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1.
Article | WPRIM | ID: wpr-835647

ABSTRACT

Objective@#We aimed to identify the relation between perioperative cerebrospinal fluid (CSF) drain through lumbar drainage (LD) and development of postoperative (POP) remote intracerebral hemorrhage (rICH) in craniotomy to treat ruptured intracranial aneurysms. @*Methods@#We retrospectively reviewed consecutive patients who underwent craniotomy for ruptured cerebral aneurysms at the authors’ institution between 1998 and 2004. We subsequently compared the incidence and characteristics of POP rICH between the patients who had a perioperative LD and those who did not. All statistical analyses were conducted using the software package SPSS 19.0 (SPSS Inc., Chicago, IL, USA). A p value of <0.05 was considered statistically significant. @*Results@#We enrolled 688 patients, of which 80 patients (11.6%) received perioperative LD, and 608 did not. LD and non-LD groups were comparable because although clinical characteristics of the two groups were significantly different considering history of hypertension, timing of surgery, and closed system negative pressure suction drain (SD) placement, none of these three variables was an independent risk factor associated with POP rICH in multivariate analysis. POP rICH incidence was significantly higher in the LD goup (12.5%) than non-LD group (0.8%) (p=0.000) in univariate analysis. LD placement was the only independent risk factor associated with the development of rICH in multivariate logistic regression analysis. @*Conclusions@#POP rICH incidence was significantly higher in patients who were managed with perioperative LD than in those who did not. LD insertion in craniotomy for ruptured intracranial aneurysm, should be closely monitored to address the occurrence of POP rICH.

2.
Article | WPRIM | ID: wpr-833555

ABSTRACT

Objective@#Recent innovations in biology are boosting gene and cell therapy, but monitoring the response to these treatments is difficult. The purpose of this study was to find an MRI-reporter gene that can be used to monitor gene or cell therapy and that can be delivered without a viral vector, as viral vector delivery methods can result in long-term complications. @*Materials and Methods@#CMV promoter-human organic anion transporting polypeptide 1B3 (CMV-hOATP1B3) cDNA or CMV-blank DNA (control) was transfected into HEK293 cells using Lipofectamine. OATP1B3 expression was confirmed by western blotting and confocal microscopy. In vitro cell phantoms were made using transfected HEK293 cells cultured in various concentrations of gadoxetic acid for 24 hours, and images of the phantoms were made with a 9.4T micro-MRI. In vivo xenograft tumors were made by implanting HEK293 cells transfected with CMV-hOATP1B3 (n = 4) or CMV-blank (n = 4) in 8-week-old male nude mice, and MRI was performed before and after intravenous injection of gadoxetic acid (1.2 μL/g). @*Results@#Western blot and confocal microscopy after immunofluorescence staining revealed that only CMV-hOATP1B3-transfected HEK293 cells produced abundant OATP1B3, which localized at the cell membrane. OATP1B3 expression levels remained high through the 25th subculture cycle, but decreased substantially by the 50th subculture cycle. MRI of cell phantoms showed that only the CMV-hOATP1B3-transfected cells produced a significant contrast enhancement effect. In vivo MRI of xenograft tumors revealed that only CMV-hOATP1B3-transfected HEK293 tumors demonstrated a T1 contrast effect, which lasted for at least 5 hours. @*Conclusion@#The human endogenous OATP1B3 gene can be non-virally delivered into cells to induce transient OATP1B3 expression, leading to gadoxetic acid-mediated enhancement on MRI. These results indicate that hOATP1B3 can serve as an MRI-reporter gene while minimizing the risk of long-term complications.

