparison with delayed phase contrast-enhanced CT].

In order to analyze the usefulness of dynamic contrast-enhanced CT, 84 patients who had hepatocellular carcinoma or suspected hypervascular metastases were studied with conventional incremental dynamic CT (CID-CT) or double helical CT (DH-CT). Delayed phase contrast-enhanced CT studies were consecutively performed in all patients. Thirty-six of 84 patients had malignant hepatic neoplasms; six had hepatocellular carcinoma and 30 had metastatic tumors. At first, the detectability of hepatic lesions was evaluated with bolus dynamic CT and delayed phase CT. Dynamic CT has detected more lesions than delayed CT. Some hepatic lesions described as isodensity were missed on CID-CT. Therefore, delayed phase CT cannot be eliminated when CID-CT is performed. Secondly, hepatic lesion detectability with CID-CT was compared with that of DH-CT. DH-CT did not miss the hepatic lesions picked up by delayed phase CT and was expected to provide excellent detectability of hypervascular hepatic neoplasms. In addition, first helical CT showed most hepatic lesions as areas of obvious hyperdensity, while CID-CT did not show their correct vascularities. So-called hypervascular hepatic tumors, however, were not always hypervascular and were demonstrated as areas of iso-hypodensity even on initial helical scanning. Second helical CT was useful to detect these so-called hypervascular, but actually hypovascular lesions. In conclusion, dynamic CT was helpful in detecting hypervascular hepatic malignant neoplasms, and DH-CT was more accurate than CID-CT for the detection of hepatic lesions and the evaluation of vascular lesion.

Adult↗
PubMed1995

Cross-sectional imaging of the pancreas.

CT is the primary modality for the evaluation of patients with pancreatic disease. A number of pitfalls can occur in interpretation of the scans, but most can be avoided by using state-of-the-art scanners and dynamic contrast enhancement techniques and by recognizing normal anatomic variants. However, in other cases, CT may show only nonspecific findings and a correct diagnosis can be reached only by utilization of additional imaging techniques or guided FNAB.

Humans↗
PubMed1995

Hepatic arterial anatomy: demonstration of normal supply and vascular variants with three-dimensional CT angiography.

Three-dimensional (3D) helical computed tomographic (CT) angiography is a promising method of determining vascular anatomy. This technique is useful in delineating the arterial anatomy of the liver, demonstrating the normal anatomy and vascular variants in a highly visual fashion. The "typical" hepatic arterial anatomy occurs in only 55% of the population, and numerous variants exist; the standard classification system for hepatic arterial anatomy includes 10 variations. After helical scanning, postprocessing with reconstruction algorithms such as shaded surface display and maximum-intensity projection provides highly graphic, easily understandable views of vascular anatomy. The 3D CT angiograms, with their global view of the anatomy and inherent advantage of volumetric rotation of the vascular system, are useful to surgeons and others with limited experience in interpreting axial anatomy. Determination of hepatic arterial anatomy with 3D CT angiography has already been shown to be clinically useful in patients being evaluated for liver transplantation.

Adult↗
PubMed1995

Helical CT during arterial portography: optimization of contrast enhancement and scanning parameters.

PURPOSE: To determine the optimal scanning parameters for helical computed tomography during arterial portography (CTAP) of the liver. MATERIALS AND METHODS: Single- and double-helix CTAP were performed in 11 and 20 adult patients, respectively, with 200 mL of contrast material (300 mg of iodine per milliliter) injected at a rate of 3 mL/sec via the superior mesenteric artery. Scanning delays were adjusted for single-helix CTAP so the last scan was obtained at 66 seconds. Delays were adjusted for double-helix CTAP so the last scan during the first helix (CTAP-1) was obtained 10 seconds before the end of the injection at 56 seconds and the first scan during the second helix (CTAP-2) was obtained at the end of the injection at 66 seconds. RESULTS: Single-helix CTAP scans were of poor quality owing to multiple perfusion abnormalities. Lesion detection for double-helix CTAP-1 was 93.2% and was 100% for CTAP-2, and CTAP-2 scans had significantly fewer perfusion abnormalities. CONCLUSION: A scanning delay of 60-66 seconds appears to be optimal. The CTAP-1 scans showed no useful information and need not be acquired.

Carcinoma, Hepatocellular↗
PubMed1995

Hepatic arterial anatomy in transplantation candidates: evaluation with three-dimensional CT arteriography.

