iothalamate-meglumine and Liver-Neoplasms

The purpose of this study was to evaluate a recently developed hardware and software system for CT scanning that generates images in real time and switches to helical CT scanning by either a visual cue or a region of interest (ROI) amplitude threshold.. We randomly and prospectively divided 120 abdominal CT examinations into three groups. Two groups received 75 ml of contrast agent at 1.5 ml/sec. Helical CT scanning began after visualization of the contrast bolus arrival in the hepatic veins (visual cue triggering) (39 patients) or after reaching an ROI threshold (automated ROI threshold triggering) (39 patients). A third group served as a control group (42 patients) and received 150 ml of contrast agent at 1 ml/sec. Quality of hepatic enhancement was assessed objectively and subjectively. Comparisons were made after stratifying each group into three weight classes.. Errors occurred in 12 (31%) of 39 examinations in the group with automated ROI threshold triggering. In that group, we found a significantly (p < .04) lower mean hepatic enhancement in two of three weight categories, and a significantly (p < .04) lower mean subjective scan quality in one of three weight categories, than we found in the group with visual cue triggering.. Optimizing portal venous phase helical CT of the liver after a low-volume bolus of contrast agent and an injection rate of 1.5 ml/sec is best achieved by initiating helical CT scanning after visualizing the contrast bolus arrival within the liver rather than after reaching a preset attenuation threshold.

Topics: Adult; Aged; Aged, 80 and over; Contrast Media; Female; Humans; Iohexol; Iothalamate Meglumine; Liver; Liver Neoplasms; Male; Middle Aged; Prospective Studies; Tomography, X-Ray Computed

To determine the effect of the rate of contrast medium injection on liver enhancement at computed tomography (CT).. Forty-five patients who underwent a follow-up CT examination of the liver were included in five different groups according to the compared rates of contrast material delivery: group A, 2 versus 3 mL/sec; group B, 2 versus 4.5 mL/sec; group C, 3 versus 4.5 mL/sec; group D, 3 versus 6 mL/sec; and group E, 4.5 versus 6 mL/sec.. Time to peak enhancement was shorter for the faster rates of injection. In each group, maximum enhancement was nearly identical for the paired examinations (group A, 57 vs 58 HU; group B, 48 vs 47 HU; group C, 55 vs 58 HU; group D, 55 vs 54 HU; group E, 62 vs 61 HU, respectively). Mean enhancement in each group was similar when calculated at 3-second intervals.. Higher rates of injection shorten the time to peak liver enhancement but have no effect on maximum liver enhancement.

Topics: Contrast Media; Female; Humans; Injections, Intravenous; Iohexol; Iopamidol; Iothalamate Meglumine; Liver; Liver Neoplasms; Male; Middle Aged; Time Factors; Tomography, X-Ray Computed; Triiodobenzoic Acids

To prospectively evaluate a dual-phase helical acquisition in computed tomography (CT) of the liver.. Two helical CT acquisitions were performed in 103 patients: hepatic arterial phase (HAP) 15 seconds after injection of 2 mL/kg contrast material at a rate of 6 mL/sec and the portal venous phase (PVP) 90 seconds after injection. Detection of focal liver lesions, vascular anatomic features, and perfusion abnormalities were assessed by two reviewers. Liver enhancement was also calculated on every section.. Of 119 detected focal liver lesions, nine were seen during HAP only and 40 during PVP only. According to a 0-3 score, visualization of the arterial anatomic landmarks was better during HAP (P < .0001). Five right replaced and two left replaced hepatic arteries were visualized only during HAP. Parenchymal perfusion abnormalities were found in 32 patients during HAP and in four patients during PVP.. A dual-phase acquisition depicted 8% additional focal liver lesions and outlined the entire vasculature of the liver.