3.
Journal of Liver Cancer ; : 120-127, 2020.
Article | WPRIM | ID: wpr-836106

ABSTRACT

Background/Aims@#This study aimed to assess the validity and diagnostic performance of the imaging criteria of Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) 2018 using magnetic resonance imaging (MRI) in high-risk patients for HCC. @*Methods@#This retrospective study included 142 treatment-naïve patients (81 patients who underwent MRI with extracellular contrast agent and 61 who underwent MRI with hepatobiliary agent; 183 lesions including 149 HCCs) with a high risk of HCC who underwent multiphasic contrast-enhanced MRI from January to December 2015. All lesions were categorized according to the KLCA-NCC 2018 imaging diagnostic criteria by two readers, and per-lesion diagnostic performances were compared. @*Results@#According to the KLCA-NCC 2018, none (0%) of the 13 benign category lesions, 11 (44.0%) of 25 indeterminate category lesions, 15 (93.8%) of 16 probable HCC category lesions, and 97 (99.0%) of 98 definite HCC category lesions were ultimately diagnosed as HCCs. The sensitivity and specificity of definite HCC category were 65.1% and 97.1%, respectively, and those of the combination of definite and probable HCC categories were 75.2% and 94.1%, respectively. The sensitivity of the combination of definite and probable HCC categories was significantly higher than that of definite HCC (P0.999). @*Conclusions@#The noninvasive imaging diagnosis of KLCA-NCC 2018 on MRI is reliable and useful for diagnosing HCC in high-risk patients. Combining definite and probable HCC categories of KLCA-NCC 2018 improves the sensitivity while maintaining a high specificity.

6.
Gut and Liver ; : 765-774, 2020.
Article in English | WPRIM | ID: wpr-833171

ABSTRACT

Background/Aims@#The Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and modified RECIST (mRECIST) criteria have been used to assess treatment responses for hepatocellular carcinoma (HCC) patients. We investigated which criteria provides better survival predictions in HCC patients treated with transarterial radioembolization (TARE). @*Methods@#In total, 102 patients with unresectable intrahe-patic HCC, who were treated with TARE between 2012 and 2017, were reviewed retrospectively. The treatment response after TARE was evaluated at 1, 3, and 6 months by the mRE-CIST and RECIST 1.1. Responders were defined as patients with complete or partial responses by each criterion. @*Results@#The median age of 83 men and 19 women was 64.3 years.The median alpha-fetoprotein and des-gamma-carboxy pro-thrombin levels were 37.1 ng/mL and 1,780.0 mAU/mL, re-spectively. The median maximal tumor size was 8.3 cm, and multiple tumors were observed in 36 patients (35.3%). Dur-ing the follow-up period (median, 20.7 months), 21 patients (20.6%) died, with a mean survival time of 55.5 months. The cumulative survival rate was 96.1% at 6 months and 89.3% at 12 months. Responders, defined by the mRECIST at 1, 3, and 6 months after TARE, showed better survival outcomes than nonresponders (hazard ratio [HR]=5.736, p=0.008 at 1 month; HR=3.145, p=0.022 at 3 months, and HR=2.887, p=0.061 at 6 months). The survival rates of responders and nonresponders defined by the RECIST 1.1 were similar (all p>0.05). @*Conclusions@#Response evaluations that use the mRECIST provide more accurate prognoses than those that use the RECIST 1.1 in HCC patients treated with TARE.

