A case of mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE)

Recently, in the scientist community of specialists dealing with structural epilepsy, it has been noticed an increasing interest in a special form of cortical development disorder not to be included in the ILAE Classification of the epilepsies the 2017 revision. It is so-called mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy (MOGHE). There are a number of publications devoted to the neuroimaging features of MOGHE, which are possible to distinguish from other epileptogenic substrates in comparisons with clinical/anamnestic data and dynamic observation. Our paper describes the case of a patient under 6 years suffering from pharmacoresistant epilepsy with histologically confirmed MOGHE, and having undergone the procedure of epileptic surgery. MRI showed an increased intensity of the T2/FLAIR signal from the white matter in combination with signs of laminar hyperintensivity, regional sulcation disturbance, smoothness of gray-white matter demarcation in the right frontal lobe. A signal intensification from the white matter with the formation similarity of the «transmantl» sign and further pronounced smoothness of the gray-white matter demarcation was observed on dynamic MRI. These changes were estimated as focal cortical dysplasia. Pre-surgical examination revealed a correlation of epileptiform activity with MRI changes. The subtotal resection of the right frontal lobe and the morphological conclusion established the presence of MOGHE was performed.

Comparison between subtraction and dynamic MRI in assessing treatment response following radiofrequency ablation in patients with hepatocellular carcinoma

Background Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide, and if left untreated, one of the most lethal. Ablative therapies including radiofrequency ablation (RFA) play increasingly important role for patients with liver tumors who are not surgical candidates. Monitoring treatment response following ablation is crucial in oncologic imaging. Dynamic contrast-enhanced MRI can assess changes in tumor vascularity and perfusion while subtraction imaging is useful in differentiating residual tumor from post-ablation parenchymal changes. The aim of this study is to compare the role of subtraction MRI and conventional dynamic MRI in assessing treatment response following RFA in patients with HCC. Results The study included 48 patients with 62 HCC lesions who underwent RFA from May to October 2020, followed by MRI evaluation with 1-month interval. Two readers with experience in hepatic imaging interpreted the dynamic and subtraction dynamic MRI. The hepatic focal lesions were classified into “well-ablated” and “residual” groups according to MRI findings, and the agreement between the two readers was evaluated. Using dynamic MRI, the first reader reported 38 well-ablated lesions, and the second reader agreed in 34 of them (89.5%). Residual disease was reported by the first reader in 22 lesions and the second reader disagreed in 10 of them (45.5%) where complete ablation was reported. Thirty-eight out 44 well-ablated lesions (86.4%) showed high signal intensity on non-enhanced T1 images, and 28 lesion (63.6%) showed intermediate T2 signal. All the mis-matched readings occurred in lesions with a high signal intensity in pre-contrast T1 images. Moderate agreement between the two readers was found with Kappa value of 0.467. Significant additive value of subtraction technique to dynamic MRI was detected with a P value of 0.009. No major complications recorded except for a single case of major portal vein branch occlusion. Conclusion MRI is a powerful imaging tool in assessing tumor viability and complications after RFA in patients with HCC. Dynamic MRI study is the gold standard in detecting recurrent lesions while subtraction technique is crucial in differentiating between arterial enhancement due to residual disease and normal hyperintense T1 signal of the ablation zone.

The influence of gravity on respiratory kinematics during phonation measured by dynamic magnetic resonance imaging

Respiratory kinematics are important for the regulation of voice production. Dynamic MRI is an excellent tool to study respiratory motion providing high-resolution cross-sectional images. Unfortunately, in clinical MRI systems images can only be acquired in a horizontal subject position, which does not take into account gravitational effects on the respiratory apparatus. To study the effect of body posture on respiratory kinematics during phonation, 8 singers were examined both in an open-configuration MRI with a rotatable gantry and a conventional horizontal MRI system. During dynamic MRI the subjects sang sustained tones at different pitches in both supine and upright body positions. Sagittal images of the respiratory system were obtained at 1–3 images per second, from which 6 anatomically defined distances were extracted to characterize its movements in the anterior, medium and posterior section of the diaphragm as well as the rip cage (diameter at the height of the 3rd and 5th rip) and the anterior–posterior position of the diaphragm cupola. Regardless of body position, singers maintained their general principles of respiratory kinematics with combined diaphragm and thorax muscle activation for breath support. This was achieved by expanding their chest an additional 20% during inspiration when singing in the supine position but not for sole breathing. The diaphragm was cranially displaced in supine position for both singing and breathing and its motion range increased. These results facilitate a more realistic extrapolation of research data obtained in a supine position.