PURPOSE: To assess the utility of three-dimensional (3D) hepatic helical computed tomographic (CT) arteriography as a replacement for conventional angiography in the evaluation of the arterial anatomy of patients being considered for liver transplantation. MATERIALS AND METHODS: Three-dimensional CT arteriograms were obtained in 115 patients. Seventeen patients also underwent conventional angiography, and 16 patients who did not undergo angiography underwent hepatic transplantation. RESULTS: Among the 3D CT arteriograms, 106 delineated the major arteries that supplied the liver. Nine were considered technical failures. In the 17 patients with angiographic correlation, there was only one marked disagreement with 3D CT arteriography. In the 16 patients with surgical correlation, no marked discrepancies were found. CONCLUSION: In transplantation candidates, successful 3D CT arteriography was as accurate as angiography in the assessment of hepatic arterial anatomy. It was also safer, more convenient, and more easily tolerated. Conventional CT plus 3D CT arteriography was only 25% as expensive as the cost of conventional CT and conventional angiography.

Adult↗
PubMed1995

Evaluation of a non-breath-hold MR cholangiography technique.

PURPOSE: To evaluate prospectively a non-breath-hold magnetic resonance (MR) cholangiographic technique. MATERIALS AND METHODS: Twenty-nine non-breath-hold, heavily T2-weighted, turbo spin-echo MR cholangiograms were obtained in 28 patients and compared with 28 direct cholangiographic studies in 24 patients. RESULTS: MR cholangiography showed the intrahepatic ducts (IHDs) within the peripheral third of the liver and within the four hepatic segments in 100% of cases with dilated ducts. IHDs were seen in the peripheral third in 82% of cases with nondilated ducts and within the four hepatic segments in 91%. The extrahepatic duct (EHD), dilated and nondilated, was visualized in 90% of cases. Filling defects were identified in the EHD in 71% of cases and in the gallbladder in 100%. All obstructions were identified and their site and character accurately shown in most cases. The presence of IHD dilatation was accurately shown, and estimates of EHD and main pancreatic duct caliber correlated closely with those of direct cholangiography. CONCLUSION: Non-breath-hold MR cholangiography is a reliable method for depiction of the biliary system.

Adult↗
PubMed1995

Carcinoma of the head of the pancreas: evaluation of the pancreaticoduodenal veins with dynamic CT--potential for improved accuracy in staging.

PURPOSE: To determine if detection of abnormal dilatation of pancreaticoduodenal veins can improve the accuracy of computed tomographic (CT) staging of pancreatic adenocarcinoma. MATERIALS AND METHODS: CT scans obtained during bolus administration of contrast material in 86 patients (aged 34-85 years) with pancreatic head carcinoma were reviewed. The diameter of the small veins that surround the head of the pancreas was measured (normal diameter of gastrocolic trunk, < or = 7 mm; of anterior superior pancreaticoduodenal vein, < or = 4 mm; of posterior superior pancreaticoduodenal vein, < or = 4 mm). RESULTS: Twenty-nine abnormally dilated peripancreatic veins were identified in 22 patients. Twenty-two of these dilated veins were in 16 patients with other CT criteria of tumor unresectability; seven dilated veins were in six patients with tumors deemed resectable at CT. All tumors in these latter six patients were unresectable at surgery. CONCLUSION: Although dilatation of these small peripancreatic veins without other CT criteria of tumor unresectability is an unusual finding, it may be a reliable sign of unresectable pancreatic carcinoma.

Adult↗
PubMed1995

Hepatic MR imaging with ferumoxides: a multicenter clinical trial of the safety and efficacy in the detection of focal hepatic lesions.

PURPOSE: To assess the safety and diagnostic efficacy of intravenous ferumoxides, a superparamagnetic iron oxide, for depiction of focal hepatic lesions on magnetic resonance (MR) images. MATERIALS AND METHODS: This open-label study included 208 patients with known or suspected focal hepatic lesions. MR images were obtained before and 45 minutes to 4 hours after intravenous infusion of ferumoxides (10 mumol/kg). The effect of ferumoxides on signal intensity of the liver was assessed with quantitative analysis. Safety was evaluated with patient monitoring and laboratory measurements. RESULTS: Mean lesion-to-liver contrast-to-noise ratio on T2-weighted images was 9.1 on unenhanced images and 12.7 on enhanced images. Signal intensity of normal liver on enhanced images decreased to 37% of that on unenhanced images. In blinded image evaluations, additional lesions were identified on 27% of enhanced images. No serious adverse events occurred. CONCLUSION: Ferumoxides is a safe and efficacious contrast agent for the detection of focal liver lesions on T2-weighted images.

