Background:The Alberta Stroke Program Early CT Score (ASPECTS) is used to assess early ischemic stroke damage. This study compared bilateral ASPECTS (ASPECTS-b) with the gray:white matter ratio (GWR) ...and quantitative regional abnormality (QRA) to evaluate the prognostic utility of early computed tomography (CT) findings in post-cardiac arrest patients.Methods and Results:Out-of-hospital cardiac arrest patients with return of spontaneous circulation (ROSC) who underwent brain CT (<6 h after onset) and therapeutic hypothermia were recruited from a university hospital over a 2-year period. General demographics, ROSC characteristics, ASPECTS-b (total score=20 points), GWR, and QRA were assessed. Multivariate logistic regression analysis was used to predict neurologic outcome using cerebral performance category (CPC) at 1 month. The study population was divided into good (n=20; CPC 1–2) and poor (n=47; CPC 3–5) outcome groups. The good (vs. poor) outcome group was younger (mean ±SD age 46.7±11.8 vs. 60.3±17.2 years; P=0.002) and had more initial shockable rhythms (40.0% vs. 8.5%; P=0.002). In addition, the good outcome group had a higher mean ASPECTS-b score (15.3±2.7 vs. 9.0±4.9; P<0.001), despite no differences in QRA and mean GWR. Age and ASPECTS-b were independent predictors of outcome after adjusting for potential confounders.Conclusions:These findings suggest that an initial CT score (ASPECTS-b) could help estimate early neurologic outcomes in post-cardiac arrest patients treated with therapeutic hypothermia.
Objective
This study was conducted in order to compare the diagnostic performance of noncontrast and abbreviated MRI using gadoxetic acid for detecting hepatocellular carcinoma (HCC) in initially ...diagnosed HCC patients.
Methods
We identified 140 consecutive patients with newly diagnosed HCC (173 HCCs) within the Milan criteria, who underwent liver MRI using gadoxetic acid between 2015 and 2016. One hundred twenty-three consecutive patients without HCC who underwent liver MRI in the same period for HCC surveillance were enrolled for the control group. Two radiologists independently reviewed two MRI sets: a noncontrast set and an abbreviated set. The noncontrast set consists of T2 FSE/ssFSE, T1 in- and out-of-phase image, DWI, and the ADC map. The abbreviated set consists of T2 FSE/ssFSE, hepatobiliary phase image 20 min after gadoxetic acid injection, DWI, and the ADC map.
Results
In a per-patient analysis, sensitivity of reviewer 1 for noncontrast and abbreviated sets was 85.7 and 90.0%, respectively. The specificity for both noncontrast and abbreviated sets was 92.7%. For reviewer 2, sensitivity of noncontrast and abbreviated sets was 86.4 and 89.3%, respectively. Per-patient specificity of reviewer 2 was 92.7% for both noncontrast and abbreviated sets. The sensitivity and specificity of two image sets were not significantly different for both reviewers. The per-tumor sensitivity of noncontrast and abbreviated sets was 81.5 and 84.4% for reviewer 1, respectively, and 79.8 and 84.4% for reviewer 2, respectively. There was no significant difference.
Conclusion
Noncontrast and abbreviated MRI using gadoxetic acid showed comparable diagnostic performance for detecting patients with HCCs in the early stage.
Key Points
• Diagnostic performance of noncontrast MRI and abbreviated MRI using gadoxetic acid for detecting HCCs is comparable in patients with HCCs in the early stage.
• Noncontrast MRI and abbreviated MRI showed high sensitivity and specificity for detecting HCCs in the early stage.
• Outcomes of surveillance for HCC in high-risk patients can be improved by adopting these simplified and focused MRI protocols.
Purpose
To assess the association between T2-weighted imaging (T2WI) texture-analysis parameters and the pathological aggressiveness or long-term outcomes in pancreatic ductal adenocarcinoma (PDAC) ...patients.
