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1.
Fan-shaped hepatic parenchymal damage after ethanol injection therapy for hepatocellular carcinoma: MRI appearances 总被引:2,自引:0,他引:2
T. Fujita K. Honjo K. Ito T. Arita S. Koike K. Takano S. Tamura T. Matsumoto N. Matsunaga 《Abdominal imaging》1999,24(1):56-60
Background: T1- and T2-weighted magnetic resonance (MR) images frequently show fan-shaped areas of hypo- or hyperintensity in the hepatic
parenchyma adjacent to a treated hepatocellular carcinoma after percutaneous ethanol injection (PEI) therapy. These areas
correspond to abnormal contrast enhancement on serial dynamic MR images. The purpose of the present study was to describe
the location, appearance, and frequency of these abnormalities because it is important to understand these entities for the
correct assessment of therapeutic efficacy.
Methods: MR imaging including a multisection dynamic study was performed in 20 consecutive patients with hepatocellular carcinoma
treated with PEI therapy. We retrospectively evaluated the presence of fan-shaped hypointensities adjacent to treated tumors
in the liver parenchyma on T1-weighted images and hyperintensities on T2-weighted images and corresponding fan-shaped contrast
enhancement on both arterial-dominant and delayed-phase dynamic MR images. We review the location, appearance, and frequency
of these findings, and we discuss the possible causes on the basis of pathologic examinations.
Results: Seven (35%) of the 20 patients showed fan-shaped hyperintense areas adjacent to the treated tumors on T2-weighted images.
These areas showed isointensity in five patients and hypointensity in two patients on T1-weighted images. Of these seven patients,
one (14%) underwent the MR imaging within 1 month after the completion of PEI therapy, and six (86%) had it 2–9 months after
the completion of PEI therapy (mean = 6 months). In all seven patients, fan-shaped hyperperfusion abnormalities corresponding
to these areas of hyperintensity on T2-weighted images were seen on both arterial-dominant and delayed-phase dynamic MR images.
Pathologically, the coagulative necrosis of the hepatocytes with sinusoidal dilatation and the restoration by the development
of fibrous tissue were seen in these fan-shaped areas.
Conclusion: The fan-shaped areas of abnormal intensity on T1- and T2-weighted images and contrast enhancement on dynamic MR images seem
to be attributable to pathologic changes in the normal liver parenchyma induced by the toxic reaction of ethanol. Awareness
of the occurrence of such abnormalities in the peripheral liver parenchyma adjacent to the treated tumor is important for
the correct assessment of therapeutic efficacy.
RID="ID="<e5>Correspondence to:</e5> T. Fujita
Received: 24 June 1997/Accepted after revision: 22 October 1997 相似文献
2.
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
3.
Focal nodular hyperplasia of the liver: detection and characterization with plain and dynamic-enhanced MRI 总被引:2,自引:0,他引:2
Mortelé KJ Praet M Van Vlierberghe H de Hemptinne B Zou K Ros PR 《Abdominal imaging》2002,27(6):0700-0707
Background: We compared nonenhanced and dynamic gadolinium (Gd)–enhanced magnetic resonance imaging (MRI) appearances of hepatic focal
nodular hyperplasia (FNH) as depicted with breath-hold MR sequences and assessed the detectability of the individual MR sequences
used. Methods: We retrospectively reviewed 48 consecutive patients with FNH. All patients underwent nonenhanced (T1 fast low-angle shot
[FLASH] and T2 half-Fourier acquisition [HASTE]) and dynamic Gd-enhanced (T1 FLASH) MRI between December 1997 and March 2000.
