Exploring the interplay between paraspinal muscular status and bone health in osteoporosis and fracture risk: a comprehensive literature review on computed tomography (CT) and magnetic resonance imaging (MRI) studies.

Background and Objective: Computed tomography (CT) and magnetic resonance imaging (MRI) of the spine are fundamental non-invasive tools to investigate the status of the bone and soft tissue in vivo. A novel and promising approach is to investigate the quality and quantity of paraspinal muscles even beyond the clinical question. The aim of the present review is to summarize current evidence on CT and MRI about the relationship between paraspinal muscular status and bone health in osteoporosis (OP) and fracture risk. Methods: Literature research was carried out on September 2023 using PubMed, Scopus, and Cochrane databases. Key Content and Findings: Research investigating the intricate interplay between musculature and bone health reveals that degenerating paraspinal muscles, characterized by shrinking and fatty infiltration, are associated with lower bone mineral density (BMD) and the development of OP. Additionally, research indicates that weaker paraspinal muscles are linked to a higher risk of fractures, including those at the spine. Conclusions: The findings suggest that paraspinal muscle health may be a significant factor in identifying individuals at risk for OP and fractures. Further investigation is needed to explore the potential of paraspinal muscles in preventing these conditions.

Retrolabyrinthine approach to the lateral skull base: The value of preoperative temporal bone CT analysis.

PURPOSE: The most used neurosurgical approach to reach cerebellar-pontine angle is the retrosigmoid route. This article describes the presigmoid approach which requires excellent knowledge of the labyrinthine block together with quantitative analysis of temporal bone CT. METHODS: CT-based quantitative measurements were obtained in patients undergoing vestibular neurectomy with a presigmoid approach. Eighteen patients were enrolled, and five measures were taken: Trautmann's area, the petro-clival angle, presigmoid dura length and its angle. The relationship between these measurements and hospitalization days, operating times, and complications was explored. RESULTS: The posterior semicircilar canal (PSC)-sigmoid sinus (SS) distance, presigmoid dura- internal auditory canal (IAC)-PSC angle, and duration of surgery are predictors of complications. Specifically, a PSC-sigmoid sinus distance <11 mm, a dura presig-IAC-PSC angle <14 are associated with the highest risk of complications. CONCLUSION: Preoperative temporal bone CT scan can guide the surgeon through the narrowest areas of the surgical approach. Trautmann's triangle area and petro-clival angle reduction are challenging and can be faced with combined microscopic-endoscopic technique, and with optics angulation-rotation. The retrolabyrinthine approach can enable hearing preservation and minimal cerebellar retraction.

Visceral adiposity in patients with lipomatous hypertrophy of the interatrial septum.

Lipomatous hypertrophy of the interatrial septum (LHIS) is a benign cardiac mass determined by abnormal deposition of adipose tissue in the interatrial septum. The quantitative relationship between LHIS and visceral adiposity has not been explored to date.In this retrospective study, three groups of consecutive patients undergoing CT imaging were enrolled: L + with LHIS, L- without LHIS, and LO- without both LHIS and history of malignancies. Areas of total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and LHIS areas were calculated on CT images. The relationship between LHIS and abdominal fat distribution was investigated with linear regression models. Bonferroni correction was applied to account for multiple testing. Statistical significance was set at 5%. In this study we enrolled a total of 175 subjects: 58 (33.14%) with LHIS (L +), 51(29.14%) without LHIS (L-) and 66 (37.71%) without both LHIS and medical history of malignancies (LO-). VAT (coeff: 105.82; 95% CI 59.37-152.27), SAT (coeff: 74.59; 95% CI 31.63-117.54), and TAT (coeff: 190.37; 95% CI 115.02-265.72), were significantly higher in L + patients. Moreover, VAT (coeff: 24.95; 95% CI 6.94-42.96) and TAT (coeff: 36.58; 95% CI 8.75-64.41) were statistically significant linear predictors for LHIS area. Here, we report a novel association between LHIS and visceral adiposity using a quantitative CT-based imaging approach. The results are of great importance also because they might drive early identification of subjects with LHIS at risk for visceral obesity, and trigger lifestyle interventions aimed at weight loss.

Neuroradiology of acute pathologies in adults with hematologic malignancies: a pictorial review.

