Pericaval fat collection mimicking an intracaval lesion on CT in patients with chronic liver disease.

BACKGROUND: Localized fat collections, which mimic fat-containing lesions of the inferior vena cava (IVC) on computed tomographic (CT) images, have been reported as rare incidental findings. Our goal was to evaluate the association of this CT finding with chronic liver disease. METHODS: Sixty-one patients with chronic liver disease were prospectively studied with contrast-enhanced abdominal CT. The prevalence, attenuation, location, shape, and size of the pericaval fat collections were assessed. Multidirectional reformatted CT images were obtained from helical CT data to identify origins of the pericaval fat collections. Sixty-one patients without chronic liver disease were studied as control subjects. RESULTS: Pericaval fat collections were seen on abdominal CT in 16 (26.2%) of the 61 patients. On the reformatted images, the fat collections were contiguous to the fat tissue around the subdiaphragmatic esophagus in all 16 patients. The fat collections were located at the posterior aspect of the IVC in 12 patients. In the control group, pericaval fat collection mimicking an intracaval lesion was not seen. CONCLUSION: In patients with chronic liver disease, pericaval fat collections are not rare CT findings and their characteristic location is considered to be posterior to the IVC. It is important not to misinterpret such CT findings as abnormalities of the IVC, such as thrombus or tumors.

Hepatic falciform artery: angiographic observations and significance.

BACKGROUND: The purpose of this study was to assess the angiographic incidence and appearance of the hepatic falciform artery (HFA) and discuss its clinical significance. METHODS: Hepatic angiograms of 53 patients obtained with digital subtraction angiography were prospectively evaluated with regard to incidence, anatomic features, and flow speed of the HFA. We analyzed whether the background of chronic liver disease affected the incidence of the HFA. Transcatheter arterial chemoinfusion or chemoembolization for liver tumors was performed in 33 patients. We noted the occurrence of supraumbilical skin complications. RESULTS: The HFA was observed in 13 (24.5%) of 53 patients on celiac or common hepatic angiograms. The blood flow of the HFA was slower than that of the peripheral hepatic arteries in all patients. No significant difference in the incidence of HFA between the 34 patients with chronic liver disease and the 19 patients with normal livers was found. One treated patient with an HFA and a history of gastrectomy developed a supraumbilical red skin rash. CONCLUSION: The angiographic incidence of the HFA is more common than previously reported. The delayed and persistent opacification of the HFA on hepatic angiograms caused by its slow blood flow is considered the key to its identification.

Relation between breastfeeding and the prevalence of asthma : the Tokorozawa Childhood Asthma and Pollinosis Study.

Many risk factors for asthma have been proposed including age, gender (male), smoking, and family history of asthma. The importance of breastfeeding to childhood asthma is a controversial issue. The present study investigated the relation between breastfeeding and the prevalence of asthma among a childhood population. The subjects were 25,767 students, representing all public elementary and junior high schools in Tokorozawa, Japan (age range, 6--15 years). The study population included 2,315 students with asthma and 21,513 controls. Participants' parents completed the Japanese version of the American Thoracic Society and Division of Lung Diseases, National Heart, Lung, and Blood Institute, questionnaire for children adopted by the Japanese Environmental Agency in 1998. The authors added supplementary questions on the parental history of asthma and feeding patterns from the age of 0--3 months. The risk of breastfeeding for asthma was compared with that of artificial feeding. After adjustment for age, gender, parental smoking status, and parental history of asthma, a significantly higher prevalence of asthma was noted among children who had been breastfed (adjusted odds ratio = 1.198; 95% confidence interval: 1.054, 1.363; p for trend < 0.01). The results indicated that breastfeeding in infancy might be related to the higher prevalence of asthma during preadolescence.

[Reexamination of hepatic falciform artery: angiographic study].

Supraumbilical skin complication during hepatic artery infusion chemotherapy or transcatheter arterial chemoembolization (TACE) for liver tumor has been reported by some authors. This complication is thought to be caused by the flow of chemotherapeutic, agent and embolus into the hepatic falciform artery (HFA). It is important for angiographers to be aware of the presence of HFA to prevent possible supraumbilical skin complication. The rate of visualization of the HFA on angiography has been considered to be only about 2%. In a retrospective study of celiac angiograms performed in 200 patients, we found an incidence of 32/200 (16%). The proximal side of this artery may be tortuous. In all cases, the flow of the HFA is slower than that of the hepatic artery. The paraumbilical vein was visualized with the HFA in 18 cases. Chemotherapy or transcatheter arterial chemoembolization was performed in 10 patients, and there was no postprocedure supraumbilical skin complication.

