Clinical prediction model for primary aldosteronism subtyping and special focus on adrenal volumetric assessment.

PURPOSE: Our aim was to develop a prediction model based on a simple score with clinical, laboratory, and imaging findings for the subtype diagnosis of primary aldosteronism (PA). The contribution of adrenal volumetric assessment to PA subtyping was also investigated. METHODS: Thirty-five patients with adequate cannulation in adrenal venous sampling (AVS) were included. Laboratory data, the saline infusion test (SIT), and the AVS results of patients with PA were retrospectively evaluated. Volumetric assessment was performed using magnetic resonance imaging (MRI) and the ratio of adrenal volumes was calculated after adjusting for gender- and side-specific mean reference values of both adrenal glands. RESULTS: The AVS was consistent with unilateral PA in 49% and bilateral in 51% of the patients. Hypertension as a reason for work-up, the highest aldosterone/lowest potassium value higher than 12, the percentage of plasma aldosterone concentration (PAC) reduction after SIT by equal or less than 43.5%, the use of oral potassium replacement, unilateral disease at pre-AVS imaging, and a ratio of adjusted adrenal volumes equal to or below 1.7 were indicative of unilateral disease in univariate logistic regression analysis concerning the distinction of PA subtyping (p < 0.05). Multivariate logistic regression analysis also revealed that adrenal volumetric assessment has an impact on PA subtyping (p < 0.05). In the prediction model, when each of the six parameters that were significant in the univariate logistic regression analysis was assigned one point, < 4 predicted bilateral PA, whereas ≥ 4 predicted unilateral PA (AUC:0.92, p < 0.001). CONCLUSION: This prediction model before AVS may serve as a convenient and practical approach, while an adjusted adrenal volumetric assessment can make a positive contribution to PA subtyping.

Comparative evaluation of brain perfusion with ASL and DSC MRI following intracranial vascular flow diverter stent replacement.

PURPOSE: The objective of this study was to asses brain perfusion parameters and ischemic changes following treatment of aneurysm with flow diverters with two different perfusion MRI technique (Arterial spin labeling and DSC MRI), and to compare the results and effectiveness of these two methods. METHODS: The prospective data was collected from patients with aneurysm who treated with flow diverters. MR examinations, including diffusion-weighted imaging (DWI), ASL, and DSC perfusion MRI, were conducted before and after treatment within the first week and at 6 months. Perfusion parameters of territory area and contralateral side were measured and analyzed by statistically. The relationships between ASL and DSC parameters were analyzed by using Sperman's correlation analysis. RESULTS: A total of 14 cases of aneurysms in 11 patients treated successfully with endovascular flow diverter stent placement. Pretreatment and post treatment (within first week and 6 months) MRI images were evaluated. Asymptomatic randomly distributed millimetric restricted diffusion foci were observed in 8 of all patients. There was no statistically difference between pre and post treatment perfusion parameters (p > 0.05). A statistically significant correlation was found between variable ASL CBF, and the variables of DSC CBF and TTP. CONCLUSIONS: Notwithstanding the fact that flow diverters change flow dynamics in aneurysm sac, there is no any perfusion abnormality in the territory area. Asymptomatic randomly distributed diffusion restricted foci in the both cerebral hemisphere can be observed. ASL and DSC MRI are effective for evaluation of brain perfusion.

Spontaneous improvement in syringomyelia in a patient with Chiari 1 malformation: illustrative case.