7.
Article | WPRIM | ID: wpr-832250

ABSTRACT

Background/Aims@#This study aimed to compare the diagnostic performances of Liver Imaging Reporting and Data System (LI-RADS) 2018 and Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) 2018 criteria on magnetic resonance imaging (MRI) for the noninvasive diagnosis of hepatocellular carcinoma (HCC) in high-risk patients. @*Methods@#This retrospective study included 273 treatment-naïve patients (71 patients with extracellular contrast agent [ECA]-MRI and 202 patients with hepatobiliary agent [HBA]-MRI; 352 lesions including 263 HCCs) with high risk of HCC who underwent contrast-enhanced MRI between 2016 and 2017. Two readers evaluated all lesions according to the criteria of LI-RADS 2018 and KLCA-NCC 2018. The per-lesion diagnostic performances were compared using the generalized estimating equation method. @*Results@#On ECA-MRI, the sensitivity and specificity of LI-RADS 2018 and KLCA-NCC 2018 were not significantly different (LR-5 vs. definite HCC: 75.8% vs. 69.4%, P=0.095 and 95.8% vs. 95.8%, P>0.999; LR-5/4 vs. definite/probable HCC: 87.1% vs.83.9%, P=0.313 and 87.5% vs. 91.7%, P=0.307). On HBA-MRI, definite HCC of KLCA-NCC 2018 showed significantly higher sensitivity (79.1% vs. 68.2%, P<0.001) than LR-5 of LI-RADS 2018 without a significant difference in specificity (93.9% vs. 95.4%, P=0.314). Definite/probable HCC of KLCA-NCC 2018 had higher specificity (92.3% vs. 80.0%, P=0.003) than LR-5/4 of LI-RADS 2018. The sensitivity was lower for definite/probable HCC than for LR-5/4 without statistical significance (85.6% vs. 88.1%, P=0.057). @*Conclusions@#On ECA-MRI, LI-RADS 2018 and KLCA-NCC 2018 showed comparable diagnostic performances. On HBA-MRI, definite HCC of KLCA-NCC 2018 provided better sensitivity than LR-5 category of LI-RADS 2018 without compromising the specificity, while definite/probable HCC of KLCA-NCC 2018 revealed higher specificity than LR-5/4 of LI-RADS 2018 for diagnosing HCC.

8.
Korean Journal of Radiology ; : 1616-1626, 2019.
Article in English | WPRIM | ID: wpr-786370

ABSTRACT

OBJECTIVE: To compare the diagnostic accuracy of dynamic computed tomography (CT) and gadoxetate-enhanced magnetic resonance imaging (MRI) for characterization of hepatic lesions by using the Liver Imaging Reporting and Data System (LI-RADS) in a multicenter, off-site evaluation.MATERIALS AND METHODS: In this retrospective multicenter study, we evaluated 231 hepatic lesions (114 hepatocellular carcinomas [HCCs], 58 non-HCC malignancies, and 59 benign lesions) confirmed histologically in 217 patients with chronic liver disease who underwent both gadoxetate-enhanced MRI and dynamic CT at one of five tertiary hospitals. Four radiologists at different institutes independently reviewed all MR images first and the CT images 4 weeks later. They evaluated the major and ancillary imaging features and categorized each hepatic lesion according to the LI-RADS v2014. Diagnostic performance was calculated and compared using generalized estimating equations.RESULTS: MRI showed higher sensitivity and accuracy than CT for diagnosing hepatic malignancies; the pooled sensitivities, specificities, and accuracies for categorizing LR-5/5V/M were 59.0% vs. 72.4% (CT vs. MRI; p < 0.001), 83.5% vs. 83.9% (p = 0.906), and 65.3% vs. 75.3% (p < 0.001), respectively. CT and MRI showed comparable capabilities for differentiating between HCC and other malignancies, with pooled accuracies of 79.9% and 82.4% for categorizing LR-M, respectively (p = 0.139).CONCLUSION: Gadoxetate-enhanced MRI showed superior accuracy for categorizing LR-5/5V/M in hepatic malignancies in comparison with dynamic CT. Both modalities had comparable accuracies for distinguishing other malignancies from HCC.


Subject(s)
Academies and Institutes , Carcinoma, Hepatocellular , Contrast Media , Humans , Information Systems , Liver , Liver Diseases , Magnetic Resonance Imaging , Retrospective Studies , Tertiary Care Centers
9.
Article in English | WPRIM | ID: wpr-785880