Individual MR sequences were analyzed separately for number of lesions, signal intensity features, dynamic enhancement pattern,
and the presence and enhancement profile of a central scar. Ninety-five percent confidence intervals of absolute discrepancy
were calculated to define differences in lesion detection. Results: Seventy-seven lesions were found in 48 patients. Nonenhanced FLASH imaging depicted 59 (76.6%) lesions in 45 patients. HASTE
images showed 55 (71.4%) lesions in 44 patients. On T1- and T2-weighted images, lesions appeared predominantly hypointense
(69.5%) and hyperintense (72.7%), respectively. Arterial and portal venous dominant phase Gd-enhanced MRI demonstrated all
77 lesions (100%), most of which showed hypervascular (94.8%), homogeneous (97.4%), and incomplete (except the central scar:
58.4%) enhancement in the arterial phase. Portal venous phase images showed lesion isointensity (50.6%) or moderate hyperintensity
(46.8%) with complete enhancement (central scar: 94.8%). A central scar was detected on nonenhanced T1-weighted images (hypointense:
100%), T2-weighted images (hyperintense: 100%), arterial phase (hypointense: 59.7%) and portal venous phase (hyperintense:
71.4%) Gd-enhanced images in 78%, 69.1%, 77.9%, and 75.3% of tumors, respectively. Conclusion: Arterial and portal venous phase Gd-enhanced T1-weighted sequences are superior to nonenhanced images in the detection of
FNH. Typical MRI appearances include hypointensity on T1-weighted and hyperintensity on nonenhanced T2-weighted images. Most
commonly, FNH shows a homogeneous (without scar) and strong enhancement during the arterial phase, with lesion isointensity
or slight hyperintensity during the portal venous phase.
Received: 15 May 2001/Revision accepted: 22 August 2001 相似文献
4.
Background: To elucidate the imaging characteristics of well-differentiated hepatocellular carcinomas (HCCs) on ultrasonography (US),
computed tomography (CT), and magnetic resonance (MR) imaging.
Methods: Ultrasonograms, CTs, and MR images of 18 histopathologically proven well-differentiated HCCs in 15 patients were reviewed.
The findings of these images were correlated with histopathologic findings.
Results: On US, seven tumors were depicted as a hyperechoic area and eight as a hypoechoic area. Three tumors were not visualized.
On precontrast CT, four tumors were depicted as a low-density area, but 14 were not visualized. On conventional contrast-enhanced
CT, 12 tumors were depicted as a low-density area but six were not visualized. On T1-weighted MR images, 10 tumors had high
signal intensity and two had low signal intensity. Six tumors were not visualized. On T2-weighted MR images, five tumors had
high signal intensity and two had low signal intensity. Eleven tumors were not visualized. Tumors with fatty change and/or
clear cell formation were frequently hyperechoic on US and hyperintense on T1-weighted MR images.
Conclusions: Well-differentiated HCCs show different findings on US, CT, and MR imaging. Therefore, reliable diagnosis of well-differentiated
HCCs by these imaging techniques may be difficult.
Received: 29 April 1998/Revision accepted: 15 July 1998 相似文献
5.
Struma ovarii: appearance on MR images 总被引:2,自引:0,他引:2
I. Joja T. Asakawa A. Mitsumori T. Nakagawa Y. Hiraki T. Kudo M. Ando N. Akamatsu 《Abdominal imaging》1998,23(6):652-656
Background: The purpose of this multi-institutional study was to examine the appearance of struma ovarii on magnetic resonance (MR) images.
Methods: MR images of 12 patients with histologically proven struma ovarii were retrospectively reviewed. All patients underwent T1-weighted
and T2-weighted imaging. Contrast-enhanced T1-weighted images with Gd-DTPA were available in 10 patients. The following determinations
were made: tumor morphology, signal intensities, contrast-enhancement effects of solid components with Gd-DTPA, and comparison
of MR images with resected specimens.
Results: All 12 patients had both cystic and solid components, with a multilobulated surface and thickened septa. Signal intensities
on T1-weighted images were mainly low, partly intermediate to high, or high, and those on T2-weighted images were mainly high,
with different signal intensities. Contrast-enhancement effects were marked or moderate. The contents that showed low signal
intensities on T1-weighted images and signal voids or low signal intensities on T2-weighted images were viscid gelatinous
materials.
Conclusions: A multicystic tumor with a solid component, a multilobulated surface, and signal intensities that indicate the presence of
viscid gelatinous materials appear to be a characteristic MR finding of struma ovarii.
Received: 10 April 1997/Accepted after revision: 7 July 1997 相似文献
6.
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
7.
