MRI in the Clinical Management of Alzheimer’s Disease: from Early Detection To Therapy Guidance

The foundation for using intravenous immunoglobulin (IVIg) to treat Alzheimer's disease (AD) can be traced back to the discovery, in the early 1990s, of naturally occurring anti-amyloid antibodies in human blood. A decade later, a number of independent investigators reported reduced levels of naturally occurring anti-amyloid antibodies in the spinal fluid and blood of AD patients relative to age-matched controls 1–3. Dodel subsequently reported that IVIg contained elevated levels of antibodies against amyloid-β (Aβ) monomers and proposed its use as a potential treatment for AD 4.

Introduction: This study aimed to survey the discrimination power of parameters from cerebrospinal fluid (CSF) biomarkers, fluorodeoxyglucose uptake on PET (FDG-PET), structural magnetic resonance imaging (MRI), and functional MRI in high- and low-risk subjects or in converters and stable subjects of normal and mild cognitive impairment (MCI) statuses.Methods: We used baseline resting-state functional MRI (rfMRI) from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset to analyze functional networks and recorded subjects’ characteristics and results of the CSF study, FDG-PET, and structural MRI from the ADNI website. All parameters were evaluated based on the between-group difference among normal (NC), MCI, and Alzheimer’s disease (AD) groups. The parameters other than CSF results were included to study the difference between high- and low-AD-risk subjects in NC or MCI groups, based on CSF results. On the basis of two-year follow-up conditions, all parameters were compared between stable subjects and converters in NC and MCI.Results: CSF biomarkers, FDG-PET, structural MRI, and functional MRI are all able to differentiate AD from MCI or NC but not between MCI and NC. As compared with low-AD-risk subjects, high-risk subjects present decreased FDG-PET in both MCI and NC groups but structural MRI change only in MCI status and rfMRI alteration only in NC status. As compared with stable subjects, converters have decreased FDG-PET, functional network changes, and structural changes in both MCI and NC groups.Conclusion: The combination of functional and structural MRI is a safer screening tool but with similar power as FDG-PET to reflect CSF change in the AD pathological process and to identify high-risk subjects and converters in NC and MCI.

We evaluated the role of magnetic resonance (MR) imaging in the diagnosis of corpus callosum agenesis - isolated or associated with other anomalies - in fetuses with mild cerebral ventriculomegaly, as depicted at prenatal sonography. Between January 2005 and March 2007, 33 fetuses with a mean gestational age of 28.9 weeks (range 17-37) and mild ventriculomegaly diagnosed at prenatal sonography were included in this prospective study. All fetuses underwent MR imaging according to the following protocol: half-Fourier T2-weighted images along the three orthogonal plane according to the longitudinal axis of the mother, and subsequently three orthogonal planes were acquired according to the fetal brain. Quantitative image analysis included the size of the transverse diameter of the lateral ventricles, in the axial plane, and the thickness of the adjacent cerebral cortex. Qualitative image analysis included morphology of the lateral ventricles (normal, parallel pattern colpocephaly), signal intensity changes of the fetal brain, interruption of the germinative matrix, agenesis of the corpus callosum (complete/partial) and associated malformations. Postnatal physical examination and diagnostic imaging, as well as surgery, were the standard of diagnosis. Mean axial diameter of the lateral ventricle was 11.6 mm (range 10-15 mm), and mean thickness of the adjacent cerebral cortex was 2.1 mm (range 1.8-3 mm); 23/33 fetuses (70%) showed normal morphology of the lateral ventricles, and 8/33 (24%) showed abnormal morphology (parallel pattern, colpocephaly). The entire corpus callosum was visualised in 20/33 fetuses (60%). In 8/33 fetuses (25%), partial agenesis was diagnosed, whereas in 5/33 (15%), there was hypogenesis. In 6/13 fetuses (46%), isolated corpus callosum agenesis was detected, and two cases of hypogenesis of the corpus callosum were misinterpreted - overestimated in one case and underestimated in another. MR imaging may prove to be a useful second-line imaging modality in the prenatal diagnosis of corpus callosum agenesis in fetuses with mild ventriculomegaly.

Accurate preoperative staging of gastric cancer and the assessment of tumor response to neoadjuvant treatment is of importance for treatment and prognosis. Current imaging techniques, mainly endoscopic ultrasonography (EUS), computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET), have their limitations. Historically, the role of magnetic resonance imaging (MRI) in gastric cancer has been limited, but with the continuous technical improvements, MRI has become a more potent imaging technique for gastrointestinal malignancies. The accuracy of MRI for T- and N-staging of gastric cancer is similar to EUS and CT, making MRI a suitable alternative to other imaging strategies. There is limited evidence on the performance of MRI for M-staging of gastric cancer specifically, but MRI is widely used for diagnosing liver metastases and shows potential for diagnosing peritoneal seeding. Recent pilot studies showed that treatment response assessment as well as detection of lymph node metastases and systemic disease might benefit from functional MRI (e.g. diffusion weighted imaging and dynamic contrast enhancement). Regarding treatment guidance, additional value of MRI might be expected from its role in better defining clinical target volumes and setup verification with MR-guided radiation treatment.

