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1.
Multiphase helical CT findings after percutaneous ablation procedures for hepatocellular carcinoma 总被引:9,自引:0,他引:9
Background: Multiple-phase helical computed tomography (CT) has been regarded as the method of choice in the evaluation of patients with
hepatocellular carcinoma (HCC) treated by nonsurgical procedures. The aim of this article was to report our experience in
the assessment of nodular and parenchymal changes recognizable after various percutaneous ablation therapies.
Methods: We reviewed the studies of 116 consecutive patients with HCC treated with multisession percutaneous ethanol injection (56
patients, 98 nodules), single-session percutaneous ethanol injection (14 patients, 31 nodules), radiofrequency thermal ablation
(32 patients, 48 nodules), and interstitial laser photocoagulation (14 patients, 25 nodules). CT had been performed 3–28 days
after the last session (mean = 18 days) with unenhanced helical acquisition and with contrast-enhanced double- or triple-phase
helical acquisition.
Results: Persisting neoplastic tissue was identified within 54.5% of the nodules. It was located centrally in 4.5% of these nodules,
peripherally in 11%, and eccentrically in 84.5%, and its shape was crescent in 58%, globular in 24.5%, and other in 16%. On
arterial phase scans, viable tumor was hyperdense in 97% of the lesions and isodense in 3%; on portal phase scans, the tumor
was hyperdense in 20%, isodense in 28%, and hypodense in 52%; on delayed phase scans, the tumor was consistently hypodense.
Tumor necrosis was always hypodense on contrast-enhanced scans. On unenhanced images, 7.4% of the nodules were undetectable.
Nodule diameter appeared as unchanged in 53% of the nodules and as larger in 47%; its shape was unchanged in 54% and modified
in 46%; its margins were unchanged in 36% and modified in 64%. A rim of granulation tissue was detected around 15% of the
nodules, and a perilesional transient attenuation difference was detected in 21%. Perihepatic effusion was seen in 13% of
the patients, segmental biliary duct dilation and local atrophy each in 9%, arterioportal fistula in 6%, portal vein thrombosis,
subcapsular collection and pleural effusion each in 7%, hepatic infarction in 5%, and inferior vena cava thrombosis in 2%.
Conclusion: Percutaneous ablation of HCC may cause several changes. Knowledge of their CT appearance is mandatory to correctly assess
and manage this tumor. RID=" ID=" <E5>Correspondence to:</E5> O. Catalano
Received: 6 April 2000/Accepted: 3 May 2000 相似文献
2.
Hepatocellular carcinoma recurrence after percutaneous ablation therapy: helical CT patterns 总被引:5,自引:0,他引:5
Background: To categorize the helical computed tomographic (CT) intrahepatic recurrence patterns of hepatocellular carcinoma (HCC) after
treatment with percutaneous ablation procedures.
Methods: Double-phase helical CT studies of 67 patients with HCC recurrence were reviewed. The study population had undergone percutaneous
ablation therapy procedures (multisession or single-session ethanol injection therapy, radiofrequency thermal ablation therapy,
and interstitial laser photocoagulation therapy) for 120 HCC nodules.
Results: Four patterns were defined. (A) Enhancing tissue within the edge of the ablated nodule on arterial phase images (ingrowth):
this pattern was seen in five treated lesions (4.2% of all treated nodules) in five patients (7.5% of all patients with recurrence)
3–7 months after treatment (mean = 4 months). (B) Enhancing tissue around the treated nodule but continuously to its border
on arterial-phase images (outgrowth): this pattern was found in 12 (10%) treated lesions in 12 patients (18%) 3–6 months after
ablation (mean = 4 months). (C) Enhancing tissue within the same segment of the treated nodule on arterial phase images (spread):
this pattern was detected in 10 (8%) treated lesions in 10 patients (15%) 3–6 months after treatment (mean = 5 months). (D)
Enhancing tissue within different segments from the treated nodule on arterial phase images (progression): this pattern was
identified in 34 patients (51%) with 53 (44%) treated tumors 5–22 months after ablation (mean = 8 months). A mixed pattern
was found in six subjects (9%) with seven (6%) treated nodules. Among the 61 patients with a nonmixed pattern, there were
85 treated nodules with persistent necrosis, 17 treated nodules with local recurrence (pattern A or B), and 107 new nodules
due to nonlocal recurrence (pattern C or D). Portal phase enhanced images and especially unenhanced images showed a lower
detection rate and a lower lesion-to-liver conspicuity score (for all patterns but mainly for pattern C).