Methods
A total of 66 patients (mean age 65.3 ± 9.0 years) who underwent preoperative MRI followed by pancreatectomy for PDAC between 2013 and 2015 were included in this study. A radiologist performed a texture analysis twice on one axial image using commercial software. Differences in the tex parameters, according to pathological factors, were analyzed using a Student’s
t
test or an ANOVA with Tukey’s test. Univariate and multivariate Cox proportional hazards regression analyses were used to evaluate the association between tex parameters and recurrence-free survival (RFS) or overall survival (OS).
Results
The mean follow-up time was 18.5 months, and there were 58 recurrences and 39 deaths. The mean of the positive pixel (MPP)-related factors was significantly lower in poorly differentiated tumors than in well-differentiated tumors as well as in cases with perineural invasion. The univariate Cox proportional hazards analysis showed a significant association between the tex parameters and RFS or OS. However, only tumor size was statistically significant after the multivariate analysis. Only tumor size and entropy with medium texture were significantly associated with OS after the multivariate analysis.
Conclusions
Tumor size was a significant predictive factor for RFS and OS in PDAC patients. Although entropy with medium texture analysis was significantly associated with OS, there were also limitations in the texture analysis; thus, further study is necessary.
Purpose
To investigate the usefulness of apparent diffusion coefficient (ADC) values derived from histogram analysis of the whole rectal cancer as a quantitative parameter to evaluate pathologic ...complete response (pCR) on preoperative magnetic resonance imaging (MRI).
Materials and Methods
We enrolled a total of 86 consecutive patients who had undergone surgery for rectal cancer after neoadjuvant chemoradiotherapy (CRT) at our institution between July 2012 and November 2014. Two radiologists who were blinded to the final pathological results reviewed post‐CRT MRI to evaluate tumor stage. Quantitative image analysis was performed using T2‐weighted and diffusion‐weighted images independently by two radiologists using dedicated software that performed histogram analysis to assess the distribution of ADC in the whole tumor.
Results
After surgery, 16 patients were confirmed to have achieved pCR (18.6%). All parameters from pre‐ and post‐CRT ADC histogram showed good or excellent agreement between two readers. The minimum, 10th, 25th, 50th, and 75th percentile and mean ADC from post‐CRT ADC histogram were significantly higher in the pCR group than in the non‐pCR group for both readers. The 25th percentile value from ADC histogram in post‐CRT MRI had the best diagnostic performance for detecting pCR, with an area under the receiver operating characteristic curve of 0.796.
Conclusion
Low percentile values derived from the ADC histogram analysis of rectal cancer on MRI after CRT showed a significant difference between pCR and non‐pCR groups, demonstrating the utility of the ADC value as a quantitative and objective marker to evaluate complete pathologic response to preoperative CRT in rectal cancer. J. Magn. Reson. Imaging 2016;44:212–220.
This study evaluated the magnetic resonance imaging (MRI) findings of endometrial cancer (EC) patients and identified differences based on risk group and molecular classification. The study involved ...a total of 175 EC patients. The MRI data were retrospectively reviewed and compared based on the risk of recurrence. Additionally, the associations between imaging phenotypes and genomic signatures were assessed. The low-risk and non-low-risk groups (intermediate, high-intermediate, high, metastatic) showed significant differences in tumor diameter (
< 0.001), signal intensity and heterogeneity on diffusion-weighted imaging (DWI) (
= 0.003), deep myometrial invasion (involvement of more than 50% of the myometrium), cervical invasion (
< 0.001), extrauterine extension (
= 0.002), and lymphadenopathy (
= 0.003). Greater diffusion restriction and more heterogeneity on DWI were exhibited in the non-low-risk group than in the low-risk group. Deep myometrial invasion, cervical invasion, extrauterine extension, lymphadenopathy, recurrence, and stage discrepancy were more common in the non-low-risk group (
< 0.001). A significant difference in microsatellite stability status was observed in the heterogeneity of the contrast-enhanced T1-weighted images (
= 0.027). However, no significant differences were found in MRI parameters related to TP53 mutation. MRI features can be valuable predictors for differentiating risk groups in patients with EC. However, further investigations are needed to explore the imaging markers based on molecular classification.
