Investigation of the effects of Gamma Knife radiosurgery on optic pathways using diffusion tensor MRI within the first year after treatment.

PURPOSE: To investigate the radiation-induced effects of Gamma Knife radiosurgery (GKRS) for sellar-parasellar tumors on optic pathways using DTI parameters within the first year after treatment. METHODS: Twenty-five patients with sellar-parasellar tumors underwent MRI before and 3 months after GKRS, including T1WI, DTI, T2WI. Moreover, 21 patients underwent follow-up DTI 6-8 months after radiosurgery. ROIs were set on optic nerves, optic radiations, and control localizations; DTI parameters for each were calculated. Pre- and post-radiosurgery differences in DTI values were statistically compared and assessed with respect to tumor size changes. RESULTS: Following GKRS, DTI parameters, notably ADC, FA, and RD, showed statistically significant changes in optic nerves and anterior optic radiations. DTI changes were more significant in the group of cases with tumor shrinkage. In this group, DTI of the anterior optic radiations further deteriorated 3 months post-GKRS, whereas acute changes in DTI parameters of the optic nerves resolved within 6-8 months. DTI of central and posterior optic radiations did not differ significantly following radiosurgery; 6-8 months after radiosurgery, visual function was stable in 14 (56%) patients and improved in 11 (44%), showing no correlation with tumor size changes or DTI parameters. CONCLUSION: White Matter (WM) injury in the optic pathways can be induced by Gamma Knife radiosurgery targeted to sellar and parasellar tumors. Following GKRS, microstructural abnormalities occurred in the optic radiations as well as the optic nerves within the first post-treatment year. Our findings could support modifications to radiosurgical treatment strategies to minimize the risk of permanent WM injury.

A comprehensive MRI analysis of osteoid osteomas in patients with diverse radiological features across various regions.

BACKGROUND: Magnetic resonance imaging (MRI), which does not involve ionizing radiation, is the preferred imaging modality for diagnosing osteoid osteoma (OO), an ailment more common in children and young adults. PURPOSE: This study aims to perform a literature review and delineate the MRI findings of OO lesions in patients exhibiting varying radiological features across different regions. MATERIALS AND METHODS: A retrospective study included 63 patients diagnosed with OO through MRI, assessed independently by two blinded radiologists using both standard and dynamic contrast-enhanced MRI techniques. After excluding 7 patients with prior biopsy, surgery, or RFA, the study included 56 patients with 57 lesions. RESULTS: Of 57 lesions evaluated, 50 were in long, and 7 in flat bones. One patient presented with two separate nidi within the intertrochanteric region. Most of the lesions, 49 (86%), were extra-articular, while 8 (14%) were intra-articular. The nidus was intracortical in 45 (78.9%) patients, intramedullary in 5 (8.8%), subperiosteal in 5 (8.8%), and endosteal in 2 (3.5%). Average nidus diameter was 7.02 ± 2.64 mm (3-12.6 mm). Central nidal calcification was present in 68.4% (n = 39) cases. Contrast enhancement was intense at 90.5%, moderate at 9.5%. Reactive sclerosis around the nidus was severe (50.9%), moderate (22.8%), and mild (26.3%). Bone marrow edema was severe (70.2%), moderate (14.0%), and mild (15.8%). Soft tissue edema was identified in 77.2% of all lesions. CONCLUSION: To minimize delays in diagnosis and treatment, radiologists should become acquainted with the typical OO MRI findings and the atypical MRI findings that might be mistaken for other conditions.

Assessment of lacrimal gland involvement in primary Sjögren's syndrome using gray-scale ultrasonography and shear wave elastography.

