Role of diffusion-weighted imaging in the diagnosis of pituitary region tumors.

PURPOSE: This study aimed to assess the role of Diffusion-Weighted Imaging (DWI) in routine pituitary Magnetic Resonance Imaging (MRI) protocols for distinguishing sellar and parasellar tumors, addressing the lack of clear guidelines in contemporary literature. METHODS: A retrospective analysis of 242 pituitary MRI scans with DWI sequences was conducted in a single-center study using a 1.5 T scanner and standard DWI sequence parameters. Measurements of both absolute and relative mean apparent diffusion coefficient (ADC) values, along with minimal ADC values within tumors, were performed. The adopted region of interest (ROI) based method used for these measurements was validated. RESULTS: Invasive pituitary adenomas exhibited significantly lower min ADC and min rADC than meningiomas, with optimal cut-off points of 0.64 (sensitivity 73%, specificity 82%) and 0.78 (sensitivity 73%, specificity 89%), respectively. Post-hemorrhagic pituitary adenomas demonstrated lower ADC values than adamantinomatous craniopharyngiomas, with an AUC of 0.893 for min rADC = 1.07, and Rathke's Cleft Cysts with mucous content, AUC 0.8 for min rADC = 1.01. Specific differentiation with high sensitivity and specificity based on diffusion parameters was observed for these tumor groups. Cystic pituitary non-functional adenomas obtained significantly lower ADC values compared to the adamantinomatous type of craniopharyngiomas and serous Rathke's Cleft Cysts (AUC up to 0.942). CONCLUSIONS: The study concludes that integrating DWI into routine pituitary MRI protocols enhances diagnostic accuracy in distinguishing sellar and parasellar tumors. The short scan time of one minute makes DWI a valuable and precise tool, supporting its recommendation as a standard component of pituitary MRI examinations.

Hepatic Hemangioma: Review of Imaging and Therapeutic Strategies.

Hepatic hemangiomas are the most common benign liver tumors. Typically, small- to medium-sized hemangiomas are asymptomatic and discovered incidentally through the widespread use of imaging techniques. Giant hemangiomas (>5 cm) have a higher risk of complications. A variety of imaging methods are used for diagnosis. Cavernous hemangioma is the most frequent type, but radiologists must be aware of other varieties. Conservative management is often adequate, but some cases necessitate targeted interventions. Although surgery was traditionally the main treatment, the evolution of minimally invasive procedures now often recommends transarterial chemoembolization as the treatment of choice.

Imaging of cerebrospinal fluid flow: fundamentals, techniques, and clinical applications of phase-contrast magnetic resonance imaging.

Cerebrospinal fluid (CSF) is a dynamic compartment of the brain, constantly circulating through the ventricles and subarachnoid space. In recent years knowledge about CSF has expended due to numerous applications of phase-contrast magnetic resonance imaging (PC-MRI) in CSF flow evaluation, leading to the revision of former theories and new concepts about pathophysiology of CSF disorders, which are caused either by alterations in CSF production, absorption, or its hydrodynamics. Although alternative non-invasive techniques have emerged in recent years, PC-MRI is still a fundamental sequence that provides both qualitative and quantitative CSF assessment. PC-MRI is widely used to evaluate CSF hydrodynamics in normal pressure hydrocephalus (NPH), Chiari type I malformations (CMI), syringomyelia, and after neurosurgical procedures. In NPH precisely performed PC-MRI provides reliable clinical information useful for differential diagnosis and selection of patients benefiting from surgical operation. Patients with CMI show abnormalities in CSF dynamics within the subarachnoid space, which are pronounced even further if syringomyelia coexists. Another indication for PC-MRI may be assessment of post-surgical CSF flow normalisation. The aim of this review is to highlight the significance of CSF as a multifunctional entity, to outline both the physical and technical background of PC-MRI, and to state current applications of this technique, not only in the diagnosis of central nervous system disorders, but also in the further clinical monitoring and prognosis after treatment.

Transarterial Bleomycin-Lipiodol Chemoembolization for the Treatment of Giant Hepatic Hemangiomas: An Assessment of Effectiveness.

This study evaluates the effectiveness of superselective transcatheter arterial chemoembolization (TACE) using a bleomycin-lipiodol emulsion in treating giant hepatic hemangiomas. A retrospective review included 31 patients with a mean age of 53 ± 10.42 years who underwent TACE from December 2014 to October 2022, with follow-up imaging examinations to assess outcomes. Technical success was defined as successful embolization of all feeding arteries, and clinical success was defined as a reduction in hemangioma volume by 50% or more on follow-up imaging. This study observed a 100% technical success rate. Post-embolization syndrome was common, and two cases of asymptomatic hepatic artery dissection were noted. Clinical success was achieved in 80.6% of patients, with significant volume reduction observed in the majority. Conclusively, superselective transcatheter arterial chemoembolization with bleomycin-lipiodol emulsions is presented as a viable and effective treatment option for giant hepatic hemangiomas. With no procedure-related mortality and significant volume reduction in most cases, this method offers a promising alternative to surgical intervention. This study's findings suggest a need for further exploration and validation in larger-scale prospective studies.