AIM To evaluate the correlation between subjective assessments of pancreatic hardness based on the palpation, objective measurements using a durometer, and magnetic resonance imaging(MRI) findings ...for assessing pancreatic hardness.METHODS Eighty-three patients undergoing pancreatectomies were enrolled. An experienced surgeon subjectively evaluated the pancreatic hardness in the surgical field by palpation. The pancreatic hardness was also objectivelyevaluated using a durometer. Preoperative MRI findings were evaluated by a radiologist in terms of the apparent diffusion coefficient(ADC) values, the relative signal intensity decrease(RSID) of the pancreatic parenchyma, and the diameter of the pancreatic parenchyma and duct. Durometer measurement results, ADC values, RSID, pancreatic duct and parenchyma diameters, and the ratio of the diameters of the duct and parenchyma were compared between pancreases judged to be soft or hard pancreas on the palpation. A correlation analysis was also performed between the durometer and MRI measurements.RESULTS The palpation assessment classified 44 patients as having a soft pancreas and 39 patients as having a hard pancreas. ADC values were significantly lower in the hard pancreas group. The ductal diameter and duct-to-pancreas ratio were significantly higher in the hard pancreas group. For durometer measurements, a correlation analysis showed a positive correlation with the ductal diameter and the duct-to-pancreas ratio and a negative correlation with ADC values. CONCLUSION Hard pancreases showed lower ADC values, a wider pancreatic duct diameter and a higher duct-to-pancreas ratio than soft pancreases. Additionally, the ADC values, diameter of the pancreatic duct and duct-to-pancreas ratio were closely correlated with the durometer results.
Objective
To systematically determine the accuracy of Liver Imaging Reporting and Data System treatment response (LR-TR) algorithm for diagnosing the viability of hepatocellular carcinoma (HCC) ...treated with locoregional therapy (LRT).
Methods
Original studies reporting the diagnostic accuracy of LR-TR algorithm on dynamic contrast-enhanced computed tomography or magnetic resonance imaging (MRI) were identified in MEDLINE and EMBASE up to June 1, 2020. The meta-analytic summary sensitivity and specificity of LR-TR algorithm were calculated using a bivariate random-effects model. Subgroup analyses and meta-regression analysis were performed to explore study heterogeneity.
Results
We found six studies reporting the accuracy of LR-TR viable category (601 observations in 453 patients). The meta-analytic pooled sensitivity and specificity of LR-TR viable category were 63% (95% confidence interval CI, 39–81%;
I
2
= 88%) and 96% (95% CI, 91–99%;
I
2
= 76%), respectively. The meta-analytic pooled sensitivity and specificity of LR-TR viable or equivocal category combined were 71% (95% CI, 55–84%;
I
2
= 89%) and 87% (95% CI, 73–94%
I
2
= 80%), respectively. Studies which used only MRI showed a trend towards higher sensitivity (71% 95% CI, 46–88%) with a comparable specificity (95% 95% CI, 86–99%) of LR-TR viable category compared to the whole group. The type of reference standard and study design were significantly associated with study heterogeneity (
p
≤ 0.01).
Conclusions
The LR-TR viable category had high specificity but suboptimal sensitivity for diagnosing the viability of HCC after LRT. Substantial study heterogeneity was noted, and it was significantly associated with the type of reference standard and study design.
Key Points
•
The meta-analytic pooled sensitivity and specificity of LR-TR viable category were 63% (95% CI, 39–81%) and 96% (95% CI, 91–99%), respectively
.
•
The meta-analytic pooled sensitivity and specificity of LR-TR viable or equivocal category combined were 71% (95% CI, 55–84%) and 87% (95% CI, 73–94%), respectively
.
•
The type of reference standard and study design were the factors significantly influencing study heterogeneity (p ≤ 0.01)
.
The purposes of this study were to analyze MRI features of small hepatocellular carcinomas (HCCs) on the basis of size and to evaluate the difference in frequency of typical radiologic hallmarks of ...HCC (arterial enhancement and washout) according to the tumor size.
