Preoperative Contrast-Enhanced MRI in Differentiating Glioblastoma From Low-Grade Gliomas in The Cancer Imaging Archive Database: A Proof-of-Concept Study

PurposeThis study aimed to develop a repeatable MRI-based machine learning model to differentiate between low-grade gliomas (LGGs) and glioblastoma (GBM) and provide more clinical information to improve treatment decision-making.MethodsPreoperative MRIs of gliomas from The Cancer Imaging Archive (TCIA)–GBM/LGG database were selected. The tumor on contrast-enhanced MRI was segmented. Quantitative image features were extracted from the segmentations. A random forest classification algorithm was used to establish a model in the training set. In the test phase, a random forest model was tested using an external test set. Three radiologists reviewed the images for the external test set. The area under the receiver operating characteristic curve (AUC) was calculated. The AUCs of the radiomics model and radiologists were compared.ResultsThe random forest model was fitted using a training set consisting of 142 patients [mean age, 52 years ± 16 (standard deviation); 78 men] comprising 88 cases of GBM. The external test set included 25 patients (14 with GBM). Random forest analysis yielded an AUC of 1.00 [95% confidence interval (CI): 0.86–1.00]. The AUCs for the three readers were 0.92 (95% CI 0.74–0.99), 0.70 (95% CI 0.49–0.87), and 0.59 (95% CI 0.38–0.78). Statistical differences were only found between AUC and Reader 1 (1.00 vs. 0.92, respectively; p = 0.16).ConclusionAn MRI radiomics-based random forest model was proven useful in differentiating GBM from LGG and showed better diagnostic performance than that of two inexperienced radiologists.

Diagnostic value of 18F-FDG PET/CT versus contrast-enhanced MRI for venous tumour thrombus and venous bland thrombus in renal cell carcinoma

The purpose of this study was to compare the ability of 18F-FDG PET/CT and contrast-enhanced MRI (CEMRI) to detect and grade venous tumour thrombus (VTT) and venous bland thrombus (VBT) in RCC and assess invasion of the venous wall by VTT. The PET/CT and CEMRI data of 41 patients with RCC were retrieved. The difference in maximum standardized uptake value (SUVmax) between VTT and VBT was analysed. According to their pathological diagnosis, the patients were divided into those with and without venous wall invasion. The PET/CT and CEMRI features, including the SUVmax of the primary lesion and VTT, maximum venous diameter, complete occlusion of the vein by VTT, and VTT morphology, were compared between the two groups. All 41 patients had VTT, and eleven of the 41 patients had VBT. The mean SUVmax of the VTT (6.33 ± 4. 68, n = 41) was significantly higher than that of the VBT (1.37 ± 0.26, n = 11; P < 0.001). Ten of the 11 cases of VBT were correctly diagnosed by 18F-FDG PET/CT, and all 11 were diagnosed by CEMRI. Both 18F-FDG PET/CT and CEMRI can effectively detect VTT and distinguish VTT from VBT. 18F-FDG PET/CT is less effective in grading VTT than CEMRI. Complete venous occlusion by VTT indicates venous wall invasion.

Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas

In this study, dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (tumor-to-background ratio, TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.

Májsejtspecifikus kontrasztanyaggal végzett MR-vizsgálat alkalmazása colorectalis eredetű májáttétek reszekciója előtt

Összefoglaló. Bevezetés: A colorectalis eredetű májáttétek (CRCLM-ek) kuratív célú kezelésében elsődleges a sebészi reszekció. A műtét előtt különböző képalkotó vizsgálatok végezhetők, az egyik ilyen speciális vizsgálat a májsejtspecifikus kontrasztanyaggal végzett MR-vizsgálat. Célkitűzés: Tanulmányunkban a májsejtspecifikus kontrasztanyaggal végzett MR-vizsgálat helyét és szerepét vizsgáltuk a májsebészeti gyakorlatban colorectalis áttétes betegek esetében. Módszer: Az Uzsoki Utcai Kórház Sebészeti-Onkosebészeti Osztályán 2017. 01. 01. és 2019. 12. 31. között CRCLM miatt májreszekcióra kerülő betegek adatait elemeztük. Retrospektív módon vizsgáltuk a betegek általános sebészeti és onkosebészeti paramétereit, a képalkotó diagnosztikai eredményeket, a műtéti adatokat és a patológiai leleteket. Eredmények: 132, CRCLM miatt operált betegből 73 szoliter áttét (55%), míg 59 beteg (45%) többszörös áttét miatt került műtétre. 94 betegnél (71%) történt májsejtspecifikus MR-vizsgálat. Szoliter áttét esetén 60%-ban, multiplex áttétek esetén 85%-ban történt májsejtspecifikus MR-vizsgálat (p = 0,02). A szoliter áttétes betegek 8%-ában, míg a multiplex áttétes betegek 39%-ában mutatott további áttétet a májspecifikus kontrasztanyaggal végzett MR-vizsgálat (p = 0,001). A betegek 5%-ában igazolódott fals pozitivitás és 6%-ában fals negativitás a májsejtspecifikus MR-vizsgálat során. 264 góc vizsgálata alapján a májspecifikus kontrasztanyaggal végzett MR-vizsgálat szenzitivitása CRCLM esetén 95%-os, míg pozitív prediktív értéke 93%-os volt vizsgálatunkban. Következtetés: A májsejtspecifikus kontrasztanyaggal végzett MR-vizsgálat hasznos diagnosztikai módszer a CRCLM-ek sebészi reszekciója előtt. Leginkább többszörös áttétek esetén, preoperatív szisztémás onkológiai kezelést követően, illetve más képalkotó vizsgálaton igazolt eltűnt áttét esetén javasolható az alkalmazása. Orv Hetil. 2021; 162(50): 2010–2016. Summary. Introduction: Liver resection is the only curtive treatment option of colorectal cancer liver metastases (CRCLMs). While different diagnostic modalities are available before surgery, a specific diagnostic tool is the liver-specific contrast-enhanced MRI. Objective: The purpose of this study was to evaluate the role of liver-specific contrast-enhanced MRI before resection of colorectal liver metastases. Method: Patients with CRCLM, resected at the Department of Surgical Oncology, Uzsoki Teaching Hospital, between 01. 01. 2017 and 31. 12. 2019 were enrolled in our study. Clinical data, diagnostic, intraoperative and pathological findings were analyzed in a retrospective setting. Results: 132 CRCLM patients were resected in this period, 73 patients had solitary (55%), and 59 patients (45%) had multiple metastases. Liver-specific contrast-enhanced MRI was performed in 94 patients (71%). 60% of the patients with solitary and 85% of the patients with multiple CRCLM had liver-specific contrast-enhanced MRI (p = 0.02). Compared to other modalities, liver-specific contrast-enhanced MRI showed additional metastases in 8% of the patients with solitary, and in 39% of the patients with multiple metastases (p = 0.001). Liver-specific contrast-enhanced MRI had a 5% false-positivity and a 6% false-negativity rate. 264 leasions were analyzed, and the sensitivity of the liver-specific contrast-enhanced MRI was 95% with a predictive positive value of 93%. Conclusion: Liver-specific contrast-enhanced MRI is a useful diagnostic tool in CRCLM patients before liver resection. It is highly recommended in the case of multiple metastases, after preoperative chemotherapy and in the case of disappearing metastases. Orv Hetil. 2021; 162(50): 2010–2016.