Topics: Adult; Aged; Aged, 80 and over; Bile Ducts, Intrahepatic; Contrast Media; Evaluation Studies as Topic; Female; Hepatic Artery; Humans; Iohexol; Iopamidol; Iothalamate Meglumine; Liver; Liver Circulation; Liver Neoplasms; Male; Middle Aged; Portography; Prospective Studies; Radiographic Image Enhancement; Tomography, X-Ray Computed; Triiodobenzoic Acids

The purpose of this study was to evaluate the sensitivity and specificity of globular enhancement for differentiating hepatic hemangiomas from hypervascular metastases on single-pass, contrast-enhanced CT scans. Globular enhancement was defined as enhancing nodules less than 1 cm seen within a lesion.. Fifty CT examinations were retrospectively evaluated in a blinded fashion by two independent reviewers. The CT studies were done with nonhelical technique after the IV injection of 150 ml of contrast material. The series included 25 patients with histologically proven hypervascular hepatic metastases (carcinoid, islet cell carcinoma, and leiomyosarcoma) and 25 patients with clinically proven hepatic hemangiomas. Patients with hemangiomas were clinically stable for at least 2 years after the CT studies. A single lesion was isolated from the first-pass, contrast-enhanced portion of each examination; the remainder of the examination was excluded from the review to minimize reviewer bias. Each lesion was evaluated for (1) the presence or absence of globular enhancement (defined as enhancing nodules less than 1 cm seen within a lesion), (2) the density of globular enhancement relative to that of the aorta, (3) the degree of border definition (well or poorly marginated), and (4) the presence or absence of a hypodense halo. A diagnostic impression was then recorded for each lesion.. Globular enhancement was 88% sensitive and 84-100% specific for differentiating hepatic hemangiomas from hypervascular metastases (p < .001). A mean of 62% of hemangiomas showed globular enhancement isodense relative to that of the aorta; none of the metastases showed globular, isodense enhancement. The majority of the metastases showed nonglobular enhancement (mean, 92%). The reviewers showed 84% agreement in the identification of (1) globular enhancement in hemangiomas, (2) lack of globular enhancement in metastases, and (3) globular enhancement in the combined set of all lesions. Neither the presence of a hypodense halo nor the degree of border definition was significant in distinguishing between the two groups of lesions. The reviewers showed 96% agreement in the categorization of metastases and 76% agreement in the categorization of hemangiomas. There was 86% agreement in the categorization of all lesions. Overall, reviewers diagnosed a mean of 89% of lesions correctly. A mean of 98% of metastases and a mean of 80% of hemangiomas were diagnosed correctly.. Globular enhancement is highly sensitive (88%) and specific (84-100%) for differentiating hepatic hemangiomas from hypervascular metastases on single-pass, contrast-enhanced CT scans.

Topics: Adult; Aged; Diagnosis, Differential; Female; Hemangioma; Humans; Iopamidol; Iothalamate Meglumine; Liver; Liver Neoplasms; Male; Middle Aged; Retrospective Studies; Sensitivity and Specificity; Tomography, X-Ray Computed

The authors prospectively compared the effects of ionic and nonionic contrast agents on hepatic enhancement at computed tomography (CT) in the same patient population.. Forty-six patients underwent abdominal CT with either ionic or nonionic contrast agents. At 6-month follow-up, the alternative agent was used. Pre- and postcontrast attenuation values of liver and vessels were obtained; enhancement and postinjection time of each image were recorded. The area under a computer-generated enhancement-time curve was calculated as a means of measuring enhancement over time. Mean liver enhancement with ionic and nonionic contrast agents was compared.. Mean hepatic enhancement with ionic contrast material was greater than with nonionic contrast material at all time intervals through 90 seconds after injection. The difference was statistically significant from 61 to 70 seconds. Mean peak liver enhancement for ionic and nonionic contrast agents was nearly identical (59 and 58 HU, respectively), but mean time to peak hepatic enhancement with nonionic contrast agent was greater by 10 seconds.. These results indicate that ionic contrast agent may effect greater liver tumor conspicuity.

