Free tissue transfer using bidirectional recipient veins in traumatic extremity reconstruction.

BACKGROUND: Reverse-flow flaps rely on retrograde or reverse flow for drainage and have shown success in reconstructive surgery. However, limited studies have been conducted on the use of reverse-flow recipient veins. Our study proposed bidirectional venous anastomoses within a single recipient vein to optimize venous outflow and evaluated the outcomes of an additional retrograde venous anastomosis group in traumatic extremity reconstruction. METHODS: We performed a retrospective analysis of 188 patients with traumatic extremity free flap using two venous anastomoses, which were divided into the antegrade and bidirectional venous anastomosis groups. We analyzed the basic demographic information, flap type, duration between injury and reconstruction, recipient vessels, postoperative flap outcomes, and complications. Propensity score matching was used for the additional analysis. RESULTS: Of the 188 patients analyzed, 63 free flaps (126 anastomoses, 33.5%) and 125 free flaps (250 anastomoses, 66.5%) were included in the bidirectional venous anastomosis and antegrade groups, respectively. In the bidirectional vein group, the median time between trauma and reconstruction was 13.0 ± 1.8 days and the mean flap area was 50.29 ± 7.38 cm2 . Radial artery superficial palmar branch perforator flap was most frequently performed (60.3%). In the antegrade vein group, the median time until surgery was 23.0 ± 2.1 days and the mean flap area was 85.0 ± 8.5 cm2 . Thoracodorsal artery perforator flap surgery was the most frequently performed surgery. The two groups were similar in terms of basic characteristics, but the bidirectional group demonstrated significantly higher success rate (98.4% vs. 89.7%, p = .004) and lower complication rate (6.3% vs. 22.4%, p = .007) than the antegrade group. However, these results were not observed after propensity score matching. CONCLUSIONS: Our study demonstrated successful results with the recipient vein using reverse flow. Additional retrograde venous anastomosis is a useful option for augmenting venous drainage for reconstruction of distal extremities in cases where dissection of additional antegrade vein is not feasible.

Chronic Intratendinous Tophaceous Gout in Repaired Second Extensor Digitorum Communis and Extensor Indicis Proprius Tendons: A Case Report.

ABSTRACT: A 26-year-old male patient visited outpatient clinic for pain and palpable mass at 2nd extensor digitorum communis zone V region since last year. He underwent a posttraumatic extensor tenorrhaphy on the same location 11 years ago. Otherwise previously healthy, his blood test revealed an elevated uric acid level. Preoperative magnetic resonance imaging scan suggested a lesion, such as tenosynovial hemangioma and neurogenic tumor. Excisional biopsy was performed, and total excision of the compromised second extensor digitorum communis and extensor indicis proprius tendons was also necessary. Palmaris longus tendon was grafted to the defect. Postoperative biopsy report confirmed a crystalloid material with giant cell associated granulomas, suggestive of gouty tophi.

Variable Adjustment Methods for Hemihamate Autograft Arthroplasty in Proximal Interphalangeal Joint Fracture/Dislocations: A Surgical Technique Revisited and Case Series.

ABSTRACT: Proximal interphalangeal joint fracture/dislocations, even after surgical correction, often lead to long-term complications including posttraumatic arthritis, prolonged joint stiffness, and chronic joint instability. A wide range of surgical techniques has been devised to resolve this issue, but none has been promising enough. Despite this circumstance, arthroplasty using a hemihamate autograft of size and contour that match the middle phalangeal base has progressed into one of more acceptable methods that provide both articular congruency and osseous stability. In this article, we introduce various types of proximal interphalangeal joint fracture/dislocations and individualized surgical approach using hemihamate autograft and lag screw and/or hook plate as fixation methods.

A rare case of eosinophilic cystitis involving the inside and outside of the urinary bladder associated with an infected urachal cyst.