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
8.
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
9.
Background: The aim of this study was to determine the imaging characteristics of presacral epidermoid cysts and correlate the imaging
findings with the histopathologic findings.
Methods: We retrospectively reviewed sonographic, computed tomographic, and magnetic resonance examinations in four consecutive patients
with a pathologically proven presacral epidermoid cyst. Imaging findings of the presacral epidermoid cyst were correlated
with the histopathologic findings.
Results: In all four patients, sonography showed a presacral mass with a heterogeneous low echogenicity, and computed tomography showed
a discrete well-defined hypodense presacral mass with a thin wall. In the three patients who underwent magnetic resonance
imaging, the mass showed a heterogeneous low signal intensity on the T1-weighted image and a high signal intensity with multiple
small foci of low signal intensity in the nondependent portion of the mass on the T2-weighted image. These imaging findings
correlated well with the pathologic results. Aggregates of keratinous material contributed to these imaging findings.
Conclusion: In the diagnosis of the presacral epidermoid cyst, sonographic and magnetic resonance imaging findings may be helpful.
Received: 16 May 2000/Accepted: 14 June 2000 相似文献
10.
Background: We compared T2-weighted and heavily T2-weighted breath-hold turbo spin-echo (TSE) sequences with T2-weighted non-breath-hold
TSE sequence to evaluate hepatic hemangiomas on magnetic resonance (MR) with a phased-array multicoil.
Methods: Twenty-two patients with 27 hemangiomas were studied at 1.0-T scanner by using T2-weighted and heavily T2-weighted breath-hold
TSE sequences (18 s each) and non-breath-hold T2-weighted TSE sequences with use of a phased-array multicoil. Images were
quantitatively analyzed for tumor-to-liver signal-difference-to-noise ratios (SD/Ns) and tumor-to-liver signal intensity ratios
(T/Ls) and qualitatively analyzed for tumor conspicuity and motion-induced image artifacts.
Results: Quantitatively, T2-weighted breath-hold TSE images showed the highest SD/Ns among the three sequences, although the differences
from the heavily T2-weighted breath-hold TSE sequence and the T2-weighted non-breath-hold TSE sequence were not statistically
significant (p= 0.61 and 0.06, respectively). Heavily T2-weighted breath-hold TSE images showed the highest T/Ls among the three sequences.
The differences from the T2-weighted breath-hold TSE sequence and the T2-weighted non-breath-hold TSE sequence were statistically
significant (p < 0.001). Qualitatively, breath-hold TSE images were superior to non-breath-hold TSE images in terms of tumor conspicuity
(p < 0.01) and motion artifacts (p < 0.01).
Conclusion: T2-weighted breath-hold TSE sequence is superior to T2-weighted non-breath-hold TSE sequence in the evaluation of hepatic
hemangiomas on MR with a phased-array multicoil.
Received: 7 April 1997/Accepted: 28 May 1997 相似文献
11.
Detection of lymph-node metastases in patients with gastric carcinoma: comparison of three MR imaging pulse sequences 总被引:9,自引:0,他引:9
Kato M Saji S Kanematsu M Fukada D Miya K Umemoto T Kunieda K Sugiyama Y Takao H Kawaguchi Y Takagi Y Kondo H Hoshi H 《Abdominal imaging》2000,25(1):25-29
Background: To compare the diagnostic accuracy of magnetic resonance (MR) images obtained with three different pulse sequences for lymph-node
metastases in patients with gastric cancer.
Methods: T1-weighted spin-echo (SE), breath-hold T2-weighted fast SE, and triphasic gadolinium-enhanced dynamic gradient-recall-echo
(GRE) MR images obtained in 16 patients with gastric carcinoma were retrospectively reviewed. Regional lymph nodes were assigned
to four different groups, and image review was conducted on a lymph-node group-by-group basis; 64 lymph-node groups were reviewed
by two radiologists. Relative sensitivity, specificity, and accuracy were determined based on the findings with definitive
surgery and follow-up imaging. Diagnostic accuracy was determined by means of receiver-operating-characteristic (ROC) analysis.
