THE DIAGNOSTIC ACCURACY OF A COMBINATION OF PREOPERATIVE 68-Ga PSMA PET/CT AND MULTIPARAMETRIC MRI IN LOCALIZED PROSTATE CANCER.

INTRODUCTION: Prostate cancer (PCa) is a common and leading course of cancer-related death in men. Although there are studies on multiparametric magnetic resonance imaging (MpMRI) with good diagnostic results in detecting clinically significant prostate cancer, new methods have been investigated due to the low positive predictive values. In this context, Prostate Specific Membrane Antigen Positron Emission Tomography (PSMA PET) emerges as an alternative imaging method to MpMRI. This study aims to compare 68Ga PSMA I&T-PET/CT and MpMRI in determining tumor location. METHODS: Preoperative MpMRI and 68Ga PSMA I&T-PET/CT scans and pathology specimens of who underwent radical prostatectomy for PCa at our clinic between 2018-2021 were retrospectively evaluated. PSMA I&T-PET/CT, MpMRI, combined imaging were compared for tumor localization according to histopathological data. RESULTS: In terms of tumor localization, MpMRI demonstrated overall accuracy rates 75.9% (p kappa (κ) 0.0001* (0.525)). 68Ga PSMA I&T-PET/CT showed 71.5% (p κ 0.0001* (0.438)). For the combined imaging approach overall accuracy rate were calculated as 79.2% (p κ 0.0001* (0.576)). Additionally, high diagnostic accuracy was achieved for the combined imaging approach, particularly in the intermediate ISUP group. Moreover, SUVmax was calculated as 6.37. CONCLUSION: The combined use of 68Ga PSMA I&T-PET/CT and MpMRI has high diagnostic rates. However, the high cost is a significant disadvantage that limits their routine combined use.

Comparison of Multiparametric and Fast MRI Protocols in Detecting Clinically Significant Prostate Cancer and a Detailed Cost Analysis.

BACKGROUND: Due to the long acquisition time and high cost of multiparametric magnetic resonance imaging (mpMRI), biparametric and, more recently, fast prostate magnetic resonance imaging (fpMRI) protocols have been described. However, there is insufficient data about the diagnostic performance and cost of fpMRI. PURPOSE: To compare the diagnostic performances and cost analysis of fpMRI and mpMRI in clinically significant prostate cancer (csPCA). STUDY TYPE: Retrospective. POPULATION: A total of 103 patients (63 had csPCA) with a mean age of 66.83 (± 7.22) years were included. FIELD STRENGTH/SEQUENCE: A 1.5-T; T1- and T2-weighted turbo spin-echo imaging (T1WI and T2WI), echo-planar diffusion-weighted images, and dynamic contrast-enhanced T1W imaging. ASSESSMENT: Three readers independently evaluated the fpMRI and mpMRI images in different sessions blinded to all patient information. Diagnostic performances of fpMRI and mpMRI were evaluated. Kappa coefficient (κ) was used to determine the interreader and intrareader agreement. A detailed cost analysis was performed for each protocol. STATISTICAL TESTS: Receiver operating characteristics analysis, area under the curve (AUC), and κ test were used. Diagnostic performance parameters were also calculated. RESULTS: Of the 63 malignant index lesions (csPCA), 53/63 of those (84.1%) originated from the peripheral zone and 10/63 lesions (15.9%) originated from the transition zone. The AUC values for fpMRI were 0.878 for reader 1, 0.937 for reader 2, and 0.855 for reader 3. For mpMRI, the AUC values were 0.893 for reader 1, 0.94 for reader 2, and 0.862 for reader 3. Inter and intrareader agreements were moderate to substantial (κ range, 0.5-0.79). The total cost per examination was calculated as €12.39 and €30.10 for fpMRI and mpMRI, respectively. DATA CONCLUSIONS: Fast MRI protocol has similar diagnostic performance with mpMRI in detecting csPCA, and fpMRI can be considered an alternative protocol that could create a lower financial burden on health-care systems. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 6.

Emissary veins prevalence and evaluation of the relationship between dural venous sinus anatomic variations with posterior fossa emissary veins: MR study.

PURPOSE: The aim of this study was to find the prevalence of emissary veins and to compare the visibility of these emissary veins with the anatomic variations of the dural venous sinuses detected in magnetic resonance venography (MRV). MATERIALS AND METHODS: All MR images of two hundred twenty patients were evaluated retrospectively. Posterior cranial fossa emissary veins diameter measurements were performed in the axial plane. The anatomic variations of the venous sinuses in MRVs of all patients were recorded. Accordingly, the presence of the emissary veins was compared with the dural venous sinus anatomic variations. p < 0.05 was considered statistically significant. An inter-observer reliability analysis was performed. RESULTS: The prevalence of emissary veins in MRI was found in the right mastoid emissary vein (MEV) 82.7% and left MEV 81.4%. Occipital emissary vein (OEV) was present in 63 patients (28.6%) for the first radiologist (R1), and it was present in 61 patients (27.7%) for the second radiologist (R2) (K = 0.978). A statistically significant correlation was detected between the diameter of the left MEV and gender (p < 0.05) for both radiologists. There was a statistically significant difference between the left MEV and OEV and transverse sinus anatomic variations. CONCLUSION: MR imaging is a noninvasive and irradiating imaging method for detecting posterior fossa major emissary veins, and we recommend using MR imaging for preoperative evaluation of posterior fossa major emissary veins and related dural venous sinuses.

