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1.
Journal of the Korean Radiological Society ; : 331-343, 2022.
Artigo em Inglês | WPRIM | ID: wpr-926417

RESUMO

Purpose@#To systematically compare the performance of liver imaging reporting and data system treatment response (LR-TR) with the modified Response Evaluation Criteria in Solid Tumors (mRECIST) for diagnosing viable hepatocellular carcinoma (HCC) treated with locoregional therapy (LRT). @*Materials and Methods@#Original studies of intra-individual comparisons between the diagnostic performance of LR-TR and mRECIST using dynamic contrast-enhanced CT or MRI were searched in MEDLINE and EMBASE, up to August 25, 2021. The reference standard for tumor viability was surgical pathology. The meta-analytic pooled sensitivity and specificity of the viable category using each criterion were calculated using a bivariate random-effects model and compared using bivariate meta-regression. @*Results@#For five eligible studies (430 patients with 631 treated observations), the pooled per-lesion sensitivities and specificities were 58% (95% confidence interval [CI], 45%–70%) and 93% (95% CI, 88%–96%) for the LR-TR viable category and 56% (95% CI, 42%–69%) and 86% (95% CI, 72%–94%) for the mRECIST viable category, respectively. The LR-TR viable category provided significantly higher pooled specificity (p < 0.01) than the mRECIST but comparable pooled sensitivity (p = 0.53). @*Conclusion@#The LR-TR algorithm demonstrated better specificity than mRECIST, without a significant difference in sensitivity for the diagnosis of pathologically viable HCC after LRT.

2.
Korean Journal of Radiology ; : 1289-1299, 2021.
Artigo em Inglês | WPRIM | ID: wpr-902420

RESUMO

Objective@#We aimed to evaluate the usefulness of arterial subtraction images for predicting the viability of hepatocellular carcinoma (HCC) after locoregional therapy (LRT) using gadoxetic acid-enhanced MRI and the Liver Imaging Reporting and Data System treatment response (LR-TR) algorithm. @*Materials and Methods@#This study included 90 patients (mean age ± standard deviation, 57 ± 9 years) who underwent liver transplantation or resection after LRT and had 73 viable and 32 nonviable HCCs. All patients underwent gadoxetic acid-enhanced MRI before surgery. Two radiologists assessed the presence of LR-TR features, including arterial phase hyperenhancement (APHE) and LR-TR categories (viable, nonviable, or equivocal), using ordinary arterial-phase and arterial subtraction images. The reference standard for tumor viability was surgical pathology. The sensitivity of APHE for diagnosing viable HCC was compared between ordinary arterial-phase and arterial subtraction images. The sensitivity and specificity of the LR-TR algorithm for diagnosing viable HCC was compared between the use of ordinary arterial-phase and the use of arterial subtraction images.Subgroup analysis was performed on lesions treated with transarterial chemoembolization (TACE) only. @*Results@#The sensitivity of APHE for viable HCCs was higher for arterial subtraction images than ordinary arterial-phase images (71.2% vs. 47.9%; p 0.999). In a subgroup of 63 lesions treated with TACE only, the use of arterial subtraction images showed a significant increase in sensitivity (81.4% [35/43] vs. 67.4% [29/43]; p = 0.031) without significant decrease in specificity (85.0% [17/20] vs. 90.0% [18/20]; p > 0.999). @*Conclusion@#Use of arterial subtraction images compared with ordinary arterial-phase images improved the sensitivity while maintaining specificity for diagnosing viable HCC after LRT using gadoxetic acid-enhanced MRI and the LR-TR algorithm.

3.
Journal of the Korean Radiological Society ; : 1066-1082, 2021.
Artigo em Inglês | WPRIM | ID: wpr-901383

RESUMO

Incidental adnexal masses considered indeterminate for malignancy are commonly observed on ultrasonography. Multiparametric MRI is the imaging modality of choice for the evaluation of sonographically indeterminate adnexal masses. Conventional MRI enables a confident pathologic diagnosis of various benign lesions due to accurate tissue characterization of fat, blood, fibrous tissue, and solid components. Additionally, functional imaging sequences, including perfusion- and diffusion-weighted imaging, improve the diagnostic efficacy of conventional MRI in differentiating benign from malignant adnexal masses. The ovarian-adnexal reporting and data system (O-RADS) MRI was recently designed to provide consistent interpretations in assigning risk of malignancy to ovarian and other adnexal masses, and to provide a management recommendation for each risk category. In this review, we describe the clinical application of multiparametric MRI for the evaluation of adnexal masses and introduce the O-RADS MRI risk stratification system.