Topics: Female; Humans; Iopamidol; Iothalamate Meglumine; Liver; Liver Neoplasms; Male; Middle Aged; Osmolar Concentration; Time Factors; Tomography, X-Ray Computed

To compare the appearance of small hepatic hemangiomas at nonenhanced and contrast material-enhanced helical computed tomography (CT) with that of small (<3-cm) hypervascular malignant liver tumors and to evaluate the accuracy of multiphase helical CT for differentiating small hemangiomas from small hypervascular malignant tumors.. Radiologists reviewed multiphase helical CT liver images in 86 patients with 37 hemangiomas and 49 malignant liver tumors. They evaluated lesion type and degree of enhancement for change from arterial to portal venous phase. They rated their confidence in the discrimination of hemangiomas from malignant tumors.. At arterial phase CT, enhancement similar to aortic enhancement was observed in 19%-32% of hemangiomas and 0%-2% of malignant tumors; globular enhancement, in 62%-68% and 4%-12%, respectively. At portal venous phase CT, enhancement similar to blood pool enhancement was observed in 43%-54% of hemangiomas and 4%-14% of malignant tumors; globular enhancement, in 46%-49% and 0%-2%, respectively. For all readers and all phases of enhancement, the area under the receiver operating characteristic curves was 0.81-0.87, indicating that inherent accuracy of CT is high and that there was no significant difference (P >.28) in overall accuracy. Readers diagnosed hemangiomas with 47%-53% mean sensitivity with all enhancement phases and diagnosed malignant lesions with 95% mean specificity.. Small hemangiomas frequently show atypical appearances at CT. Two-phase helical CT does not improve sensitivity but does improve specificity for differentiating hemangiomas from hypervascular malignant tumors.

Topics: Carcinoma, Hepatocellular; Contrast Media; Diagnosis, Differential; Female; Hemangioma; Humans; Iothalamate Meglumine; Liver Neoplasms; Male; Middle Aged; Observer Variation; ROC Curve; Sensitivity and Specificity; Tomography, X-Ray Computed; Triiodobenzoic Acids

The purpose of this study was to determine whether the interval change in hepatic colorectal metastases as assessed with serial computed tomographic (CT) scans without contrast material enhancement differs from that as assessed using serial, portal dominant phase, contrast-enhanced CT scans.. Unenhanced and contrast-enhanced abdominal CT scans were obtained in 28 patients. Three radiologists separately reviewed serial unenhanced and contrast-enhanced studies to assess the interval change in liver metastases. These radiologists recorded total number of lesions, bidimensional measurements of the largest lesions (as many as three), and overall impressions regarding the interval change (none, worse, or better).. Among the 84 judgments (28 patients x 3 radiologists), comparisons of unenhanced and contrast-enhanced CT studies were concordant in 60 assessments (71%). Nineteen (23%) showed mild disagreement. Of these, contrast-enhanced CT studies demonstrated disease stability when unenhanced CT studies demonstrated otherwise in 11 judgments, whereas unenhanced CT studies demonstrated stability when contrast-enhanced CT studies demonstrated otherwise in eight assessments. Furthermore, of the five marked disagreements, two resulted from a conclusion of interval improvement on unenhanced CT studies and a conclusion of interval worsening on contrast-enhanced CT studies, whereas three demonstrated the opposite. Neither set of serial CT studies systematically resulted in under- or overestimation of disease progression (McNemar Q test, P < .25).. The authors found no consistent pattern to demonstrate that serial unenhanced or contrast-enhanced CT studies resulted in over- or underestimation of disease progression.

Topics: Adult; Aged; Colorectal Neoplasms; Contrast Media; Disease Progression; Female; Humans; Iothalamate Meglumine; Liver Neoplasms; Male; Middle Aged; Radiographic Image Enhancement; Time Factors; Tomography, X-Ray Computed; Triiodobenzoic Acids

To investigate whether measurements of hepatic metastases from colorectal carcinoma before contrast material administration are significantly different statistically from measurements after contrast material administration.. Twenty-four patients with hepatic metastases from colorectal carcinoma underwent spiral computed tomography (CT) with 7-mm collimation. The liver was imaged before and in the portal-dominant phase after intravenous contrast material administration. For each scan, one to three discrete liver lesions were selected for measurement (n = 49). Three experienced radiologists performed independent measurements of the selected lesions on both pre- and postcontrast images at a computer workstation. A three-way analysis of variance (ANOVA) was performed: subjects by raters (the three independent radiologists) by pre- or postcontrast status. The dependent variable was the product of bidimensional measurements.. Sixty-seven percent (33 of 49) of the lesions were measured as larger on precontrast images; 33% (16 of 49), as smaller. There was high interrater reliability, with an intraclass correlation coefficient greater than 0.9 ANOVA showed significant subject, rater, and contrast material effects (P < .001) for the largest lesions in each liver. Contrast material status was a significant factor for all lesion sizes (P < .003).. On average, hepatic metastases from colorectal carcinoma are significantly smaller after contrast material administration.