BACKGROUND: "Chiari malformation" refers to a spectrum of hindbrain abnormalities characterized by impaired cerebrospinal fluid circulation through the foramen magnum. Syringomyelia is frequently found in patients with Chiari malformation type 1. Although many theories have suggested how cerebrospinal fluid enters and makes the cystic cavity in the spinal cord, the pathogenesis of syringomyelia remains controversial. This report documents a case with spontaneous resolution of syringomyelia followed up by 3-year serial magnetic resonance imaging (MRI). These kinds of cases support a more conservative approach. OBSERVATIONS: A 59-year-old female presented to the authors' clinic in June 2019 with a history of Chiari malformation type 1. This symptomatic patient has been followed up with serial MRI. When the last MRI was performed in August 2022, compared with previous imaging, resolution of the syringomyelia was recognized. LESSONS: Because the natural evolution of mildly symptomatic/asymptomatic patients with syringes is unclear, these patients pose a treatment dilemma. Although surgical intervention is a widely accepted therapeutic method, a more conservative approach can be considered in cases with spontaneous resolution. Especially for patients without progressive symptoms, the surgical approach should not be considered as the first step. In view of relapses, follow-up with periodic neurological examinations and radiological imaging is preferrable.

Volumetric Assessment of Hippocampus and Subcortical Gray Matter Regions in Alzheimer Disease and Amnestic Mild Cognitive Impairment.

BACKGROUND: Quantitative MRI assessment methods have limited utility due to a lack of standardized methods and measures for Alzheimer disease (AD) and amnestic mild cognitive impairment (aMCI). OBJECTIVE: To employ a relatively new and easy-to-use quantitative assessment method to reveal volumetric changes in subcortical gray matter (GM) regions, hippocampus, and global intracranial structures as well as the diagnostic performance and best thresholds of total hippocampal volumetry in individuals with AD and those with aMCI. METHOD: A total of 74 individuals-37 with mild to moderate AD, 19 with aMCI, and 18 with normal cognition (NC)-underwent a 3T MRI. Fully automated segmentation and volumetric measurements were performed. RESULTS: The AD and aMCI groups had smaller volumes of amygdala, nucleus accumbens, and hippocampus compared with the NC group. These same two groups had significantly smaller total white matter volume than the NC group. The AD group had smaller total GM volume compared with the aMCI and NC groups. The thalamus in the AD group showed a subtle atrophy. There were no significant volumetric differences in the caudate nucleus, putamen, or globus pallidus between the groups. CONCLUSION: The amygdala and nucleus accumbens showed atrophy comparable to the hippocampal atrophy in both the AD and aMCI groups, which may contribute to cognitive impairment. Hippocampal volumetry is a reliable tool for differentiating between AD and NC groups but has substantially less power in differentiating between AD and aMCI groups. The loss of total GM volume differentiates AD from aMCI and NC.

Treatment with biologic DMARDs may not adversely affect lung nodules in rheumatoid arthritis patients.

OBJECTIVE: Lung nodules (LNs) impose diagnostic and therapeutic challenges in patients with rheuma- toid arthritis (RA) due to unpredictable outcomes. Potential induction of nodulosis with the use of con- ventional synthetic DMARDs (csDMARD) and lack of knowledge regarding the effect of biologic disease-modifying anti-rheumatic drugs (bDMARDs)/tofacitinib on the LN raise concerns and have an impact on treatment decisions. This study aims to evaluate the possible effects of the bDMARDs/tofa- citinib and csDMARDS on LNs observed in RA patients. METHODS: Electronic health records of RA patients who had LNs detected on computed tomography (CT) between January 2015 and December 2020 were evaluated retrospectively. Patients with follow- up CT images were included in the study. Baseline and follow-up images were meticulously examined for the number, size, attenuation, and cavity formation. Clinical, histopathologic, and laboratory find- ings were analyzed. RESULTS: Forty-two RA patients with LNs were studied, 21 were on bDMARDs/tofacitinib (11 females, mean age: 59.7 6 8.4) and 21 were on csDMARDs (12 females, mean age: 71.4 6 8.3). The proportion of patients with progressed nodules during follow-up was comparable between groups (six patients in bDMARDs/tofacitinib vs seven patients in csDMARDs). Progression of LNs was observed in six patients in the bDMARDs/tofacitinib group: three in anti-TNFa, two in rituximab, and one in abatacept users and none in tofacitinib users. CONCLUSION: Our results suggest that the risk of progression in LNs in RA patients with use of bDMARDs/tofacitinib might not impose a higher risk compared to csDMARDs. Moreover, bDMARDs/ tofacitinib might result in regression in LNs.

