Clinical Utility of CT-based Attenuation-correction in Myocardial Perfusion SPECT Imaging.

Objectives: We aimed to investigate and compare the role of computed tomography (CT)-based attenuation-corrected images (AC) with non-attenuation-corrected images (NAC) obtained by single-photon emission computed tomography/computed tomography (SPECT/CT) myocardial perfusion imaging (MPI). Methods: The data of 124 patients who were applied one-day stress-rest Tc-99m sestamibi SPECT/CT MPI and who had coronary angiography (CAG) results within ±3 months were retrospectively reviewed. AC and NAC images were visually evaluated by two nuclear medicine specialists in a consensus. CAG results were used as the reference standard. Results: Specificity, sensitivity, and accuracy were calculated as 66%, 61%, 71%, 79% and 69%, 70% for AC and NAC imaging in the whole group, respectively. There was no statistically significant difference between AC and NAC images for specificity, sensitivity, and accuracy in the male and female subgroups. In the diagnosis of right coronary artery (RCA) disease, CT AC significantly increased the specificity from 87% to 96%. However, in the left anterior descending artery (LAD) region, the specificity was significantly reduced from 95% to 77%. Conclusion: CT-based AC did not significantly contribute to diagnostic performance for increased specificity for the RCA and reduced specificity in the LAD region. Therefore, AC images should always be evaluated side by side with NAC images to benefit from the different advantages of both techniques.

FDG PET/CT and Conventional Imaging Methods in Cancer of Unknown Primary: an Approach to Overscanning.

PURPOSE: To compare the performance of fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) with conventional imaging methods (CIM), including computed tomography (CT), magnetic resonance imaging (MRI), and mammography (MMG) in cancer of unknown primary (CUP). METHODS: A total of 36 patients with CUP, who referred to our clinic for a FDG PET/CT scan, were enrolled in this study. Thirty of the patients were also examined through either diagnostic CT/MRI and/or MMG. The diagnostic performance of both methods for the primary cancer location was analyzed. The results of FDG PET/CT and CIM were compared based on the standard reference of the histopathology and/or clinical and laboratory follow-up. RESULTS: The primary cancer locations were detected in 24 patients (66.6%, 24/36) by FDG PET/CT, whereas CIM identified the locations in 16 patients (53.3%, 16/30). Sensitivity, specificity, PPV, NPV, and accuracy rates of the detection of the primary tumor localizations were as follows: 83, 70, 89, 58, and 79% for FDG PET/CT; 70, 62, 84, 42, and 68% for CIM, respectively. There was no statistical significance between modalities regarding any of the categories in 30 patients. CONCLUSION: FDG PET/CT detected the primary tumors of the patients with CUP more than CIM did. However, the difference between them was not found to be statistically significant. It may be considered that FDG PET/CT scan can be performed as a first-line tool in the initial diagnosis of the patients with CUP and to add radiodiagnostic imaging in selective cases. We conclude that if the first-line examination of a CUP patient has been already performed by a CIM and the result was negative or inconclusive, FDG PET/CT can be considered to avoid unnecessary imaging procedures.

Contribution of 18F-FDG PET/CT to Staging of Head and Neck Malignancies.

OBJECTIVES: Accurate staging of head and neck cancer (HNC) plays an important role in patient management as well as protection of functional characteristics of the head and neck region. Our aim was to investigate the contribution of 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT) as part of HNC staging to clinical evaluation and treatment planning. METHODS: Clinical records of 138 HNC cases who has undergone 18F-FDG PET/CT imaging were retrospectively reviewed. Sixty-five cases who had accessible clinical follow-up data were included in the study group, and their PET/CT and conventional imaging findings were evaluated. RESULTS: In the case group with a PET/CT and magnetic resonance imaging (MRI) for evaluation of primary lesion the sensitivity rates for PET/CT and MRI were calculated as 91.3% and 82.6%, the positive predictive values (PPV) as 91.3% and 82.6%, specificity as 71.4% and 42.8%, and the negative predictive value (NPV) as 71.4% and 42.8%, respectively. In terms of metastatic lymph node evaluation, the sensitivity was calculated as 100% and 88.8%, the NPV as 100% and 83.3%, respectively. The PPV and specificity was 100% for both modalities. In the case group with CT for primary lesion evaluation, the sensitivity and PPV were found as 95.2% and 100% for PET/CT, and as 85.7% and 94.7% for CT, respectively. in metastatic lymph node evaluation, the sensitivity was found as 100% for PET/CT and 50% for CT, and the PPV, specificity and NPV were determined as 100% for both methods. PET/CT findings resulted in a change in 'tumor, node, metastasis' staging in 5 cases. CONCLUSIONS: PET/CT in HNC contributes to staging, thus playing a role in treatment planning, especially in patients with locally advanced disease.