Conclusion: Four patterns of recurrence after percutaneous ablation procedures can be categorized on double-phase helical CT and are
best depicted on arterial phase images. Knowledge of these patterns is relevant for early detection and may be helpful in
understanding the recurrence mechanism.
Received: 25 September 2000/Accepted: 15 November 2000 相似文献
3.
Spiral CT for the detection of hepatocellular carcinomas: relative value of arterial- and late-phase scanning 总被引:1,自引:0,他引:1
Background: Spiral computed tomography (CT) can image the liver during arterial and late phases of contrast and optimize the evaluation
of hypervascular tumor. The objective of this study was to evaluate the relative value of arterial- and late-phase spiral
CT in the detection of hepatocellular carcinomas.
Methods: Fifty-eight patients with hepatocellular carcinomas underwent two-phase spiral CT examination with 10-mm collimation at 10
mm/s table speed (Siemens Somatom Plus S), and 120 mL of contrast material (36 g iodine) was injected at the rate of 3 mL/s.
CT images of hepatic arterial and late phases were obtained with a 35-s and 180-s delay, respectively.
Results: In 58 patients, 111 hepatocellular carcinoma lesions were seen. The arterial phase detected 93 (84%) and the late phase 75
(68%) lesions (p < 0.01). The arterial phase detected more lesions in 11 patients, and the late phase dected more in two patients and an equal
number in 45 patients. If lesions larger than 2 cm are excluded, the arterial phase detected 40 (74%) and the late phase 21
(39%) of 54 lesions (p < 0.001).
Conclusion: The arterial phase of spiral CT greatly improves the detection of hepatocellular carcinoma when compared with the late phase.
Received: 13 April 1995/Accepted: 22 May 1995 相似文献
4.
BACKGROUND: Needle-tract implantation is an important complication of cutting biopsy of hepatocellular carcinoma (HCC). This study was performed to evaluate the frequency of needle-tract implantation after ultrasound (US)-guided percutaneous biopsy of HCC and to describe triple-phase helical computed tomographic (CT) findings of implanted nodules. METHODS: Between April 1994 and December 1997, 205 patients underwent US-guided percutaneous biopsy for HCC. Review of medical records and the pathology database disclosed seven patients who were found to have needle-tract implantation of HCC. Among these patients, five underwent triple-phase helical CT examination. We analyzed the frequency of needle-tract implantation and triple-phase helical CT findings of implanted nodules, with particular attention to the morphology and enhancement pattern. RESULTS: Seven of 205 patients (3.4%) had tumor implantation along the needle tract at histologic examination after surgical resection. Eight implanted nodules in five patients were found on triple-phase helical CT images (one nodule in three patients, two nodules in one patient, and three nodules in one patient). All implanted nodules has well-circumscribed margins and were ovoid or lobulated in contour. On triple-phase helical CT, six (75%) implanted nodules were isodense compared with abdominal wall muscle on all triple-phase CTs, and two (25%) nodules were hyperdense on hepatic arterial and portal venous phases and isodense on equilibrium phase. CONCLUSIONS: The frequency of needle-tract implantation of HCC after percutaneous needle biopsy was higher than reported previously, and careful attention should be paid during interpretation of CT images in patients with a history of previous percutaneous biopsy. 相似文献
5.
Dysplastic nodules of the liver: imaging findings 总被引:2,自引:0,他引:2
Background: To verify characteristic features of hepatic dysplastic nodules at different imaging modalities.
Methods: Twenty-eight patients with 37 dysplastic nodules of the liver (0.8–3.0 cm) underwent sonography (28 patients), computed tomography
(CT; 24 patients), magnetic resonance (MR; 11 patients), and angiography (12 patients). Each nodule was analyzed for echogenicity,
attenuation, signal intensity, and vascularity.