Prediction of IDH Mutation Status in High-grade Gliomas Using DWI and High T1-weight DSC-MRI.

RATIONALE AND OBJECTIVES: We aimed to evaluate the diagnostic performance of diffusion-weighted imaging (DWI) and dynamic susceptibility contrast-enhanced (DSC) magnetic resonance imaging (MRI) parameters in the noninvasive prediction of the isocitrate dehydrogenase (IDH) mutation status in high-grade gliomas (HGGs). MATERIALS AND METHODS: A total of 58 patients with histopathologically proved HGGs were included in this retrospective study. All patients underwent multiparametric MRI on 3-T, including DSC-MRI and DWI before surgery. The mean apparent diffusion coefficient (ADC), relative maximum cerebral blood volume (rCBV), and percentage signal recovery (PSR) of the tumor core were measured and compared depending on the IDH mutation status and tumor grade. The Mann-Whitney U test was used to detect statistically significant differences in parameters between IDH-mutant-type (IDH-m-type) and IDH-wild-type (IDH-w-type) HGGs. Receiver operating characteristic curve (ROC) analysis was performed to evaluate the diagnostic performance. RESULTS: The rCBV was significantly higher, and the PSR value was significantly lower in IDH-w-type tumors than in the IDH-m group (p = 0.002 and <0.001, respectively).The ADC value in IDH-w-type tumors was significantly lower compared with the one in IDH-m types (p = 0.023), but remarkable overlaps were found between the groups. The PSR showed the best diagnostic performance with an AUC of 0.938 and with an accuracy rate of 0.87 at the optimal cutoff value of 86.85. The combination of the PSR and the rCBV for the identification of the IDH mutation status increased the discrimination ability at the AUC level of 0.955. In terms of each tumor grade, the PSR and rCBV showed significant differences between the IDH-m and IDH-w groups (p ≤0.001). CONCLUSION: The rCBV and PSR from DSC-MRI may be feasible noninvasive imaging parameters for predicting the IDH mutation status in HGGs. The standardization of the imaging protocol is indispensable to the utility of DSC perfusion MRI in wider clinical usage.

Comparison of diagnostic performances in the evaluation of breast microcalcifications: synthetic mammography versus full-field digital mammography.

BACKGROUND: Although several studies proved that SM could substitute for FFDM, the efficacy of SM in microcalcification evaluation remains controversial. AIMS: To investigate the diagnostic performance of synthetic mammography (SM) in the evaluation of microcalcifications in comparison with full-field digital mammography (FFDM). METHODS: In this retrospective study, 76 mammograms of 76 patients who underwent FFDM and digital breast tomosynthesis (DBT) acquisitions concomitantly between 2018 and 2019 and whose final mammography interpretation revealed microcalcifications (28 malignant microcalcifications and 48 benign microcalcifications) were included. All mammograms were reviewed independently by three radiologists with different levels of breast imaging experience. Readers were blinded to patient outcomes and interpreted each case in two separate reading sessions (first FFDM, second SM + DBT), according to the BI-RADS lexicon. The area under the receiver operating characteristic (ROC) curve (AUC) was calculated using ROC analysis in all cases for FFDM and SM + DBT sessions. The readers also assigned conspicuity scores to mammograms. The interobserver agreement was calculated using intraclass correlation coefficients (ICC). RESULTS: The overall AUCs for malignant microcalcifications were 0.80 (95% CI: 0.75-0.85) in FFDM and 0.85 (95% CI: 0.80-0.89) in SM, and no significant difference was found between the groups (p = 0.0603). The sensitivity of the readers increased slightly with experience. The ICC values of BI-RADS categorization between readers were 0.93 (95% CI: 0.90-0.95) and 0.94 (95% CI: 0.91-0.96) for FFDM and SM, respectively. CONCLUSIONS: SM had similar diagnostic performance in the evaluation of breast microcalcifications in comparison with FFDM, regardless of reader experience levels.