Dynamic MRI of swallowing: real-time volumetric imaging at 12 frames per second at 3 T

Objective Dysphagia or difficulty in swallowing is a potentially hazardous clinical problem that needs regular monitoring. Real-time 2D MRI of swallowing is a promising radiation-free alternative to the current clinical standard: videofluoroscopy. However, aspiration may be missed if it occurs outside this single imaged slice. We therefore aimed to image swallowing in 3D real time at 12 frames per second (fps). Materials and methods At 3 T, three 3D real-time MRI acquisition approaches were compared to the 2D acquisition: an aligned stack-of-stars (SOS), and a rotated SOS with a golden-angle increment and with a tiny golden-angle increment. The optimal 3D acquisition was determined by computer simulations and phantom scans. Subsequently, five healthy volunteers were scanned and swallowing parameters were measured. Results Although the rotated SOS approaches resulted in better image quality in simulations, in practice, the aligned SOS performed best due to the limited number of slices. The four swallowing phases could be distinguished in 3D real-time MRI, even though the spatial blurring was stronger than in 2D. The swallowing parameters were similar between 2 and 3D. Conclusion At a spatial resolution of 2-by-2-by-6 mm with seven slices, swallowing can be imaged in 3D real time at a frame rate of 12 fps.

Role of DWI in evaluation of HCC after radiofrequency ablation compared to dynamic MRI using MRI (3 T)

Background The purpose of this study was to investigate the diagnostic performance of diffusion weight imaging (DWI), apparent diffusion coefficient (ADC) map, normalized ADC liver, and normalized ADC spleen compared to the dynamic contrast-enhanced MRI (DCE-MRI) in the evaluation of residual hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA) using 3 T (T) magnetic resonance imaging (MRI). Results A prospective study was performed on 40 patients with radiofrequency-ablated HCC, and 15 (37.5%) patients had viable lesion post-RFA, while 25 (62.5%) had non-viable lesions. DCE-MRI had a sensitivity, specificity, and accuracy of 100%, 100%, and 100%, respectively, compared to DWI which had a sensitivity, specificity, and accuracy of 80%, 88%, and 85%, respectively, for identifying post-RFA viable HCC. The sensitivity, specificity, and accuracy of ADC at a cutoff value of 1.01 × 10−3 mm2/s were 80%, 100%, and 97.1%, respectively. The optimal cutoff value of normalized ADC liver was 0.81 with a sensitivity of 73.3%, specificity of 96%, and accuracy of 92.8%. The sensitivity, specificity, and accuracy of normalized ADC spleen at a cutoff value of 1.22 were 80%, 92%, and 91.1%, respectively. Conclusions DWI-MRI is a reliable technique for assessing HCC after radiofrequency ablation. DWI-MRI with ADC may be used as an alternate sequence for assessing radiofrequency-ablated lesions in individuals who have a contraindication to the contrast media, and the normalized ADC value may be of additional benefit.

Perfusion Defects and Collateral Flow Patterns in Acute Small Subcortical Infarction: a 4D Dynamic MRI Study

The hemodynamic changes of acute small subcortical infarction (SSI) are not well understood. We evaluate the hemodynamic changes and collaterals in acute SSI using perfusion magnetic resonance imaging (MRI). A total of 103 patients with acute SSI in penetrating artery territories were recruited and underwent MRI within 24 h of stroke onset. Using 4D dynamic perfusion MRI, they were divided into three patterns: 25 (24%) with normal perfusion, 31 (30%) with compensated perfusion, and 47 (46%) with hypoperfusion. The development of anterograde or retrograde collaterals was also evaluated. Patients with hypoperfusion pattern had the highest rate of early neurological deterioration (32%, p = 0.007), the largest initial and final infarction volumes (p < 0.001 and p = 0.029), the lowest relative cerebral blood flow (0.63, p < 0.001), and the lowest rate of anterograde and retrograde collaterals (19%, p < 0.001; 66%, p = 0.002). The anterograde collaterals were associated with higher relative cerebral blood volume (0.91 vs. 0.77; p = 0.024) and a higher rate of deep cerebral microbleeds (48 vs. 21%; p = 0.028), whereas retrograde collaterals were associated with higher systolic and diastolic blood pressure (p = 0.031 and 0.020), smaller initial infarction volume (0.81 vs. 1.34 ml, p = 0.031), and a higher rate of lobar cerebral microbleeds (30 vs. 0%; p = 0.013). Both anterograde and retrograde collaterals may play a critical role in maintaining cerebral perfusion and can have an impact on patient clinical outcomes. Further studies are warranted to verify these findings and to investigate effective treatments.