Abstract: Objective: assessing the role of magnetic resonance (MRI) imaging in intraoperative evaluation of fistula in ano. Study Type: Cross Sectional Analytical Study Study Place and Duration: Department of Radiology, Combined Military Hospital Gujranwala, from September 1, 2023 to August 30, 2024. Material and methods: Sixty patients were referred to the hospital's Radiology Department. Subsequently, these patients were referred for MRI scans in the Radiology Department. The MRI scanner used was equipped with a 16 channel body coil and a surface-coil. The data of all 60 patients who underwent surgical intervention were included in the study. The interval between MRI and surgery was from one week to two months. The gold standard was considered to be surgical findings, which were recorded independently by the surgeon. The researcher personally collected the data for the study and analyzed using SPSS version24. Continuous variables (age) were examined using descriptive statistics, namely; standard and mean deviation while categorical variables (gender) were using frequency and percentage. Results: Diagnostic performance indicated sensitivity (94.9%) and specificity (100.0%). The PPV was 100.0%, and the NPV was 25.0%, with an overall diagnostic accuracy of 95.0%. Conclusion: MRI offers precise anatomical and pathological information essential for directing pre-surgical decisions and planning in the management of perianal fistulas. Keywords: Magnetic Resonance Imaging (MRI), Intra-operative, Evaluation, Fistula in Ano, Accuracy, Sensitivity, Specificity.

Alzheimer’s disease (AD) is the most common progressive neurodegenerative disorder characterized by gradual deterioration in cognition, function, and behavior. The number of patients with dementia is increasing in the Western world. Neuroimaging plays an important role in the study and clinical diagnosis of AD. It is of utmost importance to exclude potentially treatable conditions such as brain tumors, hematomas, and hydrocephalus. According to a meta-analysis potentially reversible causes were seen in 9% and actually reversed in only 0.6% of dementia cases (0.29% partially, 0.31% fully) (1). Techniques that are widely used in clinical practice are still largely based on structural magnetic resonance (MR) imaging and volumetry. Recently Wattjes et al. (2) concluded that although MR imaging should be the preferred imaging modality due its lack of ionizing radiation and higher contrast resolution, 64-detector row computed tomography (CT) is a suitable and accurate imaging method with which to evaluate global cortical atrophy, medial temporal lobe atrophy, and white matter changes in a memory clinic setting, and it can be considered a nearly equivalent alternative to MR imaging in patients who cannot undergo MR examination. However, it should be noted that measures of brain atrophy typically reflect the relatively late stages of neuronal loss and may not be ideal for identifying early neuropathological changes. There is increasing evidence showing that the pathological process associated with AD may begin years or decades before diagnosis. But: do the advanced techniques help in assessing therapeutic effects or improve patient outcome? Early detection of AD risk would enable preventive or more effective treatment of the patients, resulting in a time delay in symptom onset that may decrease the prevalence of the disease (3). Therefore, in addition to the structural MR imaging procedures a spectrum of novel MR imaging tools is being adopted for the scientific study of pathological processes underlying the development of AD, including blood oxygenation level-dependent (BOLD) functional MRI studies of brain activation and functional connectivity, perfusion measurements with arterial spin labeling (ASL), MR spectroscopy (MRS), and diffusion tensor imaging (DTI). Functional MRI on BOLD contrast allows noninvasive in vivo assessment of hemodynamic responses to external stimuli. ASL is a non-invasive MR imaging technique for the measurement of regional cerebral blood flow by labeling of the arterial water and using it as an endogenous tracer. Although challenging (4), hippocampal MRS combined with quantitative measurements of hippocampal atrophy may improve the early diagnosis of AD. DTI can be used to determine the orientation of fiber tracts and the neural network connections between different brain regions. Fractional anisotropy has become an imaging marker commonly used to study microstructural white matter abnormalities in various pathological states. There is growing interest in using DTI for AD studies (5, 6). In this issue of Acta Radiologica a comprehensive state of the art review by Dr Li Tie-Qiang (3) discusses the use of these advanced imaging techniques mainly in research. The review allows you to get an excellent overview of the advanced MR imaging techniques and the article is highly recommended reading.