OBJECTIVES: The aim of this study was to assess lacrimal gland involvement in primary Sjögren's syndrome (pSS) using lacrimal gland gray-scale ultrasound (LGUS) and two-dimensional shear wave elastography (2D-SWE). METHODS: Eighty-five pSS patients with a mean age of 51.16 ± 10.61 years and 84 sex- and age-matched healthy subjects with a mean age of 50.94 ± 11.05 years were included in the study. Lacrimal gland parenchymal findings and 2D-SWE values were compared between the two groups and the correlations of LGUS parameters with clinical findings, dry eye tests, and minor salivary gland biopsy (MSGB) were further investigated. RESULTS: LGUS parenchymal grade was 0 in 14 (16.5%), 1 in 45 (52.9%), 2 in 23 (27.1%), and 3 in 3 patients (3.5%) in the pSS group, while in the control group, parenchymal grades were 0 (57.1%) and 1 (42.9%). The mean 2D-SWE value of pSS patients was significantly higher than the control group (p < 0.05) and increased parallel with lacrimal parenchymal grade. The elasticity modulus had a high diagnostic performance in detecting lacrimal gland involvement in pSS patients (AUC 0.901, sensitivity 70.6%, specificity 97.6%), while the diagnostic performance of LGUS was much lower (AUC 0.769, sensitivity 83.5%, specificity 57.1%). LGUS and 2D-SWE values were found to be correlated with dry eye tests and MSGB results (p < 0.05). CONCLUSIONS: LGUS and 2D-SWE are both useful for assessing the lacrimal gland involvement in pSS patients; however, 2D-SWE has a better diagnostic performance than LGUS and found to be correlated with dry eye tests. CLINICAL RELEVANCE STATEMENT: Lacrimal gland US and two-dimensional shear wave elastography (2D-SWE) are imaging modalities that can be used to demonstrate parenchymal involvement of the lacrimal gland in primary Sjögren's syndrome (pSS). KEY POINTS: • Gray-scale US and two-dimensional shear wave elastography (2D-SWE) have been widely used in the recent decade to assess gland involvement in patients with primary Sjögren's syndrome (pSS). • The elasticity modulus had a high diagnostic performance in detecting lacrimal gland involvement in primary Sjögren's syndrome (pSS) patients. • Lacrimal gland US and two-dimensional shear wave elastography (2D-SWE) are both useful for assessing the lacrimal gland in primary Sjögren's syndrome (pSS) patients; however, two-dimensional shear wave elastography (2D-SWE) has a better diagnostic performance than lacrimal gland ultrasound (LGUS).

Diagnostic performance of gray-scale ultrasound and shear wave elastography in assessing salivary gland involvement in patients with primary Sjögren's syndrome.

PURPOSE: To investigate the diagnostic performance of gray-scale ultrasound (US) and shear wave elastography (SWE) for determining salivary gland involvement primary Sjögren's syndrome (pSS). METHODS: In this prospective study, the salivary glands of 72 healthy volunteers and 74 participants with pSS were examined by two blinded radiologists with consensus using gray-scale US and SWE. SWE parameters were compared between groups. The area under the curve (AUC), sensitivity, and specificity of gray-scale US and SWE was analyzed. The correlation between SWE and clinical findings was investigated. RESULT: The SWE parameters of the parotid and submandibular glands were significantly higher in the pSS group, but did not differ significantly based on serologic assays, Schirmer test, minor salivary gland biopsy, and comorbidities. The AUC values for gray-scale US of the salivary glands were significantly lower than the AUC values for SWE. The elasticity modulus (kPa) of parotid gland had the highest AUC value (0.937; 95% CI, 0.901-0.973), with a sensitivity of 93.2% and a specificity of 83.3%. SWE had no correlation with age, disease duration, laboratory values, or disease activity. CONCLUSION: SWE provides excellent diagnostic performance for submandibular and parotid gland involvement in pSS and can be used to complement gray-scale US.

Comparison of the Effects of Spreader Graft Versus Spreader Flap on Nasal Valve Angle in Open Approach Rhinoplasty.

OBJECTIVE: This study aimed to compare the spreader graft and flap techniques, which are used in nasal valve surgery, based on measurements of nasal valve angles using computed tomography. MATERIAL AND METHOD: In this retrospective study, all patients' right and left internal nasal valve angles were measured from coronal computed tomography images taken preoperatively and in the third postoperative month. A paired t-test and independent t-test were used to compare continuous numerical variables. RESULTS: There were 52 patients with 104 valves in the spreader flap group and 54 patients with 108 valves in the spreader graft group, with a mean age of 27.76 ± 8.16 years. The angles were found to be statistically significantly higher in the postoperative period (p<0.001) in all patients. While the angles did not differ significantly between the flap and graft groups in the preoperative period, they were significantly higher in the flap group in the postoperative period (p<0.001). DISCUSSION: It is essential to preserve nasal valve function in rhinoplasty. The findings show that a spreader flap is superior to a spreader graft, although both techniques increase internal nasal valve function. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The role of superb micr ole of superb microvascular imaging in detecting low-gr ascular imaging in detecting low-grade inflammation among adults and those with chronic kidney disease: A preliminary study.