BACKGROUND: Eosinophilic cystitis is a rare inflammatory disease of the bladder characterized by eosinophilic infiltration of the bladder wall. Most Eosinophilic cystitis cases present with mucosal lesions of the urinary bladder. We present a very rare case of large mass-forming eosinophilic cystitis, involving the inside and outside of the bladder associated with an infected urachal cyst. CASE PRESENTATION: A 59-year-old man presented with gross hematuria, fever, dysuria, and suprapubic pain. Computed tomography showed a heterogeneously enhancing mass that measured 7.6 cm × 4 cm located on the anterosuperior portion of the bladder with an internal fluid collection. Cystoscopy revealed a raspberry-like mass lesion on the bladder dome. Transurethral resection of the bladder was initially performed. The mass lesion protruding from inside the bladder was removed, and pus-like fluid was drained. The pathologic diagnosis was eosinophilic cystitis. Follow-up computed tomography showed a remnant mass outside the bladder and urachal cyst. To eliminate the remnant lesion, robot-assisted partial cystectomy was performed. The patient showed no evidence of recurrent disease on follow-up cystoscopy and computed tomography for up to 2 years. CONCLUSIONS: Clinicians should consider the possibility of eosinophilic cystitis in patients who present with hematuria, fever, and suprapubic pain and have both intravesical and extravesical masses.

Combined androgen blockade (CAB) versus luteinizing hormone-releasing hormone (LHRH) agonist monotherapy for androgen deprivation therapy.

PURPOSE: Combined androgen blockade (CAB) and luteinizing hormone-releasing hormone (LHRH) agonist monotherapy are commonly used in androgen deprivation therapy (ADT). In this randomized clinical trial, we aimed to compare the two methods of ADT in terms of quality of life (QOL). METHODS: Eighty patients who underwent primary ADT for newly diagnosed prostate cancer were randomly assigned to CAB group (Group 1) and LHRH agonist monotherapy group (Group 2). Leuprolide and anti-androgen (bicalutamide 50 mg) were used to minimize the confounding effects caused by medication. QOL was evaluated at baseline, 3 months and 6 months post-ADT using validated EORTC QLQ-C30, PR25, and depression questionnaires. A difference of > 10 points in the EORTC domain scores was defined as 'clinically significant'. RESULTS: In the baseline characteristics, there was no significant difference between the two groups. At 3 months after ADT, Group 1 had significantly lower pain scores than Group 2 (p = 0.004), while Group 1 had significantly poorer diarrhea symptom score than Group 2, without clinical significance (p = 0.047). No significant differences were observed in the C30, PR25 domains, and the depression score at 3 months. At 6 months, the QOL scores of all the groups were similar. CONCLUSIONS: There was no difference in the patient's QOL, except that CAB group was associated with significantly better pain relief than LHRH agonist monotherapy at 3 months following ADT, which was not sustained thereafter. Our results suggest that the benefit of prolonged (≥ 3 months) CAB is questionable in terms of patients' QOL.

Independent risk factors for contralateral patent processus vaginalis undetected by pre-operative ultrasonography in boys with unilateral inguinal hernia.

PURPOSE: Many trials have been done to make sure probability of metachronous contralateral side hernia (MCH) and contralateral patent processus vaginalis (CPPV). But the necessity of contralateral side exploration is still on debate. The aim is to investigate the risk factors for the consideration of contralateral examination on operation. MATERIALS AND METHODS: The study was designed as retrospectively. Patients with unilateral inguinal hernia from January 2010 to May 2015 were enrolled. Pre-operative ultrasonography was done in all patients. Patients with obvious contralateral side hernia on pre-operative US were excluded. The presence of CPPV was evaluated by transinguinal laparoscopy during the operation. RESULTS: In univariate analysis, hernial sac size only shows difference (P value: 0.001). The others, location of the hernia, age at surgery, gestational age (preterm), low birth weight and parent's age, did not show statistically significant differences. Multivariate analysis also demonstrates CPPV is more common in patients with large hernial sac (Odds ratio: 2.727, 95% confidence interval 1.495-4.974, P value: 0.001). CONCLUSION: We propose that surgeons should consider contralateral evaluation during operation in case with large ipsilateral hernial sac, although CPPV was not detected by pre-operative US.

Gastric cancers with microsatellite instability exhibit high fluorodeoxyglucose uptake on positron emission tomography.

BACKGROUND: Gastric cancers exhibit various degrees of (18)F-fluorodeoxyglucose (FDG) uptakes on positron emission tomography/computed tomography (PET/CT) imaging. The aim of this study was to evaluate whether FDG uptake in gastric cancer varies according to the microsatellite instability (MSI) status. METHODS: Consecutive gastric cancer patients who underwent PET/CT imaging and MSI analysis were included in the study. The maximum standardized uptake value (SUVmax) of gastric cancer was assessed using PET/CT imaging. RESULTS: Of 131 gastric cancers, 16 exhibited a high incidence of MSI (MSI-H) and 3 exhibited a low incidence of MSI (MSI-L). In 29 subjects who showed no uptake on PET/CT imaging the gastric cancers were all microsatellite stable (MSS). Gastric cancers with MSI were related to age older than 60 years (p = 0.002), cancer volume larger than 10 cm(3) (p = 0.015), and the presence of FDG uptake on PET/CT imaging (p = 0.001). A higher SUVmax of gastric cancer was linked to the presence of MSI (p < 0.001). CONCLUSION: The presence of MSI is related to FDG uptake in gastric cancer. Care should be taken with MSS gastric cancers, because they show lower SUVmax on PET/CT imaging than MSI gastric cancers.