ABSTRACT

PURPOSE: To investigate noninvasive biomarkers for predicting treatment response in patients with locally advanced HCC who underwent concurrent chemoradiotherapy (CCRTx).MATERIALS AND METHODS: Thirty patients (55.5 ± 10.2 years old, M:F = 24:6) who underwent CCRTx due to advanced HCC were enrolled. Contrast-enhanced US (CEUS) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) were obtained before and immediately after CCRTx. The third CEUS was obtained at one month after CCRTx was completed. Response was assessed at three months after CCRTx based on RECIST 1.1. Quantitative imaging biomarkers measured with CEUS and MRI were compared between groups. A cutoff value was calculated with ROC analysis. Overall survival (OS) was compared by the Breslow method.RESULTS: Twenty-five patients were categorized into the non-progression group and five patients were categorized into the progression group. Peak enhancement of the first CEUS before CCRTx (PE1) was significantly lower in the non-progression group (median, 18.6%; IQR, 20.9%) than that in the progression group (median, 59.1%; IQR, 13.5%; P = 0.002). There was no significant difference in other quantitative biomarkers between the two groups. On ROC analysis, with a cutoff value of 42.6% in PE1, the non-progression group was diagnosed with a sensitivity of 90.9% and a specificity of 100%. OS was also significantly longer in patients with PE1 < 42.6% (P = 0.014).CONCLUSION: Early treatment response and OS could be predicted by PE on CEUS before CCRTx in patients with HCC.


Subject(s)
Biomarkers , Carcinoma, Hepatocellular , Chemoradiotherapy , Humans , Magnetic Resonance Imaging , Methods , Perfusion Imaging , Response Evaluation Criteria in Solid Tumors , ROC Curve , Sensitivity and Specificity , Ultrasonography
10.
Article in English | WPRIM | ID: wpr-719722

ABSTRACT

PURPOSE: The purpose of this study was to investigate the impact of contrast enhanced pancreatic magnetic resonance imaging (MRI) in resectability and prognosis evaluation after staging computed tomography (CT) in patients with pancreatic ductal adenocarcinoma (PDA). MATERIALS AND METHODS: From January 2005 to December 2012, 298 patients were diagnosed to have potentially resectable stage PDA on CT. Patients were divided into CT+MR (patients underwent both CT and MRI; n=216) and CT only groups (n=82). Changes in resectability staging in the CT+MR group were evaluated. The overall survival was compared between the two groups. The recurrence-free survival and median time to liver metastasis after curative surgery were compared between the two groups. RESULTS: Staging was changed from resectable on CT to unresectable state on MRI in 14.4% of (31 of 216 patients) patients of the CT+MR group. The overall survival and recurrence-free survival rates were not significantly different between the two groups (p=0.162 and p=0.721, respectively). The median time to liver metastases after curative surgery in the CT+MR group (9.9 months) was significantly longer than that in the CT group (4.2 months) (p=0.011). CONCLUSION: Additional MRI resulted in changes of resectability and treatment modifications in a significant proportion of patients who have potentially resectable state at CT and in prolonged time to liver metastases in patients after curative surgery. Additional MRI to standard staging CT can be recommended for surgical candidates of PDA.


Subject(s)
Adenocarcinoma , Humans , Liver , Magnetic Resonance Imaging , Neoplasm Metastasis , Pancreatic Ducts , Prognosis , Survival Rate
11.
Article in English | WPRIM | ID: wpr-763405

ABSTRACT

Gadoxetic acid, a hepatocyte-specific magnetic resonance imaging (MRI) contrast agent, has emerged as an important tool for hepatocellular carcinoma (HCC) diagnosis. Gadoxetic acid-enhanced MRI is useful for the evaluation of early-stage HCC, diagnosis of HCC precursor lesions, and highly sensitive diagnosis of HCC. Furthermore, functional information provided by gadoxetic acid-enhanced MRI can aid in the characterization of focal liver lesions. For example, whereas lesions lack functioning hepatocytes appear hypointense in the hepatobiliary phase, preserved or enhanced expression of organic anion transporting polypeptides in some HCCs as well as focal nodular hyperplasia lead to hyperintensity in the hepatobiliary phase; and a targetoid appearance on transitional phase or hepatobiliary phase imaging can be helpful for identifying the histopathological composition of tumors. While gadoxetic acid-enhanced MRI may improve the sensitivity of HCC diagnosis and provide new insights into the characterization of focal liver lesions, there are many challenges associated with its use. This article reviews the pros and cons of HCC diagnosis with gadoxetic acid-enhanced MRI and discuss some clues in the radiological differentiation of HCC from HCC mimickers.