Additive role of dynamic subtraction MRI in assessment of unresolved HCC post-radiofrequency ablation

Background Malignant Hepatocellular carcinoma (HCC) is one amongst the foremost widespread cancers within the world. Radiofrequency ablation (RFA) is that the most generally used substitute tool for hepatic carcinoma treatment. Monitoring tumoral response to loco-regional therapy is a vital mission in oncological imaging. Dynamic contrast enhanced MR and recently added subtraction imaging technique improve assessment of the ablated hepatic focal lesions. The aim of this study is that the evaluation of the role of Subtraction MRI within the detection of recurrent or residual tumoral viability after RF ablation. Results Fifty patients were conducted during this retrospective study, all underwent RFA for 76 hepatic focal lesions and underwent Dynamic MRI study 1 month after ablation. Subtraction imaging was then performed. MRI images were interpreted by two readers who are experienced in hepatic imaging. The primary reader interpreted the standard Dynamic MRI and was blinded to the subtraction sequences; the second reader interpreted both Dynamic and Subtraction MRI images. the primary reader detected 49 resolved cases by dynamic MRI, while the second reader detected residual activity in 6 cases out of 49 via subtraction dynamic MRI (added value). The second reader agreed with first reader in 43 cases (agreement).The first reader detected 27 residual cases by dynamic MRI. The second reader disagreed with first reader in 11 cases appeared resolved out of 27 via subtraction dynamic MRI (added value). The second reader agreed with first reader in residual activity in 16 cases (agreement).The statistical analysis of those results revealed a big additive value of the subtraction imaging to the dynamic MRI (P < 0.001) with moderate degree of agreement between the 2 diagnostic tools (Kappa value = 0.491). This implies that Subtraction MRI significantly improves the reader confidence level within the assessment of treatment response following loco-regional therapies for HCC. Conclusion Dynamic Subtraction MRI is a powerful detector for real enhancement in treated HCC lesions after radiofrequency ablation and hence increasing the degree of readers’ confidence and accuracy of treated lesions in follow-up studies. So it's recommended to feature this powerful tool as a routine to any or all Dynamic MRI studies of the Liver.

Evaluation of Angiogenesis and Pathological Classification of Extrahepatic Cholangiocarcinoma by Dynamic MR Imaging for E-Healthcare

For staging cholangiocarcinoma and determining respectability, MR is an accurate noninvasive method which provides size of tumor and vascular patency information. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a noninvasive inspection method for evaluating the vascular structure and functional characteristics of tumor tissue. However, some limitations should be noted about the technology. At present, the technology cannot be used alone, which is just an assisted method during the conventional MRI examination. 50 ECC patients, admitted to Indira Gandhi Medical College and Hospital between 2016 and 2019, were selected as research subjects. They were classified pathologically according to the Steiner classification system. After image processing, regions of interest (ROIs) were selected from the image to measure the rate constant (Kep), extravascular space volume fraction (Ve), and tissue volume transfer constant (Ktrans). There were 15 cases with highly differentiated carcinoma, 23 cases with moderately differentiated carcinoma, and 12 cases with lowly differentiated carcinoma. Non-VEGF expression was noted in 21 cases, with low expression noted in 15 cases, moderate expression noted in 14 cases, and no high expression case noted. The relevant parameters in the dynamic MRI image can quantitatively reflect the angiogenesis and pathological classification of ECC, which is suggested in the clinical treatment of ECC. The Ktrans, Kep, and Ve values of the ECC patients were all not associated with the pathological classification, with no significant difference ( P < 0.05 ). Besides, due to the fact that the patient cannot completely hold his breath, the air leak reduces the image quality.

Unexplained back pain and sciatica: the added value of upright dynamic MRI of the lumbar spine in cases of clinical/radiological mismatch

Background Degenerative disease of the lumbar spine is one of the most prevalent pathologies worldwide, and MRI is the gold standard imaging modality that helps to assess soft tissue and bony abnormalities and elicit causes of neural compression. It is not uncommon in the daily practice to have patients presenting with neurological symptoms during standing or walking while MRI fails to detect lesion that explains their clinical picture. The aim of this study was to detect changes that appear on dynamic weight-bearing MRI of the lumbar spine that was hidden on conventional supine MRI and to correlate them with the clinical situation. Methodology Ninety patients with back pain were enrolled in the study, they did conventional and dynamic MRI of the lumbar spine. We compared findings in both modalities as regard alignment, ligamentum flavum buckling, foraminal narrowing and neural compression. Results Dynamic MRI showed neural compression in 87% of patients in comparison to supine MRI, ligamentum flavum buckling was reported in 80%, neural foraminal narrowing was seen in 24%, exaggeration of the lumbar lordoisis in 10% and exaggeration of the already existing disc protrusion was documented in 60% of the included patients. Conclusions Upright dynamic MRI has added to supine MRI in problem solving cases with clinical radiological mismatch. The results indicated changes in the spine alignment, neural compression and spinal canal stenosis. Since the examination is non-invasive, it could be used in the preoperative planning of patients with degenerative lumbar spine disease.