Results: Echogenicity of nodules was high in 16 (43%), homogeneous in two (6%), and low in 19 (51%) of 37 nodules. Attenuation of
nodules was high in one (7%), homogeneous in four (26%), and low in 10 (67%) of 15 nodules on the arterial-phase CT images;
homogeneous in five (33%) and low in 10 (67%) of 15 nodules on the portal-phase CT images; and high in four (17%), homogeneous
in six (26%), and low in 13 (57%) of 23 nodules on the delayed-phase CT images. Signal intensity of nodules was high in 15
(94%) and homogeneous in one (6%) of 16 nodules on T1-weighted MR images and was homogeneous in seven (44%) and low in nine
(56%) of 16 nodules on T2-weighted MR images. Vascularity of nodules was avascular in 14 (88%) and slightly vascular in two
(12%) of 16 nodules.
Conclusions: Hepatic dysplastic nodules show diverse imaging characteristics with different imaging techniques; however, common imaging
findings of hepatic dysplastic nodules are low echo, low attenuation, and high, low, or homogeneous intensity on T1- and T2-weighted
MR, and avascularity.
Received: 13 May 1998/Accepted: 1 July 1998 相似文献
6.
Background: Hyperattenuating nodules detected by arterial phase helical computed tomography (HCT) in patients with cirrhosis usually
are believed to represent hepatocellular carcinomas (HCCs). We correlated HCT morphology of hyperattenuating hepatic nodules
detected during arterial phase scans with the histopathology of explanted livers of patients with hepatic cirrhosis undergoing
liver transplantation.
Methods: Three hundred fifty-four patients had arterial and portal phase HCT performed before subsequent hepatic transplantation.
Each patient received 180 mL of contrast by power injection at 5 mL/s. All hyperattenuating nodules detected on arterial phase
HCT were assessed for morphology and evidence for contrast enhancement. Explanted livers in all patients were then sectioned
at 10-mm intervals, and the histology of the nodules was correlated with the HCT findings.
Results: Sixty-one hyperattenuating nodules were detected on the arterial phase HCT in 43 patients: 41 nodules were benign regenerating
nodules (RN), three were dysplastic nodules (DP), and 17 were HCCs. Most RN/DP nodules were 5–20 mm in diameter, had distinct
margins, were homogeneous, and were isoattenuating on precontrast, portal, and delayed scans. Thirty-six showed positive contrast
enhancement and displayed a wide range of attenuation profiles. HCC nodules were 6–50 mm. All showed positive contrast enhancement
and displayed a wide range of attenuation profiles.
Conclusion: Hyperattenuating nodules seen on arterial phase HCT are likely to be RN/DP nodules. In many cases, it is not possible to
distinguish between RN/DP and HCC. Thus, clinical decisions regarding inclusion criteria for transplantation based on CT morphology
of liver lesions may be tenuous. 相似文献
7.
M. Kanematsu H. Hoshi T. Yamada T. Murakami T. Kim M. Kato R. Yokoyama H. Nakamura 《Abdominal imaging》1999,24(1):47-55
Purpose: The purpose of this study was to assess the imaging findings of pathologically-proved small hepatic nodules 2 cm in size
or smaller detected with ultrasonography in cirrhotic patients with suspected hepatocellular carcinoma (HCC).
Materials and Methods: We evaluated sonographically detected 32 small hepatic nodules which were pathologically confirmed in 23 consecutive cirrhotic
patients who were suspected of having HCC. Twenty-six lesions were confirmed with ultrasonographically-guided aspiration needle-core
biopsy, and six with definitive surgery. Ultrasonographic examination records were retrospectively reviewed. CT, and MR images
obtained with various imaging techniques were retrospectively reviewed by two radiologists in a blind fashion.
Results: The 32 hepatic nodules were comprised of seven focal fatty changes, two large regenerative nodules, three low-grade dysplastic
nodules, five high-grade dysplastic nodules, and fifteen HCCs. Ultrasonography showed various echogenicity for the hepatic
nodules. The signal-intensity characteristics with T1-weighted spin-echo, in-phase gradient-recalled-echo, and dynamic MR
imagings may be useful in distinguishing HCC from nonHCC nodules.