Results: Relative sensitivities for lymph-node metastases with T1-weighted SE, breath-hold T2-weighted fast SE, and dynamic GRE images
were 61%, 94%, and 59%, respectively. Relative sensitivity with breath-hold T2-weighted fast SE images was significantly greater
than that with T1-weighted SE (p < 0.05) and dynamic GRE (p < 0.05) images. Diagnostic accuracy determined by ROC analysis was marginally higher with breath-hold T2-weighted fast SE (area under
ROC curve [Az]= 0.87) than with T1-weighted SE (Az = 0.78, p= 0.08) and dynamic GRE (Az = 0.79, p= 0.12) images.
Conclusion: Breath-hold T2-weighted fast SE sequence is useful in the detection of regional lymph-node metastases in patients with gastric
carcinoma.
Received: 11 November 1998/Revision accepted: 7 April 1999 相似文献
12.
Background: To compare half-Fourier acquisition single-shot turbo spin-echo (HASTE) magnetic resonance cholangiopancreatography (MRCP)
with two-dimensional turbo spin-echo (2D TSE) MRCP for imaging pancreatobiliary diseases.
Methods: Twenty-seven patients with biliary or pancreatic disease underwent MRCP on a 1.0-T scanner with a body phased-array coil.
A T2-weighted HASTE sequence (18 s) and a T2-weighted 2D TSE sequence (45 s) were used during a breath-hold by the patient.
The source images and maximum intensity projection images of both sequences were reviewed independently by two radiologists.
Results: Motion artifacts were more severely pronounced with 2D TSE sequences than with HASTE sequences (p < 0.001). All obstructions and their sites were accurately identified with both sequences. Filling defects (calculi) in bile
ducts were identified in all 22 segments (100%) with HASTE-MRCP, whereas calculi in 19 of 22 segments (86%) were identified
with 2D TSE-MRCP (p= 0.25). Three missed sites on 2D TSE-MRCP were intrahepatic bile ducts.
Conclusions: HASTE-MRCP is superior to 2D TSE-MRCP in terms of detecting motion artifacts and visualization of the pancreatic ducts. HASTE-MRCP
is comparable to 2D TSE-MRCP for visualization of the biliary ducts and their obstruction and is superior to 2D TSE-MRCP for
identification of calculi in intrahepatic bile ducts.
Received: 16 April 1997/Accepted: 28 May 1997 相似文献
13.
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
14.
Background: To evaluate the relationship between magnetic resonance (MR) imaging grading of iron deposition and serial serum ferritin
concentration in patients with chronic viral liver diseases.
Methods: In 80 patients with viral hepatitis and cirrhosis, MR images including T2*-weighted gradient echo images (echo time ≥ 6.5
ms) were reviewed. The grades of parenchymal iron deposition and iron-containing nodules in the liver and spleen and the liver-to-muscle
and spleen-to-muscle signal intensity ratios were compared with the most recent, the mean, the lowest, and the highest values
from all available serum ferritin levels.
Results: The serum ferritin concentration was significantly correlated with the grades of iron deposition in liver and spleen and
with the grades of iron-containing nodules seen on MR images (p < 0.05). Liver-to-muscle signal intensity ratio was weakly correlated with the ferritin concentrations. Among categories of ferritin
concentration, correlation with MR grades was highest for mean ferritin concentration (r = 0.487, p < 0.001).
Conclusion: MR imaging grades of hepatic iron and siderotic nodules correlate with serum ferritin, especially with the mean levels.
Received: 9 May 2000/Accepted: 28 June 2000 相似文献
15.