Do We Need Intraoperative Magnetic Resonance Imaging in All Endoscopic Endonasal Pituitary Adenoma Surgery Cases? A Retrospective Study.

There are previous reports investigating effectiveness of intraoperative magnetic resonance imaging (IO-MRI) in pituitary adenoma surgery but there is no clear data in the literature recommending when there is no need of intraoperative scan. This retrospective analysis was based on determining which patients does not need any IO-MRI scan following endoscopic endonasal pituitary adenoma surgery. Patients with functional or non-functional pituitary adenomas that were operated via endoscopic endonasal approach (EEA) between June 2017 and May 2019 were enrolled. Patients younger than 18 years old, patients who did not underwent IO-MRI procedure or not operated via EEA were excluded from the study. Hence, this study is designed to clarify if IO-MRI is useful in both functional and non-functional pituitary adenomas, functional adenomas did not split into subgroups. A total of 200 patients treated with pituitary adenoma were included. In Knosp Grade 0 - 2 group, primary surgeon's opinion and IO-MRI findings were compatible in 150 patients (98.6%). In Knosp Grade 3 - 4 correct prediction were performed in 32 (66.6%) patients. When incorrectly predicted Knosp Grade 3 - 4 patients (n = 16) was analyzed, in 13 patients there were still residual tumor in cavernous sinus and in 3 patients there were no residual tumor. Fisher's exact test showed there is a statistically significant difference of correct prediction between two different Knosp Grade groups (two-tailed P < 0.0001). Eighteen patients had a residual tumor extending to the suprasellar and parasellar regions which second most common site for residual tumor. Our findings demonstrate that there is no need of IO-MRI scan while operating adenomas limited in the sellae and not invading the cavernous sinus. However, we strongly recommend IO-MRI if there is any suprasellar and parasellar extension and/or cavernous sinus invasion.

Prevalence and associated risk factors of coronary artery disease in patients with a zero coronary calcium score.

PURPOSE: A zero coronary calcium score (CCS) is not able to provide a definite exclusion for coronary artery disease (CAD). The goal of this study was to determine the prevalence and associated cardiovascular risk factors of CAD in patients with zero CCS. METHODS: Six hundred thirteen patients with zero CCS referred to coronary calcium score analysis (CCSA) and coronary computed tomography angiography (CCTA) with suspicion of CAD were included. The descriptive, univariate, and multivariate analyses were used to determine the prevalence and predictors of CAD presence. RESULTS: Among 613 patients, 17 patients (2.7%) have NCCP, and obstructive CAD was found in 3 patients (0.48%). Multivariate analysis revealed that male gender and older age (≥50 years) were significantly associated with the presence of noncalcified coronary plaques (NCCP) (p < 0.05). The receiver operating characteristic (ROC) curve analysis showed that the male gender and older age (≥50 years) model had 70.6% sensitivity and 84.2% specificity for predicting NCCP. CONCLUSION: A non-negligible portion of patients with zero CCS had CAD. Male gender and older age (≥50 years) were independently associated with NCCP. Due to the high specificity value (84.2%) and negative predictive value (99.0%) of the male gender and older age (≥50 years) model, selective use of CCTA is recommended in <50 years old female patients to avoid unnecessary radiation exposure.

Evaluation of common carotid artery in type 1 diabetes mellitus patients through speckle tracking carotid strain ultrasonography.