Conclusions: Nearly half of small hepatic nodules detected with ultrasonography were nonHCC nodules. Ultrasonographic findings may not
be reliable in characterizing small hepatic nodules in cirrhosis. CT and MR imaging obtained with the various techniques are
still insensitive to these hepatic nodules.
RID="ID="<e5>Correspondence to:</e5> M. Kanematsu
Received: 25 August 1997/Revision accepted: 19 November 1997 相似文献
8.
Cavernous transformation of the portal vein secondary to tumor thrombosis of hepatocellular carcinoma: spiral CT visualization of the collateral vessels 总被引:14,自引:0,他引:14
Background: We investigated the constituting collateral vessels in cavernous transformation of the portal vein (CTPV) caused by tumor
thrombosis of hepatocellular carcinoma (HCC) by using contrast-enhanced spiral computed tomographic (CT) examination.
Methods: Fifty-four histopathologically proven HCC patients with tumor thrombosis-induced CTPV were retrospectively included and assigned
to cirrhosis negative (n= 31) and positive (n= 23) groups. Another 15 cirrhotic patients with portal hypertension but no HCC and CTPV were used for comparison. Standardized
dual-phase contrast-enhanced spiral CT was performed for all patients. CT appearances of the collateral vessels of CTPV were
observed, and their visualization rates were analyzed.
Results: Biliary (cystic and paracholedochal veins) and gastric (left and right gastric veins) branches of the portal vein were the
most frequently visualized collateral vessels of CTPV. There was a marked difference in CT visualization rates for biliary
branches between patients with and without CTPV (83–94% vs. 0). No difference existed in visualization rates for gastric branches
across the three groups (77–87% for left gastric, 58–61% for right gastric vein).
Conclusions: Biliary and gastric branches of the portal vein are the major collateral vessels of CTPV. The intergroup differences in CT
visualization rates may provide clues to the roles that they might play in the hemodynamic adaptation process of CTPV.
Received: 13 October 1999/Accepted: 12 January 2000 相似文献
9.
Hepatic parenchymal enhancement in the cirrhotic liver: evaluation by triple-phase dynamic MRI 总被引:7,自引:0,他引:7
Background: To evaluate the changes of liver parenchymal enhancement in the cirrhotic liver by means of triple-phase dynamic magnetic
resonance (MR) imaging.
Methods: Triple-phase multisection dynamic MR imaging was performed in 32 patients with liver cirrhosis. The control group consisted
of 19 patients without liver cirrhosis. After precontrast images were obtained, arterial phase images were acquired 20 s after
the start of intravenous bolus administration of 0.10 mmol/kg of gadopentetate dimeglumine. Portal and delayed phase images
were then acquired 1 and 3 min, respectively, after the injection of contrast material. On each phase image, the signal-to-noise
ratio (S/N) from the liver parenchyma was measured by operator-defined regions of interest (ROIs). The contrast-enhanced ratio
(CER) on each phase was then obtained according to the following formula: [S/N(arterial or portal or delayed phase image)
− S/N(precontrast image)]÷ S/N(precontrast image). The portal perfusion index (PPI) also was obtained according to the following
formula: [S/N(portal phase image − S/N(arterial phase image)]÷ S/N(arterial phase image). The results were expressed as mean
± SD.
Results: The CERs of arterial, portal, and delayed phase images in patients with and without liver cirrhosis were 0.256 ± 0.211, 0.640
± 0.384, and 0.554 ± 0.318 and 0.132 ± 0.094, 0.404 ± 0.204, and 0.324 ± 0.144, respectively. The CERs were highest in the
portal phase and lowest in the arterial phase in patients with and without liver cirrhosis. The CER of the cirrhotic liver
was significantly higher than that of the normal liver in every phase (p < 0.05). PPIs with and without liver cirrhosis were 2.90 ± 4.03 and 3.86 ± 3.89, respectively. The PPI with liver cirrhosis was
significantly lower than that without liver cirrhosis (p < 0.05).
Conclusion: The enhancement of cirrhotic liver parenchyma is greater than that of the normal liver parenchyma at every phase of triple-phase
dynamic MR imaging.
Received: 17 August 2000/Revision accepted: 7 March 2001 相似文献
10.