4.
Investigative Magnetic Resonance Imaging ; : 172-182, 2021.
Artigo em Inglês | WPRIM | ID: wpr-898857

RESUMO

Purpose@#We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. @*Materials and Methods@#We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). @*Results@#PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). @*Conclusion@#In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

5.
Korean Journal of Radiology ; : 1289-1299, 2021.
Artigo em Inglês | WPRIM | ID: wpr-894716

RESUMO

Objective@#We aimed to evaluate the usefulness of arterial subtraction images for predicting the viability of hepatocellular carcinoma (HCC) after locoregional therapy (LRT) using gadoxetic acid-enhanced MRI and the Liver Imaging Reporting and Data System treatment response (LR-TR) algorithm. @*Materials and Methods@#This study included 90 patients (mean age ± standard deviation, 57 ± 9 years) who underwent liver transplantation or resection after LRT and had 73 viable and 32 nonviable HCCs. All patients underwent gadoxetic acid-enhanced MRI before surgery. Two radiologists assessed the presence of LR-TR features, including arterial phase hyperenhancement (APHE) and LR-TR categories (viable, nonviable, or equivocal), using ordinary arterial-phase and arterial subtraction images. The reference standard for tumor viability was surgical pathology. The sensitivity of APHE for diagnosing viable HCC was compared between ordinary arterial-phase and arterial subtraction images. The sensitivity and specificity of the LR-TR algorithm for diagnosing viable HCC was compared between the use of ordinary arterial-phase and the use of arterial subtraction images.Subgroup analysis was performed on lesions treated with transarterial chemoembolization (TACE) only. @*Results@#The sensitivity of APHE for viable HCCs was higher for arterial subtraction images than ordinary arterial-phase images (71.2% vs. 47.9%; p 0.999). In a subgroup of 63 lesions treated with TACE only, the use of arterial subtraction images showed a significant increase in sensitivity (81.4% [35/43] vs. 67.4% [29/43]; p = 0.031) without significant decrease in specificity (85.0% [17/20] vs. 90.0% [18/20]; p > 0.999). @*Conclusion@#Use of arterial subtraction images compared with ordinary arterial-phase images improved the sensitivity while maintaining specificity for diagnosing viable HCC after LRT using gadoxetic acid-enhanced MRI and the LR-TR algorithm.

6.
Journal of the Korean Radiological Society ; : 1066-1082, 2021.
Artigo em Inglês | WPRIM | ID: wpr-893679

RESUMO

Incidental adnexal masses considered indeterminate for malignancy are commonly observed on ultrasonography. Multiparametric MRI is the imaging modality of choice for the evaluation of sonographically indeterminate adnexal masses. Conventional MRI enables a confident pathologic diagnosis of various benign lesions due to accurate tissue characterization of fat, blood, fibrous tissue, and solid components. Additionally, functional imaging sequences, including perfusion- and diffusion-weighted imaging, improve the diagnostic efficacy of conventional MRI in differentiating benign from malignant adnexal masses. The ovarian-adnexal reporting and data system (O-RADS) MRI was recently designed to provide consistent interpretations in assigning risk of malignancy to ovarian and other adnexal masses, and to provide a management recommendation for each risk category. In this review, we describe the clinical application of multiparametric MRI for the evaluation of adnexal masses and introduce the O-RADS MRI risk stratification system.