Contrast Media↗
PubMed1995

Hepatic helical CT: effect of reduction of iodine dose of intravenous contrast material on hepatic contrast enhancement.

PURPOSE: To evaluate the effect of a reduction in iodine dose by altering volume and/or concentration of contrast material on hepatic contrast enhancement (HCE) values during hepatic helical computed tomography (CT). MATERIALS AND METHODS: One hundred eleven patients were randomized into four contrast material protocols according to concentration (in milligrams of iodine per milliliter)/volume (in milliliters)/grams of iodine: group 1, ioversol, 320/150/48; group 2, ioversol, 320/100/32; group 3, iohexol, 300/150/45; group 4, ioversol, 300/100/30. Helical CT protocols were identical for the four groups. Time-attenuation curves were constructed; the mean HCE, contrast enhancement index (CEI), and optimal liver scanning interval (OLSI) were calculated; and the results were compared statistically. RESULTS;: Time-attenuation curves, mean HCE, CEI, and OLSI of groups 1 and 3 were significantly superior to those for groups 2 and 4. Decrease in volume from 150 to 100 mliters decreased mean HCE by 27%, CEI by 69%, and OLSI from 80%-100% to 0%-43% at threshold levels of 40-60 HU. CONCLUSION: Decrease in iodine dose from 45-48 g to 30-32 g significantly decreases all HCE values, which potentially decreases detection of focal hypovascular hepatic lesions.

Adult↗
PubMed1995

Evaluation of the portal venous system before liver transplantation: value of phase-contrast MR angiography.

OBJECTIVE: The purpose of this study was to assess the accuracy of phase-contrast MR angiography with gadolinium in evaluating the patency and blood flow direction of the portal venous system; the presence, extent, and type of varices; and the patency of surgical decompressive shunts in patients before liver transplantation. This information is essential in management and care of patients with chronic liver disease and portal hypertension and those who are candidates for liver transplantation. SUBJECTS AND METHODS: Twenty-four patients with portal venous hypertension were evaluated with phase-contrast MR angiography. Two patients had surgical splenorenal shunts and one had a mesocaval shunt. Phase-contrast angiograms were acquired as a series of two-dimensional sequential coronal sections during breath-holding and after IV administration of gadopentetate dimeglumine. Correlative findings from color flow Doppler sonography, contrast-enhanced CT scanning, and conventional angiography were available in 23, 20, and 10 patients, respectively, and were used as standards. The images from each technique were analyzed independently for patency of and flow direction in the portal vein, splenic vein, superior mesenteric vein, and surgically created shunts, and for detection, distribution, and extent of five variceal groups. RESULTS: Findings from phase-contrast MR angiography completely agreed with those of sonography, CT scanning, and conventional angiography. The main portal vein was patent in 18 patients, stenosed in one, partially thrombosed in one, and occluded in four. Phase-contrast MR angiography correctly showed hepatofugal flow in three patients and hepatopetal flow in 17 patients. Both the splenic and superior mesenteric veins were patent in 20, partially thrombosed in one, and occluded in three cases. Phase-contrast MR angiograms showed 85% of the variceal groups, and MR rating of variceal size was not significantly different from that of CT rating. Phase-contrast MR angiography correctly showed the patency of all three surgical decompressive shunts. CONCLUSION: Phase-contrast MR angiography is accurate for evaluating the patency and flow direction of the portal venous system, detecting and determining the distribution and extent of varices, and assessing the patency of surgically created shunts. Therefore, it is a reliable and noninvasive technique that can provide crucial information in the preoperative workup of liver transplant recipients.

Adult↗
PubMed1994

Utility of magnetization prepared GRE MRI for the detection of focal liver lesions.

