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Simple Summary: Whole-body magnetic resonance imaging (WB-MRI) is increasingly being used to evaluate a wider range of patients with different types of cancer and for cancer screening. To standardize acquisition, interpretation, and reporting, three WB-MRI reporting and data systems (RADSs) have been recently introduced: METastasis Reporting and Data System for Prostate Cancer (MET-RADS-P), Myeloma Response Assessment and Diagnosis System (MY-RADS), and Oncologically Relevant Findings Reporting and Data System (ONCO-RADS). The aim of this review is to provide a summary of the scientific evidence that has emerged so far regarding the clinical utility of WB-MRI RADSs. Although preliminary studies have demonstrated promising and consistent results regarding the prognostic value and reliability of WB-MRI RADSs, additional research is necessary, particularly for ONCO-RADS and inter-reader agreement for MY-RADS. Larger, prospective, multi-center studies are required to confirm and extend these encouraging initial findings. Whole-body magnetic resonance imaging (WB-MRI) is being employed with increasing frequency to evaluate a broader spectrum of patients with diverse types of cancer and for cancer screening purposes. While clinical guidelines support its use, a standardized radiological approach is still lacking. To improve consistency in the acquisition, interpretation, and reporting of WB-MRI examinations, three reporting and data systems (RADSs) have been recently suggested: METastasis Reporting and Data System for Prostate Cancer (MET-RADS-P), Myeloma Response Assessment and Diagnosis System (MY-RADS), and Oncologically Relevant Findings Reporting and Data System (ONCO-RADS). MET-RADS-P was developed to stage and monitor men with advanced prostate cancer using WB-MRI. It has emerged as a reliable imaging biomarker for predicting metastatic disease progression and assessing treatment response. MY-RADS was developed to stage and monitor patients with multiple myeloma using WB-MRI, emerging as a prognostic imaging biomarker. However, the evidence regarding inter-reader agreement for MY-RADS is currently limited. ONCO-RADS was developed to standardize the use of WB-MRI for cancer screening in individuals with cancer predisposition syndromes and in the general population. While initial findings are promising, the evidence supporting its use remains limited. To further validate and expand upon these promising preliminary findings, additional large-scale, prospective, multicenter studies are necessary. [ABSTRACT FROM AUTHOR]

The assessment of lymph node (LN) involvement with clinical imaging is a key factor in cancer staging. Node Reporting and Data System 1.0 (Node-RADS) was introduced in 2021 as a new system specifically tailored for classifying and reporting LNs on computed tomography (CT) and magnetic resonance imaging scans. The aim of this review is to compile the scientific evidence that has emerged since the introduction of Node-RADS, with a specific focus on its diagnostic performance and reliability. Node-RADS's performance has been evaluated in various cancer types and anatomical sites, revealing a trend where higher Node-RADS scores correspond to a greater probability of metastatic LN with better diagnostic performances compared to using short axis diameter alone. Moreover, Node-RADS exhibits encouraging diagnostic value for both Node-RADS ≥ 3 and Node-RADS ≥ 4 cutoffs in predicting metastatic LN. In terms of Node-RADS scoring reliability, preliminary studies show promising but partially conflicting results, with agreement levels, mostly between two readers, ranging from fair to almost perfect. This review highlights a wide variation in methodologies across different studies. Thus, to fully realize the potential of Node-RADS in clinical practice, future studies should comprehensively evaluate its diagnostic accuracy, category-specific malignancy rates, and inter-observer agreement. Finally, although limited, promising evidence has suggested the following: a potential prognostic role for Node-RADS; the possible value of diffusion-weighted imaging for LNs classified as Node-RADS ≥ 3; a correlation between Node-RADS and certain texture features in CT; and improved diagnostic performance when Node-RADS is integrated into radiomics or clinical models. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate whether the use of Maximum Intensity Projection (MIP) images derived from contrast-enhanced 3D-T1-weighted volumetric interpolated breath-hold examination (VIBE) would allow more sensitive detection of small (≤5 mm) brain metastases (BM) compared with source as well as 2D-T1-weighted spin-echo (SE) images. Methods: We performed a single center retrospective study on subjects with BM who underwent 1.5 tesla brain magnetic resonance imaging. Two readers counted the number of small BM for each of the seven sets of contrast-enhanced images created: axial 2D-T1-weighted SE, 3D-T1-weighted VIBE, 2.5 mm-thick-MIP T1-weighted VIBE, and 5 mm-thick-MIP T1-weighted VIBE; sagittal 3D-T1-weighted VIBE, 2.5 mm-thick-MIP T1-weighted VIBE, and 5 mm-thick-MIP T1-weighted VIBE. Total number of lesions detected on each image type was compared. Sensitivity, the average rates of false negatives and false positives, and the mean discrepancy were evaluated. Results: A total of 403 small BM were identified in 49 patients. Significant differences were found: in the number of true positives and false negatives between the axial 2D-T1-weighted SE sequence and all other imaging techniques; in the number of false positives between the axial 2D-T1-weighted SE and the axial 3D-T1-weighted VIBE sequences. The two image types that combined offered the highest sensitivity were 2D-T1-weighted SE and axial 2.5 mm-thick-MIP T1-weighted VIBE. The axial 2D-T1-weighted SE sequence differed significantly in sensitivity from all other sequences. Conclusion: MIP images did not show a significant difference in sensitivity for the detection of small BM compared with native images. [ABSTRACT FROM AUTHOR]