Subject(s)
Carcinoma, Hepatocellular , Diagnosis , Focal Nodular Hyperplasia , Hepatocytes , Liver , Liver Neoplasms , Magnetic Resonance Imaging , Peptides
12.
Neurointervention ; : 35-42, 2019.
Article in English | WPRIM | ID: wpr-741675

ABSTRACT

PURPOSE: The purpose of this study was to report the authors’ experience with external ventricular drainage (EVD) before endovascular treatment (EVT) in patients with acute aneurysmal subarachnoid hemorrhage (aSAH) and to investigate its relation to hemorrhagic complications. MATERIALS AND METHODS: Between March 2010 and December 2017, a total of 122 patients were recruited who had an aSAH, underwent EVT to secure the ruptured aneurysm, and had EVD performed within 72 hours of rupture. The pre-embo EVD group (n=67) comprised patients who underwent EVD before EVT, and the post-embo EVD group (n=55) comprised those who underwent EVD after EVT. RESULTS: Overall, EVD-related hemorrhage occurred in 18 patients (14.8%): six (8.9%) in the pre-embo EVD group and 12 (21.8%) in the post-embo EVD group (P=0.065). No rebleeding occurred between EVD and EVT in the pre-embo EVD group. Clinical outcomes at discharge did not differ significantly between groups (P=0.384). At discharge, the final modified Rankin Scale score in patients who experienced pre-embo rebleeding was better in the pre-embo EVD group than in the post-embo EVD group (P=0.041). Current use of an antiplatelet agent or anticoagulant on admission (odds ratio [OR], 2.928; 95% confidence interval [CI], 1.234–7.439; P=0.042) and stent use (OR, 2.430; 95% CI, 1.524–7.613; P=0.047) remained independent risk factors for EVD-related hemorrhagic complications. CONCLUSION: EVD before EVT in patients with aSAH in acute period did not increase the rate of rebleeding as well as EVD-related hemorrhagic complications. Thus, performing EVD before EVT may be beneficial by normalizing increased intracranial pressure. Especially in patients with rebleeding before the ruptured aneurysm is secured, pre-embo EVD may improve clinical outcomes at discharge.


Subject(s)
Aneurysm , Aneurysm, Ruptured , Drainage , Hemorrhage , Humans , Hydrocephalus , Intracranial Aneurysm , Intracranial Pressure , Risk Factors , Rupture , Stents , Subarachnoid Hemorrhage
13.
Article in English | WPRIM | ID: wpr-741419

ABSTRACT

OBJECTIVE: To identify an imaging predictor for the assessment of early treatment response to yttrium-90 transarterial radioembolization (TARE) in patients with hepatocellular carcinoma (HCC), using a quantitative assessment of dynamic computed tomography (CT) images. MATERIALS AND METHODS: Dynamic contrast-enhanced CT was obtained pre- and 4 weeks post-TARE in 44 patients (34 men, 10 women; mean age, 60 years) with HCC. Computer software was developed for measuring the percentage increase in the combined delayed-enhancing area and necrotic area (pD + N) and the percentage increase in the necrotic area (pNI) in the tumor-containing segments pre- and post-TARE. Local progression-free survival (PFS) was compared between patient groups using Cox regression and Kaplan-Meier analyses. RESULTS: Post-TARE HCC with pD + N ≥ 35.5% showed significantly longer PFS than those with pD + N < 35.5% (p = 0.001). The local tumor progression hazard ratio was 17.3 (p = 0.009) for pD + N < 35.5% versus pD + N ≥ 35.5% groups. HCCs with a high pNI tended to have longer PFS, although this difference did not reach statistical significance. CONCLUSION: HCCs with a larger pD + N are less likely to develop local progression after TARE.


