The latest medical research on Nuclear Radiology
The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about nuclear radiology gathered by our medical AI research bot.
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Request AccessA practical approach to the post esophagectomy CT: expected postoperative anatomy and anatomical approach to associated complication.
Emergency RadiologyThis pictorial review aims to provide a structured approach to the interpretation of post esophagectomy CT by reviewing the major esophagectomy sur...
Obstructive hydrocephalus due to developmental venous anomalies: a pediatric imaging case series.
NeuroradiologyDevelopmental venous anomalies are a rare cause of obstructive hydrocephalus in the pediatric population. In this study, we present the most extensive case series of DVA-induced obstructive hydrocephalus in the pediatric population. We thoroughly describe the imaging findings related to this uncommon entity and comprehensively discuss its clinical presentation and management strategies. The goal is to alert pediatric neuroradiologists to consider this rare condition in the differential diagnosis of hydrocephalus, particularly during prenatal screening or in pediatric cases.
The electronic patient record systems of 2 tertiary care children's hospitals were reviewed to identify pediatric patients with confirmed DVAs leading to obstructive hydrocephalus. Age at diagnosis, gender, MRI findings (including location of the obstruction), clinical presentation, and symptoms were recorded. Data on treatment and follow-up imaging were also collected.
The search yielded 5 cases of pediatric patients with DVA-induced obstructive hydrocephalus. The mean age at diagnosis of the DVA was 2.9 years (range: 0-7 years), and in two cases, ventriculomegaly was diagnosed in utero during prenatal cranial ultrasound screenings. In all patients, the DVA caused stenosis of the aqueduct of Sylvius, and one case presented with multiple DVAs.
Although aqueductal stenosis caused by a DVA is rare, it is crucial to consider it in the differential diagnosis of hydrocephalus during prenatal screening or in the pediatric population. Brain MRI, especially post-contrast T1WI, and SWI sequences are particularly valuable for visualizing the typical "caput medusae" appearance of DVAs and detecting associated complications such as hemorrhages.
Neonatal Brain MRI: Periventricular Germinal Matrix Mimicking Hypoxic-ischemic White Matter Injuries.
NeuroradiologyAs pregnancy progresses, the germinal matrix volume decreases. Residual periventricular germinal matrix may be mistaken for hypoxic-ischemic white matter injury. This study aims to determine the prevalence and imaging characteristics of these findings.
This retrospective study analyzed brain MRIs of newborns from 2012-2023, performed within the first week of life. MRIs were done for suspected hypoxic-ischemic injuries, post-natal neurological symptoms, and evaluation of prenatally diagnosed structural anomalies. Image analysis targeted the remnants of the frontal periventricular germinal matrix, assessing its imaging characteristics, including diffusion, T1, and T2 signal characteristics, and laterality. Frontal migrating cell bands were also assessed.
Seventy newborns were included (mean gestational age at delivery was 38.3 ± 2.1 weeks, mean scan age 5.1 ± 1.9 days). Frontal periventricular gray matter was detected in 39 newborns (90% bilateral) on T2-weighted images, negatively correlated with gestational age (r = -0.31, p = 0.013); none showed decreased ADC or shortened T1 signal compared with the basal ganglia. Frontal periventricular bands were found in 37 newborns (97.3% bilateral), strongly correlating with periventricular gray matter (r = 0.71, p < 0.001). No correlation was found between clinical hypoxic-ischemic injuries and these features.
The presence of frontal periventricular gray matter observed in early neonatal MRIs, without decreased ADC values or shortened T1 signal, is developmental, reflecting a late maturation phase. Careful interpretation of MRI characteristics, including diffusion, T1, and T2 signal intensities, is necessary before attributing these findings to hypoxic-ischemic white matter injury.
Dual-energy CT angiography in detecting underlying causes of intracerebral hemorrhage: an observational cohort study.
NeuroradiologyCT angiography (CTA) is often used to detect underlying causes of acute intracerebral hemorrhage (ICH). Dual-energy CT (DECT) is able to distinguish materials with similar attenuation but different compositions, such as hemorrhage and contrast. We aimed to evaluate the diagnostic yield of DECT angiography (DECTA), compared to conventional CTA in detecting underlying ICH causes.
All non-traumatic ICH patients who underwent DECTA (both arterial as well as delayed venous phase) at our center between January 2014 and February 2020 were analyzed. Conventional CTA acquisitions were reconstructed ('merged') from DECTA data. Structural ICH causes were assessed on both reconstructed conventional CTA and DECTA. The final diagnosis was based on all available diagnostic and clinical findings during one-year follow up.