BACKGROUND: Pathophysiologic changes associated with chronic inflammation occur with aging and more prominently in patients with chronic kidney disease (CKD), and an association between chronic inflammation and muscle wasting has been identified. The microcirculation is extremely sensitive to the inflammatory process and actively participates in it. In a healthy adult, angiogenesis is a strictly controlled and rare occurrence. However, aberrant angiogenesis and the development of new tiny blood vessels are known in chronic inflammatory diseases. Superb microvascular imaging (SMI) is a noninvasive technique that can evaluate tiny vessels with low blood flow and provide quantitative data. Our goal was to detect increased blood flow secondary to low-grade chronic inflammation in micro-circulation in the rectus femoris (RF) muscle using SMI. METHODS: This cross-sectional study involved 30 patients with CKD, 30 adults without CKD or other chronic illnesses, and 32 young healthy volunteers. This study was conducted in our university hospital between March and December 2021. The RF cross-sectional area (CSA) was measured, and vascular index (VI) values were obtained using SMI. All three groups' RF-CSA and VI values were compared. RESULTS: Although there was no statistically significant difference in RF-CSAs between the groups, the VI values of all three groups were statistically different (p < 0.001). The median (min-max) VI values were 0.90 (0.60-1.30), 0.50 (0.20-1.0), and 0.30 (0.10-0.50) for the CKD, adult control, and young healthy groups, respectively. The VI significantly differentiated patients with CKD from all other patients and the adult control group. When a cutoff value of 6.5 was used for the VI in detecting increased blood supply in RF muscle in patients with CKD, the accuracy, positive predictive value, and negative predictive value were 93.5%, 85.3%, and 98.3%, respectively. DISCUSSION: SMI can detect increased blood supply caused by low-grade inflammation in the RF muscle.

Texture analysis of multiparametric magnetic resonance imaging for differentiating clinically significant prostate cancer in the peripheral zone.

BACKGROUND: Texture analysis (TA) provides additional tissue heterogeneity data that may assist in differentiating peripheral zone(PZ) lesions in multiparametric magnetic resonance imaging (mpMRI). This study investigates the role of magnetic resonance imaging texture analysis (MRTA) in detecting clinically significant prostate cancer (csPCa) in the PZ. METHODS: This retrospective study included 80 consecutive patients who had an mpMRI and a prostate biopsy for suspected prostate cancer. Two radiologists in consensus interpreted mpMRI and performed texture analysis based on their histopathology. The first-, second-, and higher-order texture parameters were extracted from mpMRI and were compared between groups. Univariate and multivariate logistic regression analyses were performed using the texture parameters to determine the independent predictors of csPCa. Receiver operating characteristic (ROC) curve analysis was conducted to assess the diagnostic performance of the texture parameters. RESULTS: : In the periferal zone, 39 men had csPCa, while 41 had benign lesions or clinically insignificant prostate cancer (cisPCa). Themajority of texture parameters showed statistically significant differences between the groups. Univariate ROC analysis showed that the ADC mean and ADC median were the best variables in differentiating csPCa (p < 0.001). The first-order logistic regression model (mean + entropy) based on the ADC maps had a higher AUC value (0.996; 95% CI: 0.989-1) than other texture-based logistic regression models (p < 0.001). DISCUSSION: MRTA is useful in differentiating csPCa from other lesions in the PZ. Consequently, the first-order multivariate regressionmodel based on ADC maps had the highest diagnostic performance in differentiating csPCa.

Diagnostic Performance of Lower Extremity Venous Wall Thickness and Laboratory Findings in the Diagnosis of the Behçet Disease.

