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1.
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
2.
Cervical carcinoma: efficacy of thin-section oblique axial T2-weighted images for evaluating parametrial invasion 总被引:5,自引:0,他引:5
M. Shiraiwa I. Joja T. Asakawa K. Okuno O. Shibutani N. Akamatsu T. Kudo Y. Hiraki 《Abdominal imaging》1999,24(5):514-519
Background: To investigate the efficacy of thin-section oblique axial T2-weighted images in the assessment of parametrial invasion by
cervical carcinoma.
Methods: One hundred parametria of 50 patients with cervical carcinoma were evaluated with pathologic correlation. We compared the
sensitivity, specificity, and diagnostic accuracy in the assessment of parametrial invasion by cervical carcinoma between
axial T2-weighted images and thin-section oblique axial T2-weighted images.
Results: Thin-section oblique axial T2-weighted images provided accurate cross sections of the cervix with excellent detail and detected
parametrial invasion more accurately than did axial T2-weighted images showing cross sections of the trunk. Although the sensitivity,
specificity, and accuracy for parametrial invasion were 46.4%, 91.7%, and 79.0%, respectively, on axial T2-weighted images,
the corresponding values were 67.9%, 97.2%, and 89.0%, respectively, on thin-section oblique axial T2-weighted images. There
were statistically significant differences in the sensitivity (p = 0.014), specificity (p = 0.046), and accuracy (p = 0.002) in detecting parametrial invasion between these two types of images.
Conclusions: Thin-section oblique axial T2-weighted images are useful for the assessment of parametrial invasion by cervical carcinoma.
Received: 11 September 1998/Accepted: 2 December 1998 相似文献
3.
R. A. Huch Böni C. Meyenberger J. Pok Lundquist F. Trinkler U. Lütolf G. P. Krestin 《Abdominal imaging》1996,21(4):345-352
Background: To compare endorectal coil magnetic resonance imaging (MRI) with body coil MRI in detecting local recurrence of gynecologic
tumors and prostate and rectal cancers.
Methods: Forty-six patients with suspected recurrent pelvic malignancies (13 gynecologic, 15 prostatic, and 18 anorectal primaries)
were enrolled in the study. Axial T1- and T2-weighted body coil images and T2- and contrast-enhanced T1-weighted axial endorectal
coil images were obtained on a 1.5 T system. Results of the MR examinations were compared with histogical findings and follow-up
examinations with respect to the diagnostic accuracy and diagnostic confidence for assessment or exclusion of local recurrence.
Results: Recurrent disease was histologically confirmed in eight patients with primary gynecologic malignancies, seven with suspected
prostatic recurrence, and seven with suspected anorectal recurrence. Overall, accuracy of body coil MRI was 67% for gynecologic
tumors, 36% for prostatic recurrences, and 59% for rectal recurrences. T2- and contrast-enhanced T1-weighted endorectal sequences
yielded similar results, with an accuracy of 73% for depiction of gynecologic recurrence, 77% for prostatic recurrence, and
77% for rectal recurrence. The difference in accuracy between body coil and endorectal coil examinations was statistically
significant (p < 0.05) only for prostatic cancer. Diagnostic confidence was, however, significantly improved (p < 0.05) in all tumors (T2-weighted endorectal coil examination was superior to T2-weighted body coil images in 71% of cases).
Conclusion: Although the results of endorectal coil MRI are only slightly superior to those of body coil MRI for the detection of recurrent
gynecologic and anorectal tumors, diagnosis can be made with greater diagnostic confidence in many cases. For detection of
prostatic recurrence, endorectal MRI is highly recommended.
Received: 27 April 1995/Accepted: 17 June 1995 相似文献
4.
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
5.
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
6.
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
7.
T. C. L. Soong R. C. Lee H. C. Cheng J. H. Chiang H. S. Tseng C. W. Lin M. M. H. Teng 《Abdominal imaging》1998,23(5):515-519
Background: To report the dynamic magnetic resonance (MR) imaging findings of hepatolithiasis.
Methods: Dynamic MR images (fast spoiled gradient echo sequence with intravenous injection of gadopentate dimeglumine) and computed
tomography, cholangiography, or angiography of nine patients with hepatolithiasis are analyzed.
Results: All affected hepatic segments showed atrophic changes and contained dilated intrahepatic ducts. These segments showed either
iso- or hypointensity on T1-weighted imaging and hyperintensity on T2-weighted imaging. Preferential enhancement was noted
throughout all phases of the dynamic study and persisted to delayed T1-weighted imaging in seven patients. In the last two
patients, severe atrophic changes made evaluating signal intensity differences and enhancement patterns difficult.
Conclusion: In addition to intrahepatic stones and biliary dilatation, segmental atrophy, signal intensity differences, and preferential
and persistent enhancement are important MR findings of hepatolithiasis.
Received: 18 June 1997/Accepted: 23 July 1997 相似文献
8.
