Comparison of Image Quality and Radiation Dose in Pediatric Temporal Bone CT using Photon Counting Detectors CT and Energy Integrating Detectors CT.

BACKGROUND AND PURPOSE: To compare the image quality and radiation dose of temporal bone CT scans in pediatric patients acquired with photon counting detectors (PCD) CT and energy integrating detectors (EID) CT. MATERIALS AND METHODS: The retrospective study included a total of 110 pediatric temporal bone CT scans (PCD-CT, n=52; EIDCT, n=58). Two independent readers evaluated the spatial resolution of 4 anatomical structures (tympanic membrane, incudostapedial joint, stapedial crura, and cochlear modiolus) and overall image quality using a 4-point scale. Inter-reader agreement was assessed. Dose length product (DLP) for each CT was compared, and subgroup analyses were performed based on age (under 3 years, 3-5 years, 6-11 years, and 12 years and above). RESULTS: PCD-CT demonstrated statistically significantly higher scores than EID-CT for all items (tympanic membrane, 2.9 vs. 2.4; incudostapedial joint, 3.6 vs. 2.6, stapedial crura, 3.2 vs. 2.4; cochlear modiolus, 3.4 vs. 2.8; overall image quality, 3.6 vs. 2.8; p<0.05). Inter-reader agreement ranged from good to excellent (ICCs, 0.6-0.81). PCD-CT exhibited a 43% dose reduction compared to EID-CT, with a particularly substantial reduction of over 70% in the subgroups of children under 6 years. CONCLUSIONS: PCD temporal bone CT achieves significantly superior imaging quality at a lower radiation dose compared to EID-CT. ABBREVIATIONS: PCD-CT = photon counting detectors CT; EID-CT = energy integrating detectors CT; DLP = dose length product; AEC = automatic exposure control; ICC = interclass correlation coefficient.

NSABP FB-10: a phase Ib/II trial evaluating ado-trastuzumab emtansine (T-DM1) with neratinib in women with metastatic HER2-positive breast cancer.

BACKGROUND: We previously reported our phase Ib trial, testing the safety, tolerability, and efficacy of T-DM1 + neratinib in HER2-positive metastatic breast cancer patients. Patients with ERBB2 amplification in ctDNA had deeper and more durable responses. This study extends these observations with in-depth analysis of molecular markers and mechanisms of resistance in additional patients. METHODS: Forty-nine HER2-positive patients (determined locally) who progressed on-treatment with trastuzumab + pertuzumab were enrolled in this phase Ib/II study. Mutations and HER2 amplifications were assessed in ctDNA before (C1D1) and on-treatment (C2D1) with the Guardant360 assay. Archived tissue (TP0) and study entry biopsies (TP1) were assayed for whole transcriptome, HER2 copy number, and mutations, with Ampli-Seq, and centrally for HER2 with CLIA assays. Patient responses were assessed with RECIST v1.1, and Molecular Response with the Guardant360 Response algorithm. RESULTS: The ORR in phase II was 7/22 (32%), which included all patients who had at least one dose of study therapy. In phase I, the ORR was 12/19 (63%), which included only patients who were considered evaluable, having received their first scan at 6 weeks. Central confirmation of HER2-positivity was found in 83% (30/36) of the TP0 samples. HER2-amplified ctDNA was found at C1D1 in 48% (20/42) of samples. Patients with ctHER2-amp versus non-amplified HER2 ctDNA determined in C1D1 ctDNA had a longer median progression-free survival (PFS): 480 days versus 60 days (P = 0.015). Molecular Response scores were significantly associated with both PFS (HR 0.28, 0.09-0.90, P = 0.033) and best response (P = 0.037). All five of the patients with ctHER2-amp at C1D1 who had undetectable ctDNA after study therapy had an objective response. Patients whose ctHER2-amp decreased on-treatment had better outcomes than patients whose ctHER2-amp remained unchanged. HER2 RNA levels show a correlation to HER2 CLIA IHC status and were significantly higher in patients with clinically documented responses compared to patients with progressive disease (P = 0.03). CONCLUSIONS: The following biomarkers were associated with better outcomes for patients treated with T-DM1 + neratinib: (1) ctHER2-amp (C1D1) or in TP1; (2) Molecular Response scores; (3) loss of detectable ctDNA; (4) RNA levels of HER2; and (5) on-treatment loss of detectable ctHER2-amp. HER2 transcriptional and IHC/FISH status identify HER2-low cases (IHC 1+ or IHC 2+ and FISH negative) in these heavily anti-HER2 treated patients. Due to the small number of patients and samples in this study, the associations we have shown are for hypothesis generation only and remain to be validated in future studies. Clinical Trials registration NCT02236000.