Enrolled were 86 patients with 110 HCCs 3 cm or smaller who underwent surgical resection or transplantation. Two radiologists reviewed gadoxetic acid-enhanced MRI features for signal intensity of T2-weighted and T1-weighted imaging, diffusion restriction, presence of arterial enhancement, washout on portal and transitional phases, and signal intensity on the hepatobiliary phase. ROC curve analysis was performed to determine the optimal HCC cutoff size for radiologic hallmarks of HCC. Tumors were divided into two groups by cutoff size, and the frequencies of MRI features were assessed.
On ROC analysis, the optimal cutoff for radiologic hallmarks of HCC was 1.5 cm in independent and consensus reviews by two radiologists. HCCs smaller than 1.5 cm showed typical finding of HCC less frequently than HCCs 1.5 cm or larger in diameter. In subgroup analyses, HCCs with diameters between 1 and 1.5 cm showed similar MRI findings to HCCs with diameters 1 cm or less but significantly different findings compared with HCCs with diameters from 1.5 to 2 cm and 2-3 cm.
HCCs smaller than 1.5 cm in size less frequently showed MRI findings seen typically in larger HCCs. Therefore, small HCCs are harder to detect with certainty not only because of small size but also because of the lower frequency of typical MRI findings.
We aimed to determine the histopathological characteristics and prognosis of curatively resected pancreatic ductal adenocarcinoma (PDAC) showing intratumoral necrosis on preoperative CT or MRI. This ...study consecutively included 102 patients who underwent upfront surgery with margin-negative resection from 2012 to 2020. All patients underwent both pancreatic CT and MRI within 1 month before surgery. Two radiologists independently assessed CT/MRI findings, including the presence of CT- and MRI-detected necrosis. Histopathological characteristics of PDACs according to CT or MRI detection of necrosis were evaluated. Disease-free survival (DFS) and overall survival (OS) were assessed by the Kaplan−Meier method and the Cox proportional hazards model. Among the 102 PDAC patients, 14 patients (13.7%) had CT-detected necrosis, and 16 patients (15.7%) had MRI-detected necrosis, of which 9 showed both CT- and MRI-detected necrosis. PDACs with CT- or MRI-detected necrosis demonstrated a significantly higher degree of histopathological necrosis than those without (p < 0.001). Multivariable analysis revealed that tumor size (hazard ratio HR, 1.19; p = 0.040), tumor location (HR, 0.46; p = 0.009), and MRI-detected necrosis (HR, 2.64; p = 0.002) had independent associations with DFS. Only MRI-detected necrosis was significantly associated with OS (HR, 2.59; p = 0.004). Therefore, MRI-detected necrosis might be a potential imaging predictor of poor survival after curative resection of PDAC.
We aimed to investigate the accuracy of each imaging feature of LI-RADS treatment response (LR-TR) viable category for diagnosing tumor viability of locoregional therapy (LRT)-treated HCC. Studies ...evaluating the per feature accuracy of the LR-TR viable category on dynamic contrast-enhanced CT or MRI were identified in databases. A bivariate random-effects model was used to calculate the pooled sensitivity, specificity, and diagnostic odds ratio (DOR) of LR-TR viable features. Ten studies assessing the accuracies of LR-TR viable features (1153 treated observations in 971 patients) were included. The pooled sensitivities and specificities for diagnosing viable HCC were 81% (95% confidence interval CI, 63–92%) and 95% (95% CI, 88–98%) for nodular, mass-like, or irregular thick tissue (NMLIT) with arterial phase hyperenhancement (APHE), 55% (95% CI, 34–75%) and 96% (95% CI, 94–98%) for NMLIT with washout appearance, and 21% (95% CI, 6–53%) and 98% (95% CI, 92–100%) for NMLIT with enhancement similar to pretreatment, respectively. Of these features, APHE showed the highest pooled DOR (81 95% CI, 25–261), followed by washout appearance (32 95% CI, 13–82) and enhancement similar to pretreatment (14 95% CI, 5–39). In conclusion, APHE provided the highest sensitivity and DOR for diagnosing viable HCC following LRT, while enhancement similar to pretreatment showed suboptimal performance.
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