Evaluation of Free Breathing Versus Breath Hold Diffusion Weighted Imaging in Terms Apparent Diffusion Coefficient (ADC) and Signal-to-Noise Ratio (SNR) Values for Solid Abdominal Organs.

BACKGROUND: Our aim was to compare the apparent diffusion coefficient (ADC) values of normal abdominal parenchymal organs and signal-to-noise ratio (SNR) measurements in the same patients with breath hold (BH) and free breathing (FB) diffusion weighted imaging (DWI). MATERIAL/METHODS: Forty-eight patients underwent both BH and FB DWI. Spherical region of interest (ROI) was placed on the right hepatic lobe, spleen, pancreas, and renal cortices. ADC values were calculated for each organ on each sequence using an automated software. Image noise, defined as the standard deviation (SD) of the signal intensities in the most artifact-free area of the image background was measured by placing the largest possible ROI on either the left or the right side of the body outside the object in the recorded field of view. SNR was calculated using the formula: SNR=signal intensity (SI)(organ)/standard deviation (SD)(noise). RESULTS: There were no statistically significant differences in ADC values of the abdominal organs between BH and FB DWI sequences (p>0.05). There were statistically significant differences between SNR values of organs on BH and FB DWIs. SNRs were found to be better on FB DWI than BH DWI (p<0.001). CONCLUSIONS: Free breathing DWI technique reduces image noise and increases SNR for abdominal examinations. Free breathing technique is therefore preferable to BH DWI in the evaluation of abdominal organs by DWI.

Evaluation of abdominal computed tomography findings in patients with COVID-19: a multicenter study

PURPOSE: To evaluate the frequency of abdominal computed tomography (CT) findings in patients with coronavirus disease-2019 (COVID-19) and interrogate the relationship between abdominal CT findings and patient demographic features, clinical findings, and laboratory test results as well as the CT atherosclerosis score in the abdominal aorta. METHODS: This study was designed as a multicenter retrospective study. The abdominal CT findings of 1.181 patients with positive abdominal symptoms from 26 tertiary medical centers with a positive polymerase chain-reaction test for severe acute respiratory syndrome coronavirus 2 were reviewed. The frequency of ischemic and non-ischemic CT findings as well as the association between CT findings, clinical features, and abdominal aortic calcific atherosclerosis score (AA-CAS) were recorded. RESULTS: Ischemic and non-ischemic abdominal CT findings were detected in 240 (20.3%) and 328 (27.7%) patients, respectively. In 147 patients (12.4%), intra-abdominal malignancy was present. The most frequent ischemic abdominal CT findings were bowel wall thickening (n = 120; 10.2%) and perivascular infiltration (n = 40; 3.4%). As for non-ischemic findings, colitis (n = 91; 7.7%) and small bowel inflammation (n = 73; 6.2%) constituted the most frequent disease processes. The duration of hospital stay was found to be higher in patients with abdominal CT findings than in patients without any positive findings (13.8 ± 13 vs. 10.4 ± 12.8 days, P < 0.001). The frequency of abdominal CT findings was significantly higher in patients who did not survive the infection than in patients who were discharged after recovery (41.7% vs. 27.4%, P < 0.001). Increased AA-CAS was found to be associated with a higher risk of ischemic conditions in abdominal CT examinations. CONCLUSION: Abdominal symptoms in patients with COVID-19 are usually associated with positive CT findings. The presence of ischemic findings on CT correlates with poor COVID-19 outcomes. A high AA-CAS is associated with abdominal ischemic findings in patients with COVID-19.

Efficiency of Fat Suppression in T1-Weighted Inner Ear Magnetic Resonance Imaging: Multipoint Dixon Method Versus Hybrid Techniques.