7.
Investigative Magnetic Resonance Imaging ; : 172-182, 2021.
Artigo em Inglês | WPRIM | ID: wpr-891153

RESUMO

Purpose@#We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. @*Materials and Methods@#We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). @*Results@#PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). @*Conclusion@#In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

8.
Korean Journal of Radiology ; : 568-577, 2018.
Artigo em Inglês | WPRIM | ID: wpr-716278

RESUMO

OBJECTIVE: To preliminarily evaluate the diagnostic performance of an unenhanced MRI for detecting hepatocellular carcinoma (HCC) with a case-control study design. MATERIALS AND METHODS: The case group consisted of 175 patients with initially-diagnosed HCC, who underwent a 3T liver MRI. A total of 237 HCCs were identified. The number of HCCs that were smaller than 1 cm, 1 cm ≤ and < 2 cm, and ≥ 2 cm were 19, 105, and 113, respectively. For the control group, 72 patients with chronic liver disease, who did not have HCC, were enrolled. Two radiologists independently reviewed the T2 half-Fourier acquisition single-shot turbo spin echo, T2 fast spin echos with fat saturation, T1 gradient in- and out-of-phase images, and diffusion-weighted images/apparent diffusion coefficient maps to detect HCC. Per-patient analyses were performed to evaluate the sensitivity and specificity of the non-contrast MRI for diagnosing HCC. Furthermore, the per-lesion sensitivity was also calculated according to tumor size. RESULTS: In the per-patient analyses, the sensitivity and specificity of reader 1 were 86.3% (151/175) and 87.5% (63/72), respectively; while those of reader 2 were 82.9% (145/175) and 76.4% (55/72), respectively. When excluding HCCs smaller than 1 cm, the sensitivity of reader 1 and 2 were 88.0% (147/167) and 86.2% (144/167), respectively. In the per-lesion analyses, the sensitivities of reader 1 and reader 2 were 75.9% (180/237) and 70.5% (167/237), respectively. CONCLUSION: The per-patient sensitivity and specificity of non-contrast MRIs were within a reasonable range for the initial diagnosis of HCC. Non-contrast MRIs may have a potential for surveillance of HCC. Further confirmatory diagnostic test accuracy studies are needed.


Assuntos
Humanos , Carcinoma Hepatocelular , Estudos de Casos e Controles , Diagnóstico , Testes Diagnósticos de Rotina , Difusão , Estudos de Viabilidade , Hepatopatias , Fígado , Imageamento por Ressonância Magnética , Programas de Rastreamento , Sensibilidade e Especificidade
9.
Korean Journal of Radiology ; : 1119-1129, 2018.
Artigo em Inglês | WPRIM | ID: wpr-718937

RESUMO

OBJECTIVE: To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. MATERIALS AND METHODS: This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. RESULTS: The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. CONCLUSION: The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.


Assuntos
Humanos , Comércio , Meios de Contraste , Iodo , Ruído , Estudos Prospectivos , Exposição à Radiação , Razão Sinal-Ruído , Sistema Urinário , Urografia
10.
Investigative Magnetic Resonance Imaging ; : 162-170, 2017.
Artigo em Inglês | WPRIM | ID: wpr-107503

RESUMO

PURPOSE: To evaluate the imaging findings of desmoid tumors using various imaging modalities and to evaluate whether diffusion-weighted imaging (DWI) can help differentiate between desmoid and malignant tumors. MATERIALS AND METHODS: The study included 27 patients with pathologically confirmed desmoid tumors. Two radiologists reviewed 23 computed tomography (CT), 12 magnetic resonance imaging (MRI) and 8 positron emission tomography-computed tomography (PET-CT) scans of desmoid tumors and recorded data regarding the shape, multiplicity, size, location, degree of enhancement, and presence or absence of calcification or hemorrhage. The signal intensity of masses on T1- and T2-weighted imaging and the presence or absence of whirling or band-like low signal intensity on T2-weighted imaging were recorded. The apparent diffusion coefficient (ADC) values of the desmoid tumors in nine patients with DWIs were compared with the ADC values of 32 malignant tumors. The maximum standardized uptake value (SUV(max)) on PET-CT images was measured in 8 patients who underwent a PET-CT. RESULTS: The mean size of the 27 tumors was 6.77 cm (range, 2.5-26 cm) and four tumors exhibited multiplicity. The desmoid tumors were classified by shape as either mass forming (n = 18), infiltrative (n = 4), or combined (n = 5). The location of the tumors was either intra-abdominal (n = 15), within the abdominal wall (n = 8) or extra-abdominal (n = 4). Among the 27 tumors, 21 showed moderate to marked enhancement and 22 showed homogeneous enhancement. Two tumors showed calcifications and one displayed hemorrhage. Eleven of the 12 MR T2-weighted images showed whirling or band-like low signal intensity areas in the mass. The mean ADC value of the desmoid tumors (1493 × 10⁻⁶ mm²/s) was significantly higher than the mean of the malignant soft tissue tumors (873 × 10⁻⁶ mm²/s, P < 0.001). On the PET-CT images, all tumors exhibited an intermediate SUV(max) (mean, 3.7; range, 2.3–4.5). CONCLUSION: Desmoids tumors showed homogenous, moderate to marked enhancement on CT and MRI scans and a characteristic whirling or band-like pattern on T2-weighted images. DWI can be useful for the differentiation of desmoid tumors from malignant soft tissue tumors.