Of 206 included ICH patients, 30 (14.6%) had an underlying cause as final diagnosis. Conventional CTA showed a cause in 24 patients (11.7%), DECTA in 32 (15.5%). Both false positive and false negative findings occurred more frequently on conventional CTA. DECTA detected neoplastic ICH in all seven patients with a definite neoplastic ICH diagnosis, whereas conventional CTA only detected four of these cases. Both developmental venous anomalies (DVA) and cerebral venous sinus thrombosis (CVST) were more frequently seen on DECTA. Arteriovenous malformations and aneurysms were detected equally on both imaging modalities.
Performing DECTA at clinical presentation of ICH may be of additional diagnostic value in the early detection of underlying causes, especially neoplasms, CVST and DVAs.
Quantitative ROI differences for assessment of occult intertrochanteric extension of greater trochanteric fractures on pelvis CT.
Emergency RadiologyTo determine if difference in Hounsfield Units (HU) of the medullary bone between the injured and non-injured femurs in patients with greater trochanteric fractures is associated with occult intertrochanteric (IT) extension.
Retrospective review was performed of 81 patients (age range 54-102, 54 females and 27 males) who underwent CT and subsequent MRI after identification of a greater trochanteric fracture without evidence of IT extension on radiography and/or CT. Hounsfield units of the injured and non-injured femurs on CT were recorded at the level of the base of the greater trochanter centrally (ROI1) and the level of the upper border of the lesser trochanter posteromedially (ROI2). The difference between the injured and non-injured femur for each ROI1 and ROI2 were calculated. Absence or presence, and if present, extent of IT extension was assessed on MRI. Analysis was performed to determine if there is correlation of difference in density with presence, and extent of occult IT fractures.
81 cases met inclusion criteria, 14 (17%) had no IT extension, 11 (14%) had less than 50% IT extension and 56 (69%) had 50% or greater IT extension. There was statistical significance between presence and absence of IT extension between the injured and non-injured femur for ROI1 (HU) no IT extension median (IQR): 18.8(4-40), ROI1 (HU) present IT extension median (IQR): 65.5(46-90) p < .0001, and for ROI2 no IT extension median (IQR): 3(-8-25.5) and ROI2 present IT extension 51(40.5-76), p < .0001. There was statistical significance of the extent of IT extension: ROI1 less than 50% IT extension median (IQR): 37.5(27.5-57), ROI1 50% or greater IT extension median (IQR): 72.3(53.5-91.3), p < .0001, and for ROI2 less than 50% IT extension median (IQR): 17.5(8-49), and ROI2 50% or greater IT extension median (IQR): 55.8(45.3-81.5), p < .0001. A threshold ROI2 difference of 50 HU resulted in specificity of 92% and sensitivity 60.7% of for IT extension 50% or greater.
Patients presenting with greater trochanteric fractures, an asymmetric increased density measured by ROI differences within the medullary space of the IT region between the injured and non-injured femur is associated with occult IT extension.
Response assessment in pediatric neurooncology (RAPNO) criteria revisited: a practical navigation guide for neuroradiologists.
NeuroradiologyThe Response Assessment in Pediatric Neuro-Oncology (RAPNO) Working Group is an international, collaborative network of experts dedicated to pediat...
Visualization of cortical neoangiogenesis after combined revascularization surgery in moyamoya disease using silent MRA.
NeuroradiologyTo investigate postsurgical indirect cortical neoangiogenesis in patients with moyamoya disease (MMD) using silent magnetic resonance angiography (MRA).
We studied 44 patients with MMD (63 hemispheres) who were previously revascularized with combined bypass surgery (23 and 40 hemispheres in pediatric and adult patients, respectively). They underwent follow-up for postoperative bypass patency using time-of-flight (TOF)-MRA and silent MRA between January 2022 and December 2023. The mean duration from surgery to MRA was 8.5 years (range, 1.2-22.3 years). Two observers independently rated the revascularization as follows: 0 (near-complete signal loss or no signal); 1, poor (slightly visible donor arteries); 2, good (acceptable revascularization around the brain surface); and 3, excellent (good quality of revascularization with perfusion from the cortical surface into the middle cerebral artery).