Evaluation of Crohn disease activity with magnetic resonance imaging 总被引:11,自引:0,他引:11
Maccioni F Viscido A Broglia L Marrollo M Masciangelo R Caprilli R Rossi P 《Abdominal imaging》2000,25(3):219-228
Background: The purpose of this study was to assess the accuracy of magnetic resonance imaging (MRI) in evaluating Crohn disease (CD)
activity. The intestinal inflammatory activity is usually present in patients under pharmacologic treatment, despite their
clinical remission.
Methods: Twenty patients with CD, all under pharmacologic treatment, were prospectively studied by MRI at 1.5 T as a periodic control.
Positivity of three acute-phase reactants was considered an index of biologic activity (BA). T2-weighted, T2-weighted fat-suppressed
turbo spin-echo, and breath-hold T1-weighted turbo field-echo sequences, before and after gadolinium intravenous injection,
were obtained. A negative superparamagnetic contrast agent was orally administered. The following MRI parameters were qualitatively
evaluated by three radiologists at the level of the affected bowel and compared with clinical data: wall thickness (WT), wall
T2-weighted signal (T2W), wall contrast enhancement (WE), amount of fibrofatty proliferation (FP), and T2-weighted signal
of fibrofatty proliferation on fat-suppressed images (T2FP). The κ coefficient of agreement was calculated. The Spearman rank
correlation was used for the analysis of clinical and radiologic data.
Results: Nineteen of 20 patients were in clinical remission (Crohn Disease Activity Index < 150). On the basis of laboratory tests,
nine of 20 patients had biologically active disease. An excellent correlation was found between BA and WE, T2W, and T2FP (0.900,
0.927 and 0.961, respectively; p < 0.0001), and a lower correlation was found between BA and WT and between BA and FP (0.78 and 0.62). Excellent statistical
correlation was also found between WE and T2W and between WE and T2FP (0.876 and 0.892).
Conclusions: An excellent statistical correlation was found between biologically “active” disease and the following MRI parameters: wall
gadolinium enhancement, wall hyperintensity on T2-weighted fat-suppressed images, and hyperintensity of fibrofatty proliferation
on T2-weighted fat-suppressed images. Therefore, MRI can be valuable in assessing CD activity.
Received: 22 January 1999/Revision accepted: 3 November 1999 相似文献
9.
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
10.
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
11.
Background: To evaluate the diagnostic efficacy of fast T2-weighted magnetic resonance (MR) imaging sequences on image quality, hepatic
lesion detection, and lesion conspicuity.
Methods: Three breath-hold, fast T2-weighted sequences with turbo-spin-echo (TSE), half-Fourier acquisition single-shot TSE (HASTE),
and inversion recovery (IR) HASTE techniques were examined for 43 lesions in 20 consecutive patients. Evaluation was performed
qualitatively on image quality and lesion detectability and quantitatively on lesion conspicuity by using lesion/liver signal-intensity
and contrast-to-noise ratios.
Results: Artifacts were significantly less present on the HASTE sequence (p < 0.01). Both TSE and HASTE sequences detected 39 lesions (91% each); the IR HASTE sequence detected 37 (86%). IR HASTE sequence
showed a significantly higher signal-intensity ratio than did the others (p < 0.01).
Conclusions: Breath-hold TSE versus breath-hold HASTE or IR HASTE is still the most robust sequence in lesion detection, image quality,
and lesion conspicuity. However, the HASTE sequence offers good lesion detection and image quality, and the IR HASTE has a
better signal-intensity ratio.
Received: 15 January 1999/Accepted: 24 March 1999 相似文献
12.
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
13.
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
14.
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
15.
MR imaging of advanced gastric cancer: comparison of various MR pulse sequences using water and gadopentetate dimeglumine as oral contrast agents 总被引:14,自引:0,他引:14
Background: To evaluate clinical usefulness of oral contrast agents (gadopentetate dimeglumine and water) and to assess proper magnetic
resonance (MR) imaging in evaluating advanced gastric cancer (AGC) by comparing different MR imaging techniques.
Methods: Fifteen patients with AGC were imaged with a 1.0-T MR imager and body-array coil. All patients underwent surgery or laparascopic
biopsy. Fast low-angle shot (FLASH), half-Fourier single-shot turbo spin-echo (HASTE), and true fast imaging with steady-state
precession time (FISP) images were obtained after ingestion of 900 mL tap water in each patient, followed by postcontrast
FLASH images after additional ingestion of gadopentetate dimeglumine (Gd-DTPA). Qualitative analysis including T-staging of
AGC and scoring of imaging quality and quantitative analysis were performed prospectively.
Results: In image quality and diagnostic accuracy of T-staging, FLASH imaging showed results slightly superior to those of other imaging
modalities, and there was no great difference between using water and Gd-DTPA as an oral contrast agent. As for cancer-to-gastric
lumen contrast-to-noise ratio (CNR), HASTE and true FISP imaging were superior to FLASH imaging with Gd-DTPA (p < 0.0001). In cancer-to-pancreas CNR, FLASH imaging without Gd-DTPA showed the best result.
