Understanding the consistency of pituitary macroadenomas is crucial for neurosurgeons planning surgery. This retrospective study aimed to evaluate the utility of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) as non-invasive imaging modalities for predicting the consistency of pituitary macroadenomas. This could contribute to appropriate surgical planning and therefore reduce the likelihood of incomplete resections. The study included 45 patients with pathologically confirmed pituitary macroadenomas. Conventional MRI sequences, DWIs, ADC maps, and pre- and post-contrast MRIs were performed. Two neuroradiologists assessed all of the images. Neurosurgeons assessed the consistency of the tumor macroscopically, and histopathologists examined it microscopically. The MRI findings were compared with postoperative data. According to the operative data, macroadenomas were divided into the two following categories based on their consistency: aspirable (n = 27) and non-aspirable tumors (n = 18). A statistically significant difference in DWI findings was found when comparing macroadenomas of different consistencies (p < 0.001). Most aspirable macroadenomas (66.7%) were hyperintense according to DWI and hypointense on ADC maps, whereas most non-aspirable macroadenomas (83.3%) were hypointense for DWI and hyperintense on ADC maps. At a cut-off value of 0.63 × 10⁻³ mm²/s, the ADC showed a sensitivity of 85.7% and a specificity of 75% for the detection of non-aspirable macroadenomas (AUC, 0.946). The study concluded that DWI should be routinely performed in conjunction with ADC measurements in the preoperative evaluation of pituitary macroadenomas. This approach may aid in surgical planning, ensure that appropriate techniques are utilized, and reduce the risk of incomplete resection.

Aim: Traditional CSF evaluation has relied on invasive methods, such as lumbar puncture. Recent advances, particularly phase-contrast MRI (PC-MRI), offer a non-invasive alternative capable of both qualitative and quantitative CSF flow assessment. This study investigated whether quantitative CSF flowmetry adds diagnostic value in pediatric posterior fossa cystic malformations. Methods: In this multicenter, prospective study, 45 pediatric patients (aged 1–14 years) with suspected hydrocephalus and increased intracranial pressure completed MRI protocols between October 2024 and April 2025. Patients with mixed or solid lesions, or who did not complete the protocol, were excluded. Results: No significant intergroup differences were found in end-diastolic velocity (EDV). Peak systolic velocity (PSV) was significantly lower in the Dandy-Walker Malformation (DWM) + Vermis Hypoplasia (VH) group. Stroke volume (SV) was significantly lower in Mega Cisterna Magna (MCM) and Arachnoid Cyst (AC) groups. Hydrocephalus distribution showed no significant association with cyst type. Conclusion: Quantitative CSF flowmetry alone does not significantly enhance diagnostic differentiation among posterior fossa cystic malformations. However, qualitative assessment proved valuable in distinguishing communicating from non-communicating ACs, with implications for surgical planning. Advances in knowledge: While quantitative PC-MRI provides detailed flow metrics, its standalone diagnostic value in routine evaluation of pediatric posterior fossa malformations appears limited. Its role may be best reserved for complementing qualitative CSF flowmetry in select cases.