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1.
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
2.
M. T. Keogan C. E. Spritzer E. K. Paulson S. S. Paine L. Harris J. L. Dahlke J. R. MacFall 《Abdominal imaging》1996,21(5):433-439
Background: The purpose of this study was to compare a fast spin-echo sequence combined with a respiratory triggering device (R. trig.
FSE) with conventional T2-weighted spin-echo (CSE) and inversion recovery (STIR) sequences for the detection of focal hepatic
lesions.
Methods: We performed a prospective study of 33 consecutive patients with known or suspected hepatic tumors. All patients underwent
R. trig. FSE, CSE, and STIR imaging at 1.5 T. Acquisition times were 10.7 min for the CSE sequence and ranged from 12 to 15
min for STIR and from 5 to 7 min for R. trig FSE. For each sequence, liver–spleen contrast-to-noise ratio (CNR) and liver–lesion
CNR were determined quantitatively. Image artifact and sharpness were graded by using a four-point scale on each sequence
by two independent readers. Both readers also independently identified hepatic lesions (up to a maximum of eight per patient).
For patients with focal lesions, the total number of lesions detected (on each sequence) and the minimum size of detected
lesions were also determined by each reader.
Results: No significant difference was detected between R. trig. FSE and CSE or STIR in either liver–spleen CNR or liver–lesion CNR.
R. trig. FSE images were equivalent to CSE and superior to STIR in sharpness (p < 0.01) and presence of artifact (p < 0.01). R. trig. FSE detected a higher number of lesions (reader 1: n = 92, reader 2: n = 86) than CSE (reader 1: n = 70,
reader 2: n = 69) and a significantly higher number than STIR (reader 1: n = 71, reader 2: n = 76). Lesion structure was significantly
better defined with R. trig. FSE than with STIR (p < 0.01) and CSE (p < 0.05).
Conclusions: Compared with CSE and STIR, R. trig. FSE produces hepatic images of comparable resolution and detects an increased number
of focal hepatic lesions in a shorter period of time.
Received: 5 April 1995/Accepted: 2 May 1995 相似文献
3.
We present three patients with peritoneal metastases from transitional cell carcinoma of the urinary tract. CT scan in one
patient showed massive ascites with subtle peritoneal thickening and infiltration of omental fat. We had the opportunity to
study the other patients with both CT and MR. Both examinations showed numerous large and small peritoneal implants in the
abdomen and pelvis, mostly in the greater omentum.
Received: 6/10/96/Accepted: 7/12/96 相似文献
4.
Diffusion-weighted MR imaging with single-shot echo-planar imaging in the upper abdomen: preliminary clinical experience in 61 patients 总被引:48,自引:0,他引:48
Background: To determine the potential ability of diffusion-weighted magnetic resonance (MR) imaging with single-shot echo-planar imaging
(DW imaging) in the upper abdomen by apparent diffusion coefficient (ADC) and signal:intensity ratio (SIR) measurements.
Methods: DW imaging was performed in 61 clinical patients. ADCs in the liver, pancreas, spleen, kidney, and different pathological
conditions were calculated. Spleen-to-liver SIR and segmental intensity difference of the liver (SID) were also calculated.
Results: The mean ADCs (mm2/s) were 2.28 × 10−3± 0.07 in the liver, 1.44 × 10−3± 0.05 in the spleen, 1.94 × 10−3± 0.19 in the pancreas, and 5.76 × 10−3± 0.06 in the kidney. The mean ADC of cirrhotic liver was 1.96 × 10−3± 0.62, which was lower than that of normal liver. Other pathologic conditions also showed ADCs different from those of normal
tissues. All DW images showed significantly higher spleen-to-liver SIRs and SIDs than did T2-weighted images (p < 0.05).
Conclusion: The mean ADCs obtained with DW imaging were different in each upper abdominal organ and with each pathologic condition. DW
images showed better soft tissue contrast than did T2-weighted images with regard to SIR and CNR in depicting and characterizing
upper abdominal disorders.
Received: 24 July 1998/Revision accepted: 2 December 1998 相似文献
5.
