T1-Weighted Contrast Enhancement, Apparent Diffusion Coefficient, and Cerebral-Blood-Volume Changes after Glioblastoma Resection: MRI within 48 Hours vs. beyond 48 Hours.

BACKGROUND: The aim of the study is to identify the advantages, if any, of post-operative MRIs performed at 48 h compared to MRIs performed after 48 h in glioblastoma surgery. MATERIALS AND METHODS: To assess the presence of a residual tumor, the T1-weighted Contrast Enhancement (CE), Apparent Diffusion Coefficient (ADC), and Cerebral Blood Volume (rCBV) in the proximity of the surgical cavity were considered. The rCBV ratio was calculated by comparing the rCBV with the contralateral normal white matter. After the blind image examinations by the two radiologists, the patients were divided into two groups according to time window after surgery: ≤48 h (group 1) and >48 h (group 2). RESULTS: A total of 145 patients were enrolled; at the 6-month follow-up MRI, disease recurrence was 89.9% (125/139), with a mean patient survival of 8.5 months (SD 7.8). The mean ADC and rCBV ratio values presented statistical differences between the two groups (p < 0.05). Of these 40 patients in whom an ADC value was not obtained, the rCBV values could not be calculated in 52.5% (21/40) due to artifacts (p < 0.05). CONCLUSION: The study showed differences in CE, rCBV, and ADC values between the groups of patients undergoing MRIs before and after 48 h. An MRI performed within 48 h may increase the ability of detecting GBM by the perfusion technique with the calculation of the rCBV ratio.

Learning curves in radiological reporting of whole-body MRI in plasma cell disease: a retrospective study.

BACKGROUND: The plasma cell disease is been studying by the whole-body MRI technology. However, the time requested to learn this radiological technique is unknown. PURPOSE: To esteem, quantitatively and qualitatively, the essential time to learn the whole-body MRI diffusion-weighted imaging with background body signal suppression in patients with plasma cell disease. MATERIALS AND METHODS: Between January 2015 and February 2017, three readers in-training with different levels of experience examined the anonymised and randomised whole-body MRI images of 52 patients with a diagnosis of plasma cell disease and analysed their morphological (T1w, T2w with and without fat suppression) and functional sequences. Reports of an expert radiologist were considered the standard of reference. Images were analysed in two sessions, during which each reader was timed. Readers reported the number of segments with lesions and staged the disease using the Durie-Salmon PLUS staging system. Weighted Cohen's ĸ and Z-test were used to compare the trainees' reports with those of the expert radiologist, and learning curves were drawn up to show changes between the two sessions. RESULTS: Weighted Cohen's ĸ of number of lesioned segments increased from 0.536 ± 0.123 to 0.831 ± 0.129 (Prob > Z under 0.005), thus approaching the goal of ĸ > 0.8. Trainees reached the level of experienced radiologist in terms of time by the 33rd patient. Agreement concerning the Durie-Salmon PLUS increased from 0.536 ± 0.123 to 0.831 ± 0.129 (Prob > Z under 0.005). CONCLUSIONS: The findings of this study demonstrate that whole-body MRI with DWIBS can be learned in about 80 reports and leads to a high level of inter-observer concordance when using the Durie-Salmon PLUS staging system.

Evaluation of Left Ventricular Volumes and Ejection Fraction from Gated Myocardial Perfusion SPECT Processed with "Myovation Evolution": Comparison of Three Automated Software Packages using Cardiac Magnetic Resonance as Reference.