PURPOSE: We aimed to evaluate the effectiveness of speckle tracking carotid strain (STCS) technique, which enables measurement of arterial stiffness and strain parameters, in the detection of early atherosclerotic findings in type 1 diabetes mellitus (T1DM). METHODS: We prospectively enrolled 30 T1DM patients and 30 age- and sex-matched control participants with no history of cardiovascular disease. All study population underwent carotid ultrasonography. Radial and circumferential movement of the common carotid artery (CCA) in the transverse plane as the well as the radial movement of the CCA in the longitudinal plane were calculated automatically by using the STCS method. In addition, the strain (%), strain rate (per second), and peak circumferential and radial displacements (mm) were calculated. Arterial stiffness parameters, such as elastic modulus, distensibility, arterial compliance, and ß-stiffness index, were calculated using the radial measurements. The mean value of the carotid intima media thickness (CIMT) was calculated semi-automatically for each CCA, in the longitudinal plane. We also analyzed the patients' overall body composition. RESULTS: T1DM and control groups were compared in terms of strain and stiffness parameters and no statistically significant difference was found (p > 0.05). CIMT was higher in diabetic patients than in the control group (p = 0.039). In both groups, age was correlated with all arterial stiffness and strain parameters (p < 0.05). The duration of diabetes was also correlated with ß-stiffness index, distensibility, and elastic modulus in the longitudinal plane (p < 0.05). In the diabetic group, abdominal fat ratio, whole body fat ratio, and fat mass were correlated with radial and circumferential displacement and strain parameters in transverse plane, and radial displacement in longitudinal plane (p < 0.05, for each). Diabetic patients were divided into subgroups according to the presence of nephropathy and dyslipidemia. Although no significant difference was found between the groups in terms of CIMT, patients with nephropathy had higher values for transverse and longitudinal elastic modulus, pulse-wave velocity, and longitudinal ß-stiffness index, as well as lower values for longitudinal arterial compliance and distensibility, compared with patients without nephropathy (p < 0.05). Also, patients with dyslipidemia had higher longitudinal ß-stiffness and elastic modulus values compared with patients without dyslipidemia (p < 0.05). CONCLUSION: STCS ultrasonography is an effective, easy, and noninvasive method for evaluating the arterial elasticity. It may provide an early assessment of atherosclerosis in patients with T1DM, especially in the presence of nephropathy and dyslipidemia; thus, together with CIMT measurement, it may be used more frequently to detect subclinical damage and stratify atherosclerosis.

Added Value of CT Pelvic Bone Unfolding Software to Radiologist Performance in Detecting Osteoblastic Pelvic Bone Lesions in Patients With Prostate Cancer.

PURPOSE: To evaluate the contribution of CT Bone Unfolding software to the diagnostic accuracy and efficiency for the detection of osteoblastic pelvic bone lesions in patients with prostate cancer. METHODS: A total of 102 consecutive (January 2016-September 2019) patients who underwent abdominopelvic CT with prostate cancer were retrospectively evaluated for osteoblastic pelvic bone lesions, using commercially available the post-processing-pelvic bone flattening-image software package "CT Bone Unfolding." Two radiologists with 3 and 15 years of experience in abdominal radiology evaluated CT image data sets independently in 2 separate reading sessions. At the first session, only MPR images and at the second session MPR images and additionally unfolded reconstructions were assessed. Reading time for each patient was noted. A radiologist with 25 years of experience, established the standard of reference. RESULTS: In the evaluations performed with the MPR-Unfold method, the diagnostic accuracy were found to be 2.067 times higher compared to the MPRs method (P < 0.001). The location of the lesions or the reader variabilities did not show any influence on accuracy (P > 0.05) For all readers the reading time for MPR was significantly longer than for MPR-Unfold (P < 0.05). For both methods substantial to almost-perfect inter-reader agreement was found (0.686-0.936). CONCLUSIONS: The use of unfolded pelvic bone reconstructions increases diagnostic accuracy while decreasing the reading times in the evaluation of pelvic bone lesions. Therefore, our findings suggest that utilizing unfolded reconstructions in addition to MPR images may be preferable in patients with prostate cancer for the screening of osteoblastic pelvic bone lesions.

Accuracy in tumor size measurements: Comparison of digital mammography, digital breast tomosynthesis and synthetic mammography.