Hypoplasia of left vertebral artery with intimal fibromuscular dysplasia in a Korean woman.

We found a case of hypoplasia of vertebral artery with fibromuscular dysplasia in an 82-yr-old Korean female cadaver during a routine dissection course. In the present case, intracranial hypoplasia in left vertebral artery and bilateral origin of posterior inferior cerebellar artery at the vertebrobasilar junction were recognized. Histopathologically, left vertebral artery showed intimal type of fibromuscular dysplasia both in its extracranial and intracranial courses. These results indicate that the association of fibromuscular dysplasia and hypoplasia does exist in the vertebral artery, although the etiologies are not verified yet.

Video recording of hand surgeries using a field of view (FOV) matching USB camera module and smartphone in the era of COVID-19.

BACKGROUND: As the online medium has gained in popularity due to the recent coronavirus disease (COVID-19) pandemic, video recording of surgical procedures has become crucial in medical education. Various methods for recording are available but many require professional equipment and experienced personnel. Here, we propose a feasible and acceptable method for video recording of surgeries. METHODS: An M12 mount USB camera, which is based on an Android micro-USB, was utilized. The device was purchased from a website for $32-$40. The camera was mounted between the eyes of the binocular loupes. Surgical procedures were recorded with the camera. The optimal settings were determined according to the types of surgeries. RESULTS: We recorded the following surgical procedures: radial artery superficial palmar branch (RASP) free flap harvest, carpal tunnel release, and free flap operation. The default values were retained for all settings, but the highest image quality (1080 p) was selected with an 8 mm lens. The camera battery was sufficient to record each surgery in its entirety. CONCLUSIONS: The USB camera produced high-quality videos that perfectly matched the surgeon's field of view without the need for additional staff for recording. This low-cost equipment could be widely employed for the recording of educational videos for surgeons, especially in the era of COVID 19.

Alpha-2-macroglobulin as a novel diagnostic biomarker for human bladder cancer in urinary extracellular vesicles.

Extracellular vesicles (EVs) derived from urine are promising tools for the diagnosis of urogenital cancers. Urinary EVs (uEVs) are considered potential biomarkers for bladder cancer (BC) because urine is in direct contact with the BC tumor microenvironment and thus reflects the current state of the disease. However, challenges associated with the effective isolation and analysis of uEVs complicate the clinical detection of uEV-associated protein biomarkers. Herein, we identified uEV-derived alpha-2-macroglobulin (a2M) as a novel diagnostic biomarker for BC through comparative analysis of uEVs obtained from patients with BC pre- and post-operation using an antibody array. Furthermore, enzyme-linked immunosorbent assay of uEVs isolated from patients with BC (n=60) and non-cancer control subjects (n=23) validated the significant upregulation of a2M expression in patient uEVs (p<0.0001). There was no significant difference in whole urine a2M levels between patients with BC and controls (p=0.317). We observed that compared to classical differential centrifugation, ExoDisc, a centrifugal microfluidic tangential flow filtration device, was a significantly more effective separation method for uEV protein analysis. We expect that our approach for EV analysis will provide an efficient route for the identification of clinically meaningful uEV-based biomarkers for cancer diagnosis.

Risk of fracture incidence in prostate cancer survivors: a nationwide cohort study in South Korea.