BACKGROUND: Temporal bone is a region where fat suppression is difficult due to the inhomogeneity of various structures with different molecular properties. INTRODUCTION: We aimed to determine the most effective fat suppression sequence in order to increase the visibility of the inner ear region. MATERIALS AND METHODS: The hybrid techniques and T1-Weighted mDIXON images of 40 patients with Magnetic Resonance (MR) imaging of the inner ear were prospectively compared by two experienced radiologists in terms of fat suppression efficacy. In all fat-suppressed sequences, the Signal to Noise Ratio (SNR), the spinal cord signal intensity / mean fat signal intensity ratio and spinal cord signal to noise ratio were calculated. The suppression efficacy of MR techniques for fat areas in the inner ear was visually graded. RESULTS: Qualitative assessment of image quality due to fat suppression in the inner ear was made; the Dixon technique performed significantly better than SPAIR and SPIR techniques (p<0.0001). The mean signal intensity of the inner ear fat and SNR for the Dixon technique were significantly lower than that for SPIR and SPAIR techniques (p<0.0001). Inter-observer agreement regarding the assessment of the inner ear fat, mean signal intensity values and mean SNR values for fat suppression techniques was significant. CONCLUSION: The Dixon technique exhibited higher image quality and fat suppression efficiency than the hybrid techniques in the MR imaging of the inner ear.

VI-RADS score and tumor contact length in MRI: A potential method for the detection of muscle invasion in bladder cancer.

BACKGROUND: Vesical Imaging Reporting and Data System (VI-RADS) is a useful tool for evaluating muscle layer invasion of bladder cancer (BCa) on magnetic resonance imaging (MRI). PURPOSE: To evaluate the diagnostic performance of bladder MRI to detect the muscle layer invasion of BCa using VI-RADS score and quantitative MRI parameters. METHODS: Preoperative bladder MRI was performed in 73 BCa patients. Two observers independently evaluated the MR blinded to histopathological data and classified the tumors according to VI-RADS criteria. Moreover, the quantitative parameters (maximum tumor diameter; Dmax, tumor contact length; TCL, and tumor apparent diffusion coefficient; ADC values) were independently measured by observers. The diagnostic performance of the VI-RADS score and quantitative values were evaluated by using receiver operating characteristic (ROC) analysis. Interobserver agreement was evaluated using the weighted-kappa coefficient (κ). RESULTS: For the VI-RADS score, the AUC (area under the curve) was 0.968 and accuracy was 90.4% for Observer 1, and AUC was 0.953, accuracy was 89% for Observer 2. The AUC of TCL, TCL/DMax, and ADC values was 0.918, 0.675, and 0.832. In patients with a VI-RADS score ≥ 3, when a threshold value of TCL > 19.5 mm is used as complementary to the VI-RADS score, the accuracy of MRI for Observer-1 increases 100% and 97.26% for Observer-2. There was a good-excellent agreement between the observers in assessing the VI-RADS scores and quantitative parameters. CONCLUSION: Evaluation of bladder MRI using both VI-RADS criteria and TCL is successful and highly reproducible for detecting muscle layer invasion in patients with BCa.

Cardio-ankle vascular index is linked to deranged metabolic status, especially high HbA1c and monocyte-chemoattractant-1 protein, in predialysis chronic kidney disease.

INTRODUCTION AND PURPOSE: Arterial stiffness is an independent predictor of cardiovascular disease in chronic kidney disease (CKD). Cardio-ankle vascular index (CAVI) is a newly developed method used to assess arterial stiffness, independent of changes in blood pressure. CAVI reflects stiffness and atherosclerosis at the thoracic, abdominal, common iliac, femoral, and tibial artery levels. In predialysis stage 3-5 diabetic and nondiabetic CKD patients, CAVI levels and its relation to atherosclerosis-associated risk factors including monocyte-chemoattractant protein-1 (MCP-1), sclerostin, fibroblast growth factor-23 (FGF-23), Klotho, and 25-OH vitamin D were determined. MATERIALS AND METHODS: The study was performed on three age-matched and gender-matched groups. Group 1 included 46 stage 3-5 nondiabetic CKD patients, group 2 included 44 stage 3-5 diabetic CKD patients, and group 3 included 44 non-uremic controls. All subjects underwent CAVI measurement. Serum glycated hemoglobin (HbA1c), total calcium, phosphorus, parathormone, FGF-23, Klotho, MCP-1, sclerostin, and 25-OH vitamin D were determined using standard methods. RESULTS: CAVI level was 8.22 ± 0.18 m/s in diabetic CKD patients and significantly higher than in nondiabetic CKD (7.61 ± 0.18 m/s) and control (7.59 ± 0.17 m/s) patients. FGF-23 level was higher in the CKD groups than controls but not statistically significant. MCP-1 level was significantly higher in diabetic CKD patients. Klotho and sclerostin levels were significantly lower in diabetic CKD patients. In the whole cohort, CAVI showed positive correlations with age (r = 0.447, p < 0.0001), smoking (r = 0.331, p = 0.035), mean arterial blood pressure (MABP; r = 0.327, p < 0.0001), fasting blood glucose (r = 0.185, p = 0.033), and HbA1c (r = 0.258, p = 0.003). Stepwise regression analysis revealed that age (p = 0.0001, B = 0.461), MABP (p < 0.0001, B = 0.365), HbA1c (p = 0.003, B = 0.251), and MCP-1 (p = 0.013, B = 0.214) independently predicted CAVI levels. CONCLUSION: Our results indicate higher CAVI levels, therefore, resulting in increased arterial stiffness in the setting of diabetic CKD. Apart from age and MABP, deranged metabolic status, especially increased HbA1c and MCP-1 levels, is also independently associated with increasing CAVI levels in CKD patients. These results emphasize the importance of metabolic control in the development of arterial stiffness in CKD patients, which is an early predictor of developing cardiovascular complications.