PURPOSE: The aim of this study was to assess the accuracy of digital mammography (DM), digital breast tomosynthesis (DBT) and synthetic mammography (SM) in tumor size measurements compared with histological tumor sizes. MATERIALS AND METHODS: 71 breast cancer patients who underwent DM and DBT acquisitions simultaneously were included in this study. One radiologist with 8 years of experience in breast imaging measured tumor sizes independently in three separate sessions which include DM, DBT and SM images, respectively. The correlations between the measured tumor sizes on each imaging technique and histological sizes were analyzed using Spearman correlation test. The patients were categorized into two subgroups according to assigned breast density categories (dense and non-dense), and histological tumor sizes (≤2 cm and > 2 cm). To assess the agreement levels between the measured tumor sizes and histological sizes Bland-Altman analyses were performed for each imaging technique. RESULTS: The mean of histological size of tumors was 23.85 ±â€¯16.57 mm (median: 20). The means of measured tumor sizes were 21.21 ±â€¯13.59 mm (median: 19), 21.52 ±â€¯13.42 mm (median: 19) and 18.97 ±â€¯11.21 mm (median: 17) in DM, DBT and SM, respectively. The Spearman correlation values with histologic sizes were 0.814 (P < 0.001), 0.887 (P < 0.001), and 0.852 (P < 0.001) for DM, DBT and SM, respectively. In subgroup analyses, the correlation values showed decrement for tumors >2 cm in size compared to tumors ≤2 cm in size. CONCLUSION: DBT provides the most accurate tumor size measurements among mammographic imaging techniques and if mammography will be used in tumor size measurements, DBT should be preferred.

Validation of combined use of DWI and percentage signal recovery-optimized protocol of DSC-MRI in differentiation of high-grade glioma, metastasis, and lymphoma.

PURPOSE: With conventional MRI, it is often difficult to effectively differentiate between contrast-enhancing brain tumors, including primary central nervous system lymphoma (PCNSL), high-grade glioma (HGG), and metastasis. This study aimed to assess the discrimination ability of the parameters obtained from DWI and the percentage signal recovery- (PSR-) optimized protocol of DSC-MRI between these three tumor types at an initial step. METHODS: DSC-MRI using a PSR-optimized protocol (TR/TE = 1500/30 ms, flip angle = 90°, no preload) and DWI of 99 solitary enhancing tumors (60 HGGs, 24 metastases, 15 PCNSLs) were retrospectively assessed before treatment. rCBV, PSR, ADC in the tumor core and rCBV, and ADC in peritumoral edema were measured. The differences were evaluated using one-way ANOVA, and the diagnostic performance was evaluated using ROC curve analysis. RESULTS: PSR in the tumor core showed the best discriminating performance in differentiating these three tumor types with AUC values of 0.979 for PCNSL vs. others and 0.947 for HGG vs. metastasis. The ADC was only helpful in the tumor core and distinguishing PCNSLs from others (AUC = 0.897). CONCLUSION: Different from CBV-optimized protocols (preload, intermediate FA), PSR derived from the PSR-optimized protocol seems to be the most important parameter in the differentiation of HGGs, metastases, and PCNSLs at initial diagnosis. This property makes PSR remarkable and carries the need for comprehensive DSC-MRI protocols, which provides PSR sensitivity and CBV accuracy together, such as the preload use of the PSR-optimized protocol before the CBV-optimized protocol.

The Role of 18F-FDG PET/MRI in the Assessment of Primary Intrahepatic Neoplasms.