Evaluation of Intra- and Inter-Network Connectivity within Major Brain Networks in Drug-Resistant Depression Using rs-fMRI.

Background: Major Depressive Disorder (MDD) is a significant challenge in modern medicine due to its unclear underlying causes. Brain network dysfunction is believed to play a key role in its pathophysiology. Resting-state functional MRI (rs-fMRI), a neuroimaging technique, enables the in vivo assessment of functional connectivity (FC) between brain regions, offering insights into these network dysfunctions. The aim of this study was to evaluate abnormalities in FC within major brain networks in patients with drug-resistant MDD. Methods: The study group consisted of 26 patients with drug-resistant MDD and an age-matched control group (CG) of 26 healthy subjects. The rs-fMRI studies were performed on a 3T MR scanner (Philips, Ingenia) using a 32-channel head and neck coil. Imaging data were statistically analyzed, focusing on the intra- and inter-network FC of the following networks: default mode (DMN), sensorimotor (SMN), visual (VN), salience (SN), cerebellar (CN), dorsal attention (DAN), language (LN), and frontoparietal (FPN). Results: In patients with MDD, the intra-network analysis showed significantly decreased FC between nodes within VN compared to CG. In contrast, the inter-network analysis showed significantly increased FC between nodes from VN and SN or VN and DAN compared to CG. Decreased FC was found between SN and CN or SN and FPN as well as VN and DAN nodes compared to CG. Conclusions: Patients with MDD showed significant abnormalities in resting-state cortical activity, mainly regarding inter-network functional connectivity. These results contribute to the knowledge on the pathomechanism of MDD and may also be useful for developing new treatments.

Investigation of cerebellar damage in adult amyotrophic lateral sclerosis patients using magnetic resonance imaging and diffusion tensor imaging.

BACKGROUND: Research on amyotrophic lateral sclerosis (ALS) reveals that the disorder is not restricted to motor neurons. OBJECTIVES: This neuroimaging study aimed to investigate the presence of cerebellar damage in adult ALS patients. MATERIAL AND METHODS: The study retrospectively analyzed magnetic resonance imaging (MRI) examinations performed on a 1.5T MR unit of 33 patients (17 men and 16 women with a mean age of 59.3 years) diagnosed with ALS. Cerebellar and posterior fossa dimensions were calculated using plain MR images. In addition, diffusion tensor imaging (DTI) was used to obtain white matter integrity measurements, represented as fractional anisotropy (FA) values, in the posterior limbs of internal capsules (PLIC) and middle cerebellar peduncles (MCPs). These measurements were compared to 36 healthy volunteers (11 men and 25 women with a mean age of 55.3 years). The study also assessed clinical data for correlations with cerebellar imaging findings. RESULTS: The linear measurements of the cerebellum did not differ between groups. However, the transverse cerebellar dimension (TCD) ratio to the maximum length of the posterior fossa (0.973 compared to 0.982, t = -2.76, p < 0.01) and FA value in both MCPs (0.67 compared to 0.65 and 0.69 compared to 0.67, p < 0.05) were significantly lower in ALS patients. No significant differences were found in FA value in the PLIC, and no significant correlations were observed between patient clinical characteristics and cerebellar damage. CONCLUSION: This study provides evidence of cerebellar damage in adult ALS patients. These findings contribute to ALS understanding and highlight the importance of considering cerebellar involvement in the disease process. The results suggest that measuring the TCD ratio and FA value in both MCPs could be potential biomarkers for cerebellar damage in ALS patients.

Evaluation of the Value of Perfusion-Weighted Magnetic Resonance Imaging in the Differential Diagnosis of Sellar and Parasellar Tumors.

The purpose of this study was to assess the value of perfusion-weighted imaging (PWI) in the differential diagnosis of sellar and parasellar tumors, as an additional sequence in the magnetic resonance imaging (MRI) protocol. Analysis was based on a substantial group of subjects and included 124 brain and pituitary MRI examinations with a dynamic susceptibility contrast (DSC) PWI sequence. The following perfusion parameters were determined for the tumors: relative cerebral blood volume (rCBV), relative peak height (rPH) and relative percentage of signal intensity recovery (rPSR). To ensure greater repeatability, each of the aforementioned parameters was calculated as: arithmetic mean of the values of the whole tumor, arithmetic mean of the maximum values on each axial slice within the tumor and maximum values derived from the whole tumor. In our study, we established that meningiomas compared to both non-functional and hormone-secreting pituitary adenomas (pituitary neuroendocrine tumors-PitNET) had significantly higher values of rCBV with cut-off points set at 3.45 and 3.54, respectively (mean rCBV). Additionally, meningiomas presented significantly higher maximum and mean maximum rPH values compared to adenomas. DSC PWI imaging adds significant value to conventional MRI examinations and can be helpful in differentiating equivocal pituitary tumors.