Glioblastoma is the most frequent form of adult-type diffuse gliomas, and it carries a very poor prognosis. Magnetic resonance imaging (MRI) is an indispensable tool for diagnosing and monitoring brain tumors, potentially influencing choices like repeat surgery, biopsy, or alternative management strategies. However, interpreting post-surgical MRI for gliomas can be particularly demanding, especially in differentiating between tumor progression and treatment effects. Recently, a novel score specifically designed for classifying and reporting post-treatment brain tumors on MRI was proposed by a team of neuroradiologists, neurosurgeons, and neuro-oncologists: the Brain Tumor Reporting and Data System (BT-RADS). This review examines the current body of evidence regarding the use of BT-RADS in monitoring adult-type diffuse gliomas following surgery. This classification has demonstrated a number of benefits in terms of prognostic value, treatment decisions, reliability, and the quality of radiology reports. On the other hand, despite the promising diagnostic value in identifying recurrent glioblastoma, there is still some uncertainty in defining the presence or absence of tumor recurrence in the intermediate category 3. In such a category, incorporating advanced techniques such as perfusion-weighted imaging and diffusion-weighted imaging may improve the stratification of patients, avoiding repeat surgery on false positive findings. [ABSTRACT FROM AUTHOR]

Despite cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) being the current gold standard for non-invasive myocardial characterization and fibrosis quantification, its accessibility is limited, particularly in acute settings and in certain patient populations with contraindications to magnetic resonance imaging. Late iodine enhancement (LIE) in computed tomography (CT) imaging has emerged as a potential alternative, capitalizing on the similarities in the contrast kinetics between gadolinium and iodinated contrast agents. Studies have investigated LIE-CT's effectiveness in myocardial infarction (MI) detection, revealing promising outcomes alongside some disparities compared to LGE-CMR. LIE-CT also proves beneficial in diagnosing non-ischemic heart diseases such as myocarditis, hypertrophic cardiomyopathy, and sarcoidosis. While LIE-CT demonstrates good accuracy in detecting certain myocardial pathologies, including acute MI and chronic fibrotic changes, it has limitations, such as the inability to detect diffuse myocardial enhancement. Nonetheless, thanks to the availability of optimized protocols with minimal radiation doses and contrast medium administration, integrating LIE-CT into cardiac CT protocols could enhance its clinical utility, particularly in acute settings, providing valuable prognostic and management insights across a spectrum of cardiac ischemic and non-ischemic conditions. [ABSTRACT FROM AUTHOR]

Brain spaces around (perivascular spaces) and alongside (paravascular or Virchow–Robin spaces) vessels have gained significant attention in recent years due to the advancements of in vivo imaging tools and to their crucial role in maintaining brain health, contributing to the anatomic foundation of the glymphatic system. In fact, it is widely accepted that peri- and para-vascular spaces function as waste clearance pathways for the brain for materials such as ß-amyloid by allowing exchange between cerebrospinal fluid and interstitial fluid. Visible brain spaces on magnetic resonance imaging are often a normal finding, but they have also been associated with a wide range of neurological and systemic conditions, suggesting their potential as early indicators of intracranial pressure and neurofluid imbalance. Nonetheless, several aspects of these spaces are still controversial. This article offers an overview of the current knowledge and magnetic resonance imaging characteristics of peri- and para-vascular spaces, which can help in daily clinical practice image description and interpretation. This paper is organized into different sections, including the microscopic anatomy of peri- and para-vascular spaces, their associations with pathological and physiological events, and their differential diagnosis. [ABSTRACT FROM AUTHOR]