Recurrence Incidence in Differentiated Thyroid Cancers and the Importance of Diagnostic Iodine-131 Scintigraphy in Clinical Follow-up.

OBJECTIVE: Differentiated thyroid cancers (DTC) are tumors with good prognosis. However, local recurrence or distant metastasis can be observed. In our study, we aimed to investigate the incidence of recurrence and the importance of diagnostic iodine-131 whole body scan (WBS) in clinical follow-up in patients with DTC. METHODS: The clinical data of 217 patients with DTC who were followed-up more than 3 years were reviewed retrospectively. The incidence of recurrence was investigated in a group of patients who had radioactive iodine (RAI) treatment and showed no sign of residual thyroid tissue or metastasis with diagnostic WBS that was performed at 6-12 months after therapy and had a thyroglobulin (Tg) level lower than 2 ng/dl. RESULTS: At the time of diagnosis, ten cases had thyroid capsule invasion, 25 cases had extra-thyroid soft tissue invasion, 11 patients showed lymph node metastasis and four patients had distant organ metastasis. One hundred forty-five patients had RAI treatment at ablation dose (75-100 mCi), whereas 35 patients had RAI treatment at metastasis dose (150-200 mCi). Thirty-seven patients with papillary microcarcinoma did not receive RAI treatment. In 12 (%7.5) of the 160 patients who were considered as "successful ablation", a recurrence was identified. Recurrence was detected by diagnostic WBS in all cases and stimulated Tg level was <2 ng/dL with the exception of the two cases who had distant metastasis. CONCLUSION: Identification of pathological findings with WBS in patients who developed local recurrence in the absence of elevated Tg highlights the importance of diagnostic WBS in clinical follow-up.

Laparoscopic-Assisted Live Donor Nephrectomy: A Comparison of Conventional and Transvaginal Routes for Kidney Extraction.

BACKGROUND: Laparoscopic approach has become the standard procedure for living donor nephrectomy in many transplant centers. Because the conventional approach results in cosmetic problems and pain during laparoscopic live donor nephrectomy, transvaginal extraction of an intact kidney has been recently introduced as a minimally invasive technique. Here, we aimed to investigate whether transvaginal extraction of an intact kidney during laparoscopic live donor nephrectomy is associated with decreased postoperative pain, nausea and vomiting, and morphine consumption. MATERIAL AND METHODS: This prospective data analysis included a total of 27 female donors who underwent laparoscopic removal of a single kidney for living donor nephrectomy through conventional or transvaginal route. Data collected included age, body mass index, ASA scores, histocompatibility, additional medical disorders, peri- and postoperative complications, postoperative pain scores with visual analogue pain scores (VAS), length of postoperative stay, morphine consumption, degree of nausea and vomiting, level of sedation, and pruritus. RESULTS: No significant differences between the transvaginal and conventional groups were observed in VAS scores and morphine consumption at postoperative 1, 3, 6, 12, and 24 hours. Although not reaching statistical significance, according to analysis of morphine consumption, there was a trend toward decreasing analgesic requirements in the transvaginal group at postoperative 12 and 24 hours. There were no significant differences between the groups in terms of degree of nausea or vomiting, or length of postoperative hospital stay. CONCLUSIONS: We suggest that with a more desirable cosmetic result, transvaginal natural orifice transluminal endoscopic surgery-assisted living donor nephrectomy (TVNALDN) is a suitable new minimally invasive laparoscopic technique associated with reduced postoperative pain and analgesic requirements in select women.

Does Atraucan cause more postdural puncture backache?

BACKGROUND/AIM: Postdural puncture backache (PDPB) is the most frequent complaint after spinal anesthesia. In the literature its importance is generally overshadowed by postdural puncture headache. We studied two different kinds of spinal anesthesia needles to compare their technical handling capacities and incidences of PDPB. MATERIALS AND METHODS: Data of 256 pregnant female patients undergoing cesarean delivery under spinal anesthesia were collected for the study. Patients were divided into two groups as Group A (n = 109) and Group Q (n = 147) according to the spinal needle used for spinal anesthesia (i.e. 26-gauge atraumatic and 26-gauge Quincke needles, respectively). Backache incidences during a 1-week period postoperatively and handling characteristics of the needles were noted. RESULTS: Spinal anesthesia was successfully performed at one attempt in 92.7% and 86.4% of patients in Groups A and Q, respectively. PDPB was encountered in 62.4% and 44.2% of patients in Groups A and Q, respectively, and the difference was statistically significant (P = 0.037). CONCLUSION: Both 26-gauge Atraucan and Quincke needles have excellent handling characteristics. PDPB seems to be less common with the 26-gauge Quincke needle than with the Atraucan needle.