Subject(s)
Carcinoma, Hepatocellular , Disease-Free Survival , Female , Humans , Male , Tomography, X-Ray Computed , Treatment Outcome , Yttrium Radioisotopes
14.
Ultrasonography ; : 311-320, 2019.
Article in English | WPRIM | ID: wpr-761995

ABSTRACT

PURPOSE: The purpose of this study was to examine the associations between ultrasonography (US) quality and clinical outcomes in patients undergoing surveillance for hepatocellular carcinoma. METHODS: Between 2008 and 2013, 155 patients were diagnosed with liver cancer during regular surveillance by positive US results (US group, n=82) or by computed tomography (CT) or magnetic resonance image (MRI) scanning as alternative modalities (CT/MRI group, n=73). The quality of the echogenic window, macronodularity of the liver parenchyma, and occurrence of surveillance failure (initial tumor diagnosis beyond the Milan criteria or at Barcelona Clinic Liver Cancer stage B or C) were evaluated. Overall survival was compared according to whether surveillance failure occurred. RESULTS: The patients in the CT/MRI group with negative US results had a higher proportion of parenchymal macronodularity on US than those in the US group (79.5% vs. 63.4%, P=0.028). Surveillance failure tended to be more common in the US group than in the CT/MRI group (40.2% vs. 26.0% by the BCLC staging system [P=0.061]). In the US group, surveillance failure occurred more frequently when the echogenic window was inadequate (50.0% vs. 19.4% by the Milan criteria [P=0.046]). Significantly poorer 5-year overall survival was associated with surveillance failure (P≤0.001). CONCLUSION: Parenchymal macronodularity hindered the detection of early-stage tumors during US surveillance. Using an alternative imaging modality may help prevent surveillance failure in patients with macronodular parenchyma on US. Supplemental surveillance strategies than US may also be necessary when the echogenic window is inadequate.


Subject(s)
Carcinoma, Hepatocellular , Diagnosis , Humans , Liver , Liver Neoplasms , Population Surveillance , Ultrasonography
15.
Article in English | WPRIM | ID: wpr-788696

ABSTRACT

OBJECTIVE: To evaluate the efficacy of fractionated stereotactic radiosurgery (FSRS) performed using the Novalis Tx® system (BrainLAB AG, Feldkirchen, Germany; Varian Medical Systems, Palo Alto, CA, USA) for brain metastases.METHODS: Between March 2013 and July 2016, 23 brain metastases patients were admitted at a single institute. Twenty-nine lesions too large for single session stereotactic radiosurgery or located in the vicinity of eloquent structures were treated by FSRS. Based on the results obtained, we reviewed the efficacy and toxicity of FSRS for the treatment of brain metastases.RESULTS: The most common lesion origin was lung (55%) followed by breast (21%). Median overall survival was 10.0 months (95% confidence interval [CI], 4.9–15.0), and median progression-free survival was 10.0 months (95% CI, 2.1–13.9). Overall survival rates at 1 and 2 years were 58.6% and 36.0%, respectively. Local recurrence and neurological complications affecting morbidity each occurred in two cases.CONCLUSION: FSRS using the Novalis-Tx® system would appear to be an effective, safe noninvasive treatment modality for large and eloquently situated brain metastases. Further investigation is required on a larger number of patients.