Nodular regenerative hyperplasia of the liver in Budd–Chiari syndrome: CT and MR features 总被引:1,自引:0,他引:1
We report the imaging findings of spiral computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography in
a patient with nodular regenerative hyperplasia of the liver associated with Budd–Chiari syndrome. Spiral CT showed multiple
enhancing nodules during the hepatic arterial and portal venous phases. MR images showed multiple hyperintense nodules on
T1-weighted images and hypointense or isointense nodules on T2-weighted images. MR angiography showed thrombotic occlusion
of three hepatic veins, suggesting Budd–Chiari syndrome.
Received: 25 June 1999/Revision accepted: 22 September 1999 相似文献
11.
Small hepatocellular carcinoma: differentiation from adenomatous hyperplasia with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging 总被引:4,自引:0,他引:4
Background: To investigate the usefulness of color Doppler ultrasound (US) and dynamic Gd-DTPA-enhanced magnetic resonance (MR) imaging
in the differentiation of small hepatocellular carcinoma (HCC) and adenomatous hyperplasia (AH).
Methods: Thirty-eight small (3 cm or less) nodular lesions (in 38 cirrhotic patients) with US features consistent with HCC underwent
evaluation with color Doppler US and MR imaging. Breath-hold T1-weighted rapid acquisition spin echo MR sequence after bolus
injection of 0.1 mmol/kg gadopentetate dimeglumine was used to evaluate dynamic enhancement. US-guided tissue-core percutaneous
biopsy established the diagnosis: HCC in 28 cases and AH in 10.
Results: Color signals with pulsatile or continuous Doppler spectrum were demonstrated in 19 of 28 HCCs (68%) but in none of the AHs.
Although there was considerable overlap in signal intensity between HCC and AH on both unenhanced T1- and T2-weighted images,
early enhancement on breath-hold T1-weighted images obtained 40 s after starting contrast administration was observed in 22
of 28 HCCs (79%) but in none of the AHs. In 26 of 28 HCCs (93%), pulsatile or continuous flow at color Doppler US, early enhancement
at dynamic MR imaging, or both were observed.
Conclusion: Findings with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging enable a reliable distinction between small HCC and
AH.
Received: 8 August 1994/Accepted after revision: 27 January 1995 相似文献
12.
Struma ovarii: MR appearances 总被引:1,自引:0,他引:1
Background: Analysis of unenhanced and contrast-enhanced magnetic resonance (MR) images of struma ovarii, a rare benign neoplasm of the
ovary, is the aim of this study.
Methods: T2-weighted and Gd-DTPA-enhanced T1-weighted MR images of five histologically proven struma ovarii were evaluated retrospectively.
Results: In all patients, unenhanced and contrast-enhanced T1-weighted MR images showed complex cystic masses composed of multiple
cysts and a solid component, indicating the presence of large and small thyroid follicles. In four patients, the cyst fluid
was hypointense on T1-weighted images and hyperintense on T2-weighted images. In one patient, the fluid was hyperintense on
T1-weighted images and hypointense on T2-weighted images due to hemorrhage.
Conclusion: A complex mass composed of multiple cysts and a solid component, indicating the presence of large and small thyroid follicles,
appeared to be a characteristic MR finding of struma ovarii.
Received: 11 December 1995/Accepted: 15 December 1995 相似文献
13.
Preoperative evaluation of Klatskin tumor: accuracy of spiral CT in determining vascular invasion as a sign of unresectability 总被引:6,自引:0,他引:6
Cha JH Han JK Kim TK Kim AY Park SJ Choi BI Suh KS Kim SW Han MC 《Abdominal imaging》2000,25(5):500-507
Background: To assess the accuracy of spiral computed tomography (CT) in predicting the resectability of Klatskin tumor as determined
by vascular invasion.
Methods: Twenty-one consecutive patients with Klatskin tumor who had undergone laparotomy were included in this study. The preoperative
thin-section (5-mm-thick) spiral CT scans of these patients were assessed for the surgical resectability of tumor by evaluating
the vascular invasion. The criterion for vascular invasion indicating unresectability was the tumoral invasion of the proper
hepatic artery or main portal vein or simultaneous invasion of one side of the hepatic artery and the other side of the portal
vein.