PURPOSE: We analyzed the risk of fracture in prostate cancer (PC) survivors compared to that in the general population in South Korea and according to the primary treatment. METHODS: From 2007 to 2013, a total of 41,733 PC survivors newly diagnosed with PC in South Korea were identified and matched to non-cancer controls. Cox proportional hazards regression analysis was performed to determine the relative risk of fracture. RESULTS: Compared to the matched controls, PC survivors had a higher risk of fracture (adjusted hazard ratio (aHR) 1.39; 95% confidence interval (CI) 1.33-1.45). Compared to the matched controls, the active surveillance/watchful waiting and radiotherapy group showed a similar risk of fracture (aHR 1.08; 95% CI 0.98-1.20, and aHR 1.04; 95% CI 0.63-1.73, respectively). PC survivors who underwent surgery showed a lower risk of fracture (aHR 0.89; 95% CI 0.82-0.96), while those who underwent surgery + androgen deprivation therapy (ADT) (aHR 1.41; 95% CI 1.26-1.57), radiotherapy + ADT (aHR 1.86; 95% CI 1.50-2.32), and only ADT (aHR 1.92; 95% CI 1.82-2.02) showed a higher risk of fracture than the control group. CONCLUSION: The risk of fracture differed according to the primary treatment method for PC; survivors who underwent surgery had a lower risk of fracture compared to that of the general population. However, PC survivors treated with ADT showed a higher risk of fracture than the other PC treatment groups or the general population. Therefore, more attention and preventive bone care are required for PC survivors who receive ADT.

Improving the production efficiency of high-titania slag in Ti extraction process: fluxing effect on formation of pseudobrookite.

We investigated the carbothermic reduction process of ilmenite ore at 1873 K with flux addition. Without flux, the pseudobrookite phase with a high melting temperature was precipitated during ilmenite smelting. This could be the main reason for decreased reduction of iron in ilmenite. To accelerate reduction of ilmenite, two factors were considered. One is increasing the reduction driving force during smelting. Activity of FeO is the major factor to control reduction in driving force. The other factor is delay in formation of the pseudobrookite phase, a high-melting point precipitation phase. In this system, MgO in ilmenite could be used to form pseudobrookite. To control these factors, in this study, flux agent (i.e., Na2O or SiO2) addition was considered. The thermochemical simulation program, FactSageTM7.0 was used to calculate the viscosity of slag and the activity of components as fluxing agents were added. High-temperature experiments using an induction furnace were also conducted to confirm the computational results. To determine the composition of final products, i.e., titanium slag, X-ray fluorescence analysis was executed. As a result of Fe and Ti behaviours in slag, SiO2 addition showed no significant difference from the slag without flux. However, Fe reduction in ilmenite, i.e. TiO2-enrichment, was more accelerated when Na2O was added. X-ray diffraction, scanning electron microscopic and transmission electron microscopic analyses results also showed that even 1 wt% Na2O addition significantly influenced the titanium slag production compared to no flux addition.

Seminal Vesicle Involvement by Carcinoma In Situ of the Bladder: Clonal Analysis Using Next-Generation Sequencing to Elucidate the Mechanism of Tumor Spread.

We present a rare case of urothelial carcinoma in situ (CIS), which invades the prostate and seminal vesicle (SV). A 70-year-old man underwent transurethral resection of bladder (TURB), and the pathologic examination revealed multiple CIS. Although the patient received intravesical bacillus Calmette-Guerin (BCG) therapy following TURB, recurrence of CIS was confirmed in the bladder and left distal ureter at 3 months following BCG. Radical cystectomy was performed due to BCG-refractory CIS. Microscopically, CIS was found throughout the mucosa of the bladder, left ureter, prostatic duct, and both SVs. Next-generation sequencing revealed significant differences in tumor clonality between bladder and SV CIS cells. Among 101 (bladder CIS) and 95 (SV CIS) somatic mutations, only two were shared, and only one gene (ARHGAP23) was common exon coding region gene. In conclusion, multicentric genetic changes, in line with the field-cancerization effect, may result in SV involvement by CIS of the bladder.

Extended thenar flap for two adjacent fingertip amputations.

The thenar flap is a well-described technique, but reports about its use in patients with multiple fingertip injuries are limited. This study aims to introduce a surgical technique of using an extended thenar flap for two adjacent fingertip amputations and to evaluate the clinical outcomes and related complications. From October 2013 to October 2016, 12 patients (24 fingers) underwent soft tissue reconstruction of two adjacent fingers with an extended thenar flap. At the last follow-up, the patients were assessed for cold intolerance in the reconstructed fingers; two-point discrimination (2PD); range of motion (ROM); functional outcomes using the quick disabilities of the arm, shoulder, and hand (DASH) score; functional and appearance outcomes using the Michigan Hand Outcome Questionnaire (MHQ); and time taken to return to work. The mean follow-up time was 13.5 (range: 12-16) months. All flaps survived. The mean total active ROM in flexion measured at the last follow-up was 255° (range: 245°-260°). Objective sensibility in the flaps was ascertained as an average static 2PD of 6.9 (range: 3-10) mm. The mean quick DASH score was 3.3 (range: 0-9.1). The mean MHQ score was 93.8 (range: 88-100). All patients returned to work within 6.2 weeks on average. There were no complications. The extended thenar flap technique is a good alternative for simultaneous coverage of small-to-large defects in two adjacent fingertips.