Hematopoietic and lymphoid tumors are a heterogeneous group of diseases including lymphomas, multiple myeloma (MM), and leukemias. These diseases are associated with systemic involvement and various clinical presentations including acute neurological deficits. Adult patients with hematologic malignancies (HM) are at risk for developing a wide array of acute conditions involving the nervous system. HM in adults may present as tumoral masses responsible for mass effect, possibly resulting in acute neurological signs and symptoms caused by tumor growth with compression of central nervous system (CNS) structures. Moreover, as result of the hematologic disease itself or due to systemic treatments, hematologic patients are at risk for vascular pathologies, such as ischemic, thrombotic, and hemorrhagic disorders due to the abnormal coagulation status. The onset of these disorders is often with acute neurologic signs or symptoms. Lastly, it is well known that patients with HM can have impaired function of the immune system. Thus, CNS involvement due to immune-related diseases such as mycotic, parasitic, bacterial, and viral infections linked to immunodeficiency, together with immune reconstitution inflammatory syndrome, are frequently seen in hematologic patients. Knowledge of the etiology and expected CNS imaging findings in patients with HM is of great importance to reach a fast and correct diagnosis and guide treatment choices. In this manuscript, we review the computed tomography (CT) and magnetic resonance findings of these conditions which can be related to the disease itself and/or to their treatments.

Computed tomography density changes of bone metastases after concomitant denosumab.

OBJECTIVE: To evaluate bone density changes at the level of normal trabecular bone and bone metastases (BMs) after denosumab (DM) treatment in oncologic patients. MATERIALS AND METHODS: We retrospectively evaluated 31 consecutive adult patients with histologically confirmed solid tumors with at least one newly diagnosed bone metastatic lesion detected at CT. Patients received treatment with DM, 120 mg subcutaneous every 28 days for at least 6 months. Bone density was determined at the level of BMs and at the level of normal trabecular bone of lumbar vertebrae using a region of interest (ROI)-based approach. RESULTS: A progressive increase in CT bone density was demonstrated at the level of normal trabecular bone at 6 months (18% ± 5%) and 12 months (23% ± 7%) after the treatment begins. BMs showed a significant increase in CT bone density (p < 0.05) as compared to baseline after 6 months (57% ± 15%) and 12 months (1.06 ± 0.25 times higher) after treatment. CONCLUSION: We have found that long-term treatment with DM increases bone density progressively in oncologic patients. This effect can be observed not only at the level of secondary lesions but also at the level of apparently normal trabecular bone and is more pronounced for osteolytic metastases.

Brain functional connectivity differences between responders and non-responders to sleeve gastrectomy.

PURPOSE: To compare resting-state functional connectivity (RSFC) of obese patients responders or non-responders to sleeve gastrectomy (SG) with a group of obese patients with no past medical history of metabolic or bariatric surgery. METHODS: MR images were acquired at 1.5 Tesla. Resting-state fMRI data were analyzed with statistical significance threshold set at p < 0.05, family-wise error (FWE) corrected. RESULTS: Sixty-two subjects were enrolled: 20 controls (age range 25-64; 14 females), 24 responders (excess weight loss > 50%; age range 23-68; 17 females), and 18 non-responders to sleeve gastrectomy (SG) (excess weight loss < 50%; age range 23-67; 13 females). About within-network RSFC, responders showed significantly lower RSFC with respect to both controls and non-responders in the default mode and frontoparietal networks, positively correlating with psychological scores. Non-responders showed significantly higher (p < 0.05, family-wise error (few) corrected) RSFC in regions of the lateral visual network as compared to controls. Regarding between-network RSFC, responders showed significantly higher anti-correlation between executive control and salience networks (p < 0.05, FWE corrected) with respect to both controls and non-responders. Significant positive correlation (Spearman rho = 0.48, p = 0.0012) was found between % of excess weight loss and executive control-salience network RSFC. CONCLUSION: There are differences in brain functional connectivity in either responders or non-responders patients to SG. The present results offer new insights into the neural correlates of outcome in patients who undergo SG and expand knowledge about neural mechanisms which may be related to surgical response.

Bilateral MCP Infarct Due to Vertebral Giant Cell Arteritis.

We present the case of an 83-year-old woman with an isolated bilateral middle cerebellar peduncles stroke caused by complete occlusion of the right vertebral artery and focal occlusion of the left vertebral artery due to giant cell arteritis. The diagnosis was achieved by integrating MRI, ultrasound study, laboratory data and subsequent pathology analysis after biopsy of the temporal artery.

Anterior pituitary gland T1 signal intensity is influenced by time delay after injection of gadodiamide.