Multiple Sclerosis Part 2: Advanced Imaging and Emerging Techniques.

Multiple advanced imaging methods for multiple sclerosis (MS) have been in investigation to identify new imaging biomarkers for early disease detection, predicting disease prognosis, and clinical trial endpoints. Multiple techniques probing different aspects of tissue microstructure (ie, advanced diffusion imaging, magnetization transfer, myelin water imaging, magnetic resonance spectroscopy, glymphatic imaging, and perfusion) support the notion that MS is a global disease with microstructural changes evident in normal-appearing white and gray matter. These global changes are likely better predictors of disability compared with lesion load alone. Emerging techniques in glymphatic and molecular imaging may improve understanding of pathophysiology and emerging treatments.

Disease Status and Interval between Hematopoietic Cell Transplantations Predict Outcome of Pediatric Patients Who Undergo Subsequent Transplantation for Relapsed Hematologic Malignancy.

Patients with hematologic malignancies who relapse after allogeneic hematopoietic cell transplantation (HCT) have a poor prognosis. Although proceeding to subsequent HCT can provide potential for long-term survival, there are limited data to guide which patients are most likely to benefit and which HCT strategies are best in this heavily pretreated population. The goals of this study were to describe the clinical outcomes of subsequent HCT in pediatric patients with relapsed hematologic malignancies in a cohort enriched for haploidentical donors, and to evaluate the associations of patient-, disease-, and treatment-related factors with survival. We retrospectively evaluated patients who underwent a subsequent HCT for management of post-HCT relapse at a single institution between 2000 and 2021. Among 106 patients who underwent a second allogeneic HCT, the 1-year event-free survival (EFS) was 34% and 1-year overall survival (OS) was 46%, with a 5-year EFS of 26% and 5-year OS of 31%. Only disease-related factors were associated with outcome after second HCT-specifically, the interval between HCTs and the presence or absence of active disease at the time of HCT. In this cohort, patient- and treatment-related factors were not associated with differences in EFS or OS. Patients undergoing a third or fourth HCT (n = 13) had comparable survival outcomes to those undergoing a second HCT. Our experience highlights that a subsequent HCT has curative potential for a subset of patients who relapse after HCT, including those who undergo a subsequent HCT from a haploidentical donor. Although relapse and treatment-related toxicities remain major challenges, our study indicates that achieving complete remission prior to subsequent HCTs has the potential to further improve outcomes.

Apparent diffusion coefficient for differentiation between extra-nodal lymphoma and squamous cell carcinoma in the head and neck: a systematic review and meta-analysis.