Subject(s)
Brain Neoplasms , Brain , Breast , Disease-Free Survival , Germany , Humans , Lung , Neoplasm Metastasis , Radiosurgery , Recurrence , Survival Rate
16.
Article in English | WPRIM | ID: wpr-765266

ABSTRACT

OBJECTIVE: To evaluate the efficacy of fractionated stereotactic radiosurgery (FSRS) performed using the Novalis Tx® system (BrainLAB AG, Feldkirchen, Germany; Varian Medical Systems, Palo Alto, CA, USA) for brain metastases. METHODS: Between March 2013 and July 2016, 23 brain metastases patients were admitted at a single institute. Twenty-nine lesions too large for single session stereotactic radiosurgery or located in the vicinity of eloquent structures were treated by FSRS. Based on the results obtained, we reviewed the efficacy and toxicity of FSRS for the treatment of brain metastases. RESULTS: The most common lesion origin was lung (55%) followed by breast (21%). Median overall survival was 10.0 months (95% confidence interval [CI], 4.9–15.0), and median progression-free survival was 10.0 months (95% CI, 2.1–13.9). Overall survival rates at 1 and 2 years were 58.6% and 36.0%, respectively. Local recurrence and neurological complications affecting morbidity each occurred in two cases. CONCLUSION: FSRS using the Novalis-Tx® system would appear to be an effective, safe noninvasive treatment modality for large and eloquently situated brain metastases. Further investigation is required on a larger number of patients.


Subject(s)
Brain Neoplasms , Brain , Breast , Disease-Free Survival , Germany , Humans , Lung , Neoplasm Metastasis , Radiosurgery , Recurrence , Survival Rate
17.
Article in English | WPRIM | ID: wpr-717626

ABSTRACT

OBJECTIVE: The purpose of this study was to determine the diagnostic utility of low-dose CT with knowledge-based iterative model reconstruction (IMR) for the evaluation of parotid gland tumors. MATERIALS AND METHODS: This prospective study included 42 consecutive patients who had undergone low-dose contrast-enhanced CT for the evaluation of suspected parotid gland tumors. Prior or subsequent non-low-dose CT scans within 12 months were available in 10 of the participants. Background noise (BN), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were compared between non-low-dose CT images and images generated using filtered back projection (FBP), hybrid iterative reconstruction (iDose⁴; Philips Healthcare), and knowledge-based IMR. Subjective image quality was rated by two radiologists using five-point grading scales to assess the overall image quality, delineation of lesion contour, image sharpness, and noise. RESULTS: With the IMR algorithm, background noise (IMR, 4.24 ± 3.77; iDose⁴, 8.77 ± 3.85; FBP, 11.73 ± 4.06; p = 0.037 [IMR vs. iDose⁴] and p < 0.001 [IMR vs. FBP]) was significantly lower and SNR (IMR, 23.93 ± 7.49; iDose⁴, 10.20 ± 3.29; FBP, 7.33 ± 2.03; p = 0.011 [IMR vs. iDose⁴] and p < 0.001 [IMR vs. FBP]) was significantly higher compared with the other two algorithms. The CNR was also significantly higher with the IMR compared with the FBP (25.76 ± 11.88 vs. 9.02 ± 3.18, p < 0.001). There was no significant difference in BN, SNR, and CNR between low-dose CT with the IMR algorithm and non-low-dose CT. Subjective image analysis revealed that IMR-generated low-dose CT images showed significantly better overall image quality and delineation of lesion contour with lesser noise, compared with those generated using FBP by both reviewers 1 and 2 (4 vs. 3; 4 vs. 3; and 3–4 vs. 2; p < 0.05 for all pairs), although there was no significant difference in subjective image quality scores between IMR-generated low-dose CT and non-low-dose CT images. CONCLUSION: Iterative model reconstruction-generated low-dose CT is an alternative to standard non-low-dose CT without significantly affecting image quality for the evaluation of parotid gland tumors.