Background: To determine the feasibility of magnetic resonance (MR) imaging in the evaluation of intestinal Behçet's disease. Methods: Eight patients diagnosed to have intestinal Behçet's disease prospectively underwent MR imaging. Five patients had previously undergone abdominal surgery for intestinal Behçet's disease 27–81 months previously. Breath-hold T2-weighted single-shot fast spin echo, T1-weighted multiplanar spoiled gradient recalled echo, and postgadolinium-enhanced fat-suppressed T1-weighted opposed-phase multiplanar spoiled gradient recalled echo images were obtained. MR findings were analyzed by three independent radiologists in terms of the presence and location of bowel wall thickening and ulcer, maximal bowel wall thickness, grade of bowel wall enhancement, and presence and nature of extraluminal manifestations. K statistics were used to evaluate interobserver variability. Results: Seven cases (88%), including the five cases with previous operations, demonstrated bowel thickening of more than 9 mm and increased enhancement. Ulcer was depicted in four cases (50%) in the terminal ileum or an anastomosis site. Three cases (38%) showed extraluminal manifestation, such as mesenteric infiltration around the involved bowel (two cases) and a sinus tract to subhepatic abscess from perforation (one case). Conclusion: Breath-hold MR imaging is useful for the evaluation of bowel wall thickening, enhancement, mesentery infiltration, and abscess formation. Characteristic ulcerative lesions may be also depicted on T1- and T2-weighted breath-hold images. MR imaging is a useful method for postoperative follow-up study for the evaluation of recurrence. 相似文献
16.
Value of the dynamic and delayed MR sequence with Gd-DTPA in the T-staging of stomach cancer: correlation with the histopathology 总被引:21,自引:0,他引:21
Background: To evaluate the usefulness of dynamic and delayed magnetic resonance (MR) imaging in the T-staging of stomach cancer and
to compare the enhancement pattern of the cancerous lesion and the normal wall.
Methods: We performed MR imaging in 46 patients with stomach cancer (including four early gastric cancers and 42 advanced gastric
cancers). Axial, sagittal, or coronal two-dimensional fast low-angle shot) MR images for the water-distended stomach were
obtained with dynamic protocol, including precontrast images and images obtained 30, 60, 90, and 240–300 s after intravenous
injection of the 0.1 mM Gd-DTPA/kg solution. We evaluated the thickness, interruption (or not) of the low signal intensity
bands, and enhancement pattern of the cancerous wall and normal gastric wall. We prospectively evaluated the depth of cancer
invasion, perigastric infiltration (extraserosal invasion), perigastric organ invasion, and regional lymph nodes and determined
tumor staging on MR images. These MR evaluations including MR-determined staging were correlated with the surgicopathologic
findings.
Results: Stomach cancer was shown as having a thickened wall with a rapid enhancing pattern after intravenous Gd-DTPA administration.
The mucosa (and/or submucosa) affected by stomach cancer showed an early enhancement pattern (30–90 s after Gd-DTPA administration)
in 43 of 46 patients (93%). The normal gastric mucosa demonstrated a delayed peak enhancement pattern (>90 s after Gd-DTPA
administration) in 29 of 46 patients (63%) and variable enhancement pattern in 17 of 46 patients (37%). An interrupted low
signal intensity band or highly enhanced tumorous lesion penetrating through the gastric wall was seen in 17 of 19 pT3 patients
(90%). Consistency between MR-determined staging and surgicopathologic staging occurred in three of four pT1 tumors (75%),
10 of 13 pT2 tumors (77%), 17 of 19 pT3 tumors (90%), and eight of 10 pT4 tumors (80%); overall accuracy was 83%. Overall
accuracy of regional lymph node involvement, as determined by enhanced MR, was 52%; 24 of 46 node groups were positive.
Conclusions: Dynamic and delayed MR imaging can be useful for predicting depth of cancer invasion, perigastric infiltration (extraserosal
invasion), and perigastric organ invasion by gastric cancer.
Received: 28 July 1998/Revision accepted: 27 January 1999 相似文献
17.
P. Reimer E. J. Rummeny M. Wissing G. M. Bongartz G. Schuierer P. E. Peters 《Abdominal imaging》1996,21(5):427-432
Background: We compared two T2-weighted turbo spin echo (TSE) sequences with a T2-weighted conventional SE (CSE) sequence to determine
whether sequences derived from rapid acquisition with relaxation enhancement such as TSE could replace CSE for the detection
and subsequent characterization of focal liver lesions.