Background: The case of disseminated cancer cell spreading throughout the brain is called "miliary metastases" or "carcinomatous encephalitis", a very rare and critical condition (primarily associated with lung and breast cancer) in which there are multiple plaque with a perivascular distribution, made of punctate lesions spread in all the brain. To our knowledge this represents the fourth case of melanotic miliary brain metastases described in the literature, also associated with melanin content of the lesions that is already evident on unenhanced T1-weighted images. Case presentation: A 75-year-old patient with history of metastatic cutaneous melanoma (BRAF V600E mutate, PD-L1 negative) in treatment with dabrafenib and trametinib after 9 years from the diagnosis developed severe cognitive-motor slowing. Contrast-enhanced brain MRI showed miliary enhancing intra-axial brain lesions involving supra- and sub-tentorial regions and also the perivascular spaces, characterized by a bright appearance on unenhanced T1-weighted images without signal hypointensity in T2*-weighted images, as for melanotic pattern. Thus, the radiological diagnosis of "carcinomatous encephalitis" was made. Neurological examination showed an alert and cooperative subject with increased reaction time in verbal and motor responses. No ocular motility disturbances were found, and there were no motor or sensory deficits in the four limbs. The finger-to-nose test was normal, and no coordination deficit was found bilaterally. Blood tests and body temperature demonstrated no signs of ongoing infection. Electroencephalography showed slow and punctate abnormalities in bilateral fronto-temporal regions, with left prevalence. Corticosteroid therapy was started during hospitalization, improving the clinical picture. The patient was then discharged after 4 days in good clinical conditions with the indication to start second-line treatment with ipilimumab and nivolumab and to perform a whole-brain irradiation. Conclusions: Brain MRI plays a crucial role for the non-invasive diagnosis of carcinomatous encephalitis and for the differential diagnosis with other pathologies. Awareness of the existence of this disorder even in patients with melanoma is necessary to avoid diagnostic delays. Miliary brain metastases should be suspected in all melanoma patients with new neurological findings and contrast-enhanced MRI should be performed to assess the real burden of the disease. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-24-968/coif). C.A.M. serves as an unpaid editorial board member of Quantitative Imaging in Medicine and Surgery. A.J.v.d.M. received consultancy fees from Guerbet and royalties from Thieme Verlag KG. I.A.D. received consultancy fees from Guerbet. The other authors have no conflicts of interest to declare.

Brain metastases in prostate cancer are rare (<2% of cases). In magnetic resonance imaging, nearly all brain metastases exhibit contrast-enhancement, which may be affected by the time elapsed since the administration of the contrast agent. We discuss a case where the brain metastases in a patient with prostate cancer do not show a clear contrast-enhancement on magnetic resonance imaging using a standard brain metastases protocol. It also emphasizes the usefulness of delayed imaging in identifying blood-brain barrier damage. We present the case of a 69-year-old man diagnosed with prostate adenocarcinoma, currently in castration-resistant phase (last value of serum prostate-specific antigen: 45.1 ng/mL) with bone, mediastinal and inguinal lymph nodes, pulmonary, and hepatic metastases. In a contrast-enhanced whole-body computed tomography examination, the appearance of intra-axial brain lesions suspicious for metastases was documented. The subsequent contrast-enhanced brain magnetic resonance imaging showed the presence of 5 intra-axial lesions consistent with brain metastases. These lesions exhibited hyperintense signals in T2-fluid-attenuated inversion recovery images; after contrast agent administration, a ring-like contrast-enhancement was more clearly visible in T1-weighted images acquired later (about 15 minutes after contrast agent administration) than in those acquired earlier (about 5-7 minutes after contrast agent administration). In conclusion, for oncological subjects with multiple brain lesions lacking obvious contrast-enhancement using a standard magnetic resonance imaging protocol, we suggest acquiring late images. These might allow for the detection of even minimal post-contrast impregnation, improving confidence in the diagnosis of brain metastases., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-1037/coif). C.A.M. serves as an unpaid editorial board member of Quantitative Imaging in Medicine and Surgery. The other authors have no conflicts of interest.

Background: Brain irradiation is considered a cofactor influencing the dentate nucleus (DN) signal intensity (SI) on unenhanced T 1 -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 T 1 -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 T 1 -weighted sequences., Assessment: The DN-to-pons SI ratio on unenhanced T 1 -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., (© 2020 International Society for Magnetic Resonance in Medicine.)