Topics: Adult; Aged; Barium Sulfate; Colorectal Neoplasms; Contrast Media; Diatrizoate; Diatrizoate Meglumine; Female; Humans; Iothalamate Meglumine; Liver; Liver Neoplasms; Male; Middle Aged; Sensitivity and Specificity; Tomography, X-Ray Computed; Triiodobenzoic Acids

To determine the feasibility and clinical benefit of routine performance of helical computed tomography (CT) with 2.5-mm collimation for the detection of liver lesions.. Twenty patients with small (< or = 10-mm-diameter) liver lesions (total number of lesions, 167) were evaluated with a dual-detector-array CT scanner during the portal venous phase of contrast material enhancement. The acquisition was performed with 2.5-mm collimation during a single breath hold. The identical data set was used to perform reconstructions with 2.5-mm, 5.0-mm, 7.5-mm, and 10.0-mm section thicknesses with 50% section overlap. Each set of images was evaluated by three radiologists to determine lesion detection rates and conspicuity.. Use of 2.5-mm-thick sections resulted in a 46% increase in detection rate versus use of 10.0-mm-thick sections (167 lesions vs 90 lesions), a 33% increase versus use of 7.5-mm-thick sections (167 vs 112), and an 18% increase versus use of 5-mm-thick sections (167 vs 137). Lesion conspicuity and radiologist confidence in lesion detection and characterization of lesion margins increased as section thickness decreased.. CT of the liver can be performed routinely with 2.5-mm collimation with a dual-detector CT system, yielding greater conspicuity of small lesions and improved lesion detection.

Topics: Contrast Media; Feasibility Studies; Female; Humans; Image Processing, Computer-Assisted; Iothalamate Meglumine; Liver Neoplasms; Male; Observer Variation; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed; Triiodobenzoic Acids

To evaluate the added value of hepatic arterial-dominant phase (HAP) imaging to portal venous-dominant phase (PVP) imaging in patients with hepatocellular carcinoma (HCC) at computed tomography (CT).. Sixty-six patients with proved HCC underwent biphasic contrast-enhanced CT. HAP and PVP images were obtained at 20-50 and 60-100 seconds, respectively. PVP images were evaluated for the number of HCC foci. Then, HAP images were reviewed to determine whether any additional HCCs were seen.. Three hundred twenty-six tumor foci were seen. HAP images depicted 309 foci (95%) and PVP images 268 (82%). In seven patients (11%), tumor was visible only on HAP images. During the HAP, tumors were hyperattenuating compared with liver in 26 patients, of mixed attenuation in 26, and hypoattenuating in 14 without correlation with histologic appearance. Portal vein thrombosis was identified in 17 of 21 patients on HAP images; in 12 patients, the thrombosis was diagnosed as malignant with neovascularity within the thrombus or diffuse thrombus enhancement.. Use of both HAP and PVP contrast-enhanced CT optimizes the evaluation of patients with or at risk for HCC.

Topics: Carcinoma, Hepatocellular; Contrast Media; Female; Humans; Image Processing, Computer-Assisted; Iothalamate Meglumine; Liver Neoplasms; Male; Middle Aged; Neoplastic Cells, Circulating; Portal Vein; Sensitivity and Specificity; Time Factors; Tomography, X-Ray Computed; Triiodobenzoic Acids

To follow up the growth of renal angiomyolipomas (AMLs).. Patients with known AML (n = 55) were divided into three groups on the basis of initial clinical and computed tomographic (CT) findings: group 1, isolated AML (n = 43); group 2, multiple AMLs without tuberous sclerosis (TS) (n = 6); group 3, multiple AMLs with TS (n = 6). Follow-up ultrasonography (US) and CT were performed in 55 and 31 patients, respectively. Growth of the AMLs (n = 59) was evaluated on the basis of area on initial and follow-up images.. Mean percentage growth was 17%, 128%, and 47%, and mean growth rate per year was 5%, 22%, and 18% in groups 1, 2, and 3, respectively. New renal lesions were noted in three patients in groups 1 and 2, but no new lesions were detected in group 3, because of the large number of AMLs. New extrarenal lesions were observed in four, two, and three patients in groups 1, 2, and 3, respectively. No correlation was found between percentage of fatty tissue and growth rate.. Multiple AMLs show more growth than solitary AMLs.