Spontaneous regeneration capacity of controlled small bowel perforations: an experimental study in rats.

BACKGROUND: Selective observation method has started to replace routine laparotomy application for abdominal penetrating trauma patients after Shaftan's selective observation method applied in the 1960s. In this respect, there is a possibility of bowel perforations healing without operations. An experimental model was established in this study in order to clarify this possibility. METHODS: Fifty Wistar-Albino rats were divided into five groups, ten in each. While one group served as the control, distal part of the small bowel of the rats in the other four groups was perforated 1, 2, 3, and 4 mm in diameter with appropriate cutters. After a week of observation, test rats were sacrificed and relaparotomy was applied. The test material consisting of the perforated bowel, covering 1 cm of proximal and distal margins, and some peritoneal tissue was taken for histopathological examination. RESULTS: Small bowel perforations with a diameter of 2 mm or below healed spontaneously without any operation. Peritonitis intensity increased in direct ratio with perforation diameters. Wall repair capacity of the bowel diminished with increasing perforation diameters. CONCLUSION: It was observed that small perforations in the small bowel of rats could be limited by the organism itself without a necessity of any surgical intervention.

Diagnosis, PET/CT imaging, and treatment of extranodal non-Hodgkin lymphoma in keratinized gingiva: a case report.

A 58-year-old patient who smoked and had uncontrolled type 2 diabetes mellitus was referred to our clinic. The patient had a suspicious asymptomatic lesion that was diagnosed as B-cell non-Hodgkin lymphoma (NHL). Immunohistochemistry revealed intense and diffuse expression of CD20, CD10, BCL-6, and Ki-67. A positron emission tomography/computed tomography (PET/CT) scan showed focal pathological uptake of F-18-fluorodeoxyglucose only in the subcutaneous tissue anterior to the left maxillary sinus. After lesion excision and five courses of chemotherapy, PET/CT scans demonstrated complete resolution of the lesion. Smoking, uncontrolled diabetes mellitus, and periodontal disease might be predisposing factors for oral NHL.

Intraocular Pressure Changes After Spinal Anesthesia--Acute and Subacute Effects on Surgery Patients.

BACKGROUND: Spinal anesthesia has become appropriate for many surgical procedures. Neuraxial anesthesia can result in acute and late complications like hypotension, bradycardia, local anesthetic toxicity, postdural-puncture headache, backache and spinal nerve damage. Although the body's physiological responses to spinal anesthesia are well understood, its effects on intraocular pressure (IOP) haven't been mentioned before. OBJECTIVES: The aim of this study was to investigate the effects of spinal anesthesia on IOP. MATERIAL AND METHODS: Forty patients receiving spinal anesthesia for subumblical surgery were recruited for the study, after ethics committee approval and patients' written informed consent. IOP was measured by Icare PRO tonometer (Icare, Finland) before spinal anesthesia (BS), immediately after spinal anesthesia (AS) and finally on the first postoperative day (PO1). Both eyes of the patients were included in the study. RESULTS: Thirty-eight patients completed the study. Mean BS, AS and PO1 intraocular pressures were 16.53±3.17 (9.40-24.00), 17.08±3.16 (10.00-24.00) and 16.76±2.80 (10.20-23.00) mm Hg, respectively. Mean IOP measurements were not statistically different among the three groups (p=0.104). CONCLUSIONS: Spinal anesthesia alone has no acute or subacute effects on IOP. Studies can be made to evaluate the chronic effects. Further studies must be focused on the relationship between postdural puncture headache and intraocular pressure changes after spinal anesthesia.

Comparison of gated myocardial perfusion SPECT, echocardiography and equilibrium radionuclide ventriculography in the evaluation of left ventricle contractility.

OBJECTIVES: In this study, we investigated the reliability of gated myocardial perfusion single-photon emission computerized tomography (GSPECT) for the evaluation of left ventricle (LV) function. We compared left ventricle ejection fraction (LVEF) calculated with GSPECT with the values derived from planar equilibrium-gated radionuclide ventriculography (ERVG) and echocardiography (ECHO). STUDY DESIGN: Forty-eight patients with suspected coronary artery disease (CAD), who were referred for evaluation of myocardial perfusion and LV function and underwent two-day 99mTc-MIBI protocol GSPECT and ERVG, were examined retrospectively. LVEF was calculated with GSPECT Myometrix software, and wall motion and thickness were calculated with QGS analysis program. In the ERVG study, LVEF values were calculated using left anterior oblique images. In the GSPECT and ERVG study, wall motion was evaluated visually and scored. LVEF values and wall motion data measured with ECHO were noted. RESULTS: For all cases, there was a significant correlation between LVEF values calculated by GSPECT and ERVG. Numerical LVEF values of 30 patients measured with ECHO showed no significant difference from the values measured with GSPECT. When 240 segments obtained from 48 patients were examined, the correlation between GSPECT and ERVG was 77.5% and between GSPECT and ECHO was 75.4% by visual wall motion analysis. Quantitatively calculated wall motion and thickness scores of segments visually defined as normokinetic were significantly higher than segments visually defined as having contraction defect. CONCLUSION: GSPECT can be used safely in clinical practice for the evaluation of LV function. Quantitatively calculated wall motion and thickness scores are promising methods to verify the visual evaluation.