To test the hypothesis of washout from the anterior pituitary (AP) gland after serial injections of gadodiamide. We included 59 patients with history of at least 5 injections of gadodiamide. Values of mean signal intensity of the AP and of the central pons were measured on unenhanced sagittal T1-weighted images. AP-to-pons signal intensity ratios were calculated dividing the values of the AP by those of the pons. The measurements were performed using MR images acquired at four different time points including baseline (prior to any gadodiamide injection), minimum post-injection time delay, maximum post-injection time delay, and last available MR scans. Normalized ratios (i.e. ratios divided total volume of injected gadodiamide) were also calculated. To assess the difference between ratios, non-parametric Wilcoxon signed-rank test was applied. The correlations were tested with non-parametric Spearman correlation coefficient. A p-value < 0.05 was considered as statistically significant. A statistically significant increase of AP signal intensity was found by comparing the baseline scans with both the minimum time delay (p = 0.003) and maximum time delay scans (p = 0.005). We found significant higher normalized ratios for minimum post-injection time delay with respect to maximum post-injection time delay (p < 0.001). The normalized ratios demonstrated a statistically significant negative correlation with the post-injection time delay (r = - 0.31; p = 0.006). The findings of this study suggest that washout phenomena of retained/deposited gadolinium from the AP are influenced by the total injected volume and post-injection time delay.

Effect of Exposure to Gadodiamide and Brain Irradiation on T1 -Weighted Images and ADC Maps of the Dentate Nucleus.

BACKGROUND: Brain irradiation is considered a cofactor influencing the dentate nucleus (DN) signal intensity (SI) on unenhanced T1 -weighted images in patients exposed to gadolinium-based contrast agents (GBCAs). PURPOSE: To assess the effect of gadodiamide and whole-brain radiation therapy (WBRT) on T1 -weighted images and on apparent diffusion coefficient (ADC) maps of DN. STUDY TYPE: Single-center retrospective. POPULATION: In all, 125 patients who underwent brain MRIs were classified into four groups: 1) patients who did neither receive intravenous GBCAs injections nor irradiation (controls); 2) patients having ≥3 GBCAs-enhanced scans and no WBRT; 3) patients having WBRT and < 3 GBCAs-enhanced scans; and 4) patients having WBRT and ≥ 3 GBCAs-enhanced scans. FIELD STRENGTH/SEQUENCE: 1.5T magnet, echo-planar diffusion weighted imaging (DWI) and unenhanced T1 -weighted sequences. ASSESSMENT: The DN-to-pons SI ratio on unenhanced T1 -weighted images and ADC values of the DN were calculated. Values were compared between groups and relative to the cumulative gadolinium dose and to the time delay after WBRT. STATISTICAL TESTS: Statistical analysis included the Mann-Whitney U-test and Spearman's rank-order correlation. RESULTS: DN ADC values were not significantly different (P = 0.34) between patients exposed to gadodiamide (0.81 ± 0.06) and controls (0.83 ± 0.07). There were no differences in DN ADC values (P = 0.28) and DN-to-pons SI ratios (P = 0.42) between patients exposed to WBRT (ADC values: 0.85 ± 0.09; SI ratio: 1.11 ± 0.10) and controls (ADC values: 0.83 ± 0.06; SI ratio: 1.09 ± 0.06). There was a significant negative correlation between DN ADC values and the time (days) since the end of WBRT (r = - 0.33; 95% confidence interval [CI]: -0.55, -0.06; P < 0.05). DATA CONCLUSION: We did not find changes suggestive of gadolinium-related tissue microstructural damage of the DN. The ADC values of the DN are associated with the time from WBRT. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 5.

Within-network brain connectivity in Crohn's disease patients with gadolinium deposition in the cerebellum.