Assuntos
Humanos , Parede Abdominal , Difusão , Elétrons , Fibroma , Fibromatose Agressiva , Hemorragia , Imageamento por Ressonância Magnética
11.
Ultrasonography ; : 124-130, 2016.
Artigo em Inglês | WPRIM | ID: wpr-731188

RESUMO

PURPOSE: The goal of this study was to perform a retrospective analysis of the ultrasonographic findings associated with low-grade endometrial stromal sarcoma. METHODS: Ten pathologically confirmed cases of low-grade endometrial stromal sarcoma at our institution from January 2007 to April 2014 were retrospectively reviewed. All patients underwent a preoperative transvaginal ultrasound. Two radiologists came to a consensus regarding the location, size, margin, and echogenicity of the tumor, as well as the presence of intratumoral cystic degeneration and its extent and configuration. RESULTS: Low-grade endometrial stromal sarcoma manifested as an intramural mass protruding into the endometrial cavity (n=6) or as a purely intramural mass (n=4). The maximal diameter of the lesion ranged from 4 to 9.1 cm (mean, 6.2 cm). The imaging features of low-grade endometrial stromal sarcoma were variable: six cases involved predominantly solid masses containing cystic degeneration, one was a predominantly unilocular cystic mass, two were ill-defined infiltrative solid masses, and one was a well-defined solid mass. Among the seven cases with internal cystic degeneration, five patients showed a multiseptated cystic area or a cystic area with multiple small clusters, while a unilocular cystic area within the tumor was found in two patients. CONCLUSION: Low-grade endometrial stromal sarcoma is associated with variable ultrasonographic findings with regard to the location, margin, and configuration of the lesion. Multiseptated cystic areas and multiple small areas of cystic degeneration are common.


Assuntos
Humanos , Consenso , Tumores do Estroma Endometrial , Estudos Retrospectivos , Sarcoma , Sarcoma do Estroma Endometrial , Ultrassonografia , Útero
12.
Ultrasonography ; : 91-97, 2014.
Artigo em Inglês | WPRIM | ID: wpr-731028

RESUMO

PURPOSE: To evaluate intra- and interobserver reliability of the gray scale/dynamic range of the phantom image evaluation of ultrasonography using a standardized phantom, and to assess the effect of interactive education on the reliability. METHODS: Three radiologists (a resident, and two board-certified radiologists with 2 and 7 years of experience in evaluating ultrasound phantom images) performed the gray scale/dynamic range test for an ultrasound machine using a standardized phantom. They scored the number of visible cylindrical structures of varying degrees of brightness and made a 'pass or fail' decision. First, they scored 49 phantom images twice from a 2010 survey with limited knowledge of phantom images. After this, the radiologists underwent two hours of interactive education for the phantom images and scored another 91 phantom images from a 2011 survey twice. Intra- and interobserver reliability before and after the interactive education session were analyzed using K analyses. RESULTS: Before education, the K-value for intraobserver reliability for the radiologist with 7 years of experience, 2 years of experience, and the resident was 0.386, 0.469, and 0.465, respectively. After education, the K-values were improved (0.823, 0.611, and 0.711, respectively). For interobserver reliability, the K-value was also better after the education for the 3 participants (0.067, 0.002, and 0.547 before education; 0.635, 0.667, and 0.616 after education, respectively). CONCLUSION: The intra- and interobserver reliability of the gray scale/dynamic range was fair to substantial. Interactive education can improve reliability. For more reliable results, double-checking of phantom images by multiple reviewers is recommended.