BACKGROUND: Radiological differentiation between extra-nodal lymphoma and squamous cell carcinoma in the head and neck is often difficult due to their similarities. PURPOSE: To evaluate the diagnostic benefit of apparent diffusion coefficient (ADC) calculated from diffusion-weighted imaging (DWI) in differentiating the two. MATERIAL AND METHODS: A systematic review was performed by searching the MEDLINE, Scopus, and Embase databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. Forest plots and the pooled mean difference of ADC values were calculated to describe the relationship between extra-nodal lymphoma and squamous cell carcinoma in the head and neck. Heterogeneity among studies was evaluated using the Cochrane Q test and I2 statistic. RESULTS: The review identified eight studies with 440 patients (441 lesions) eligible for meta-analysis. Among all studies, the mean ADC values of squamous cell carcinoma was 0.88 × 10-3mm2/s and that of lymphoma was 0.64 × 10-3mm2/s. In the meta-analysis, the ADC value of lymphoma was significantly lower than that of squamous cell carcinoma (pooled mean difference = 0.235, 95% confidence interval [CI] = 0.168-0.302, P <0.0001). The Cochrane Q test (chi-square = 55.7, P <0.0001) and I2 statistic (I2 = 87.4%, 95% CI = 77.4-93.0%) revealed significant heterogeneity. CONCLUSION: This study highlights the value of quantitative assessment of ADC for objective and reliable differentiation between extra-nodal lymphoma and squamous cell carcinoma in the head and neck. Conclusions should be interpreted with caution due to heterogeneity in the study data.

Low-parameter supervised learning models can discriminate pseudoprogression and true progression in non-perfusion-based MRI.

Discrimination of pseudoprogression and true progression is one challenge to the treatment of malignant gliomas. Although some techniques such as circulating tumor DNA (ctDNA) and perfusion-weighted imaging (PWI) demonstrate promise in distinguishing PsP from TP, we investigate robust and replicable alternatives to distinguish the two entities based on more widely-available media. In this study, we use low-parametric supervised learning techniques based on geographically-weighted regression (GWR) to investigate the utility of both conventional MRI sequences as well as a diffusion-weighted sequence (apparent diffusion coefficient or ADC) in the discrimination of PsP v TP. GWR applied to MRI modality pairs is a unique approach for small sample sizes and is a novel approach in this arena. From our analysis, all modality pairs involving ADC maps, and those involving post-contrast T1 regressed onto T2 showed potential promise. This work on ADC data adds to a growing body of research suggesting the predictive benefits of ADC, and suggests further research on the relationships between post-contrast T1 and T2.Clinical relevance- Few studies have investigated predictive potential of conventional MRI and ADC to detect PsP. Our study adds to the growing research on the topic and presents a new perspective to research by exploiting the utility of ADC in PsP v TP distinction. In addition, our GWR methodology for low-parametric supervised computer vision models demonstrates a unique approach for image processing of small sample sizes.

Performance of Neck Imaging Reporting and Data System (NI-RADS) for Diagnosis of Recurrence of Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-analysis.

BACKGROUND: The Neck Imaging Reporting and Data System (NI-RADS) is a reporting template used in head and neck cancer posttreatment follow-up imaging. PURPOSE: Our aim was to evaluate the pooled detection rates of the recurrence of head and neck squamous cell carcinoma based on each NI-RADS category and to compare the diagnostic accuracy between NI-RADS 2 and 3 cutoffs. DATA SOURCES: The MEDLINE, Scopus, and EMBASE databases were searched. STUDY SELECTION: This systematic review identified 7 studies with a total of 694 patients (1233 lesions) that were eligible for the meta-analysis. DATA ANALYSIS: The meta-analysis of pooled recurrence detection rate estimates for each NI-RADS category and the diagnostic accuracy of recurrence with NI-RADS 3 or 2 as the cutoff was performed. DATA SYNTHESIS: The estimated recurrence rates in each category for primary lesions were 74.4% for NI-RADS 3, 29.0% for NI-RADS 2, and 4.2% for NI-RADS 1. The estimated recurrence rates in each category for cervical lymph nodes were 73.3% for NI-RADS 3, 14.3% for NI-RADS 2, and 3.5% for NI-RADS 1. The area under the curve of the summary receiver operating characteristic for recurrence detection with NI-RADS 3 as the cutoff was 0.887 and 0.983, respectively, higher than 0.869 and 0.919 for the primary sites and cervical lymph nodes, respectively, with NI-RADS 2 as the cutoff. LIMITATIONS: Given the heterogeneity of the data of the studies, the conclusions should be interpreted with caution. CONCLUSIONS: This meta-analysis revealed estimated recurrence rates for each NI-RADS category for primary lesions and cervical lymph nodes and showed that NI-RADS 3 has a high diagnostic performance for detecting recurrence.