BACKGROUND/OBJECTIVE: Behçet disease (BD) is not a single unique entity but a syndrome with different clinical phenotypes that can involve arterial and venous vessels of all sizes. To date, there has been no specific test or serum marker to measure and determine the severity of BD, and diagnosis remains based on clinical findings. This study aimed to assess lower extremity venous wall thickness (VWT) measured by ultrasound and laboratory findings and diagnostic performance in patients with BD. METHODS: A total of 106 participants were recruited from the rheumatology department in this single-center, case-control study. Participants meeting the eligibility criteria were divided into healthy controls (n = 52) and BD (n = 54). The VWT values of the common femoral vein, great saphenous vein, and popliteal vein were measured using ultrasonography. Laboratory data were obtained from the electronic registration database. Venous wall thicknesses and laboratory findings in patients with BD and healthy subjects were compared. RESULTS: Venous wall thickness of the lower extremity veins was higher in the BD group and higher in those with a history of deep vein thrombosis than in those without. The mean leukocyte, monocyte, erythrocyte sedimentation rate (ESR), C-reactive protein, plateletcrit (PCT), red cell distribution width (RDW), mean platelet volume (MPV) values, and monocyte-to-lymphocyte ratio (MLR) were higher in BD patients than in the control group. There was a correlation among increased VWT, ESR, PCT, MPV, RDW, and MLR. CONCLUSIONS: C-reactive protein, ESR, MPV, PCT, MLR, RDW, and VWT can be used to assist in the diagnosis of BD.

Computed Tomography Analysis of Nasal Anatomy in Dorsal Preservation Rhinoplasty.

BACKGROUND: Subdorsal septal resection and radix osteotomy are distinctive surgical steps in preservation rhinoplasty. OBJECTIVES: The aim of this study was to evaluate the nasal bone thickness, the level of the septal bony-cartilaginous junction (K area), and the distances of the frontal sinus and skull base from the transverse osteotomy line in the Turkish population by means of conventional computed tomography (CT). METHODS: A retrospective evaluation was made of 203 consecutive preoperative paranasal CT scans of patients (classified in terms of age and gender) who had undergone rhinoplasty surgery between January 2020 and June 2021. The nasal bone thickness at the medial canthus level, and the distances between the transverse osteotomy line and the K area, the frontal sinus, and the cribriform plate were measured. RESULTS: The mean measurements were similar in terms of age groups (P = 0.402, P = 0.542, P = 0.134 and P = 0.276 for ages 18-30, 30-40, 40-50, and >50 years, respectively). The mean nasal bone thickness and the distance between the transverse osteotomy line and the K area showed statistical significance (P = 0.001 and P = 0.001, respectively). In both genders, the mean distances between the transverse osteotomy line and the frontal sinus and the cribriform plate were similar (P = 0.921 and P = 0.280, respectively). The nasal bone was thinner and the K area position more cephalic in females. CONCLUSIONS: CT plays an important role in preoperative planning. The need for resection of the ethmoid perpendicular bone may be greater in males when lowering the dorsal hump, and hence they may be more prone to skull base complications. It is therefore necessary to be more careful in the surgical stage of subdorsal septal excision in males.

Correlation of language lateralization with resting state hippocampal connectivity in temporal lobe epilepsy patients

Background/aim: The main purpose of this study is to evaluate the resting state hippocampal connectivity with language areas and to correlate them with laterality index calculations on single subject basis, hence to present hippocampal lateralization for language with rs-fMRI. Materials and methods: Task based and rs-fMRI data were gathered from a total of 45 subjects in 3T scanner. BrainVoyager QX, SPM, and CONN softwares were used for data analysis. LI score of each subject was calculated and converted into normalized LI score (nLI). Intrahemispheric rs-connectivity analysis was performed between hippocampus and Broca's regions on both sides. Correlation between these variables was measured with SPSS software. Results: Right-TLE patients were found to have highest whereas left-TLE group were found to have lowest mean LI scores. Regarding hippocampal-lingual networks; left intrahemispheric connectivity values showed strong positive correlation with nLI values in left, right-TLE patients and healthy controls (P = 0.035, 0.014, 0.047). There were no significant correlation between right intrahemispheric connectivity values and nLI scores in all groups. Conclusions: This study seems to depict the existence of resting state hippocampal-lingual functional network which correlates well with lateralization of language function in the left hemisphere in both temporal lobe epilepsy patients and healthy controls.

Increased 68Ga-FAPI-04 Uptake in Meningioma.

ABSTRACT: A 65-year-old woman with long-standing symptoms of COVID-19 participated in our clinical study on the role of 68Ga-FAPI-04 PET/CT in pulmonary fibrosis. Neither sequela parenchymal changes nor 68Ga-FAPI-04 uptake was observed in the lungs. However, focal 68Ga-FAPI-04 uptake was localized in a smoothly circumscribed mass observed in the right frontal region. A meningioma diagnosis was made based on the radiological findings.