Assuntos
Educação , Imagens de Fantasmas , Garantia da Qualidade dos Cuidados de Saúde , Reprodutibilidade dos Testes , Ultrassonografia
13.
Korean Journal of Radiology ; : 918-922, 2013.
Artigo em Inglês | WPRIM | ID: wpr-184187

RESUMO

We report MR imaging findings of a rare case of endocervical mucinous borderline tumor (MBT) involving the cul-de-sac and left fallopian tube arising from extensive pelvic endometriosis with pathologic correlation in a 35-year-old woman presented with vague pelvic pain. Endocervical MBT is a type of endometriosis-associated carcinoma. Imaging findings of endocervical MBT are unilocular or oligolocular cystic lesions with enhancing mural nodules, which are different from those of the more common intestinal type MBT.


Assuntos
Adulto , Feminino , Humanos , Cistadenoma Mucinoso/diagnóstico , Diagnóstico Diferencial , Endometriose/complicações , Seguimentos , Imageamento por Ressonância Magnética/métodos , Neoplasias Ovarianas/diagnóstico , Pelve , Lesões Pré-Cancerosas/diagnóstico
14.
Journal of the Korean Society of Medical Ultrasound ; : 193-196, 2011.
Artigo em Coreano | WPRIM | ID: wpr-725617

RESUMO

Adenofibroma is an extremely rare benign mullerian mixed tumor composed of epithelium and mesenchymal cells. Most uterine adenofibromas occur in the endometrium, but they rarely protrude into the vagina. To date, only a few such cases with the imaging findings have been reported. Therefore, we report here on the sonographic and magnetic resonance (MR) imaging findings of a case of endometrial adenofibroma protruding into the vaginal cavity in a 28-year-old woman. The uterine adenofibroma appeared as a large intracavitary echogenic mass containing multiple small internal cysts, and it was distending the vaginal cavity on transrectal sonography. T2- weighted MR images showed a large intracavitary mass with heterogeneous high signal intensity protruding into the vaginal cavity. On gadolinium-enhanced T1-weighted MR images, heterogeneous septa-like enhancement was noted in the mass. Although uterine adenofibroma is extremely rare, adenofibroma can be suggested as a possible diagnosis when an intracavitary uterine mass, with multiple internal small cystic components and enhancing septa-like structures, is protruding into the vaginal cavity on imaging.


Assuntos
Adulto , Feminino , Humanos , Adenofibroma , Endométrio , Epitélio , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Tumor Mulleriano Misto , Útero , Vagina
15.
Korean Journal of Radiology ; : 261-265, 2011.
Artigo em Inglês | WPRIM | ID: wpr-73317

RESUMO

Lymphangioleiomyomatosis (LAM) is a rare idiopathic disease and this is characterized by a proliferation of abnormal smooth muscle cells in the lungs and in the lymphatic system of the thorax and retroperitoneum. The female genital tract is rarely affected by LAM. We report here on the CT and MR imaging findings of extensive LAM involving the uterus and pelvic cavity, and this was seen as multiple cystic uterine and parauterine masses with internal hemorrhage in a young female with tuberous sclerosis complex.


Assuntos
Adulto , Feminino , Humanos , Doenças dos Anexos/diagnóstico , Diagnóstico Diferencial , Histerectomia , Linfangioleiomiomatose/diagnóstico , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Esclerose Tuberosa/diagnóstico , Neoplasias Uterinas/diagnóstico
16.
Korean Journal of Radiology ; : 560-565, 2010.
Artigo em Inglês | WPRIM | ID: wpr-207983

RESUMO

Intrahepatic bile duct adenoma is a rare benign epithelial hepatic tumor derived from bile duct cells. We report the imaging findings of a patient with bile duct adenoma, which appeared as a small heterogeneously enhancing mass with focal small cystic change on CT and MRI. Follow-up images at seven months showed a slight increase in tumor size, which could be partly explained by intratumoral hemorrhage on pathologic examination. Although rare, bile duct adenoma should be considered as a differential diagnosis of a small hypervascular tumor located in the periphery of liver. Focal cystic change and intratumoral hemorrhage may occur.