BACKGROUND: The development of resolution recovery (RR) algorithms has made it possible to preserve the good quality of cardiac images despite a reduced number of counts during study acquisition. OBJECTIVE: Our purpose was to evaluate the performance of three different software packages in the quantification of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) from gated perfusion SPECT, applying a resolution recovery (RR) algorithm (GE Myovation Evolution), with respect to cardiac MRI (cMRI) as a gold standard. METHODS: We retrospectively enrolled 21 patients, with suspected or known coronary heart disease. Images at rest were reconstructed by filtered back projection (FBP) and by an iterative protocol with the RR algorithm. EDV, ESV, and LVEF were automatically computed employing Quantitative Gated SPECT (QGS), Myometrix (MX), and Corridor 4DM (4DM). Any difference in EDV, ESV, and LVEF calculation between cMRI and the three packages (with FBP and iterative reconstruction with RR) was tested using Wilcoxon or paired t-test, with the assumption of normality assessed using the Shapiro-Wilk test. Agreement between imaging reconstruction algorithms and between gated-SPECT software packages and cMRI was studied with Pearson's (r) or Spearman's (R) correlation coefficients and Lin's concordance correlation coefficient (LCC). RESULTS: Intra-software evaluation always revealed very strong correlation coefficients (R, r ≥ 0.8) and excellent LCC coefficients (LCC > 0.95), except for the LCC coefficient between MX-FBP and MX-RR in EDV evaluation, nevertheless considered very good (LCC = 0.94). EDV and ESV had significantly lower value when calculated with the RR algorithm with respect to FBP reconstruction in QGS and MX. LVEF estimation did not show significant differences for QGS-FBP, QGS-RR, MX, and 4DM-RR with respect to cMRI. CONCLUSION: All reconstruction methods systematically underestimate EDV and ESV, with higher underestimation applying only the RR. No significant differences were observed between 4DM - RR and 4DM-FBP, for each parameter, when the 4DM package was used.

Apparent diffusion coefficient and tumor volume measurements help stratify progression-free survival of bevacizumab-treated patients with recurrent glioblastoma multiforme.

BACKGROUND: The aim of this study was to determine whether apparent diffusion coefficient (ADC) bi-component curve-fitting histogram analysis and volume percentage change (VPC) prior to bevacizumab treatment can stratify progression-free survival (PFS) and overall survival (OS) in patients with glioblastoma multiforme (GBM) on first recurrence. METHODS: We retrospectively evaluated 17 patients with recurrent GBM who received bevacizumab and fotemustine (n = 13) or only bevacizumab (n = 4) on first recurrence at our institution between December 2009 and July 2015. Both T2/FLAIR abnormalities and enhancing tumor on T1 images were mapped to the ADC images. ADC-L and ADC-M values were obtained trough bi-Gaussian curve fitting histogram analysis. Furthermore, the study population was dichotomized into two subgroups: patients displaying a reduction in enhancing tumor volume of either >55% or <55% between the mean value calculated at baseline and first follow-up. Subsequently, a second dichotomization was performed according to a reduction in the T2 / FLAIR volume >41% or <41% at first check after treatment. OS and PFS were assessed using volume parameters in a Cox regression model adjusted for significant clinical parameters. RESULTS: In univariate analysis, contrast-enhanced (CE)-ADC-L was significantly predictive of PFS (p = 0.01) and OS (p = 0.03). When we dichotomized our sample using the 55% cut-off for enhancing tumor volume, CE-VPC was able to predict PFS (p = 0.01) but not OS (p = 0.08). In multivariate analysis, only the CE-ADC-L was predictive of PFS (p = 0.01), albeit not predictive of OS (p = 0.14). CE-ADC-M, T2/FLAIR-ADC-L, T2/FLAIR-ADC, and T2/FLAIR VPC were not significantly predictive of PFS and OS (p > 0.05) in both univariate and multivariate analysis. CONCLUSIONS: CE-ADC and CE-VPC can stratify PFS for patients with recurrent glioblastoma prior to bevacizumab treatment.

Overcoming metallic artefacts from orthopaedic wrist volar plating on a low-field MRI scanner.

PURPOSE: To quantitatively compare the artefact reduction between standard and metallic artefact reduction (MAR) fast spin echo (FSE) T2 sequences in a low-field magnetic resonance imaging (MRI) scanner (0.3 T) in patients with titanium volar wrist plating. MATERIALS AND METHODS: Sixteen patients with fractures of the distal radius, treated with titanium volar wrist plating and screws, were examined using a dedicated 0.3 T MRI scanner. Coronal standard FSE T2, FSE T2 high bandwidth (HiBW) and FSE T2 view angle tilting (VAT) sequences were performed. Metallic artefact volume, consisting of both "black" and "bright" artefacts, was calculated for each sequence. Quantitative differences were compared using repeated measures ANOVA test (P < 0.05). RESULTS: FSE T2 HiBW and FSE T2 VAT showed a significant reduction in artefact volume compared to the standard sequence. Differences between the artefact volume of the standard FSE T2, HiBW and VAT sequences were statistically significant for both the "black" and "bright" artefacts (P < 0.0001). Differences between the 1.5 HiBW and VAT sequences were statistically significant (black P < 0.0001, bright P < 0.0302). CONCLUSIONS: MAR sequences significantly reduced metallic artefacts in vivo using a 0.3 T MRI scanner.