Retroaortic left renal vein with renal vein hypertension causing hematuria.

We describe a case of retroaortic left renal vein with hematuria. In this case, pullback pressure from the retroaortic left renal vein to the inferior vena cava revealed left renal vein hypertension according to criteria of the "nutcracker phenomenon." We stress that left renal vein anomaly including retroaortic left renal vein can cause clinical symptoms such as hematuria.

Intra-arterial digital subtraction angiography with extra-large fields using a computed radiography system in evaluating peripheral vascular disease.

The authors evaluated the usefulness of intra-arterial digital subtraction angiography (DSA) with extra-large field sizes using a computed radiography (CR) system in evaluating peripheral vascular disease (PVD). Intra-arterial DSA using CR was performed in 55 patients with suspected PVD. A 4 F catheter was advanced into the abdominal aorta via the transbrachial approach and 90 ml of contrast medium was injected during six exposures using a long leg changer mounting a total of 18 imaging plates on six surfaces. Visualization of the superficial femoral and popliteal arteries was judged as diagnostic in all cases. The abdominal aorta, iliac arteries, and subtrifurcation were also visualized in most cases, but visualization was suboptimal in some cases. As a complication, median nerve palsy occurred in one case. This technique is thought to be a useful method for evaluating PVD because of the advantages of a large field of view and wide exposure latitude, in spite of its relatively long processing time.

Hepatocellular carcinoma: correlation of CT, angiographic, and histopathologic findings.

PURPOSE: To elucidate the causes of various enhancement patterns of hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Computed tomographic (CT) scans of 68 surgically resected HCCs (62 patients) were obtained 45 seconds and 6 minutes after administration of contrast material. These scans were compared with angiographic and histopathologic findings. RESULTS: On the early images, 24 HCCs (35%) were hypoattenuating, 33 were totally or partially hyperattenuating (48%), and 11 were isoattenuating (16%) compared to adjacent liver. On the delayed images, 55 HCCs (81%) were hypoattenuating and 13 (19%) were isoattenuating. Twenty-nine of the 48 very hypervascular or hypervascular tumors (60%) were hyperattenuating or partially hyperattenuating at early CT. Sixteen of the 20 slightly hypervascular or hypovascular tumors (80%) were isoattenuating or hypoattenuating. CONCLUSION: Although there was relatively good agreement between tumor vascularity and enhancement pattern (60% correlation for hypervascular tumors, 80% correlation for hypovascular tumors), hyperattenuation of the large HCCs (> or = 5 cm) at CT appeared to be a function of dilated sinusoids within the tumor (peliotic changes) as well as vascularity. In patients with advanced cirrhosis, hypovascular HCCs could be hyperattenuating at CT.

[Contrast-enhanced MR imaging using double doses of gadolinium-DTPA in evaluating brain and spinal diseases].

Forty-one lesions of intracranial and spinal diseases underwent magnetic resonance (MR) imaging at both standard-dose (0.1 mmol/kg) and double-dose (0.2 mmol/kg) levels of gadolinium (Gd)-DTPA in order to reassess the optimal dose of Gd-DTPA. Each patient received an initial injection of 0.1 mmol/kg and an additional dose of 0.1 mmol/kg 5 min later. In quantitative analysis of contrast enhancement ratios of the enhancing part of the lesion, choroid plexus, cavernous sinus and pituitary stalk were significantly (P < 0.01) increased in double-dose studies. For visual comparison, we defined delineation as the extent to which the lesion may be defined; detectability was defined as the ability to visualize the lesion. With respect to delineation, double-dose studies were superior to standard-dose studies in nine of 20 intraaxial tumor (four of eight malignant gliomas, three of eight benign gliomas and two of four metastatic brain tumors) and five of six cerebral infarcts. The detectability of the lesion was improved in four cases (one astrocytoma, two metastatic brain tumors and one cerebral infarct) in double-dose studies. It was concluded that contrast-enhanced MR imaging using double doses of Gd-DTPA may be useful in the detection and evaluation of the extent of intraaxial lesions enhanced by Gd-DTPA.