Acute right lower abdominal pain in women of reproductive age: clinical clues.

AIM: To study possible gynecological organ pathologies in the differential diagnosis of acute right lower abdominal pain in patients of reproductive age. METHODS: Following Clinical Trials Ethical Committee approval, the retrospective data consisting of physical examination and laboratory findings in 290 patients with sudden onset right lower abdominal pain who used the emergency surgery service between April 2009 and September 2013, and underwent surgery and general anesthesia with a diagnosis of acute appendicitis were collated. RESULTS: Total data on 290 patients were obtained. Two hundred and twenty-four (77.2%) patients had acute appendicitis, whereas 29 (10%) had perforated appendicitis and 37 (12.8%) had gynecological organ pathologies. Of the latter, 21 (7.2%) had ovarian cyst rupture, 12 (4.2%) had corpus hemorrhagicum cyst rupture and 4 (1.4%) had adnexal torsion. Defense, Rovsing's sign, increased body temperature and increased leukocyte count were found to be statistically significant in the differential diagnosis of acute appendicitis and gynecological organ pathologies. CONCLUSION: Gynecological pathologies in women of reproductive age are misleading in the diagnosis of acute appendicitis.

Protective effects of intravenous anesthetics on kidney tissue in obstructive jaundice.

AIM: To evaluate the protective effects on kidney tissue of frequently used intravenous anesthetics (ketamine, propofol, thiopental, and fentanyl) in rats with obstructive jaundice. METHODS: There is an increased incidence of postoperative acute renal failure in patients with obstructive jaundice. Thirty-two Wistar-albino rats were randomly divided into four equal groups. Laparatomy was performed on each animal in the four groups and common bile ducts were ligated and severed on day 0. After 7 d, laparotomy was again performed using ketamine, propofol, thiopental, or fentanyl anesthesia whose antioxidative properties are well known in oxidative stress in a rat liver model of obstructive jaundice. After 2 h, the rats were sacrificed. Renal tissue specimens were analyzed for catalase, superoxide dismutase and malondialdehyde enzymes activities. All values are expressed as the mean ± SD. P values less than 0.05 were considered statistically significant. RESULTS: All animals survived without complications until the end of the study. Enlargement in the bile duct and obstructive jaundice were observed in all rats. Catalase was found to be significantly lower in the fentanyl group than in the ketamine (P = 0.039), propofol (P = 0.012), and thiopental (P = 0.001) groups. Superoxide dismutase activities were similar in all groups (P > 0.05). Malondialdehyde was found to be significantly lower in the ketamine group than in the propofol (P = 0.028), thiopental (P = 0.002) and fentanyl (P = 0.005) groups. Malondialdehyde was also lower in the fentanyl group than in the thiopental group (P = 0.001). The results showed that obstructive jaundice sensitizes renal tissue to damage under the different anesthetics. CONCLUSION: Among the agents tested, ketamine and propofol generated the least amount of oxidative stres on renal tissues in this rat model of obstructive jaundice created by common bile duct ligation. The importance of free radical injury in renal tissue in obstructive jaundice under different intravenous anesthetics during hepatobiliary and liver transplant surgery should be considered for prevention of postoperative acute renal failure.

Effect of laparoscopic abdominal surgery on splanchnic circulation: historical developments.

With the developments in medical technology and increased surgical experience, advanced laparoscopic surgical procedures are performed successfully. Laparoscopic abdominal surgery is one of the best examples of advanced laparoscopic surgery (LS). Today, laparoscopic abdominal surgery in general surgery clinics is the basis of all abdominal surgical interventions. Laparoscopic abdominal surgery is associated with systemic and splanchnic hemodynamic alterations. Inadequate splanchnic perfusion in critically ill patients is associated with increased morbidity and mortality. The underlying pathophysiological mechanisms are still not well understood. With experience and with an increase in the number and diversity of the resulting data, the pathophysiology of laparoscopic abdominal surgery is now better understood. The normal physiology and pathophysiology of local and systemic effects of laparoscopic abdominal surgery is extremely important for safe and effective LS. Future research projects should focus on the interplay between the physiological regulatory mechanisms in the splanchnic circulation (SC), organs, and diseases. In this review, we discuss the effects of laparoscopic abdominal surgery on the SC.