Evaluation of signal intensity changes in dentate nucleus and globus pallidus on magnetic resonance imaging after intrathecal gadolinium-based contrast agent administration.

PURPOSE: Gadolinium deposition has been reported in several normal anatomical structures in the brain after repeated administration of intravenous gadolinium-based contrast agents (GBCAs) used in magnetic resonance imaging (MRI). This study presents preliminary results to see if there is any gadolinium deposition in the dentate nucleus and globus pallidus after using intrathecal GBCAs. METHODS: Between November 2018 and November 2020, 29 patients who underwent intrathecal contrast-enhanced MR cisternography with the suspicion of rhinorrhea were included in this prospective study. In contrast-enhanced MR cisternography, gadoterate meglumine was administered by intrathecal injection at a dose of 1 ml. One month later, patients had a control MRI with 3D T1 SPACE fat-saturated (FS) and susceptibility weighted images (SWI) sequences. The ratio of dentate nucleus signal intensity to middle cerebellar peduncle signal intensity (DN/MCP ratio) and the ratio of globus pallidus signal intensity to thalamus signal intensity (GP/T ratio) were calculated using region of interest (ROI) on pre-contrast and control MRI sequences. RESULTS: There was no significant difference for DN/MCP ratio and GP/T ratio on 3D T1 SPACE FS and SWI sequences after intrathecal GBCAs administration compared to baseline MRI. CONCLUSION: Administration of intrathecal GBCAs did not cause a measurable change in the signal intensity of the dentate nucleus and globus pallidus after a single injection.

Can magnetic resonance imaging texture analysis change the breast imaging reporting and data system category of breast lesions?

PURPOSE: This study aimed to reveal magnetic resonance imaging (MRI) texture analysis (TA)'s contribution to categorizing breast lesions according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. METHOD: Two hundred and seventeen women with BI-RADS category 3, 4, and 5 lesions on breast MRI were included in the study. For TA, the region of interest was drawn manually to encompass the entire lesion on the fat-suppressed T2W and the first post-contrast T1W images. To identify the independent predictors of breast cancer, multivariate logistic regression analyses were performed using texture parameters. Estimated benign and malignant groups were formed according to the TA regression model. RESULTS: Texture parameters extracted from T2WI, including median, gray-level co-occurrence matrix (GLCM) contrast, GLCM correlation, GLCM joint entropy, GLCM sum entropy, and GLCM sum of squares, and parameters extracted from T1WI, including maximum, GLCM contrast, GLCM joint entropy, GLCM sum entropy, were independent predictors of breast cancer. In the estimated new groups according to the TA regression model, 19 (91%) of the benign 4a lesions were downgraded to BI-RADS category 3. CONCLUSIONS: The addition of quantitative parameters obtained by MRI TA to BI-RADS criteria significantly increased the accuracy rate in differentiating benign and malignant breast lesions. When categorizing BI-RADS 4a lesions, the use of MRI TA in addition to conventional imaging findings may reduce unnecessary biopsy rates.

Fetal Orbital Epidermal Cyst Pre-postnatal Imaging Findings: A Case Report and Literature Review.

BACKGROUND: Fetal ultrasonographic evaluation is a routine part of pregnancy follow-up, and examination of orbital structures is also part of the routine evaluation. Although orbital developmental anomalies are common in the neonatal period, diagnosis in the intrauterine period is not common. To our knowledge, three cases with a diagnosis of congenital orbital epidermal cysts have been reported in the literature, and two of them had fetal imaging findings. In this article, we present the prepostnatal imaging findings of a case diagnosed with orbital cyst in the fetal period and histopathologically diagnosed as epidermal cyst in the neonatal period. CASE REPORT: A 25-year-old woman applied for ultrasonography (USG) examination at 22 weeks of gestation. A 35x45 mm cystic lesion causing proptosis, without solid component and vascularity, surrounding the optic nerve and causing its thinning was observed in the left orbit. In fetal magnetic resonance imaging (MRI), the intraorbital cystic lesion, which was hyperintense on T2W images and hypointense on T1W images, had no relationship with intracranial structures and no solid component. The lesion of the patient, followed up with a multidisciplinary approach, was shown similarly with computed tomography (CT) and magnetic resonance imaging (MRI) in the postnatal period. Subsequently, the patient underwent globe-sparing surgery, and the pathological diagnosis was made as the epidermal cyst. CONCLUSION: Orbital epidermal cysts are rarely seen, and detection in the fetal period is even rarer. It should be considered in the differential diagnosis of orbital cystic lesions that cause proptosis in fetal and neonatal periods.