Topics: Adipose Tissue; Adult; Aged; Aged, 80 and over; Angiomyolipoma; Contrast Media; Female; Follow-Up Studies; Humans; Iothalamate Meglumine; Kidney Neoplasms; Liver Neoplasms; Male; Middle Aged; Radiographic Image Enhancement; Splenic Neoplasms; Tomography, X-Ray Computed; Tuberous Sclerosis; Ultrasonography

To evaluate the efficacy of two distinct imaging techniques to predict, before operation, unresectability compared with standard computed tomographic scan (CT).. Accurate preoperative identification of the number, size, and location of hepatic lesions is crucial in planning hepatic resection for colorectal hepatic metastases. Although infusion-enhanced CT is the standard, its limitations are the imaging of relatively isodense and/or small (< 1 cm) lesions. The increased sensitivity of CT arterial portography (CTAP) may be offset by false-positive results caused by benign lesions and flow artifacts.. Fifty-eight selected patients considered to be eligible for resection by standard CT had laparotomy. Before operation and in addition to CT, all patients had CT arterial portography and hepatic artery perfusion scintigraphy (HAPS) using radiolabeled macroaggregated albumin. Early studies showed an increased sensitivity for detecting small lesions using the invasive CTAP. Similarly, the HAPS study has detected malignant lesions not observed by standard CT.. Of 58 patients having laparotomy, 40 were resectable by either lobectomy (22) or trisegmentectomy (1) and the rest by single or multiple wedge resections. Eighteen patients could not be resected because of combined intra- and extrahepatic disease or the number and location of metastases. Standard CT detected 64% of all lesions (12% of lesions less than 1 cm). Unresectability was accurately predicted by CTAP and HAPS in 16 (88%) and 15 (83%), respectively, of the 18 patients considered ineligible for resection at laparotomy. Of the 40 patients who had resection for possible cure, CTAP and HAPS falsely predicted unresectability in 6 of 40 patients (15%) and in 10 of 40 patients (25%), respectively. The positive predictive value for unresectability of CTAP and HAPS was 73% and 60%, respectively. False-positive lesions after CTAP included hemangiomas, cysts, granulomas, and flow artifacts. False-positive HAPS lesions included patients in whom no tumor was found at surgery but with some identified by intraoperative ultrasound, blind biopsy, and blind resection.. False-positive results by HAPS and CTAP may limit the ability of these tests to accurately predict unresectability before operation and may deny patients the chance for surgical resection. The HAPS study does, however, detect small lesions not seen by CT or CTAP. Standard CT, although less sensitive, followed by surgery and intraoperative ultrasound, does not necessarily preclude patients who could be resected.

Topics: Adult; Aged; Colorectal Neoplasms; False Positive Reactions; Female; Humans; Iothalamate Meglumine; Liver Neoplasms; Male; Middle Aged; Portography; Predictive Value of Tests; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Aggregated Albumin; Tomography, X-Ray Computed

The purpose of this study was to determine whether delayed computed tomography (DCT) of the liver would more accurately detect hepatic malignancy when compared with bolus contrast-enhanced dynamic computed tomography (BCDCT). Fifty-one patients who required operation for intra-abdominal malignancy (92% with colorectal cancers) underwent preoperative BCDCT followed by DCT. At operation, palpation and intraoperative ultrasound (IOUS) examination of the liver were performed for localization and biopsy of tumor nodules. The standard for diagnosis was defined for this study as the combined results of IOUS, palpation, and biopsy. The sensitivities of BCDCT and DCT for hepatic metastases were 50% and 54%, respectively, with a corresponding specificity of 72% for each. DCT demonstrated no significant improvement over BCDCT in the detection of individual hepatic lesions. The sensitivity of palpation for the detection of metastases was 82%, equal to that of IOUS. Both palpation and IOUS were significantly superior to BCDCT or DCT in excluding false-positive and false-negative results (p < 0.001). IOUS failed to identify surface lesions less than 1.0 cm in diameter (sensitivity: 40%). Conversely, palpation was limited in the detection of subsurface tumors less than 1.0 cm in diameter (sensitivity: 33%). Combined IOUS and palpation were significantly more accurate in the detection of hepatic metastases than any single modality that was evaluated (p < 0.001).