Methods: A total of 55 consecutive patients with 107 liver lesions underwent magnetic resonance imaging examinations at 1.5 Tesla,
with a constant imaging protocol. TSE pulse sequences were acquired with eight echo trains (repetition time [TR], 4718 ms;
echo time [TE], 90 ms; acquisition time [TA], 4.03 min; and a symmetric k-space ordering scheme) and 11 echo trains (TR, 4200
ms; TE, 140 ms; TA, 4.40 min; and an asymmetric k-space ordering scheme) and compared with CSE (TR, 2300 ms; TE, 45/90 ms;
TA, 9.53 min). Images were analyzed qualitatively by scoring image quality and artifacts and counting focal liver lesions
by independent reading with consensus obtained for discrepancies. Quantitative analysis was performed by measuring signal-to-noise
(S/N), contrast-to-noise (C/N), and tumor–liver signal intensity (T/L) ratios.
Results: T2-weighted TSE sequences provided better subjective image quality and reduced artifacts as compared with the T2-weighted
CSE sequence. CSE and TSE sequences exhibited no statistically significant differences in liver S/N, lesion–liver C/N (CSE
TE, 90 ms: 18.6 ± 14.0; TSE TE, 90 ms: 16.5 ± 12.9) and the detectability of focal liver lesions. Heavily T2-weighted TSE
with a TE of 140 ms allowed correct characterization of focal liver lesions based on a T/L ratio of 3.0 in 84% of patients.
Conclusions: T2-weighted TSE sequences are as suited as CSE for the detection (TE, 90 ms), and appear to be superior for the characterization
(TE, 140 ms), of focal hepatic lesions. Whether a single sequence, such as a double-echo TSE or a single-echo TSE sequence
with a TE between 110 and 120 ms, might perform both functions as well or better than CSE is unknown. However, because of
time savings, TSE eventually may be preferred over CSE.
Received: 13 December 1994/Accepted after revision: 31 March 1995 相似文献
18.
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
19.
Sung Eun Song Deuk Jae Sung Beom Jin Park Min Ju Kim Sung Bum Cho Kyeong Ah Kim 《Abdominal imaging》2011,36(4):483-488
Background
To evaluate the magnetic resonance (MR) imaging features of uterine adenomyoma in comparison with histopathologic findings.Materials and methods
MR images of seven patients who had surgically proven uterine adenomyoma were retrospectively reviewed by two radiologists in consensus regarding the morphologic appearance, including tumor size, location, margin, presence of concomitant adenomyosis, presence and signal intensity of cavity within tumor, and signal intensity and enhancement pattern of solid portion of tumor. MR imaging findings were correlated with histopathologic findings.Results
Tumor location was submucosal in three cases, subserosal in two, and mixed mural/subserosal in two. All tumors were well circumscribed on T2-weighted images and contrast-enhanced fat-suppressed T1-weighted images. In six cases, well defined cavities of high signal intensity, which reflected hemorrhagic cavities pathologically, were demonstrated within the tumors on T1-weighted images. Concomitant adenomyosis was observed in five cases. Solid portion of all tumors except hemorrhagic cavities exhibited iso-signal intensity on T1-weighted images, various signal intensity on T2-weighted images, and homogeneous enhancement on contrast-enhanced fat-suppressed T1-weighted images in five cases.Conclusion
When MR imaging shows a well circumscribed mass with hemorrhagic cavities of high signal intensity on T1-weighted images and concomitant adenomyosis in the uterus, adenomyoma should be considered in the differential diagnosis. 相似文献20.
Ovarian fibroma of high signal intensity on T2-weighted MR image 总被引:1,自引:0,他引:1
J. Ueda T. Furukawa K. Higashino K. Ueda S. Kobayashi K. Shimura T. Tsujimura Y. Araki 《Abdominal imaging》1998,23(6):657-658
It has been reported that ovarian fibromas display low signal intensity on both T1- and T2-weighted magnetic resonance images.
We report an ovarian fibroma exhibiting low signal intensity on a T1-weighted image and high signal intensity on a T2-weighted
image. Microscopically pronounced myxomatous changes were shown in the fibroma. The signal intensity of ovarian fibromas differs
with the degree of myxomatous change.
Received: 5 March 1997/Accepted after revision: 23 May 1997 相似文献