RATIONALE AND OBJECTIVES: To evaluate the results of 18F-FDG PET/MRI in relation to the histopathologic subtypes and histologic grades of mass-forming primary intrahepatic neoplasms. MATERIALS AND METHODS: We retrospectively evaluated 18F-FDG positron emission tomography/magnetic resonance imaging (PET/MRI) results for 39 patients with histopathologically confirmed primary hepatic neoplasms, 15 with mass-forming intrahepatic cholangiocarcinoma (ICC) and 24 with hepatocellular carcinoma (HCC). The apparent diffusion coefficient (ADC) and standardized uptake value (SUV) were analyzed in relation to the histopathologic diagnosis and histologic grade, including calculating the sensitivity and specificity of the imaging findings. RESULTS: The median SUV of ICC (6.0 [interquartile range, 5-10]) was significantly higher than that of HCC (4.0 [2.62-6.50]) (p = 0.002). An area under the curve (AUC) of 0.79 (95% confidence interval 0.649-0.932) had a sensitivity of 86.7% and a specificity of 67% at the best cut-off SUV of 4.41 to differentiate between ICC and HCC. ADC values did not differ significantly between HCCs and ICCs (p = 0.283). Both SUV and ADC values differed significantly between low-grade (well- and moderately differentiated) and high-grade (poorly differentiated) HCCs. Combining ADC and SUV further improved differentiation of low- from high-grade HCCs to a significant level (0.929). The SUV did not differ significantly between ICC histologic grades (p = 0.280), while the ADC differed significantly only between well and poorly differentiated ICCs (p = 0.004). CONCLUSION: Assessing primary hepatic neoplasms with 18F-Fluorodeoxyglucose PET/MRI may help to predict tumor grade and differentiate between types of intrahepatic neoplasms.

Intraoperative Magnetic Resonance Imaging Assisted Endoscopic Endonasal Resection of Clival Chordomas.

BACKGROUND: Cranial base chordomas are typically indolent and usually appear as encapsulated tumors. They slowly grow by infiltrating the bone, along with the lines of least resistance. Due to its relationship with important neurovascular structures, skull base chordoma surgery is challenging. OBJECTIVE: The usefulness of intraoperative magnetic resonance imaging (IO-MRI) in achieving the goal of surgery, is evaluated in this study. METHODS: Between March 2018 and March 2020, 42 patients were operated on for resection of skull base chordomas in our institution. All of them were operated on under IO-MRI. Patients were analyzed retrospectively for identifying common residue locations, complications and early post-operative outcomes. RESULTS: In 22 patients (52,4%) gross total resection was achieved according to the final IO-MRI. In 20 patients (47,6%) complete tumor removal was not possible because of extension to the petrous bone (8 patients), pontocerebellar angle (6 patients), prepontine cistern (4 patients), temporobasal (1 patient), cervical axis (1 patient). In 13 patients, the surgery was continued after the first IO-MRI control was performed, which showed a resectable residual tumor. 7 of these patients achieved total resection according to the second IO-MRI, in the other 6 patients all efforts were made to ensure maximal resection of the tumor as much as possible without morbidity. Repeated IO-MRI helped achieve gross total resection in 7 patients (53.8%). CONCLUSIONS: Our study proves that the use of IO-MRI is a safe method that provides the opportunity to show the degree of resection in skull base chordomas and to evaluate the volume and location of the residual tumor intraoperatively. Hence IO-MRI can improve the life expectancy of patients because it provides an opportunity for both gross total resection and maximal safe resection in cases where total resection is not possible.

The utility of shear wave elastography in the evaluation of muscle stiffness in patients with cerebral palsy after botulinum toxin A injection.

PURPOSE: The first aim of this study was to evaluate changes in the stiffness of the medial gastrocnemius muscle (GM) after a botulinum toxin A (BoNT-A) injection in children with cerebral palsy (CP) using shear wave elastography (SWE). We also wanted to investigate the usability of SWE for evaluating spasticity in a clinical setting. The second aim of this study was to show how treatment of the gastrocnemius muscle spasticity caused a change in the elasticity of the anterior tibial (TA) muscle. METHODS: Twenty-four pediatric patients diagnosed with a spastic type of CP, who were scheduled to receive a BoNT-A injection in the gastrocnemius muscle, were included in the study. There was a total of 43 lower extremities to evaluate, and muscle stiffness was measured before the injection and a month post injection using SWE. The physiatrist evaluated muscle spasticity using the Modified Ashworth Scale (MAS) and the Modified Tardieu Scale at about the same time. RESULTS: SWE values of the GM (pre-BoNT-A: 45.9 ± 6.5 kPa, post-BoNT-A: 25.0 ± 5.7 kPa) decreased significantly post BoNT-A injection (P < 0.01). SWE measurements of the GM had positive correlations with MAS, V1X, V3X, and R2-R1 (P < 0.01); and negative correlations with R2 and R1 (P < 0.05). SWE values of the TA muscle (pre: 36.9 ± 7.9 kPa, post: 28.4 ± 5.2 kPa) decreased significantly (P < 0.01). CONCLUSION: Quantitative measurement of muscle stiffness using SWE may provide important information for the evaluation of spasticity and treatment efficiency in pediatric CP patients.