Magnetic Resonance Imaging (MRI) has emerged as a powerful and non-invasive imaging technique, playing a pivotal role in neuroimaging research and clinical diagnosis. This comprehensive review explores the significance of MRI in the precise measurement of the corpus callosum, a key structure connecting the two hemispheres of the brain. The corpus callosum plays a crucial role in inter hemispheric communication and is implicated in various neurological and psychiatric disorders. The review begins by elucidating the anatomy and functions of the corpus callosum, emphasizing its importance in facilitating seamless communication between the cerebral hemispheres. Subsequently, the paper delves into the historical evolution of MRI techniques and how advancements have enhanced the visualization and measurement capabilities of the corpus callosum. A detailed examination of various MRI modalities, including structural MRI, diffusion tensor imaging (DTI), and functional MRI, is presented in the context of corpus callosum analysis. Structural MRI provides high-resolution images for accurate morphological assessments, while DTI offers insights into white matter microstructure and fiber tractography, allowing for a more comprehensive understanding of the corpus callosum's integrity. The review also highlights the role of MRI in investigating alterations in the corpus callosum associated with neurological disorders such as multiple sclerosis, epilepsy, and neurodevelopmental disorders. Additionally, the paper explores how functional MRI contributes to understanding the functional connectivity and inter hemispheric interactions mediated by the corpus callosum. Challenges and limitations in the measurement of the corpus callosum using MRI are discussed, including methodological considerations, image artifacts, and potential sources of variability. The review concludes by outlining future directions in corpus callosum imaging research, including the integration of advanced imaging techniques, artificial intelligence, and large-scale multi-center studies to enhance the precision and reliability of measurements.In summary, this comprehensive review underscores the pivotal role of MRI in advancing our understanding of the corpus callosum, providing valuable insights into both normal brain function and pathological conditions. The continual evolution of MRI techniques holds promise for further refining the assessment of the corpus callosum, ultimately contributing to improved diagnostic accuracy and therapeutic interventions in neurological and psychiatric disorders.

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Neuropsychiatric Significance of Subcortical Hyperintensity

The diagnosis of Alzheimer's disease (AD) remains at times difficult to make using available neuropsychological measures. Neuro-imaging is a relatively new form of detecting the changes associated with dementia. The present study investigated the role of magnetic resonance imaging (MRI) in diagnosing AD in adults with Down's syndrome (DS). Subjects with DS and Alzheimer-type dementia were matched to non-demented controls with DS. Magnetic resonance imaging findings (i.e. volumetric and two-dimensional scans) were compared between the two groups in order to show a relationship between the changes of AD and structural MRI abnormalities. Specific structural abnormalities which are seen in non-intellectually disabled subjects with dementia are also found in individuals with both DS and AD. However, such findings cannot be used to diagnose clinical AD with good accuracy in adults with DS. A number of practical issues of patient compliance and over-sedation are demonstrated by the findings. Magnetic resonance imaging has an important but limited role to play in the management of AD in the population with DS. If intravenous sedation is used, medical support is essential to prevent a serious mishap.

Battle against Alzheimer's Disease: The Scope and Potential Value of Magnetic Resonance Imaging Biomarkers

Magnetic Resonance Imaging/Ultrasound Fusion Guided Prostate Biopsy Improves Cancer Detection Following Transrectal Ultrasound Biopsy and Correlates With Multiparametric Magnetic Resonance Imaging

Structural magnetic resonance imaging for the early diagnosis of dementia due to Alzheimer's disease in people with mild cognitive impairment.

Background. Assessment of the ratio between tumour volume and breast volume in therapeutic mammoplasty is paramount. Traditionally based on clinical assessment and conventional breast imaging, the role of breast magnetic resonance imaging (MRI) in this context has not been established. Methods. Data was collected from all women undergoing therapeutic mammoplasty (TM) between 2006 and 2011. Each case was discussed at an MDT where MRI was considered to facilitate surgical planning. The contribution of MRI to disease assessment and surgical outcome was then reviewed. Results. 35 women underwent TM, 15 of whom had additional MRI. 33% of patients within the MRI subgroup had abnormalities not seen on either mammography or USS. Of those undergoing MRI, 1/15 patients required completion mastectomy versus 3 patients requiring completion mastectomy and 1 patient requiring further wide local excision (4/20) in the conventional imaging group. No statistical difference was seen between size on MRI and size on mammography versus final histological size, but a general trend for greater correlation between size on MRI and final histological size was seen. Conclusion. MRI should be considered in selected patients undergoing therapeutic mammoplasty. Careful planning can identify those who are most likely to benefit from MRI, potentially reducing the need for further surgery.

BackgroundThe management of asymptomatic congenital lung malformations is debated. Particularly, there is a lack of information regarding long-term growth and development of the remaining lung in children following lung resection for congenital lung malformations. In addition to conventional pulmonary function tests, we used novel functional magnetic resonance imaging (MRI) methods to measure perfusion and ventilation.ObjectiveTo assess functionality of the remaining lung expanded into the thoracic cavity after resection of congenital lung malformations.Materials and methodsA prospective, cross-sectional pilot study in five children who had surgery for congenital lung malformations during infancy. Participants had structural and functional MRI as well as spirometry, body plethysmography and multiple breath washout at school age.ResultsStructural MRI showed an expansion of the remaining lung in all cases. Fractional ventilation and relative perfusion of the expanded lung were locally decreased in functional MRI. In all other parts of the lungs, fractional ventilation and relative perfusion were normal in all children. There was an association between overall impairment of perfusion and elevated lung clearance index. The results of spirometry and body plethysmography varied between patients, including normal lung function, restriction and obstruction.ConclusionFractional ventilation and relative perfusion maps from functional MRI specifically locate impairment of the remaining lung after lung resection. These changes are not captured by conventional measures such as structural MRI and standard pulmonary function tests. Therefore, following lung resection for congenital lung malformation, children should be investigated more systematically with functional lung MRI.