Results: All nine patients with tumors thought to be unresectable on the basis of CT findings had tumors that were unresectable at
surgery (positive predictive value, 100%). Of 12 patients with tumors thought to be resectable, six had resectable tumors
(negative predictive value, 50%). Spiral CT failed to detect small hepatic metastasis (n= 1), lymph node metastasis (n= 1), extensive tumor (n= 2) and variation of bile duct (n= 2), which precluded surgical resection.
Conclusion: Spiral CT is a reliable method for detecting vascular invasion and unresectable tumors. However, it has limitations in detecting
variations of the bile duct or the intraductal extent of tumor.
Received: 24 November 1999/Accepted: 26 January 2000 相似文献
14.
Plain and gadolinium-DTPA-enhanced MR imaging of hepatocellular carcinoma treated with transarterial chemoembolization 总被引:12,自引:0,他引:12
M. Castrucci S. Sironi F. De Cobelli M. Salvioni A. Del Maschio 《Abdominal imaging》1996,21(6):488-494
Background: To assess unenhanced and gadolinium-enhanced magnetic resonance (MR) imaging patterns of hepatocellular carcinoma (HCC) treated
with transarterial chemoembolization (TACE).
Methods: Thirty-two patients with 48 HCC lesions underwent MR imaging before and 15 days after TACE. Fifteen lesions were then surgically
resected. The remaining 33 lesions were not removed and were followed up with MR imaging at 3, 6, 12, and 18 months after
treatment. Spin echo (SE) T1- and T2-weighted and gadolinium-enhanced SE T1-weighted sequences were employed. Qualitative
evaluation of signal intensity pattern of the treated lesions was performed in all cases. Histological evaluation and selective
hepatic arteriography were considered the gold standard of the study for the 15 resected lesions and the 33 unresected lesions,
respectively.
Results: On follow-up enhanced T1-weighted images of the 15 resected lesions, seven showed no area of enhancement corresponding to
complete necrosis at histologic examination. The remaining eight resected lesions showed areas of enhancement; in six of these
cases, viable tumor tissue was found at histology; in the other two lesions, histologic examination revealed the presence
of complete tumor necrosis. In the group of resected lesions, T2-weighted images showed no pattern characteristic of necrosis.
In 24 of 33 unresected lesions, loss of enhancement on follow-up enhanced T1-weighted images was a characteristic finding,
which correlated to devascularization at arteriography. Of these 24 lesions, 17 were completely hypointense on follow-up T2-weighted
images; the remaining seven showed small foci of hyperintensity. The other nine unresected lesions showed enhanced portions
on follow-up enhanced T1-weighted images, which corresponded to hyperintense areas on T2-weighted images. These findings correlated
to persistence of hypervascular areas at arteriography.
Conclusion: Gadolinium-enhanced T1-weighted MR imaging is a reliable method for evaluating the outcome of TACE treatment and is more
accurate than unenhanced T2-weighted MR imaging.
Received: 2 June 1995/Accepted: 18 July 1995 相似文献
15.
Computed tomographic evaluation and guided correction of malpositioned nephrostomy catheters 总被引:1,自引:0,他引:1
Background: To determine the utility of computed tomography (CT) in the detection and correction of malpositioned nephrostomy catheters
after contrast spillage during nephrostograms.
Methods: CT was performed in nine patients after an abnormal (contrast spillage) tube nephrostogram performed during or after nephrostomy
tube placement. CT was used to locate the nephrostomy catheter position in relation to the renal collecting system. If possible,
CT was also used for guidance and repositioning of the nephrostomy catheters into the intrarenal collecting system.
Results: In all nine cases, CT was successful in detecting the position of the suspected malpositioned catheter. In seven of nine
cases, CT demonstrated the catheter outside the renal collecting system and effectively helped reposition the catheters into
the intrarenal collecting system. In one case, the malpositioned nephrostomy catheter was within the intraperitoneal cavity
and required surgical correction. Another case required fluoroscopic-guided repositioning for the initial nephrostomy catheter,
which was partly posterior to the kidney and partly within the kidney. The catheter in this latter case was successfully advanced
over a guidewire into the collecting system.
Conclusions: CT may be used to detect possible catheter malposition associated with nephrostomy tube placement. CT may also be used to
successfully guide catheter repositioning in the renal collecting system.