PURPOSE: Patients with Crohn's disease (CD) undergo multiple gadolinium-based contrast agent injections across their lifespan to enhance signal intensity of the intestinal wall and differentiate active from quiescent inflammatory disease. Thus, CD patients are prone to gadolinium accumulation in the brain and represent a non-neurological population to explore gadolinium-related brain toxicity. Possible effects are expected to be greater on the cerebellar network due to the high propensity of the dentate nucleus to accumulate gadolinium. Herein, we provide a whole-brain network analysis of resting-state fMRI dynamics in long-term quiescent CD patients with normal renal function and MRI evidence of gadolinium deposition in the brain. METHODS: Fifteen patients with CD and 16 healthy age- and gender-matched controls were enrolled in this study. Relevant resting-state networks (RSNs) were identified using independent component analysis (ICA) from functional magnetic resonance imaging data. An unpaired two-sample t test (with age and sex as nuisance variables) was used to investigate between different RSNs. Clusters were determined by using threshold-free cluster enhancement and a family-wise error corrected cluster significance threshold of p < 0.05. RESULTS: Patients showed significantly decreased resting-state functional connectivity (p < 0.05, FWE corrected) of several regions of the right frontoparietal (FPR) and the dorsal attention (DAN) RSNs. No differences between the two groups were found in the functional connectivity maps of all the other RSNs, including the cerebellar network. CONCLUSION: Our findings suggest a non-significant impact of gadolinium deposition on within-network cerebellar functional connectivity of long-term quiescent CD patients.

Increased T1 Signal Intensity of the Anterior Pituitary Gland on Unenhanced Magnetic Resonance Images After Chronic Exposure to Gadodiamide.

OBJECTIVE: The aim of this study was to assess the signal intensity of the anterior pituitary (AP) gland on unenhanced T1-weighted images in patients with history of serial intravenous injections of gadodiamide and normal renal function. MATERIALS AND METHODS: We included 53 patients who had undergone at least 5 injections of gadodiamide and a control group of 15 subjects who underwent at least 5 brain magnetic resonance imaging without gadolinium-based contrast agents. Using unenhanced sagittal T1-weighted images, values of mean signal intensity of the AP and of the central pons were obtained. Anterior pituitary-to-pons signal intensity ratios were calculated dividing the values of the AP by those of the pons. Then, the ratios were compared between the first and the last magnetic resonance imaging scans for all the subjects. To assess the difference between the first and the last ratios, nonparametric Wilcoxon signed-rank test with Monte Carlo resampling was applied. A P value less than 0.05 was considered as statistically significant. RESULTS: The comparison between the first and the last scan revealed a statistically significant increase of AP-to-pons ratio in the last scan for the gadolinium-exposed group (P < 0.001), whereas nonsignificant results were found for the control group (P = nonsignificant). CONCLUSIONS: We found an increased signal intensity of the AP on unenhanced T1-weighted images in patients with history of serial intravenous injections of gadodiamide and normal renal function, suggesting gadolinium deposition or long-term retention within the AP gland. Our findings need to be confirmed by further histochemical analysis of AP gland tissue samples.

Absence of dentate nucleus resting-state functional connectivity changes in nonneurological patients with gadolinium-related hyperintensity on T1 -weighted images.

BACKGROUND: The dentate nuclei of the cerebellum are the areas where gadolinium predominantly accumulates. It is not yet known whether gadolinium deposition affects brain functions. PURPOSE/HYPOTHESIS: To assess whether gadolinium-dependent high signal intensity of the cerebellum on T1 -weighted images of nonneurological adult patients with Crohn's disease is associated with modifications of resting-state functional connectivity (RSFC) of the cerebellum and dentate nucleus. STUDY TYPE: Observational, cross-sectional. POPULATION: Fifteen patients affected by Crohn's disease were compared with 16 healthy age- and gender-matched control subjects. All participants underwent neurological, neurocognitive-psychological assessment, and blood sampling. FIELD STRENGTH/SEQUENCE: 1.5-T magnet blood oxygenation level-dependent (BOLD) functional MRI. ASSESSMENT: High signal intensity on T1 -weighted images, cerebellum functional connectivity, neurocognitive performance, and blood circulating gadolinium levels. STATISTICAL TESTS: An unpaired two-sample t-test (age and sex were nuisance variables) was used to investigate between-group differences in cerebellar and dentate nucleus functional connectivity. Z-statistical images were set using clusters determined by Z > 2.3 and a familywise error (FWE)-corrected cluster significance threshold of P = 0.05. RESULTS: Dentate nuclei RSFC was not different (P = n.s.) between patients with gadolinium-dependent high signal intensity on T1 -weighted images and controls. Pre- and postcentral gyrus bilaterally and the right supplementary motor cortex showed a decrease of RSFC with the cerebellum hemispheres (P < 0.05 FWE-corrected) and was related to disease duration but not to gadodiamide cumulative doses (P = n.s.). DATA CONCLUSION: Crohn's disease patients with gadolinium-dependent hyperintense dentate nuclei on unenhanced T1 -weighted images do not show dentate nucleus RSFC changes. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2019;50:445-455.