Intrahepatic peripheral cholangiocarcinoma: two-phased dynamic incremental CT and pathologic correlation.

To elucidate the characteristic CT findings of intrahepatic peripheral cholangiocarcinoma, two-phased dynamic incremental CT scans of 20 cholangiocarcinomas in 16 patients were carefully analyzed. Dynamic incremental CT scanning was performed after intravenous administration of 100 ml iodinated contrast medium at a rate of 2 ml/s using a power injector. The CT scans (8-16 sections) were obtained during 45-110 s (early phase) and 6-7 min (delayed phase) after commencement of the injection of the contrast medium. On CT, 55% (11 of 20) of intrahepatic peripheral cholangiocarcinomas appeared hypodense in both phases. Most of the tumors (80%) appeared hypodense in the early phase and had increased CT numbers in their delayed images. Lymphadenopathy was observed in 69% (11 of 16) of patients whose main tumors exceeded 3 cm in diameter. All tumors appeared irregular or indistinct. Twenty percent (4 of 20) of the cholangiocarcinomas were difficult to distinguish from hepatocellular carcinomas or hemangiomas.

Hepatocellular carcinoma: prospective assessments of the T-factor with CT, US, and MR imaging.

The capabilities of computed tomography (CT), ultrasonography (US), and magnetic resonance (MR) imaging were studied in order to determine the role of each of these noninvasive examinations for estimating the T-factor of hepatocellular carcinomas (HCCs). Fifty-one patients with surgically proven HCCs received CT (50 patients), US (46 patients), and MR (44 patients). The images of CT, US, and MR were prospectively evaluated for main tumor size, intrahepatic metastases, and vascular invasion, which compose the T-factor of HCC, and compared to pathological results. The sizes of the main tumor were estimated correctly by all examinations. For estimating intrahepatic metastases, US (74%) and MR (73%) were superior to CT (65%). For estimating portal invasion, CT (79%) was superior to US (70%) and MR (66%), because CT could demonstrate the segmental staining caused by portal invasion. The estimates of hepatic venous invasion were difficult during any of the examinations. We conclude that presurgical evaluations of the T-factor require the use of US and CT or MR and CT.

[MR imaging of stereotactic thalamotomy using radiofrequency methods].

Sixty-eight stereotactic radiofrequency (rf) thalamic lesions in 57 patients with movement disorders were evaluated by magnetic resonance (MR) imaging. Postoperative periods ranged from 5 days to 4 years and 9 months. All 68 rf lesions were clearly detected on T2-weighted images (T2WI). Changes in signal intensity on T2WI were classified into five patterns, as follows: Pattern I: lesions with three concentric zones consisting of an inner hypointense, middle hyperintense and outer hypointense zone (31 lesions); Pattern II: lesions consisting of an inner hypointense and outer hyperintense zone (4 lesions); Pattern III: lesions consisting of an inner hyperintense and outer hypointense zone (27 lesion); Pattern IV: lesions of a hyperintense area alone (2 lesions); Pattern V: lesions of a hypointense area alone (4 lesions). The outer hypointense rim in Patterns I and III is thought to represent hemosiderin deposition. The abnormal signal intensity on T2WI caused by rf ranged from 2 to 12 mm in diameter, and lesions in the late phase were smaller than lesions in the early phase.

[MR imaging of intraocular lesions--a comparison with CT].

Thirty-two intraocular lesions were studied with magnetic resonance (MR) imaging and computed tomography (CT). These lesions included retinoblastoma (n = 11), uveal melanoma (n = 6), metastatic choroidal tumor (n = 3), choroidal hemangioma (n = 2), retinochoroiditis (n = 6) and Coats' disease (n = 4). MR imaging was superior to CT in the depiction of intraocular masses and retinal detachment. Gd-DTPA enhanced MR imaging was more useful than contrast enhanced CT in evaluating the contrast enhancement of intraocular tumors. Differential diagnosis of intraocular tumors was difficult with both MR imaging and CT. Intratumoral calcification was noticed on CT in nine cases of retinoblastoma. It was concluded that MR imaging, including contrast enhancement study, is more useful than CT in the evaluation of intraocular lesions, except for calcification, and contrast enhanced CT may be unnecessary in the diagnosis of intraocular lesions.