Received: 29 May 1998/Accepted: 20 July 1998 相似文献
16.
Background: We investigatedspiral computed tomographic (CT) findings and underlying hemodynamic alterations in acute hepatic vein occlusion.
Methods: In nine dogs, immediately after balloon occlusion of the right (n = 4) or left (n = 5) hepatic vein through the transjugular or transfemoral route, we performed single-level dynamic CT with intravenous administration
of contrast medium. We created time attenuation curves of individual hepatic segments showing attenuation differences. To
investigate underlying hemodynamic alterations, hepatic arteriograms were obtained in two dogs.
Results: In all cases, there were three compartments with different time attenuation curves: normal, occluded, and adjacent. The normal
compartment, which comprised segments far from the occluded hepatic compartment, showed the normal pattern of hepatic enhancement.
The occluded compartment, which was the drainage territory of the occluded hepatic vein, showed high attenuation in the early
arterial phase and low attenuation in the portal phase. The adjacent compartment, which shared the same portal vein with the
occluded compartment and was drained by the patent hepatic vein adjacent to the occluded one, showed strong contrast enhancement
in the late arterial and early portal phase. Spiral CT and hepatic arteriography demonstrated the arterioportal shunt and
reversed portal venous flow in the occluded compartment, which drained into the adjacent compartment.
Conclusion: Acute hepatic vein occlusion on spiral CT appears as mild, early arterial, high attenuation and portal low attenuation of
the occluded compartment and strong enhancement in the late arterial and early portal phases of the adjacent compartment due
to arterioportal shunt and reversed portal flow.
Received: 15 March 2001/Revision accepted: 4 July 2001 相似文献
17.
Late-phase enhancement of the upstream portion of pancreatic adenocarcinoma on dual-phase helical CT 总被引:1,自引:0,他引:1
Background: Late-phase enhancement of pancreatic parenchyma upstream (tail side) of pancreatic adenocarcinoma is found frequently on
dual-phase helical computed tomography (CT). We measured the frequency of late-phase enhancement of the upstream portion of
pancreatic adenocarcinoma and normal pancreatic parenchyma using dual-phase helical CT.
Methods: Twenty-one patients with pancreatic adenocarcinoma and nontumorous pancreas upstream of tumors were compared with 100 control
patients without pancreatic disease. Early and late scans started at 25 and 75 s, respectively, after intravenous injection
of contrast material. The attenuation values of normal and nontumorous pancreas upstream of tumors were assessed in three
phases: precontrast, early, and late enhanced. Enhancement ratio (ER) was calculated as ER = (late phase − precontrast)/(early
phase − precontrast).
Results: Late-phase enhancements (ER > 1.0) were seen in 86% of upstream pancreas and 10% of normal pancreas. The mean ER of upstream
pancreas was significantly higher than that of normal pancreas (p < 0.01).
Conclusion: Late-phase enhancement of the pancreas upstream of the tumor is frequently observed in patients with pancreatic adenocarcinoma.
Late-phase enhancement and histology showed a correlation for chronic obstructing pancreatitis in five patients.
Received: 30 October 2000/Revision accepted: 7 February 2001 相似文献
18.
Detection of pancreatic adenocarcinoma: relative value of arterial and late phases of spiral CT 总被引:11,自引:0,他引:11
Background: Spiral computed tomography (CT) allows the pancreas to be imaged during peak contrast levels owing to the capability of fast
data acquisition. The objective of this study was to evaluate the relative value of the arterial and late phases of spiral
CT for detecting pancreatic adenocarcinomas.
Methods: Twenty-two patients with pathologically proved pancreatic adenocarcinomas underwent two-phase spiral CT. The CT scans were
performed with 5 mm collimation and 5 mm/s table speed. Images during the arterial and late phases were obtained at 30- and
180-second delays, respectively. The images of the arterial phase were compared with those of the late phase in terms of tumor
conspicuity from surrounding pancreatic parenchyma and tumor detectability by means of a 3-point grading system: 1 (poor),
2 (fair), and 3 (good).