Topics: Colorectal Neoplasms; Female; Humans; Intraoperative Care; Iothalamate Meglumine; Laparotomy; Liver; Liver Neoplasms; Male; Middle Aged; Palpation; Predictive Value of Tests; Prospective Studies; Sensitivity and Specificity; Tomography, X-Ray Computed; Ultrasonography

In this study we describe the investigation and treatment of 14 patients with primary hepatocellular carcinoma. Patients were treated with intra-arterial infusion of iodized oil and doxorubicin hydrochloride. Five of these patients were alive after 1 year. Twelve patients showed a fall in alpha-fetoprotein, and in seven of these patients, the fall in alpha-fetoprotein was greater than 50%.

Topics: Adult; Carcinoma, Hepatocellular; Cell Line; DNA Replication; Doxorubicin; Female; Follow-Up Studies; Humans; Infusions, Intra-Arterial; Iodized Oil; Iothalamate Meglumine; Liver Neoplasms; Male; Pilot Projects; Tomography, X-Ray Computed

The enhancement characteristics in different portions of the liver during dynamic sequential bolus computed tomography (CT) with iodinated contrast material (DSBCT) were prospectively evaluated in 75 patients by using iothalamate meglumine, iopamidol, and iohexol (25 patients received each agent). After baseline noncontrast CT was performed, DSBCT was performed with a 180-mL intravenous bolus administered at 2 mL/sec. Scanning was started 25 seconds after the bolus was initiated, by using a 3-second scan time and rapid cephalocaudal table incrementation, yielding contiguous 8-mm-thick sections at a rate of nine sections per minute. On postcontrast images, peak enhancement was 115% for iopamidol and 117% for iohexol, both of which were superior to iothalamate meglumine at 95% (P less than .05). After peaking, enhancement then decreased for all three contrast agents, although the decline was more precipitous for iothalamate meglumine. Enhancement on the more caudal sections with both iopamidol and iohexol was superior to that with iothalamate meglumine (P less than .05). The data suggest that the enhancement characteristics for the two nonionic agents may be more optimal for detection of focal hepatic lesions than the ionic agent.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Injections, Intravenous; Iohexol; Iopamidol; Iothalamate Meglumine; Liver; Liver Neoplasms; Male; Middle Aged; Prospective Studies; Tomography, X-Ray Computed

Prolonged dynamic CT up to 32 minutes after intravenous bolus injection of 100 ml contrast medium improves the differentiation between benign (hemangiomas) and malignant (metastases) liver lesions. Our study shows that there are three distinct types of hemangiomas and that all three of them behave differently than metastases. Prolonged dynamic improves the problem of differentiation between hemangiomas and metastases but does not solve the problem completely.

Topics: Diagnosis, Differential; Hemangioma; Humans; Iothalamate Meglumine; Liver; Liver Neoplasms; Tomography, X-Ray Computed

Thirty-two patients with hepatocellular carcinoma less than 5 cm in diameter were examined by computed tomography. At the examination 26 patients (81%) were correctly diagnosed. A common type of CT image series was detectable as low density on the precontrast scan, a positive or mixed pattern on dynamic scan, and visible on postcontrast scan. In 10 patients with minute tumors (less than 2 cm), 7 were correctly diagnosed. CT was valuable for diagnosis of the small hepatocellular carcinomas larger than 1 cm by using the dynamic study after an intravenous bolus injection of the contrast medium.

Topics: Adult; Aged; Carcinoma, Hepatocellular; Female; Humans; Iothalamate Meglumine; Liver Neoplasms; Male; Middle Aged; Tomography, X-Ray Computed