Oğuzhan Özdemir

Background: The cold pressor test (CPT), which has long been used to test autonomic functions by causing sympathetic excitation, increases systolic and diastolic blood pressure and heart rate and causes coronary vasodilation within physiological limits in healthy individuals. This study aimed to evaluate internal jugular vein (IJV) flow parameters using the CPT with systolic and diastolic blood pressure and heart rate in 40 healthy volunteers aged 18-40 years. Material/Methods: The volunteers' IJV diameter, blood flow peak velocity, and volumetric flow values were recorded. Then, their right hands were immersed in a bucket of cold water maintained at 1 degrees C up to the wrist level. At the end of the first minute (CPT-1), systolic and diastolic blood pressure, heart rhythm, IJV diameter, peak velocity, and volumetric flow measurements were performed again. Results: Systolic and diastolic blood pressure values were significantly higher at CPT-1 compared to baseline values (P<0.001, P<0.001). Heart rate and peak velocity values also showed a significant increase at CPT-1 compared to baseline values (P<0.001, P=0.001). While diameter values showed a significant decrease compared to baseline, volumetric flow rate values showed a significant increase at CPT-1 (P=0.003, P<0.001). Conclusions: Sympathetic nervous system activation triggered by CPT increases IJV volumetric flow and flow velocity in healthy young individuals, and sympathetic nervous system activation causes a venoconstrictive effect in the IJV.

Background: In various situations such as pain, exposure to hot or cold, and mental stress, where physiological stress occurs, the increased excitatory response in the sympathetic efferent neurons leads to an increased return of blood flow from the peripheral veins to the right atrium. The cold pressor test (CPT) is based on the effects of a cold stimulus that activates afferent sensory pathways to trigger a sympathetic response, resulting in an increase in blood pressure. This study aimed to evaluate the effects of the cold pressor test on popliteal vein diameter, flow velocity, and blood flow in the lower limbs in 60 healthy individuals. Material/Methods: We included 30 men and 30 women age 18-40 years. Baseline vein diameter, flow velocity, and blood flow of the left popliteal vein were measured by Doppler ultrasound, then the left hand was immersed in a bucket of cold water. After immersing the hand in cold water for 1 minute (CPT -1), 3 measurements of vein diameter, flow velocity, and blood flow were taken again, and their averages were calculated. Results: In the study, data obtained from the individuals were statistically analyzed. At CPT -1, venous diameter and flow values showed significant increase compared to baseline ( P =0.001, P <0.001, respectively). Conclusions: In healthy volunteers, CPT increases venous flow in the popliteal veins. However, our study did not provide evidence for the hypothesis that the increase in venous return is due to venoconstriction mechanisms.

Gallstone disease (GD) is a common gastrointestinal disease. Although traditional diagnostic techniques, such as ultrasonography, CT, and MRI, detect gallstones, they have some limitations, including high cost and potential inaccuracies in certain populations. This study proposes a machine learning-based prediction model for gallstone disease using bioimpedance and laboratory data. A dataset of 319 samples, comprising161 gallstone patients and 158 healthy controls, was curated. The dataset comprised 38 attributes of the participants, including age, weight, height, blood test results, and bioimpedance data, and it contributed to the literature on gallstones as a new dataset. State-of-the-art machine learning techniques were performed on the dataset to detect gallstones. The experimental results showed that vitamin D, C-reactive protein (CRP) level, total body water, and lean mass are crucial features, and the gradient boosting technique achieved the highest accuracy (85.42%) in predicting gallstones. The proposed technique offers a viable alternative to conventional imaging techniques for early prediction of gallstone disease.

PURPOSETo evaluate the image quality and tumor morphology depiction ability of high resolution (HR) dif-fusion-weighted imaging (f-DWI) in comparison to conventional DWI (c-DWI) and dynamic con-trast-enhanced magnetic resonance imaging (DCE-MRI) in the primary breast cancer setting.METHODSThe f-DWI, c-DWI, and DCE-MRIs of 160 malignant breast masses were evaluated retrospectively by two independent radiologists. Data on image quality [sharpness, distortion, and perceived signal-to-noise ratio (SNR)], apparent diffusion coefficient (ADC) value, lesion size, and tumor morphology (shape, margin, and internal pattern) obtained on f-DWI, c-DWI, and DCE-MRI were compared. Con-sistency between the readers and imaging methods for morphological parameters was analyzed.RESULTSThe ADC values measured on f-DWI were significantly lower than those measured on c-DWI for both readers (P < 0.001 for each), whereas mean lesion size was significantly larger in c-DWI than in f-DWI and DCE-MRI for both readers (P < 0.001 for each). Higher consistency values were obtained for f-DWI compared with c-DWI when correlated with DCE-MRI for each morphological parame-ter. The least distorted images were obtained using DCE-MRI compared with c-DWI and f-DWI for both readers, whereas the highest distortion scores were obtained using c-DWI. Sharpness and per-ceived SNR scores were rated as significantly higher for f-DWI and DCE-MRI images compared with c-DWI by both readers (P < 0.001 for all). The concordance between c-DWI and DCE-MRI was fair to slight (& kappa; = 0.15 to 0.41), whereas concordance between f-DWI and DCE-MRI was significantly better (& kappa; = 0.68 to 0.87) for each reader and for all morphological parameters (P < 0.001). The highest con-cordance between the readers was achieved in margin assessment (& kappa; = 0.87 to 0.89) regardless of the MRI method, followed by shape and internal pattern parameters (& kappa; = 0.63 to 0.79).CONCLUSIONThe results demonstrated that f-DWI produces higher-quality images than c-DWI, enabling the morphological features to be identified in similar detail to that offered by HR DCE-MRI. Accordingly, f-DWI, as a method that highly correlates with DCE in determining the morphological character-istics of breast cancers, seems to have potential in the evaluation of breast tumors in patients for whom the use of contrast media is contraindicated.