Subject(s)
Feasibility Studies , Humans , Image Processing, Computer-Assisted , Noise , Parotid Gland , Prospective Studies , Radiation Dosage , Signal-To-Noise Ratio , Tomography, X-Ray Computed , Weights and Measures
18.
Article in English | WPRIM | ID: wpr-165808

ABSTRACT

BACKGROUND/AIMS: To suggest a lexicon for liver ultrasonography and to identify radiologic features indicative of benign or malignant lesions on surveillance ultrasonography. METHODS: This retrospective study included 188 nodules (benign, 101; malignant, 87) from 175 at-risk patients identified during surveillance ultrasonography for hepatocellular carcinoma. We created a lexicon for liver ultrasonography by reviewing relevant literature regarding the ultrasonographic features of hepatic lesions. Using this lexicon, two abdominal radiologists determined the presence or absence of each ultrasonographic feature for the included hepatic lesions. Independent factors associated with malignancy and interobserver agreement were determined by logistic regression analysis and kappa statistics, respectively. RESULTS: Larger tumor size (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.06-1.183; P<0.001), multinodular confluent morphology (OR, 7.712; 95% CI, 1.053-56.465; P=0.044), thick hypoechoic rim (OR, 5.878; 95% CI, 2.681-12.888; P<0.001), and posterior acoustic enhancement (OR, 3.077; 95% CI, 1.237-7.655; P=0.016) were independently associated with malignant lesions. In a subgroup analysis of lesions <2 cm, none of the ultrasonographic features were significantly associated with malignancy or benignity. Interobserver agreement for morphology was fair (κ=0.36), while those for rim (κ=0.427), echogenicity (κ=0.549), and posterior acoustic enhancement (κ=0.543) were moderate. CONCLUSIONS: For hepatic lesions larger than 2 cm, some ultrasonography (US) features might be suggestive of malignancy. We propose a lexicon that may be useful for surveillance US.


Subject(s)
Acoustics , Carcinoma, Hepatocellular , Humans , Liver , Logistic Models , Retrospective Studies , Ultrasonography
19.
Article in English | WPRIM | ID: wpr-109032

ABSTRACT

PURPOSE: Extraosseous Ewing's sarcoma (EOE) of the rectum is extremely rare: only three cases have been reported in the literature and none of these reports described their imaging findings in detail. Herein, we describe the tumor imaging and pathological features in detail. MATERIALS AND METHODS: We report a case of rectal EOE in a 72-year-old female who received local excision and was provisionally diagnosed with a rectal submucosal spindle cell tumor. We used immunohistochemistry, histopathology, and fluorescence in situ hybridization to characterize the tumor and provide a definitive diagnosis of EOE. RESULTS: MRI revealed a well-demarcated submucosal tumor with heterogeneous enhancement and hemorrhagic foci in rectum. EOE was diagnosed by positive staining of tumor cells for CD99 and Fli-1 by immunohistochemistry and the presence of the EWSR1 gene translocation by fluorescence in situ hybridization. Although the patient underwent radiation treatment and surgery, the tumor recurred after 4 months as revealed by computed tomography and magnetic resonance imaging. CONCLUSION: Rectal EOE may present as a rectal submucosal tumor. The understanding of imaging and histological characteristics of this tumor are critical for accurate diagnosis and appropriate aggressive treatment.


Subject(s)
Aged , Diagnosis , Female , Fluorescence , Humans , Immunohistochemistry , In Situ Hybridization , Magnetic Resonance Imaging , Rectum , Sarcoma, Ewing
20.
Article in English | WPRIM | ID: wpr-36768

ABSTRACT

Pancreatic surgery remains the only curative treatment for pancreatic neoplasms, and plays an important role in the management of medically intractable diseases. Since the original Whipple operation in the 20th century, surgical techniques have advanced, resulting in decreased postoperative complications and better clinical outcomes. Normal postoperative imaging findings vary greatly depending on the surgical technique used. Radiologists are required to be familiar with the normal postoperative imaging findings, in order to distinguish from postoperative complications or tumor recurrence. In this study, we briefly review a variety of surgical techniques for the pancreas, and present the normal postoperative computed tomography findings.


Subject(s)
Pancreas , Pancreatic Neoplasms , Postoperative Complications , Recurrence
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