Dural and Leptomeningeal Diseases: Anatomy, Causes, and Neuroimaging Findings.

Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to provide a better understanding of the localization and extension of these diseases and summarize the clinical and imaging features of various conditions that cause dural and/or leptomeningeal enhancing lesions. These conditions include infectious meningitis (bacterial, tuberculous, viral, and fungal), autoimmune diseases (vasculitis, connective tissue diseases, autoimmune meningoencephalitis, Vogt-Koyanagi-Harada disease, neuro-Behçet syndrome, Susac syndrome, and sarcoidosis), primary and secondary tumors (meningioma, diffuse leptomeningeal glioneuronal tumor, melanocytic tumors, and lymphoma), tumorlike diseases (histiocytosis and immunoglobulin G4-related diseases), medication-induced diseases (immune-related adverse effects and posterior reversible encephalopathy syndrome), and other conditions (spontaneous intracranial hypotension, amyloidosis, and moyamoya disease). Although meningeal lesions may manifest with nonspecific imaging findings, correct diagnosis is important because the treatment strategy varies among these diseases. ©RSNA, 2023 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Dynamic contrast-enhanced MRI parameters and apparent diffusion coefficient as treatment response markers of skull base osteomyelitis: a preliminary study.

Purpose: Currently, there is no definitive consensus on the optimal imaging modality for determining the treatment response in patients with skull base osteomyelitis (SBO). This study aimed to investigate the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and apparent diffusion coefficient (ADC) as treatment response markers of SBO. Material and methods: This study included 6 patients with SBO, who underwent both pre- and post-treatment DCE-MRI and diffusion-weighted imaging (DWI). Quantitative DCE-MRI parameters and ADC of the region-of-interest were analysed. These normalized parameters were calculated by dividing the region-of-interest by the reference region. The Wilcoxon signed rank test was used to compare these parameters between pre- and post-treatment periods. Results: The normalized fraction of the extravascular extracellular space (Ve) and ADC of the post-treatment status of SBO was significantly lower than those of pre-treatment measures (p = 0.03). The normalized fraction of blood plasma (Vp), normalized rate of transfer from the blood plasma into the extravascular extracellular space (Ktrans), and normalized backflow leakage of material from the extravascular extracellular space into the blood plasma (Kep) demonstrated no significant differences between pre- and post-treatment. Conclusions: DCE-MRI parameters Ve and ADC demonstrated a significant reduction when comparing measures across the pre- and post-treatment periods. These parameters may potentially serve as a valuable surrogate treatment response marker for SBO activity.

Comparison of Haemonetics Cell Saver 5+ and manual density separation for optimum depletion of red blood cells and preservation of CD34+ cells in major ABO-incompatible bone marrow grafts.

BACKGROUND AIMS: The current approach for preventing hemolysis of red blood cells (RBCs) in major ABO-incompatible bone marrow (BM) grafts after infusion is to deplete RBCs from BM products before transplantation. Traditionally, manual density separation (MDS) using Ficoll-Hypaque (Cytiva Sweden AB, Uppsala, Sweden has been used to accomplish RBC depletion. This process yields good CD34+ cell recovery, but it requires open manipulation and is labor-intensive and time-consuming. We hypothesized that an alternative automated method using Haemonetics Cell Saver 5+ (Haemonetics Corporation, Boston, MA, USA) would offer equivalent RBC depletion and CD34+ cell recovery. Small marrow volumes from pediatric donors can be processed using Cell Saver (CS) without adding the third-party RBCs necessary for other automated methods. METHODS: This retrospective analysis comprised data from 58 allogeneic BM grafts. RBC depletion and CD34+ cell recovery from BM using MDS (35 grafts) were compared with CS (14 grafts). Nine products underwent RBC depletion using CS with Ficoll (CS-F) when RBC volume was less than 125 mL. RESULTS: Linear regression analysis of log transformation of CD34+ cell recovery adjusted for log transformation of both baseline CD34+ cell content and baseline total volume showed no significant difference between MDS and CS (estimated coefficient, -0.121, P = 0.096). All products contained an RBC volume of less than 0.25 mL/kg post-processing. CD34+ cell recovery with CS-F was comparable to MDS and CS and suitable for pediatric recipients of allogeneic hematopoietic cell transplantation. CONCLUSIONS: We provide evidence that an automated method using Haemonetics Cell Saver 5+ achieves RBC depletion and CD34+ cell recovery comparable to MDS when adjusting for baseline factors.