Tr en Giriş ve Amaç: İntrakraniyal anevrizmaların tedavisinde cerrahi yolla klipleme altın standart tedavi metodu iken son 30 yıldır endovasküler tedavi cerrahi tedaviye alternatif hale gelmiştir. Endovasküler yol ile tedavi edilen anevrizmalarda, total oklüzyon sağlanmasına rağmen koillerin mekanik başarısızlığına bağlı nüks gelişebilir. Bu çalışmanın amacı; endovasküler yol ile tedavi edilmiş anevrizmaların takibi olarak planlanmıştır. Gereç ve Yöntem: Çalışmaya Ocak 2004-Aralık 2013 tarihleri arasında endovasküler yolla tedavi edilen ve kontrollerine uyan 130 hastaya ait 149 anevrizma dahil edildi. Hastaların 72’si kadın, 58’i erkektir. Hastaların yaşı 13 ile 81 yaş arasında olup ortalama yaş 50,9’dur. Hastalar 6-84 ay arasında manyetik rezonans anjiyografi ve dijital substraksiyon anjiyografi ile takip edildi. Morfolojik sonuçlar Raymond sınıflamasına göre değerlendirildi. Raymond 1 (total oklüzyon), Raymond 2 (anevrizma boynunda doluş var) ve Raymond 3 (rezidü anevrizma) şeklindedir. Bulgular: Endovasküler yolla tedavi edilmiş 116 anevrizmada (%77,9) Raymond sınıf 1, 16 anevrizmada (%10,9) Raymond sınıf 2, 17 anevrizmada (%11,4) Raymond sınıf 3 oklüzyon elde edilmiştir. Toplam rekanalizasyon oranı %22,1 bulunmuştur. Raymond sınıf 2 ve 3 olan 33 hastanın 17 tanesi 6.ay kontrollerinde tespit edilmiştir. Kalan 14 hasta 1.yıl kontrollerinde 2 hasta ise 2.yıl kontrollerinde tespit edilmiştir. Remnant-nüks tespit edilen 33 anevrizmanın 5 tanesi dev anevrizma (>25mm), 14 tanesi büyük anevrizma (10-25 mm), 14 tanesi ise küçük anevrizmlarda ( 25 mm), 14 were large aneurysms (10-25 mm), and 14 were small aneurysms (<10 mm). Conclusion: It is important to assess the stability of follow-up treatment after endovascular treatment and to detect early of recurrence. Many studies have reported that at least two controls should be performed within the first year after endovascular treatment. Long term follow-up is an appropriate choice to perform with magnetic resonance angiography.

To assess the role of DWI in differentiation haemorrhagic ovary infarction from non-haemorrhagic one. For this prospectively designed study, of 117 female patients who presented with acute lower quadrant pain and underwent MRI for suspicion of ovary torsion, results of only 29 patients (mean age, 24.7; SD, ±5.7; age range, 18–37), with surgical and pathological confirmation of adnexal torsion, were included to the study. All patients underwent DWI after conventional MRI. Quantitative and qualitative analysis of both the torsed and contralateral normal ovary were performed. Results of conventional MRI and DWI were noted. At operation 15 patients were found to have haemorrhagic infarction while 14 had non-haemorrhagic infarction. Of the 29 patients, 17 torsed ovaries could be salvaged in a viable state. We found statistically significant correlation of the ADC values, between haemorrhagic and non-haemorrhagic ovary infarction. The ADC values were significantly lower in patients with haemorrhagic infarction than non-haemorrhagic ones (p < 0.001). Using an ADC threshold of 1.27, the sensitivity of DWI for haemorrhagic infarction was 0.93 and specificity 0.85. DWI may be used with a significant success for the preoperative diagnosis of haemorrhagic infarction. This may be alerting for pre-emptive surgery in avoiding serious complications and preventing irreversible structural damage of the ovary.

Background: Although non-enhanced CT (NECT) can be applied for the diagnosis of acute appendicitis in obligatory conditions such as impaired renal function, it is not as effective as contrast-enhanced CT. Objectives: This prospective study aims to determine the added value of diffusion weighted imaging (DWI) in the diagnosis of acute appendicitis when combined with non-enhanced computed tomography (NECT). Methods: Between June 2014 and September, 94 patients (48 male, 46 female) imaged with NECT and DWI for acute appendicitis were enrolled in this prospective study. DWI was obtained with b factors 0, 500 and 1000 s/mm², and assessed with visual and quantitative analysis. Results of NECT and DWI, and combined imaging (NECT and DWI) were analyzed by means of sensitivity, specificity and accuracy. Results: NECT and DWI provided 91.5% - 94.3% sensitivity, 82.6% - 86.9 specificity and 89.3% - 92.5% accuracy, respectively. The combined protocol (NECT and DWI) revealed 98.5% sensitivity, 95.8% specificity and 97.8% accuracy. The addition of DWI to NECT provided a 7%, 13.2% and 8.5% increase in the sensitivity, specificity and accuracy, respectively. This increase was statistically significant (P < 0.05). Conclusions: DWI is an efficient technique for the diagnosis of acute appendicitis. This even may become more efficient if added to a NECT scan. We recommend using DWI when NECT is inevitable for different reasons. It may increase the diagnostic accuracy of NECT to avoid an additional contrast-enhanced CT scan. Keywords: Acute Appendicitis; Computed Tomography; Diffusion-Weighted Imaging; Emergency Department