Evaluation of effects of aging on skeletal muscle elasticity using shear wave elastography.

PURPOSE: To evaluate the effects of aging on skeletal muscle stiffness in relaxed and contracted status using shear wave elastography (SWE). MATERIALS AND METHODS: A total of 57 participants were enrolled to this institutional review board approved prospective study. Medial head of the gastrocnemius muscle (GM) of all participants were examined bilaterally by a single radiologist in prone position. Muscle thickness, stiffness values in both relaxed and contracted status were measured. Stiffness increase rate (SIR) was calculated for all muscles. The Spearman's correlation test was used for correlation analyses. Mann-Whitney U test was used to compare subgroups. RESULTS: The mean age of the participants was 41.15 ±â€¯16.19 (range, 18-74). The means of stiffness values of medial head of GM were 12.51 ±â€¯2.56 kPa and 81.74 ±â€¯15.77 kPa in relaxed and contracted status, respectively. The mean of SIR values was 5.62 ±â€¯1.05 (range, 3.18-8.66). The stiffness values of relaxed and contracted medial head of GM had moderate to strong inverse correlations with age for both dominant and non-dominant extremities (r range: -0.703 to -0.590). Age subgroup analyses revealed significant differences in muscle thickness and stiffness values, whereas no significant difference was found in SIR values. CONCLUSION: In conclusion, despite the decrease in stiffness of skeletal muscle with advancing age, SIR remained similar. Any improvement in stiffness values of skeletal muscle in relaxed status may play pivotal role in the management of sarcopenia.

Quantification of liver fat content with ultrasonographic attenuation measurement function: Correlation with unenhanced multidimensional computerized tomography.

PURPOSE: To evaluate the efficacy of attenuation measurement function (ATT), a newly developed quantitative ultrasonography(US) method based on measurement of the attenuation coefficient, using unenhanced computerized tomography(CT) attenuation values as a reference standard, for the detection and measurement of hepatosteatosis. MATERIAL AND METHODS: A total of 98 patients were analyzed. The diagnostic ability of ATT was evaluated using receiver operating characteristic (ROC) curve analysis, and the correlation between liver attenuation index (LAI), the liver-to-spleen attenuation ratio (CTL/S), liver attenuation value (CTL), and ATT was determined. RESULTS: ATT is negatively correlated with LAI (r = -0.571, p < 0.001), CTL/S (r = -0.532, p < 0.001), and mean CTL (r = -0.50, p < 0.001). A significant difference was found between ATT values of patients with different grades of hepatosteatosis (p < 0.001). A significant difference was found between ATT values of patients with LAI < -10 and LAI > -10, CTL < 40 and CTL > 40, and CTL/S < 1 and CTL/S > 1 (p < 0.001). An ATT ≥ 0.665 showed a sensitivity of 100% and a specificity of 90% in diagnosing moderate-severe steatosis. The corresponding area under the ROC curve(AUROC) was 0.935. The intraclass correlation coefficient for the interobserver variability of ATT was 0.907 (95% CI, 0.85-0.95). CONCLUSION: In conclusion, ATT values for evaluation of hepatosteatosis was closely correlated with the degree of hepatosteatosis and liver fat content. It can be used as a noninvasive method in the diagnosis and follow-up.