Whole-Body MRI with Diffusion-Weighted Imaging in Bone Metastases: A Narrative Review.

Whole body magnetic resonance imaging (MRI) with diffusion-weighted imaging (WB-MRI-DWI) is currently emerging as a diagnostic technique in the evaluation of bone metastases from breast, prostate, lung, thyroid, and melanoma tumors. The most relevant articles regarding the detection of solid tumor bone metastases with MRI have been reviewed and cited. The imaging methods currently used in the detection of bone metastases are bone scintigraphy, computed tomography (CT), and positron emission tomography (PET/CT) with 2-deoxy-2-[fluorine-18] fluoro-d-glucose (18F-FDG PET/CT). WB-MRI-DWI allows qualitative and quantitative evaluation of focal lesions through signal intensity evaluation on DWI images and the reconstruction of the apparent diffusion coefficient (ADC) map. In prostate and breast cancer, WB-MRI-DWI is useful in assessing the response of bone lesions to therapy and to detecting early non-responders, while in lung cancer the method shows a similar sensitivity to 18F-FDG PET/CT in the detection of bone metastases. In bone metastases of thyroid tumors and melanoma, the WB-MRI-DWI shows a higher sensitivity when compared to 18F-FDG PET/CT. With a standardization of the WB-MRI-DWI protocol, this method seems to play an important role in the diagnosis of bone solid tumor metastases.

Computed tomography perfusion and computed tomography angiography in vasospasm after subarachnoid hemorrhage.

BACKGROUND: The aim of the study was to evaluate the effectiveness and reliability of a combined computed tomography angiography (CTA) and computed tomography perfusion (CTP) approach in the diagnosis of cerebral vasospasm after subarachnoid hemorrhage. METHODS: Nineteen patients with clinical signs of arterial vasospasm and positive transcranial Doppler (TCD) were enrolled and underwent CTP. Mean time transit (MTT), cerebral blood flow (CBF) and cerebral blood volume (CBV) values of 20 standardized ROI (regions of interest) were analyzed, and CTA used to measure the gauge of 26 arterial ramifications. CTA measurements were compared with those taken upon hospitalization. Of the 19 patients, 11 were scheduled for digital subtraction angiography (DSA), performed less than 12 hours after execution of the CTA-CTP protocol. The results were compared with findings of DSA and/or clinical follow-up and CT or TCD. RESULTS: Computed tomography angiography diagnosis of vasospasm was confirmed in all cases (100% sensitivity and 100% specificity), while CTP yielded 3 false negatives (70% sensitivity and 100% specificity). All patients sent for endovascular treatment had received diagnostic confirmation of vasospasm by angiography. CTP thresholds proved reliable in both diagnosis and indicating treatment. CONCLUSIONS: Combined one-shot CT angiography and CT perfusion represents a valid alternative to DSA in the diagnosis and management of cerebral vasospasm.

Can neuroimaging differentiate PFO and AF-related cardioembolic stroke from the other embolic sources? Clinical-radiological correlation on a retrospective study.

PURPOSE: The aim of this retrospective study was to map the specific ischemic lesion patterns of distribution in patent foramen ovale-related stroke (PFO-stroke) and atrial fibrillation-related stroke (AF-stroke) in patients with idiopatic ischemic stroke. MATERIALS AND METHODS: 750 ischaemic strokes were screened on basis of diagnostic imaging and tests: patients with known causes were excluded. 171 patients with unknown cause were selected and divided in two groups: AF-stroke (43 patients) and PFO-stroke (128 patients). Vascular territories of ischemic involvement were divided into four classes in each group: the anterior cerebral artery, the middle cerebral artery, the vertebro-cerebral artery (including the posterior cerebral artery) and multisite (MS) involvement. RESULTS: Infarcts in vertebro-basilar territory and multisite represented each one about 32% of infarcts in PFO-stroke group and their involvement are more frequent than AF-stroke group (p = 0.03). Ischemic lesions in PFO-group were predominantly cortical (34.3%), and in AF-group cortical-subcortical (60.4%). Multisite pattern of ischemic lesion was more frequent in patients with severe degree of right to left shunts (37.5%). CONCLUSION: In clinical practice, PFO may be considered a cause of cortical stroke on the basis of radiological findings, when VB vascular territory or MS brain involvement is present in younger patients (<50 age).