Performance of axial diameter on MR imaging for identification of retropharyngeal lymph node metastases in head and neck cancer: a systematic review and meta-analysis.

PURPOSE: To summarize previous studies' data and to calculate the diagnostic performance of minimum axial diameter (MIAD) and maximum axial diameter (MAAD) on each of the cutoff values in retropharyngeal lymph node (RPLNs) metastases in head and neck cancer. METHODS: MEDLINE, Scopus, and Embase databases were searched for systematic review. Meta-analysis was performed to summarize estimates of sensitivity, specificity, and diagnostic odds ratio (DOR) and generate summary recipient operator characteristic (sROC). RESULTS: The review identified 5 studies with a total of 634 patients (971 lesions) that were eligible for the meta-analysis. The estimated sensitivity, specificity, and DOR at MIAD 5 mm cutoff and MIAD 6 mm cutoff were 89.8% and 74.3%, 82.7% and 92.7%, and 39.1 and 57.9, respectively. The estimated sensitivity, specificity, and DOR at MAAD 7 mm cutoff and MAAD 8 mm cutoff were 90.3% and 84.7%, 62.7% and 79.9%, and 17.8 and 21.7, respectively. The AUCs of sROC at MIAD 5 mm cutoff and MIAD 6 mm cutoff were 0.922 and 0.943. At MAAD 7 mm and MAAD 8 mm, they were 0.840 and 0.888. CONCLUSION: The diagnostic performance of the MIAD 6 mm cutoff in RPLN metastases from head and neck cancer was 2% higher than the MIAD 5 mm cutoff. The diagnostic performance of MIAD was higher than that of MAAD.

Dynamic susceptibility contrast perfusion-weighted and diffusion-weighted magnetic resonance imaging findings in pilocytic astrocytoma and H3.3 and H3.1 variant diffuse midline glioma, H3K27-altered.

OBJECTIVE: This study compared the dynamic susceptibility contrast (DSC) magnetic resonance imaging parameters and apparent diffusion coefficient (ADC) between pilocytic astrocytoma (PA) and diffuse midline glioma, H3K27-altered (DMG) variants. METHODS: The normalized relative cerebral blood volume (nrCBV), normalized relative flow (nrCBF), percentile signal recovery (PSR), and normalized mean ADC (nADCmean) of 23 patients with midline PAs (median age, 13 years [range, 1-71 years]; 13 female patients) and 40 patients with DMG (8.5 years [1-35 years]; 19 female patients), including 35 patients with H3.3- and five patients with H3.1-mutant tumors, treated between January 2016 and May 2022 were statistically compared. RESULTS: DMG had a significantly lower nADCmean (median: 1.48 vs. 1.96; p = 0.00075) and lower PSR (0.97 vs. 1.23, p = 0.13) but higher nrCBV and nrCBF (1.66 vs. 1.17, p = 0.058, respectively, and 1.87 vs. 1.19, p = 0.028, respectively) than PA. The H3.3 variant had a lower nADCmean than the H3.1 variant (1.46 vs. 1.80, p = 0.10). CONCLUSION: DMG had lower ADC and PSR and higher rCBV and rCBF than PA. The H3.3 variant had a lower ADC than the H3.1 variant. Recognizing the differences and similarities in the DSC parameters and ADC between these tumors may help presurgical diagnosis.