Isolated Liver Metastasis Detected by 68 Ga-PSMA PET/CT in Newly Diagnosed Prostate Cancer.

ABSTRACT: Lymph nodes, bones, and liver are the most typical metastatic sites for prostate cancer. However, isolated liver metastasis from prostate cancer is extremely rare. Here, we report a 75-year-old man with newly diagnosed prostate adenocarcinoma, with isolated liver metastasis detected by 68 Ga-PSMA ( 68 Ga-prostate-specific membrane antigen) PET/CT. There was no sign of regional or distant metastases elsewhere. This case highlights the value of 68 Ga-PSMA PET/CT in detecting a very uncommon solitary liver metastasis from prostate cancer.

Two-dimensional shear wave elastography can improve the diagnostic accuracy of ultrasonography in acute appendicitis.

AIM: We aimed to evaluate the effectiveness of combining 2-dimensional shear wave elastography (2D-SWE) with ultrasonography (US) in diagnosing acute appendicitis in patients with suspected acute appendicitis. METHODS: Clinical and laboratory findings, gray-scale US and 2D-SWE imaging features, operation information, and pathology results of 48 patients diagnosed with acute appendicitis who presented with right lower quadrant pain were prospectively evaluated. We compared the findings to the US and SWE imaging features of 79 asymptomatic patients. RESULTS: Mean Alvarado score and appendix diameter were statistically significantly higher for acute appendicitis (p < 0.001). In patients with acute appendicitis, mesenteric lymphadenopathy and fat stranding were also more frequent (p < 0.001). The mean velocity and kPa values for appendix and mesenteric fat were statistically significantly higher in acute appendicitis (p < 0.001). CONCLUSION: In the diagnosis of acute appendicitis, 2D-SWE increases the diagnostic performance of gray-scale US in the differentiation of inflamed and normal appendixes.

Orbital structures in the pediatric age group: A normative assessment using magnetic resonance imaging.

PURPOSE: Many diseases of traumatic, infectious, endocrinologic and neoplastic origin can lead to orbital involvement and related morphological changes. In the present study, we aimed to determine the age-based normal orbital measurements using magnetic resonance imaging (MRI) in pediatric patients. METHODS: Our retrospective study included 186 patients with normal orbital MRI findings. The patients were divided into the following five groups based on their age. Group 1: 1-24 months; Group 2: 25-60 months; Group 3: 61-120 months; Group 4: 121-168 months; and Group 5: 169-216 months. Globe position relative to interzygomatic line (IZL) and orbital rim, optic nerve-sheath complex, extraocular muscle diameters, were measured. RESULTS: The differences among the age groups for the distances between cornea and sclera in relation to IZL, for the distances between cornea and sclera relative to orbital rim, and for the extraocular muscle diameters were statistically significant. In terms of the extraocular muscle diameter, it was found that the thinnest muscle of all groups was the lateral rectus muscle while the thickest was the medial rectus muscle. CONCLUSION: In pediatric patients who were divided into five groups based on their age, the positions of bulbus oculi relative to IZL or orbital rim and the normal diameter ranges of extraocular muscles and of the optic nerve-sheath complex in orbital MRI were determined. We are of the opinion that the presence of such a scale could be a guide in the evaluation of orbital MRI in pediatric patients.

Dynamic contrast-enhanced magnetic resonance imaging for evaluating early response to radiosurgery in patients with vestibular schwannoma.