Retroperitoneal Bronchogenic Cyst Originating from Diaphragmatic Crura.

Bronchogenic cyst is a benign lesion which is commonly seen in the posterior mediastinum. Diaphragmatic origin in retroperitoneum is an unusual location for a bronchogenic cyst. Cross-sectional imaging modalities describe the origin and content of the cyst evidently. Magnetic resonance (MR) images of a 42-year-old male patient who attended ER with back pain revealed a huge retroperitoneal complicated bronchogenic cyst arising from the diaphragm and surrounding the abdominal aorta anteriorly. Bronchogenic cysts in the retroperitoneum rarely originate from the diaphragm and should be kept in mind in the differential diagnoses of abdominal cystic lesions. MR imaging (MRI) is superior to other imaging techniques such as computerized tomography (CT) in detecting the origin and content of these cystic lesions.

Renal diffusion-weighted imaging in diabetic nephropathy: correlation with clinical stages of disease.

PURPOSE: We aimed to assess the correlation between renal apparent diffusion coefficient (ADC) values measured by diffusion-weighted imaging (DWI) and the clinical stages of diabetic nephropathy. MATERIALS AND METHODS: DWI (b value, 0 and 600 s/mm2) was performed in 78 patients with clinically confirmed diabetic nephropathy (study group) and 22 volunteers without diabetes mellitus or any renal disease (control group). The mean ADCs were calculated from multiple region-of-interest circles positioned in the renal cortex. Diabetic nephropathy was clinically categorized into five stages based on the values of urinary albumin excretion and glomerular filtration rate (GFR). RESULTS: Mean renal ADC values of patients with stage 3 or 4 disease were significantly lower than those in patients with stage 1 or 2 disease and the control group (P < 0.001). ADC values of patients with stage 5 disease were significantly lower than those in patients with stage 4 (P = 0.003), stage 3 (P = 0.020), stages 2 and 1, and the control group (P < 0.001). Significant correlations were found between mean renal ADC values and clinical stages of diabetic nephropathy (r=-0.751, P < 0.001), between mean renal ADC values and estimated GFR values (r=0.642, P < 0.001), and between mean renal ADC values and urinary albumin excretion (r=-0.419, P < 0.001). CONCLUSION: Renal ADC values show a significant correlation with clinical stages of diabetic nephropathy. As a relatively simple and noninvasive tool without contrast media administration, renal quantitative DWI may potentially play a role in making clinical decisions in the follow-up of diabetic patients.

The value of diffusion-weighted MRI for prostate cancer detection and localization.

PURPOSE: The aim of this study was to evaluate the role of prebiopsy T2-weighted imaging (T2WI), quantitative diffusion-weighted imaging (DWI), and the combination of these magnetic resonance (MR) techniques (T2WI+DWI) in the detection and localization of peripheral zone prostate cancer. MATERIALS AND METHODS: T2WI and DWI (b value = 800 s/mm2) with an endorectal coil at 1.5 T were performed prospectively in 43 consecutive male patients with suspicion of prostate cancer before a systematic 12-core prostate biopsy. The peripheral zone of the prostate was evaluated after dividing it into sextants (n = 258). Minimum apparent diffusion coefficient (ADC) values of each sextant in the peripheral zone were measured. Two core biopsies were obtained from each sextant under transrectal ultrasound guidance. RESULTS: The mean minimum ADC values of the malignant sextants were significantly lower than that of noncancerous tissue, with a significant negative correlation between the ADC value and the Gleason score. The sensitivity, specificity, and area under the receiver operating characteristic curve for the detection and localization of prostate cancer within the peripheral zone were 71%, 77%, and 0.741 for T2WI alone; 84%, 82%, and 0.830 for quantitative DWI alone; and 81%, 92%, and 0.863 for T2WI+DWI, respectively. The use of quantitative DWI, alone or combined with T2WI, improved diagnostic performance in prostate cancer detection and localization compared with T2WI alone (P = 0.020 and P = 0.001, respectively). CONCLUSION: Prebiopsy DWI is valuable in detecting, localizing, and grading prostate cancer within the peripheral zone, and the lowest ADC values can indicate the regions to be biopsied.