Proof-of-concept and Randomized, Placebo-controlled Trials of an FcRn Inhibitor, Batoclimab, for Thyroid Eye Disease.

CONTEXT: Inhibition of the neonatal fragment crystallizable receptor (FcRn) reduces pathogenic thyrotropin receptor antibodies (TSH-R-Ab) that drive pathology in thyroid eye disease (TED). OBJECTIVE: We report the first clinical studies of an FcRn inhibitor, batoclimab, in TED. DESIGN: Proof-of-concept (POC) and randomized, double-blind placebo-controlled trials. SETTING: Multicenter. PARTICIPANTS: Patients with moderate-to-severe, active TED. INTERVENTION: In the POC trial, patients received weekly subcutaneous injections of batoclimab 680 mg for 2 weeks, followed by 340 mg for 4 weeks. In the double-blind trial, patients were randomized 2:2:1:2 to weekly batoclimab (680 mg, 340 mg, 255 mg) or placebo for 12 weeks. MAIN OUTCOME: Change from baseline in serum anti-TSH-R-Ab and total IgG (POC); 12-week proptosis response (randomized trial). RESULTS: The randomized trial was terminated because of an unanticipated increase in serum cholesterol; therefore, data from 65 of the planned 77 patients were analyzed. Both trials showed marked decreases in pathogenic anti-TSH-R-Ab and total IgG serum levels (P < .001) with batoclimab. In the randomized trial, there was no statistically significant difference with batoclimab vs placebo in proptosis response at 12 weeks, although significant differences were observed at several earlier timepoints. In addition, orbital muscle volume decreased (P < .03) at 12 weeks, whereas quality of life (appearance subscale) improved (P < .03) at 19 weeks in the 680-mg group. Batoclimab was generally well tolerated, with albumin reductions and increases in lipids that reversed upon discontinuation. CONCLUSIONS: These results provide insight into the efficacy and safety of batoclimab and support its further investigation as a potential therapy for TED.

Outcomes following intolerance to calcineurin inhibitor-based graft-versus-host disease prophylaxis in children after allogeneic hematopoietic cell transplantation.

Calcineurin inhibitors (CNI), cyclosporine and tacrolimus, are commonly used for pharmacologic prophylaxis of graft-versus-host disease after allogeneic hematopoietic cell transplantation (HCT). Unfortunately, their use is associated with significant toxicities. While intolerance to CNI is well defined, there is very little information on how they impact outcomes after HCT in children. Our retrospective study in a cohort of 82 children shows a high intolerance rate of 39% in this population associated with lower event-free survival and a higher transplant-related mortality.

The role of MRI in the prognosis of Wernicke's encephalopathy.

BACKGROUND AND PURPOSE: Wernicke's encephalopathy (WE) is a severe acute disorder related to thiamine deficiency. This study was aimed at revealing the relationship between clinical and imaging findings and WE recovery. METHODS: We retrospectively reviewed 34 cases of WE diagnosed between 2003 and 2020 (median age: 57 years, 14 females) at two academic institutions. WE cases were divided into two groups with symptomatic recovery within 4 weeks (group 1) or later (group 2). The lesion sites were divided into typical and atypical sites (total sites defined as when either typical or atypical sites were involved). Clinical and MRI features were compared between them as appropriate. RESULTS: WE patients were divided into group 1 (19 cases, median age: 57 years, 10 females) and group 2 (15 cases, median age: 57 years, four females). Regarding clinical features, only cerebellar ataxia was more often observed in group 1 than in group 2. Regarding MRI features, signal abnormality on T2-weighted image (WI)/fluid-attenuated inversion recovery (FLAIR) was more often observed in atypical sites between groups 1 and 2 (1/19 vs. 7/15; p = .01). There were significant differences between groups 1 and 2 regarding the presence of both vasogenic edema and cytotoxic edema in total sites (4/11 vs. 11/15, p = .005; 1/19 vs. 6/15, p = .03), with a significant difference in the presence of vasogenic edema in typical sites (4/19 vs. 10/15, p = .01). CONCLUSION: The early recovered group showed a lower incidence of T2WI/FLAIR abnormality in atypical sites and diffusion signal abnormality in total or typical sites with a lower incidence of cerebellar ataxia.