Risk of Ischemic Heart Disease and Stroke in Prostate Cancer Survivors: A Nationwide Study in South Korea.

In this study using national health insurance data, we investigated the risk of ischemic heart disease (IHD) and stroke among prostate cancer (PC) survivors compared with the general population, as well as the risk of cardiovascular disease (CVD) according to primary treatment. A total of 48,298 PC patients diagnosed from 2007 to 2013 were included and matched to non-cancer controls. Compared to the general population, PC survivors had a slightly lower risk of IHD (adjusted hazard ratio [aHR] = 0.89, 95% confidence interval [CI] 0.83-0.96) or stroke (aHR 0.90, 95% CI 0.87-0.95). Especially, survivors who underwent surgery had lower risks of IHD (aHR 0.70, 95% CI 0.61-0.80) or stroke (aHR 0.73, 95% CI 0.67-0.81). Compared to survivors in the active surveillance/watchful waiting group, the androgen deprivation therapy (ADT) group had a significantly greater risk of stroke (aHR 1.16, 95% CI 1.02-1.32), but the IHD risk was not significantly elevated (aHR 1.06, 95% CI 0.88-1.29). In conclusion, PC survivors had a slightly lower risk of CVD compared to the general population, which was attributable to self-selection for PSA screening, specifically in the surgery-only group. CVD risk was dependent on treatment received, and attention should be given to patients who receive ADT.

A novel process of extracting precious metals from waste printed circuit boards: Utilization of gold concentrate as a fluxing material.

Waste printed circuit boards (PCBs) are highly toxic materials because of the hazardous substances that are incorporated into them. An advanced recycling technology based on pyrometallurgical treatment using Au concentrate as a flux material was developed in this study. The benefits of employing roasted gold concentrate (RGC) in the smelting process of waste PCBs were demonstrated through high-temperature experiments. The major oxide compositions of PCBs (CaO, Al2O3, and SiO2) were fluxed using oxidized Au concentrate composed of FetO and SiO2. Quaternary slag systems (CaO-FetO-Al2O3-SiO2) were formed during the smelting process, which rendered the process of separation of oxide impurities from Cu-based alloys easier. Precious metals (Au and Ag) were effectively recovered from waste PCBs and Au concentrate in the form of a metal alloy that required further treatment by leaching and extraction. Residual S in the RGC significantly changed the alloy phases. A large quantity of S was formulated into a matte phase, while a small amount of S was dissolved into a Cu-Fe metal alloy. The subsequent hydrometallurgical process was optional. Electrorefining or pressure leaching could be applied depending on the type of Cu alloy.

Diffuse Large B-Cell Lymphoma Arising within Ileal Neobladder: An Expanding Spectrum of Diffuse Large B-Cell Lymphoma Associated with Chronic Inflammation.

Diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI), specifically arising in ileal neobladder, is a rare neoplasm. We present an unusual case of Epstein- Barr virus (EBV)-positive DLBCL-CI arising within neobladder with detailed clinical, histological, and immunophenotypical features in an immunocompetent patient. An 88-year-old male was admitted for gross hematuria. He had undergone radical cystectomy and ileal neobladder 17 years ago for invasive bladder cancer. Computed tomography showed enhancing lesions on dome and posterior wall of neobladder with mucosal thickening and multiple enlarged retroperitoneal lymphadenopathies. Transurethralresection of neobladder lesion revealed the diffuse infiltration of large lymphoid cells which were positive for CD20, CD30, and multiple myeloma oncogen-1 with EBV-encoded small RNAs co-localizing, and diagnosis of EBV-positive DLBCL-CI was made. After multi-agent chemotherapy, the lesion disappeared. We suggest that clinicians should consider the possibility of DLBCL-CI in patients presented with hematuria during follow-up after bladder reconstruction.

Suppression of CD81 promotes bladder cancer cell invasion through increased matrix metalloproteinase expression via extracellular signal-regulated kinase phosphorylation.