Endorectal surface coil MR imaging as a staging technique for rectal carcinoma: a comparison study to rectal endosonography 总被引:16,自引:0,他引:16
Background: Preoperative staging of rectal cancer is critical for guiding therapy and prescribing the most appropriate treatment option.
The purpose of this investigation was to compare the accuracy of endorectal surface coil magnetic resonance imaging (ERSCMRI)
with endosonography (EUS) in staging rectal lesions.
Methods: Fourteen patients with rectal carcinoma, initially detected by barium enema or sigmoidoscopy underwent ERSCMRI and EUS. Subsequent
resection of the lesions was performed, and the staging accuracies of these two modalities are compared.
Results: MR T-staging agreement with pathologic T-staging was similar to that of EUS, but MR enabled more accurate identification
of nodal involvement.
Conclusion: ERSCMRI produced greater overall accuracy in staging for rectal carcinoma than did EUS.
Received: 10 September 1998/Revision accepted: 10 February 1999 相似文献
6.
Background: We used magnetic resonance (MR) pyelography to compare the value of thick-slab single-shot rapid acquisition with relaxation
enhancement (RARE) sequence with that of multislice half-Fourier acquisition single-shot turbo-spin-echo (HASTE) sequence
in evaluating the full spectrum of morphologic features in a group of patients with hydronephrosis.
Methods: MR pyelographic images, with the use of thick-slab RARE and multislice HASTE sequences in 90 patients, were evaluated for
image quality, presence of hydronephrosis, and level and cause of obstruction.
Results: HASTE sequences provided images of better quality than did RARE sequences (p < 0.001). There was no statistically significant difference in demonstrating the presence of hydronephrosis (p = 0.5) and level of obstruction (p = 0.125). Sensitivity, specificity, and accuracy in diagnosing cause of obstruction were 61.7%, 62.5%, and 62%, respectively,
for RARE sequences and 80%, 82.5%, and 81%, respectively, for HASTE sequences, with a statistically significant difference
(all p < 0.05).
Conclusion: Multislice HASTE sequence provides better diagnostic information than does thick-slab RARE sequence, particularly in evaluating
the cause of obstruction. 相似文献
7.
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
8.
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
9.
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
10.
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
11.
A. La Fianza E. M. Di Maggio L. Preda M. R. Schifino R. Campani 《Abdominal imaging》1997,22(5):522-523
Implantation subcutaneous metastases from ovarian cancer are an uncommon event in surgery, and diagnostic procedures such
as laparoscopy, fine-needle biopsy, and intraperitoneal catheter access are usually used. Findings of tumor implantations
are rarely reported with diagnostic imaging techniques. In this case, an infiltrative subcutaneous metastasis appeared on
computed tomography 4 months after paracentesis in a patient with untreated ovarian cancer. Differential diagnostic problems
are discussed.
Received: 19 April 1996/Accepted: 22 May 1996 相似文献
12.
Cirrhosis: spectrum of findings on unenhanced and dynamic gadolinium-enhanced MR imaging 总被引:1,自引:0,他引:1
The appearance of the cirrhotic liver on computed tomography can be difficult to evaluate and can frustrate the radiologist
distinguishing benign from malignant lesions. Hepatic edema, fibrosis, atrophy, and vascular abnormalities are common in the
cirrhotic liver and produce derangements in morphology, attenuation, and perfusion, limiting the accurate characterization
of hepatic masses. With the development of fast magnetic resonance (MR) sequences and dynamic postgadolinium-enhanced imaging,
most hepatic lesions with uncertain etiology on computed tomography can be accurately characterized on MR imaging. We describe
MR imaging techniques useful for imaging cirrhosis and its complications. We also illustrate the spectrum of findings in the
cirrhotic liver on dynamic gadolinium-enhanced MR imaging, including reticular and confluent fibrosis, fatty infiltration,
hemochromatosis, regenerating nodules, dysplastic nodules, hepatocellular carcinoma, and sequela of portal hypertension.
Received: 16 November 2000/Revision accepted: 7 February 2001 相似文献
13.