Dual-energy computed tomography for improved visualization of internal jugular chain neck lymph node metastasis and nodal necrosis in head and neck squamous cell carcinoma.

PURPOSE: To evaluate and compare the utility of 40-keV virtual monochromatic imaging (VMI) reconstructed from dual-energy computed tomography (DECT) in the assessment of neck lymph node metastasis with 70-keV VMI, which is reportedly equivalent to conventional 120-kVp single-energy computed tomography. MATERIALS AND METHODS: Patients with head and neck squamous cell carcinoma who had neck lymph node metastasis in contact with the sternocleidomastoid muscle (SCM) and underwent contrast-enhanced DECT were included. In 40- and 70-keV VMI, contrast differences and contrast noise ratio (CNR) between the solid component of neck lymph node metastasis (SC) and the SCM and between SC and nodal necrosis (NN) were calculated. Two board-certified radiologists independently and qualitatively evaluated the boundary discrimination between SC and SCM and the diagnostic certainty of NN. RESULTS: We evaluated 45 neck lymph node metastases. The contrast difference between SC and SCM and SC and NN were significantly higher at 40-keV VMI than at 70-keV VMI (p < 0.001). The CNR between SC and SCM was significantly higher at 40-keV VMI than at 70-keV VMI (p < 0.001). Scoring of the boundary discrimination between SC and SCM as well as the diagnostic certainty of NN at 40-keV VMI was significantly higher than that at 70-keV VMI (p < 0.001). The inter-rater agreements for these scores were higher at 40-keV VMI than at 70-keV VMI. CONCLUSION: Additional employing 40-keV VMI in routine clinical practice may be useful in the diagnosis of head and neck lymph node metastases and nodal necrosis.

MRI features of sinonasal tract angiofibroma/juvenile nasopharyngeal angiofibroma: Case series and systematic review.

BACKGROUND AND PURPOSE: To comprehensively summarize the radiological characteristics of sinonasal tract angiofibroma (STA) (commonly known as juvenile nasopharyngeal angiofibroma). METHODS: Forty-four lesions from 41 cases provided by 33 study articles identified through a systematic review and 13 lesions from 13 cases from our institution associated with patients with STA who underwent MRI were included in the review study, carried out by two board-certified experienced radiologists. RESULTS: The study participants were all male patients with a mean age of 15.6 years at the time of diagnosis. All of them presented with nasal cavity lesions (100%), predominantly in the nasopharynx (98.2%). The sphenopalatine foramen/pterygopalatine fossa was involved in 76.0%, and compressive shift of the posterolateral wall of the maxillary sinus was present in more than half (57.9%). T2-weighted imaging signal intensity was heterogeneous with mixed high and iso intensities as compared to skeletal muscle (100%). T1-weighted imaging showed partial high signal intensity in 61.1% of the cases. Flow void and intense enhancement were present in almost all cases. Cystic/nonenhancement changes on contrast-enhanced MRI were relatively common (40.8%). The mean apparent diffusion coefficient value (2.07 × 10-3  mm2 /second) and some quantitative dynamic contrast-enhanced MRI parameters were high. There was a significant difference in the frequency of residual/recurrent lesions based on the presence of MRI findings of skull base invasion (p = .017) and intracranial extension (p = .003). CONCLUSIONS: We summarized the MRI findings of STA that can facilitate timely diagnosis and appropriate management.