Silent MRA visualized indirect bypass significantly better than TOF-MRA (2.6 ± 0.7 and 1.4 ± 0.8) (P < 0.01). In silent MRA, the mean score of indirect bypass was significantly higher than that of direct bypass (2.6 ± 0.7 and 1.7 ± 1.0; P < 0.01) and indicated good indirect bypass development in both children and adults (91.3% and 85.0%; score ≥ 2). Children exhibited a higher rate of excellent indirect bypass patency than adults (73.9% and 55.0%; score 3). Poor bypass development in indirect bypass (8 hemispheres, mean age: 35.5 ± 17.5 years, mean follow-up period: 11.3 years) was significantly observed in male patients (P < 0.01).
Silent MRA enables better precision in postsurgical visualization of indirect cortical neoangiogenesis during long-term follow-up and reveals indirect bypass development even in adult patients.
Integrating standard epilepsy protocol, ASL-perfusion, MP2RAGE/EDGE and the MELD-FCD classifier in the detection of subtle epileptogenic lesions: a 3 Tesla MRI pilot study.
NeuroradiologyMalformations of cortical development (MCDs) in children with focal epilepsy pose significant diagnostic challenges, and a precise radiological diagnosis is crucial for surgical planning. New MRI sequences and the use of artificial intelligence (AI) algorithms are considered very promising in this regard, yet studies evaluating the relative contribution of each diagnostic technique are lacking.
The study was conducted using a dedicated "EPI-MCD MR protocol" with a 3 Tesla MRI scanner in patients with focal epilepsy and previously negative MRI. MRI sequences evaluated included 3D FLAIR, 3D T1 MPRAGE, T2 Turbo Spin Echo (TSE), 3D T1 MP2RAGE, and Arterial Spin Labelling (ASL). Two paediatric neuroradiologists scored each sequence for localisation and extension of the lesion. The MELD-FCD AI classifier's performance in identifying pathological findings was also assessed. We only included patients where a diagnosis of MCD was subsequently confirmed on histology and/or sEEG.
The 3D FLAIR sequence showed the highest yield in detecting epileptogenic lesions, with 3D T1 MPRAGE, T2 TSE, and 3D T1 MP2RAGE sequences showing moderate to low yield. ASL was the least useful. The MELD-FCD classifier achieved a 69.2% true positive rate. In one case, MELD identified a subtle area of cortical dysplasia overlooked by the neuroradiologists, changing the management of the patient.
The 3D FLAIR sequence is the most effective in the MRI-based diagnosis of subtle epileptogenic lesions, outperforming other sequences in localisation and extension. This pilot study emphasizes the importance of careful assessment of the value of additional sequences.
Mechanical properties of pediatric low-grade gliomas in children with and without neurofibromatosis type 1.
NeuroradiologyPrognoses for pediatric brain tumors are suboptimal, as even in low-grade tumors, management techniques can lead to damage in the developing brain. Therefore, advanced neuroimaging methods are critical for developing optimal management plans and improving patient care. Magnetic resonance elastography (MRE) has allowed for the characterization of adult gliomas by their mechanical properties, which are uniquely sensitive to the complex interplay of cellularity, vasculature, and interstitium. However, pediatric tumors differ in behavior and cytoarchitecture, and their mechanical properties have never been assessed.
Here, we conduct the first study of pediatric brain tumor mechanical properties by using MRE to measure tissue stiffness and damping ratio in low grade gliomas (LGGs). We additionally measure the mechanical properties of non-neoplastic focal abnormal signal intensities (FASIs) in children with neurofibromatosis type 1 (NF1).
23 patients age 4-17 years who had MR imaging results consistent with a primary LGG or with NF1 were included in this study. We found that pediatric gliomas are on an average 10.9% softer (p = 0.010) with a 17.3% lower (p = 0.009) viscosity than reference tissue. Softness of tumors appeared consistent across tumor subtypes and unrelated to tumor size or contrast-enhancement. In NF1 we found that, unlike gliomas, FASIs are stiffer, though not significantly, than reference tissue by an average of 10.4% and have a 16.7% lower damping ratio.
Measuring tumor mechanical properties patterning and heterogeneity has potential to aid in prediction of biological behavior and inform management strategies for pediatric patients.
The utilisation of fMRI for pre-operative mapping in the paediatric population with central nervous system tumours: a systematic review.
NeuroradiologyFunctional MRI (fMRI) is a well-established tool for pre-operative planning, providing neurosurgeons with a roadmap of critical functional areas to preserve during surgery. Despite its increasing use, there is a need to compare task-based (tb-fMRI) and resting-state fMRI (rs-fMRI) in the peadiatric population to comprehensively evaluate the existing literature on the use of fMRI for pre-operative mapping in pediatric patients, comparing tb-fMRI and rs-fMRI.