Assuntos
Feminino , Humanos , Pessoa de Meia-Idade , Adenoma de Ducto Biliar/diagnóstico , Neoplasias dos Ductos Biliares/diagnóstico , Meios de Contraste , Hamartoma/diagnóstico , Hepatectomia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
17.
Journal of the Korean Society of Magnetic Resonance in Medicine ; : 151-155, 2010.
Artigo em Coreano | WPRIM | ID: wpr-198469

RESUMO

Primary hepatic lymphoma is extremely rare, representing less than 1% of all extranodal lymphomas. We report MR imaging features and pathologic correlation of a case of primary hepatic lymphoma. MR images showed a large lobulated mass with gradual contrast enhancement, resembling intrahepatic cholangiocarcinoma. However, both hepatobiliary phase image obtained 20 minutes after injection of hepatocyte specific contrast agent and diffusion-weighted image demonstrated characteristic three layered pattern representing viable lymphoma in the outer layer, tumor necrosis in the middle layer and necrotic hepatic parenchyma in the center.


Assuntos
Colangiocarcinoma , Hepatócitos , Fígado , Neoplasias Hepáticas , Linfoma , Necrose
18.
Journal of the Korean Medical Association ; : 1065-1073, 2010.
Artigo em Coreano | WPRIM | ID: wpr-53313

RESUMO

Due to the development of dedicated receiver coils for 3 tesla (T) magnetic resonance (MR) imaging and increased gradient performance, 3T MR imaging of the abdomen is rapidly becoming a part of routine clinical practice. The most important advantage of 3T MR imaging is a higher signal-to-noise ratio and contrast-to-noise ratio compared with 1.5T systems, which can be used to improve spatial resolution and shorten image acquisition time. In the abdomen, the improved image quality of non-enhanced and enhanced solid organ imaging, MR angiography, MR cholangiopancreatography, and MR spectroscopy can be obtained at 3T due to the increased signal-to-noise ratio and contrast-to-noise ratio. However, 3T abdominal MR imaging also presents several technical challenges, such as increased energy deposition within the patient's body, standing wave artifacts, and increased susceptibility artifacts. Therefore, abdominal MR imaging at 3T requires adjustments in the sequence parameters of pulse sequences designed for 1.5T to optimize image quality. At present, 3T abdominal MR imaging is feasible with high image quality in an acceptable scan time, but 3T imaging is not significantly superior to 1.5T imaging in terms of cost-effectiveness. Future improvements in coil technology and new sequences suitable for 3T may enable wider clinical use of 3T for abdominal MR imaging.


Assuntos
Abdome , Angiografia , Artefatos , Imidazóis , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Magnetismo , Imãs , Nitrocompostos , Razão Sinal-Ruído
19.
Journal of the Korean Society of Magnetic Resonance in Medicine ; : 1-9, 2010.
Artigo em Coreano | WPRIM | ID: wpr-141091

RESUMO

Although ultrasonography is the most commonly used first-line imaging modality of the female pelvis because of diagnostic accuracy, low cost and safety, MRI is the best imaging modality of choice for the evaluation of the female pelvis. The indication of female pelvis MRI is diverse and includes the evaluation of Mullerian duct anomaly, differential diagnosis and characterization of uterine and ovarian tumors, and staging of malignant uterine and ovarian tumors. Understanding of MR protocols according to the specific gynecologic pathology allows accurate diagnosis and proper patient management.


Assuntos
Feminino , Humanos , Diagnóstico Diferencial , Ovário , Pelve , Útero
20.
Journal of the Korean Society of Magnetic Resonance in Medicine ; : 1-9, 2010.
Artigo em Coreano | WPRIM | ID: wpr-141090

RESUMO

Although ultrasonography is the most commonly used first-line imaging modality of the female pelvis because of diagnostic accuracy, low cost and safety, MRI is the best imaging modality of choice for the evaluation of the female pelvis. The indication of female pelvis MRI is diverse and includes the evaluation of Mullerian duct anomaly, differential diagnosis and characterization of uterine and ovarian tumors, and staging of malignant uterine and ovarian tumors. Understanding of MR protocols according to the specific gynecologic pathology allows accurate diagnosis and proper patient management.


Assuntos
Feminino , Humanos , Diagnóstico Diferencial , Ovário , Pelve , Útero
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