PURPOSE: This study aimed to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate early treatment response in vestibular schwannoma (VS) patients after radiosurgery. METHODS: Twenty-four VS patients who underwent gamma knife radiosurgery were prospectively followed up for at least four years. DCE-MRI sequences, in addition to standard MRI protocol, were obtained prior to radiosurgery, at 3 and 6 months. Conventionally, treatment responses based on tumor volume changes were classified as regression or stable (RS), transient tumor enlargement (TTE), and continuous tumor enlargement (CTE). DCE-MRI parameters, such as Ktrans, Kep and Ve, were compared according to follow-up periods and between groups. The diagnostic performance was tested using receiver operating characteristic (ROC) curves. RESULTS: Changes in tumor volume were as follows at the last 48 months of follow-up: RS in 11 patients (45.8%), TTE in 10 patients (41.7%), and CTE in three patients (12.5%). The median time required to distinguish TTE from CTE using conventional MRI was 12 months (range 9-18). The Ktrans and Ve were significantly decreased in patients with RS and TTE at 3 and 6 months, but did not differ significantly in patients with CTE. There were no significant differences in Ktrans and Ve between patients with RS and TTE at 3 and 6 months. Both Ktrans and Ve demonstrated high diagnostic performance in evaluating early treatment response to radiosurgery in patients with VS. CONCLUSION: DCE-MRI may aid in the monitoring and early prediction of treatment response in patients with VS following radiosurgery.

Which one is better for predicting extraprostatic extension on multiparametric MRI: ESUR score, Likert scale, tumor contact length, or EPE grade?

PURPOSE: To evaluate the European Society of Urogenital Radiology (ESUR) score, the Likert scale, tumor contact length (TCL) > 1 cm, and EPE (extraprostatic extension) grade in predicting EPE at multiparametric magnetic resonance imaging (mp-MRI). METHODS: Seventy-nine patients who underwent 3-T MRI and were histopathologically confirmed by microblocks were enrolled in this retrospective study. The index lesions were interpreted by two experienced radiologists. Apparent diffusion coefficient (ADC) values were also noted. Weighted κ statistics were used to compare interreader agreement. Univariate logistic regression analysis was performed to define independent predictors of EPE status. Multivariable logistic regression and receiver operating characteristic (ROC) analysis were performed to compare the MRI-based methods and clinical variables (ISUP grade, prostate volume and PSA density) + MRI-based methods for pathologic EPE prediction by using the area under the curve (AUC) value. RESULTS: The mean age was 64.5 years ± 6.2. 33/79 (41.8%) patients had pathologic EPE. As ESUR score showed weak interreader agreement (κ = 0.537), Likert scale, TCL, and EPE grade showed moderate agreement (κ = 0.608, κ = 0.747, κ = 0.647 respectively). Univariate ROC analysis result showed that all MRI-based score systems, mean ADC value, the ISUP grade, prostate volume, PSA density were the best variables in predicting EPE. ROC analysis results of four MRI-based methods showed good diagnostic performance. At multivariate analysis, all clinical models showed excellent diagnostic performance. CONCLUSION: All four MRI-based methods had good diagnostic performance. Furthermore, consisting of both qualitative and quantitative parameters and being less reader experience dependent, EPE grade was a promising method in predicting EPE. All clinical models showed excellent diagnostic performance.

Chest CT findings in RT-PCR positive asymptomatic COVID-19 patients.

PURPOSE: To investigate chest computed tomography (CT) findings in asymptomatic patients tested positive for coronavirus disease (COVID-19) by reverse transcription-polymerase chain reaction (RT-PCR). MATERIAL AND METHODS: The chest CT images of 64 patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who were RT-PCR test-positive but asymptomatic were retrospectively evaluated for the appearance and distribution of abnormal parenchymal findings. RESULTS: Of the 64 patients (mean age 59.4 ± 12; range 23-85), 42 (65%) were female, and 22 (35%) were male, and 16 (25%) of the patients had no abnormal findings on chest CT. Of the remaining 48 patients, lung involvement was bilateral in 32 (67%). Right upper lobe in 26 (54%), right middle lobe in 20 (42%), right lower lobe in 38 (79%), left upper lobe in 27 (56%), and left lower lobe were affected in 34 (71%) patients. The mean number of opacities detected in patients was 7.5 ± 5.7. The opacities were located only peripherally/subpleural in 22 (46%), only centrally/peribronchovascular in 5 (10%), and mixed in 21 (44%) patients. The frequency of pure ground glass opacities (GGO) was 63% GGO with a crazy-paving pattern or consolidation was 33%. Pure consolidation was detected in only two (4%) patients. Parenchymal opacities were only round in 27 (56%), only geographic demarcated in 3 (6%), only patchy in 2 (4%), and mixed in 16 (33%) patients. CONCLUSION: Chest CT was normal in only one-quarter of the asymptomatic patients. CT findings in asymptomatic COVID-19 patients were often peripherally located, mostly round-shaped GGO.