Purpose: CD81 is a prognostic biomarker for high-grade bladder cancer (BC). In this study, we aimed to determine the functional mechanisms underlying the role of CD81 in BC progression. Materials and Methods: In two invasive BC cell lines (T24, J82), CD81 expression was suppressed by the transfection of lentiviral vectors including CD81-specific shRNAs, and then the migration and invasion of BC cells was analyzed. Enzymatic activity of matrix metalloproteinases (MMPs) was also analyzed by collagen-zymography. The expression of MMPs was confirmed by western blotting using culture supernatants from each cell line. Signaling pathways related to MMPs were investigated using various antibodies. Results: CD81 was successfully knocked down by shRNAs in T24 and J82 cell lines. While the migration of BC cells was not affected after the knockdown of CD81, the invasive activity was significantly increased in both cell lines. Zymography produced distinct bands using supernatants from CD81-knockdown cells, whereas only faint bands were observed with empty vector-transfected cells. We also observed an increased expression of MMPs, specifically MMP2 and 9, in the conditioned media from CD81-knockdown cells by western blotting. Mechanistically, the phosphorylation of extracellular signal-regulated kinase (ERK) was associated with the invasive activity of BC cells, while U0126 (an ERK inhibitor) reduced the invasive activity of CD81-knockdown BC cells. Conclusions: Taken together, CD81 suppression promotes the invasive property of BC cells through MMP signaling via ERK phosphorylation. Our results suggest that the regulation of CD81 expression may have some therapeutic potential in BC.

Health-Related Quality of Life, Perceived Social Support, and Depression in Disease-Free Survivors Who Underwent Curative Surgery Only for Prostate, Kidney and Bladder Cancer: Comparison among Survivors and with the General Population.

PURPOSE: The purpose of this study was to compare health-related quality of life (HRQoL) of disease-free prostate (PC), kidney (KC), and bladder cancer (BC) survivors with that of the general population. MATERIALS AND METHODS: Our study included 331 urological cancer (UC) survivors (114 PC, 108 KC, and 109 BC) aged ≥ 50 years disease-free for at least 1 year after surgery. The control group included 1,177 subjects without a history of cancer. The HRQoL was assessed using the European Organization for Research and Treatment of Cancer QLQ-C30, the Duke-UNC Functional Social Support Questionnaire, and the Patient Health Questionnaire-9. RESULTS: There was no significant difference between the groups in terms of any of the functioning sub-scales and symptoms, except significantly lower social functioning observed in BC survivors than that observed in KC survivors. Although the three groups of UC survivors showed essentially similar functioning sub-scales and symptoms when compared to the general population, PC and BC survivors showed significantly lower social functioning and a lower appetite than that observed in controls. KC survivors showed lower physical functioning, as well as higher pain and dyspnea. Although all three groups of UC survivors reported higher financial difficulties, they also reported higher perceived social support than that reported by the non-cancer control group. No statistically significant difference was observed in terms of depressive symptoms between each group of UC survivors and the general population. CONCLUSION: Disease-free survivors of the three major types of UCs showed generally similar HRQoL compared to the general population, as well as compared to each other.

The position of fluorine in CP-118,954 affects AChE inhibition potency and PET imaging quantification for AChE expression in the rat brain.

The in vitro inhibition potency against acetylcholinesterase (AChE) of fluorinated derivatives of CP-118,954 (1) has been shown to depend upon the position of aromatic fluorine (F) substitution on the N-benzyl moiety. Indeed, the meta-F-substituted compound 3 (IC50=1.4nM) shows similar potency with the parent compound 1 (IC50=1.2nM), whereas the ortho-F derivative 2 (IC50=3.2nM) and para-F derivative 4 (IC50=10.8nM) were found to be less potent AChE inhibitors. A comparative in vivo microdialysis study in rats showed that 3 has the strongest effect on the neuropharmacological properties as AChE inhibitor. For PET imaging studies, a radiolabeled ligand ([18F]3) was synthesized through nucleophilic aromatic substitution reaction of diaryliodonium salt-based aldehyde precursor followed by reductive alkylation in a two-step radiolabeling procedure with 11.5 ± 1.2% (n=24, non-decay corrected) radiochemical yield and over 99% radiochemical purity. In a comparative PET imaging study of the three 18F-containing derivatives of CP-118,954 ([18F]2-4), [18F]3 showed the highest radioactivity in the AChE-rich region of normal rat brain which visually reflected the in vitro AChE-binding affinity of 3. These findings support [18F]3 as a promising AChE-targeted PET imaging ligand for the assessment of cholinergic activity into the brain, providing also insights into the AChE ligand disposition, which depends upon the position of the aromatic fluorine in the benzyl moiety.