Conclusions: The use of Gd-DTPA as a positive contrast agent may not be imperative, and T1-weighted FLASH imaging in combination with
true FISP imaging with ingestion of tap water can be very useful in evaluating AGC with MR imaging.
Received: 29 October 1998/Revision accepted: 27 January 1999 相似文献
16.
MR imaging of cervical carcinoma: comparison among T2-weighted,dynamic, and postcontrast T1-weighted images with histopathological correlation 总被引:4,自引:0,他引:4
K. Tsuda T. Murakami H. Kurachi H. Ogawa H. Oi A. Miyake Y. Narumi H. Nakamura 《Abdominal imaging》1997,22(1):103-107
Background: To identify the reasons for misdiagnosis of the degree of stromal invasion by uterine cervical cancer with various magnetic
resonance sequences.
Methods: T2-weighted, dynamic, and postcontrast T1-weighted images were obtained in the sagittal plane in 20 patients with uterine
cervical cancer. After evaluating these sequences for the degree of stromal invasion, histologic specimens were directly correlated
with these images.
Results: The degree of stromal invasion was correctly diagnosed in 15 of the 20 cases on T2-weighted images, in 12 on dynamic images,
and in eight on postcontrast T1-weighted images. All misdiagnoses were due to overestimation. Histologically, peritumoral
stroma showed inflammation or edema in two patients, whereas no histological abnormality was found in the other patients.
A hyperintense rim, i.e., a peritumoral enhanced ring-shaped structure, was observed on the enhanced images of five patients.
The hyperintense rim corresponded to the periphery of the tumor in three patients and to the cervical stroma in two patients.
Conclusion: T2-weighted images permitted the most accurate evaluation of stromal invasion by uterine tumors. Overdiagnosis may be due
to an abnormal intensity of the cervical stroma, which was observed more frequently on dynamic and postcontrast T1-weighted
images than on T2-weighted images.
Received: 10 November 1995/Accepted after revision: 13 March 1996 相似文献
17.
Diuretic contrast-enhanced magnetic resonance urography (MRU) is analogous to conventional intravenous urography (IVU) and,
hence, designated as excretory MRU. It is performed with a T1-weighted fast gradient-echo sequence to obtain breath-hold,
dynamic MRU after intravenous injection of low-dose furosemide (5–10 mg) and gadolinium (Gd) chelate. The combination of Gd
and furosemide is the key for achieving a uniform distribution of the contrast material inside the entire urinary tract. It
provides high-resolution images of nondilated urinary tracts and information about the renal function. This pictorial essay
reviews the technical aspects and practical consideration of diuretic Gd-enhanced MRU and underlines its diagnostic capability
in comparison with IVU in the depiction of nondilated collecting systems. We discuss its potential applications, as in young
patients with anatomic anomalies, patients with renal transplants, patients allergic to iodinated contrast medium, and avoiding
multimodality work-up in the evaluation of kidney donors and patients with renal and extrarenal tumor diseases.
Received: 1 December 2001/Accepted: 5 January 2002 相似文献
18.
We summarize and discuss our previous research results on the correlation between findings on magnetic resonance (MR) imaging
and angiographically assisted computed tomography (CT) and the intensity of vascular endothelial growth factor (VEGF) expression
in hepatocellular carcinoma (HCC) and in the surrounding nontumorous liver. MR images (n = 22), CT during arterial portography (n = 20), and CT hepatic arteriography (n = 17) were retrospectively correlated quantitatively and qualitatively with VEGF expression in HCCs and in the surrounding
liver assessed by western blotting. HCC-to-liver contrast-to-noise ratio correlated with VEGF expression index (VEGFIND) values of HCCs inversely on opposed-phase, T1-weighted, spoiled gradient recalled-echo (GRE) images, directly on T2-weighted,
fast spin-echo images, and marginally and inversely on gadolinium-enhanced hepatic arterial-phase GRE images. On T2-weighted
fast spin-echo images, standard deviation ratio of HCCs correlated directly with VEGFIND values of HCCs. By CT hepatic arteriography, the contrast-enhancement index of HCCs showed a moderate inverse correlation
with VEGFIND values of HCCs, and the contrast-enhancement index of the liver showed marginal, moderate direct correlation with VEGFIND values in the liver. Heterogeneities of HCCs on images correlated directly with VEGFIND values of HCCs on opposed-phase T1-weighted GRE images, T2-weighted fast spin-echo images, hepatic arterial-phase GRE images,
equilibrium-phase GRE images, and CT hepatic arteriogram. Our results may reflect that MR signal intensity, hepatic arterial
vascularity, and heterogeneity of HCCs on CT or MR images are closely related to the intensity of VEGF expression in HCC as
upregulated by hyper- or hypoxia in HCCs. Although the real effects of our results on radiologic practice are debatable at
this moment, we believe that our results may help future radiologic practice in conjunction with biomolecular or genetic treatment
for HCCs. 相似文献
19.
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
20.
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