Two databases were searched for relevant studies published before July 2024 following the PRISMA guidelines. Eleven studies were selected and comprised 431 participants: 377 patients with different types and locations of brain tumours, and 54 healthy controls (HC).
Results indicate that tb-fMRI could reliably locate the eloquent cortex with more than an 80% success rate. Furthermore, results were comparable with intraoperative mapping. Two studies reported that 68-81% of patients did not develop deficits in the postoperative period. Results also found that rs-fMRI can fill the gap in the situation of paediatric patients when other techniques do not apply to younger patients.
This study suggests that tb-fMRI is more effective for pre-operative mapping in pediatric patients, offering precise localisation of critical brain functions and enhancing surgical planning. Although rs-fMRI is less demanding and compatible with light sedation, it lacks the specificity needed for accurate identification of language, sensory, and motor areas, which limits its clinical relevance. rs-fMRI can aid in function-preserving treatments for brain tumour patients and reduce the need for invasive procedures. Combining tb-fMRI with intraoperative mapping optimizes precision and safety in pediatric-neurosurgery.
Comparison of Syn T2-FLAIR and Syn DIR with conventional T2-FLAIR in displaying white matter hyperintensities in migraine patients.
NeuroradiologyYoung migraine patients often present with white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI). This study aimed to analyze whether synthetic (Syn) T2-FLAIR and Syn double inversion recovery (DIR) can reveal WMHs more clearly and sensitively than conventional T2-FLAIR.
Conventional MRI and Syn MRI data from 50 young migraine patients were analyzed prospectively. WMHs in each anatomical region (periventricular, deep white matter, and juxtacortical) were recorded separately. The differences in the clarity of lesion boundaries and the number of lesions displayed in the three sequences in the same anatomical region were analyzed.
A total of 80 (periventricular area, 15; deep white matter, 31; juxtacortical area, 34), 163 (17, 50, 96), and 134 (18, 42, 74) lesions were observed with conventional T2-FLAIR, Syn T2-FLAIR, and Syn DIR, respectively. Syn T2-FLAIR and Syn DIR can show lesions more clearly than conventional T2-FLAIR (all P < 0.001). There was no significant difference in the number of lesions observed in the periventricular white matter among the three sequences (P = 0.159, 0.083, 0.322). Syn T2-FLAIR and Syn DIR can detect more lesions in the deep white matter than conventional T2-FLAIR (P < 0.001, P = 0.006). Syn T2-FLAIR revealed more lesions in the juxtacortical white matter than Syn DIR and conventional T2-FLAIR imaging (all P < 0.001), and conventional T2-FLAIR revealed the fewest lesions (P < 0.001).
Syn T2-FLAIR and Syn DIR sequences can clearly and sensitively detect WMHs, especially in deep and juxtacortical white matter areas.
Internal hematoma architecture predicts subdural hematoma responsiveness to standalone middle meningeal artery embolization.
NeuroradiologySubdural hematoma (SDH) is quickly becoming the most common neurosurgical pathology due to the aging population. Middle meningeal artery embolization (MMAE) has recently emerged as an effective adjunct to surgical SDH evacuation by decreasing recurrence risk. MMAE has also shown promise as a standalone SDH intervention, but clinical and radiographic predictors of successful MMAE remain ill-defined.
Retrospective chart review from 2020 to 2023 at a single center identified all MMAE cases performed as primary SDH treatment. Cases were classified by hematoma internal architecture as homogeneous, separated, laminar, or trabecular. SDH maximal thickness was assessed on all follow-up imaging and any recurrences or expansions requiring surgery were denoted as treatment failures.
164 standalone MMAE cases were reviewed. Most cases were in male patients (75.0%) with a mean age of 73.2 years. The overall MMAE treatment failure rate was 6.7% with a 4.9% periprocedural complication rate. The cases with trabecular and laminar collections were slightly larger than those with homogeneous and separated collections (16.2 mm vs. 14.2 mm, p = 0.008*), but other baseline characteristics were similar. The MMAE failure rate was significantly lower in the laminar and trabecular subgroup (1.2%) compared to the homogeneous and separated subgroup (12.4%) (p = 0.005*). Homogeneous and separated internal hematoma architecture was the only predictor of MMAE failure in multivariate analysis (OR 10.5, p = 0.027*) and was also associated with delayed SDH resorption (ANOVA: F = 4.8, p = 0.0025*).
Standalone MMAE is an effective, safe, and durable treatment for non-acute SDHs, and is especially effective for SDHs with more membranous internal architecture.