Results: In terms of tumor conspicuity from surrounding pancreatic parenchyma, 16 lesions (73%) were good, 5 lesions (23%) were fair,
and 1 lesion (4%) was poor during the arterial phase, whereas 6 lesions (27%) were good, 9 lesions (41%) were fair, and 7
lesions (32%) were poor during the late phase (p= 0.0007). The arterial phase was superior to the late phase in 16 patients (73%) and equal in 6 patients (27%). For tumor
detectability, 18 lesions (82%) were good, 3 lesions (14%) were fair, and 1 lesion (4%) was poor during the arterial phase,
whereas 10 lesions (45%) were good, 7 lesions (32%) were fair, and 5 lesions (23%) were poor during the late phase (p= 0.0033). For detectability, the arterial phase was superior to the late phase in 14 patients (64%) and equal in 8 patients
(36%).
Conclusion: The arterial phase of spiral CT is superior to the late phase, which is equivalent to conventional CT for detecting pancreatic
adenocarcinoma.
Received: 1 August 1995/Accepted: 12 September 1995 相似文献
19.
Arbab AS Ichikawa T Araki T Toyama K Nambu A Ohsawa S Kumagai H Aikawa Y 《Abdominal imaging》2000,25(2):151-158
Background: To identify the most useful combinations of various pre- and postcontrast magnetic resonance (MR) image sequences in detecting
hepatocellular carcinoma (HCC) and its intrahepatic metastases before and after injection of SHU-555-A.
Methods: Thirty-eight lesions in 16 patients were evaluated before and after administration of SHU-555-A by using fast spin echo (FSE),
gradient echo (GRE), and echo planar (EP) imaging sequences using a 1.5-Tesla superconducting MR system. The signal intensity
ratio (SIR) and contrast-to-noise ratio (CNR) of the lesions, signal-to-noise ratios, and other parameters were calculated.
Results: Tumors were better detected after injection of SHU-555-A on all pulse sequences except on out-of-phase T1-weighted (T1W)-GRE
sequences. Tumor detectability was higher for precontrast EP imaging and T2*-weighted (T2*W)-GRE sequences, whereas detectability
at postcontrast was higher for T2*W-GRE, proton-density-weighted-FSE, and in-phase T1W-GRE sequences. The SIR and CNR at precontrast
were highest for EP imaging, and those at postcontrast were highest for T2*W-GRE.
Conclusion: SHU-555-A will increase the detectability of HCC and its liver metastases. T1W- and T2*W-GRE sequences would be the sequences
of choice.
Received: 21 December 1998/Revision accepted: 5 May 1999 相似文献
20.
Helical CT of the small bowel with an alternative oral contrast material in patients with Crohn disease 总被引:7,自引:0,他引:7
Doerfler OC Ruppert-Kohlmayr AJ Reittner P Hinterleitner T Petritsch W Szolar DH 《Abdominal imaging》2003,28(3):0313-0318
Background: We assessed the usefulness of helical computed tomography (CT) with a negative oral contrast material for detecting Crohn
disease.
Methods: Thirty-eight patients with proven Crohn disease were examined. We administered a large volume of a new negative oral contrast
material (Mucofalk suspended in water) and then proceeded with helical CT scanning. This technique is an alternative to CT
and conventional enteroclyses that use a nasojejunal tube. Two radiologists interpreted the scans, and patients were interviewed
about their tolerance of the procedure. We created multiplanar reformatted images in all cases. Potential of small bowel distention
by Mucofalk was evaluated by two observers on a three-point scale, and interobserver agreement was calculated with κ statistics.
Results: All patients who underwent enteroclysis stated that CT was the more comfortable method, the taste of the peroral contrast
medium was considered good by 52.6% and acceptable by 47.4%. Small bowel distention was excellent in 55% of cases, moderate
in 26%, and poor in 19%, with an interoberserver agreement of 78%. CT findings correlated with enteroclysis in 27 patients
who underwent both methods. Analysis of CT versus enteroclysis showed a sensitivity of 89% for CT versus 78% for small bowel
enteroclysis.
Conclusion: Mucofalk CT is a simple, rapid, noninvasive, and accurate method of evaluating extramucosal manifestations of Crohn disease.
The tubeless procedure improved patients' comfort and decreased time, cost, and radiation exposure. 相似文献