Rarely, hepatic metastases can simulate hepatic infiltrative diseases. We present a case of a patient with advanced metastatic
renal cell carcinoma who developed hepatomegaly and clinical signs of hepatocellular injury. On magnetic resonance imaging,
the injury simulated a diffuse process, e.g., acute fulminant viral or chemical hepatitis or drug toxicity. Despite its high
resolution, magnetic resonance imaging might not depict focal lesions in patients with extensive metastases. In correlation
with clinical history, malignant disease should be considered when diffusely abnormal hepatic signal intensity is noted.
Received: 2 April 2001/Revision accepted: 21 April 2001 相似文献
14.
K. Shinozaki K. Yoshimitsu H. Honda T. Kuroiwa H. Irie H. Aibe S. Naito T. Migita Y. Asayama K. Masuda 《Abdominal imaging》2001,26(4):439-442
We present a case of adrenal metastasis from clear-cell renal cell carcinoma in which presence of a small amount of fat was
shown on chemical shift gradient-echo magnetic resonance imaging. Radiologists should be aware that signal loss of the adrenal
tumor on out-of-phase gradient-echo images does not always suggest the diagnosis of benign adenoma, particularly in patients
with a history of renal cell carcinoma.
Received: 16 May 2000/Accepted after revision: 13 September 2000 相似文献
15.
Thoracic esophageal carcinoma: evaluation in the sagittal section with magnetic resonance imaging 总被引:2,自引:0,他引:2
A. Nakashima K. Nakashima H. Seto M. Kakishita T. Sakamoto A. Yamada M. Fujimaki 《Abdominal imaging》1997,22(1):20-23
Among 54 patients with thoracic esophageal carcinoma (53 squamous cell carcinoma, 1 adenosquamous carcinoma), the usefulness
of MR sagittal imaging for evaluating local extent (T factor) was examined by measuring the anteroposterior (AP) diameter
of the tumor. The MR examination was performed using ECG gated scans with a 3 mm slice at 1.5 Tesla. T1-weighted sagittal
images were obtained. In 10 patients the appearance of the esophagus was normal, and in 44 patients a tumor was detected in
the sagittal section. Thirty-seven lesions were histologically proved (Tis, 1; T1, 3; T2, 3; T3, 15; T4, 15). Lesions classified
as <T2 were not visible, and the appearance of the esophagus was normal. The tumors detected in sagittal section were T3 (15
tumors) or T4 (15 tumors). The mean diameter of T4 lesions (34.0 ± 7.9 mm, range 24–57 mm) was larger than that of T3 lesions
(25.0 ± 4.4 mm, range 18–33 mm) (p < 0.05). Only two masses with an AP diameter > 30 mm were resected. They were located in the lower esophagus. It is concluded
that lesions detected in MR sagittal images might be T3 or T4 tumors, and masses of >30 mm might extend to adjacent organs,
although two tumors with an AP diameter < 25 mm also invaded the trachea.
Received: 30 August 1995/Accepted: 10 October 1995 相似文献
16.
MR angiography: noninvasive vascular imaging of the abdomen 总被引:23,自引:0,他引:23
Magnetic resonance angiography (MRA) has been used to image abdominal vessels less frequently than renal arteries. Until the
use of fast contrast-enhanced (CE) techniques, an important limitation was the acquisition time of phase-contrast or time-of-flight
imaging and, consequently, the creation of motion artifacts. Recent advances in MRA technology have shortened acquisition
times, so it is now possible to obtain successive images in the arterial and then the portal phase. MRA can be used as an
adjunct to any MR examination to assess, e.g., the arterial feeding of hepatocellular carcinoma, the encasement of arteries,
and segmental portal thrombosis in pancreatic carcinoma. However, MRA has been used mainly to study chronic mesenteric ischemia,
portal vein diseases, and complications from liver transplantation. The portal venous system is exquisitely portrayed with
this method; MRA is as accurate as digital subtraction angiography (DSA) in the diagnosis of portal vein diseases. Acute mesenteric
ischemia is an emergency in which computed tomography is the most appropriate imaging modality. Conversely, chronic mesenteric
ischemia is best examined with CE-MRA, which is almost as accurate as DSA. CE-MRA is superior to DSA for the simultaneous
exploration of the aorta, renal arteries, and iliac arteries, thereby providing a panoramic view of abdominal vascular involvement.
