Background: Parkinson’s disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta, accompanied by neuromelanin loss. Neuromelanin-sensitive magnetic resonance imaging (NM-MRI) enables in vivo visualization of these changes; however, its diagnostic and clinical utility remains incompletely defined. This study evaluated the feasibility, reliability, and biological sensitivity of semi-automated NM-MRI–based substantia nigra volumetry in PD. Methods: In this prospective case–control study, 50 participants (25 PD patients and 25 healthy controls) underwent 3T NM-sensitive MRI using a high-resolution T1-weighted spin-echo sequence. Semi-automated segmentation of hyperintense substantia nigra regions was performed using Mango v3.5.1, with intracranial volume normalization derived from FreeSurfer v7.3. Four participants were excluded due to motion artifacts, yielding a final cohort of 46 subjects. Clinical assessment included the Unified Parkinson’s Disease Rating Scale (UPDRS) Part III and Hoehn and Yahr (H&Y) staging. Group comparisons, receiver operating characteristic (ROC) analysis, and reliability testing using intraclass correlation coefficients (ICC) were performed. Results: Corrected substantia nigra volume was significantly reduced in PD patients compared with controls (18% reduction; p = 0.039, Mann–Whitney U test). Semi-automated measurements demonstrated excellent agreement with manual segmentation (ICC = 0.945). ROC analysis showed moderate discriminative performance for corrected volume (AUC = 0.700; sensitivity 68.4%, specificity 74.1%). No significant correlation was observed between corrected substantia nigra volume and UPDRS-III motor scores, while a trend toward lower SNc volume was observed with advancing H&Y stage. Conclusions: Semi-automated NM-MRI volumetry detects biologically meaningful substantia nigra volume loss in early-stage Parkinson’s disease with high measurement reliability. However, diagnostic performance was moderate and insufficient for standalone clinical diagnosis or motor severity prediction. These findings support the role of NM-MRI as a complementary imaging marker within multimodal diagnostic and research frameworks rather than as an independent diagnostic tool.
Background: Unilateral basal ganglia calcinosis (BGC) is a rare radiological finding that can be diagnosed on computed tomography (CT) and magnetic resonance imaging (MRI) but often presents challenges for clinicians and radiologists in determining its underlying cause. So far, only a few potential causes that could explain unilateral BGC have been described in the literature. Case Report: A 54-year-old Caucasian male was admitted to a tertiary university hospital due to the sudden onset of speech impairment and right-sided weakness. The patient had no significant medical history prior to this event. Non-enhanced computed tomography (NECT) of the brain revealed no evidence of acute ischemia; CT angiography (CTA) showed acute left middle cerebral artery (MCA) M2 segment occlusion. CT perfusion (CTP) maps revealed an extensive penumbra-like lesion, which is potentially reversible upon achieving successful recanalization. However, a primary neoplastic tumor with calcifications in the basal ganglia was initially interpreted as the potential cause; therefore, acute stroke treatment with intravenous thrombolysis was contraindicated. A follow-up CT examination at 24 h revealed an ischemic lesion localized to the left insula, predominantly involving the left parietal lobe and the superior gyrus of the left temporal lobe. Subsequent gadolinium-enhanced brain MRI revealed small blood vessels draining into the subependymal periventricular veins on the left basal ganglia. Digital subtraction angiography was conducted, confirming the diagnosis of venous angioma. Conclusions: Unilateral BGC caused by venous angioma is a rare entity with unclear pathophysiological mechanisms and heterogeneous clinical presentation. It may mimic conditions such as intracerebral hemorrhage or hemorrhagic brain tumors, complicating acute stroke management, as demonstrated in this case. Surrounding tissue calcification may provide a valuable radiological clue in diagnosing venous angiomas DVAs and vascular malformations.
Background and Objectives: Enlarged perivascular spaces (ePVS) demonstrated by MRI have recently been associated with cerebral small vessel disease and glymphatic dysfunction, implicated in Parkinson’s disease (PD) pathophysiology. This study aimed to quantify the burden of ePVS in PD patients versus healthy controls and to examine associations with cognitive performance. Materials and Methods: A total of 51 participants underwent 3T MRI, including a T2-weighted sequence. Twenty-one patients with Parkinson’s disease and 21 age-matched healthy controls were included in the final analysis. The ePVS burden was assessed quantitatively by counting visible PVS in the basal ganglia and centrum semiovale, and qualitatively using Potter and Heier rating scales. Cognitive function was measured with the Montreal Cognitive Assessment (MoCA). Statistical analyses used Mann–Whitney U tests and Spearman correlations. Results: PD patients had significantly higher total PVS counts in the basal ganglia (84.8 vs. 48.0; p < 0.001) and centrum semiovale (290.6 vs. 143.9; p < 0.001). Potter scale ratings were higher in PD across regions (p ≤ 0.025). Largest per-slice PVS counts negatively correlated with MoCA scores in right basal ganglia (ρ = −0.362, p = 0.012) and bilateral centrum semiovale (right: ρ = −0.421, p = 0.003; left: ρ = −0.431, p = 0.002). Heier scale differences were significant only in the right centrum semiovale (p = 0.023). PVS diameters were larger in PD only in the centrum semiovale (right: p = 0.010; left: p = 0.040). Conclusions: In this cohort, increased ePVS burden in the basal ganglia and centrum semiovale was associated with cognitive impairment in PD patients. Qualitative and quantitative PVS assessment, notably the largest-per-slice counts, may serve as a sensitive, non-invasive imaging biomarker for neurodegeneration and cognitive decline in PD. Larger group studies and longitudinal data are needed to assess their prognostic value in the long term, as well as the development of automatic quantification applications for better reproducibility.
Background. Unilateral basal ganglia calcinosis (BGC) is a rare radiological finding that can be diagnosed on CT and MRI but often presents challenges for clinicians and radiologists in determining its underlying cause. So far, only a few potential causes that could explain unilateral basal ganglia calcification have been described in the literature. Case Report. A 54-year-old Caucasian male was admitted to a tertiary university hospital due to the sudden onset of speech impairment and right-sided weakness. The patient had no significant medical history prior to this event. Non-enhanced computed tomography (NECT) of the brain revealed no evidence of acute ischemia, CTA shows acute MCA M2 segment occlusion. CT perfusion (CTP) maps reveal an extensive penumbra-like lesion, which is potentially reversible upon achieving successful recanalization. However, a primary neoplastic tumor with calcifications in the basal ganglia was initially interpreted as the potential cause, therefore, acute stroke treatment with intravenous thrombolysis was contraindicated. A follow-up CT examination at 24 hours revealed an ischemic lesion localized to the left insula, predominantly involving the left parietal lobe and the superior gyrus of the left temporal lobe. Subsequent gadolinium-enhanced brain MRI revealed small blood vessels draining into the subependymal periventricular veins on the left basal ganglia. Digital subtraction angiography was conducted, confirming the diagnosis of venous angioma. Conclusion. Unilateral BGC caused by venous angioma is a rare entity with unclear pathophysiological mechanisms and heterogeneous clinical presentation. It may mimic conditions such as intracerebral hemorrhage or hemorrhagic brain tumors, complicating acute stroke management, as demonstrated in this case. Surrounding tissue calcification may provide a valuable radiological clue in diagnosing venous angiomas DVAs and vascular malformations.