We compared the efficacy of rapidly acquired magnetization prepared gradient-echo (MP-GRE) sequences with CT and standard MRI pulse sequences for the detection of focal liver lesions. Fourteen patients with 28 focal liver lesions were scanned. TI times of 300, 450, and 600 ms were used. MP-GRE lesion conspicuity was compared to corresponding CT, T1, T2, T2-post-superparamagnetic-iron-oxide (SPIO), and STIR images. It was found that the differences between MP-GRE and CT and MP-GRE and T1 MRI were not significant. However, overall anatomic detail was better with CT and T1 MRI than MP-GRE. Lesion conspicuity was significantly worse with the MP-GRE than with the T2, T2-post-SPIO, and STIR sequences (all p values = 0.00). Maximal liver signal nulling occurred at TI = 300 ms in 13 out of 14 patients. However, the T1 for optimal focal liver lesion conspicuity varied widely and could not be predicted before scanning. No new lesions were seen on the MP-GRE sequence that could not be seen on the CT or standard MRI sequences. As currently implemented, MP-GRE imaging offers no advantage in the detection of focal liver lesions over CT and standard MRI pulse sequences.

Adult↗
PubMed1994

Early advanced hepatocellular carcinoma: evaluation of CT and MR appearance with pathologic correlation.

PURPOSE: To determine the computed tomographic (CT) and magnetic resonance (MR) imaging appearances of early advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-seven surgically resected cases of early advanced HCC were studied with CT, CT during arterial portography, CT arteriography, and MR imaging. RESULTS: The sensitivity of standard CT (unenhanced, early, and late CT combined) for the detection of early advanced HCC was 81%, while that of standard MR imaging (T1- and T2-weighted MR imaging combined) was 83%. A nodule-in-nodule appearance was identified in approximately one-third to one-half of cases. Signal behavior of early and advanced components of early advanced HCC followed the expected behaviors of isolated early HCC and isolated advanced HCC, respectively. Tumor size was accurately estimated with standard CT and standard MR imaging. CONCLUSION: More research must be performed to ascertain whether any relationship exists between the different types of HCC and the clinical outcome.

Aged↗
PubMed1994

Imaging and intervention in acute pancreatitis.

An International Symposium was held in Atlanta in 1992 to present the state of the art of diagnostic evaluation and management of acute pancreatitis and to agree on an acceptable series of clinical definitions for classifying the disease and its complications. The symposium was composed of 40 internationally recognized experts in pancreatic disease from 15 countries representing six disciplines (anatomy, gastroenterology, internal medicine, pathology, radiology, and surgery). The purpose of this article is to present the radiologically relevant aspects of the symposium; to define the state of the art of imaging and intervention in acute pancreatitis, particularly how and when to use computed tomography and how and when to perform percutaneous therapy versus surgery; and to encourage radiologists to use precise and proper nomenclature when describing the morphologic manifestations of acute pancreatitis as depicted by various imaging modalities.

Acute Disease↗
PubMed1994

Phase-contrast MR angiography of the portal venous system: preoperative findings in liver transplant recipients.

Sequential two-dimensional phase-contrast MR angiography can be used to accurately evaluate the anatomy, patency, and flow direction of the portal venous system and the presence, extent, and distribution of portosystemic collaterals. Its large field of view, insensitivity to the patient's body habitus, and graphic display format make this MR technique extremely useful for preoperative evaluation of patients with chronic liver disease and portal hypertension. This pictorial essay illustrates the spectrum of abnormalities seen on phase-contrast MR angiography of the portal venous system in patients with endstage liver diseases and portal hypertension.

Collateral Circulation↗
PubMed1994

Radiologic staging of pancreatic adenocarcinoma.

Dynamic CT currently is the imaging modality of choice for staging of pancreatic carcinoma. It has an accuracy of 72% in predicting tumor resectability and an accuracy of virtually 100% in predicting tumor unresectability. However, it is important that the CT criteria of unresectability be defined for each individual institution. In some hospitals, extended pancreatectomy, including resection of involved major extrapancreatic vessels, contiguous solid or hollow organs, and regional lymph nodes, is performed for pancreatic carcinoma. Thus, these CT findings would not be considered to obviate surgical resection, whereas in other hospitals, surgeons consider tumor spread beyond the gland, particularly vascular involvement, as a contraindication for resection. It is also important to note that enlarged regional lymph nodes that would be included in the resection are not considered to be a CT criteria of unresectability when they occur as an isolated finding. MR imaging, EUS, and angiography have less significant roles compared with CT in the staging of pancreatic carcinoma; however, MR imaging and EUS can be valuable staging techniques in patients in whom an optimal dynamic contrast-enhanced CT cannot be obtained, although angiography now is indicated primarily to provide the surgeon with a vascular roadmap prior to resection or to evaluate patients in whom CT is equivocal.

Adenocarcinoma↗