MRA can be coupled with measurements of flow. With this functional approach, MRA is the only modality that can completely
assess vascular diseases of the abdomen. 相似文献
17.
Mature teratomas of the adrenal gland: imaging features 总被引:1,自引:0,他引:1
Background: We describe the imaging features of three, histologically confirmed, mature teratomas of the adrenal gland not described
previously in the radiologic literature and discuss the differential diagnosis of lipomatous tumors of the adrenal gland.
Methods: Computed tomographic (n= 3), magnetic resonance imaging (n= 1), and sonographic (n= 1) features were reviewed retrospectively and the findings correlated with gross pathology and histology.
Results: There were two females (age 8 and 18 years) and one male (age 17 years). Tumor size ranged from 5 to 11 cm (mean = 7.3 cm).
All tumors were well circumscribed and contained fat components. Calcification was demonstrated in two tumors and was the
predominant component in one. Only one was cystic.
Conclusion: The radiologic features of these tumors were typical of mature teratomas occurring elsewhere in the body. This should be
considered in the differential diagnosis of lipomatous tumors of the adrenal gland, especially in children and adolescents.
Received: 29 March 2001/Revision accepted: 13 June 2001 相似文献
18.
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
19.
MRI of recurrent rectosigmoid carcinoma 总被引:6,自引:0,他引:6
Background: A prospective study was performed to determine the most reliable MRI criteria to distinguish recurrent rectosigmoid carcinoma
from benign postoperative fibrosis.
Methods: Twenty-two consecutive patients who were suspected to have recurrent rectosigmoid carcinoma were examined by T2 and precontrast
and contrast enhanced T1 weighted images. The prospective interpretations, the presence of high signal on T2 weighted images,
the shape of the margins of a mass and the degree of contrast enhancement were correlated with histology and follow up to
determine their respective accuracies, sensitivities and specificities.
Results: The best criteria for recurrent tumor was the combination of high signal on T2 weighted images, round margins and > 40% contrast
enhancement, which had an accuracy of 92%, sensitivity of 100% and specificity of 85%. In patients who were more than one
year postoperative the specificity was 100%.
Conclusions: The most reliable MRI criteria for distinguishing recurrent rectosigmoid carcinoma from benign postoperative fibrosis are
the combination of the signal intensity on T2 weighed images, the shape of the margins of a mass and the presence of greater
than 40% contrast enhancement.
Received: 6 February 1996/Accepted after revision: 19 June 1996 相似文献
20.
Background: This study was performed to determine the echo layer structures of the normal gastric wall and early gastric cancer when
visualized with a 30-MHz ultrasonic miniprobe.
Methods: Twelve surgically resected gastric specimens were used for an ex vivo study. Eighteen normal sites and 12 early gastric cancer
sites were scanned with an Olympus (XUM-S30-25R) probe with a frequency of 30-MHz. Endoscopic ultrasound images were compared
with corresponding histopathologic sections stained with hematoxylin and eosin.
Results: The normal mucosa was visualized as at least four alternating echo layers; the muscularis mucosa was delineated at all normal
sites. Lymphoid aggregates within the mucosa could be seen. The submucosa was clearly visualized in most cases, but the muscularis
propria and subserosa were seldom depicted due to attenuation of ultrasound waves. At the sites of gastric cancer, the layered
architecture of the mucosa was disturbed by an irregular hypoechoic lesion. Minimal submucosal infiltration (400 and 750 μm)
was clearly depicted in two cases, without ulceration at or around the tumor site. However, attenuation at the site of a deep
ulcer scar prevented adequate visualization of the tumor extent in two other cases with ulceration.
Conclusion: A 30-MHz ultrasonic miniprobe may provide additional imaging information of the gastric wall and could play a role in the
assessment of early cancer lesions.
Received: 29 January 2002/Accepted: 27 February 2002 相似文献