Is ChatGPT a “Fire of Prometheus” for Non-Native English-Speaking Researchers in Academic Writing?

Large language models (LLMs) such as ChatGPT have garnered considerable interest for their potential to aid non-native English-speaking researchers. These models can function as personal, round-the-clock English tutors, akin to how Prometheus in Greek mythology bestowed fire upon humans for their advancement. LLMs can be particularly helpful for non-native researchers in writing the Introduction and Discussion sections of manuscripts, where they often encounter challenges.However, using LLMs to generate text for research manuscripts entails concerns such as hallucination, plagiarism, and privacy issues; to mitigate these risks, authors should verify the accuracy of generated content, employ text similarity detectors, and avoid inputting sensitive information into their prompts. Consequently, it may be more prudent to utilize LLMs for editing and refining text rather than generating large portions of text. Journal policies concerning the use of LLMs vary, but transparency in disclosing artificial intelligence tool usage is emphasized. This paper aims to summarize how LLMs can lower the barrier to academic writing in English, enabling researchers to concentrate on domain-specific research, provided they are used responsibly and cautiously.

Deep-Seated Giant Lipoma on the Hand Inducing Carpal Tunnel Syndrome

Lipoma is a very frequent benign soft tissue tumor, but its occurrence in the hands is rare. Lipoma in the hands is generally asymptomatic; however, symptoms may develop if local neurovascular structures are compressed due to size or location of the lipoma. Carpal tunnel syndrome, which is a compressive neuropathy of the median nerve, is the most common neuropathy in the hands and presents pain, numbness, hypoesthesia, and atrophy of the thenar muscle. We present a case of carpal tunnel syndrome by deep-seated giant lipoma with a literature review.

Evaluation of lymph node metastasis in a rabbit tumor model: correlations between contrast-enhanced ultrasound and pathologic findings

Purpose@#The purpose of this study was to evaluate the ability of contrast-enhanced ultrasonography (CEUS) with microbubbles to detect metastatic lymph nodes (LNs) for treatment planning and prognosis. @*Methods@#For the metastatic LN model, ground VX2 tumor tissues were injected subcutaneously in 12 rabbits, just below the right hind limb. The rabbits were classified into three groups based on the LN area: group A (n=4, >1.9 cm2 ), group B (n=4, 1-1.9 cm2 ), and group C (n=4, <1 cm2 ). The LNs were monitored on CEUS for 10 seconds after injecting 2.5 mL of microbubbles. The percent area of metastatic LNs was calculated on pathologic images and compared with CEUS images. @*Results@#In group A, the mean percent area of metastasis was 40.7%±19.4%. In all cases of metastasis, round-shaped perfusion defects were clearly observed in CEUS images. The metastatic areas were strongly correlated with pathologic findings. The mean percent area in group B was 21.5%±14.4%. The CEUS findings showed multiple nodular perfusion defects, clearly revealing the metastatic areas. In group B, the CEUS and pathologic findings were concordant for three of the four cases. The mean percent area in group C was 9.1%±6.4%. However, in this group, CEUS only detected a small perfusion defect in one case. @*Conclusion@#CEUS has the potential to depict characteristic imaging features of metastatic LNs but still has limitations in early detection.

Comparison of the diagnostic yield of various systematic randomized prostate biopsy protocols using prostate phantoms made of devil's tongue jelly

PURPOSE: The purpose of this study was to compare the diagnostic yield of five systematic randomized protocols using 12–20 biopsy cores with variably-sized phantoms. METHODS: A total of 100 prostate phantom models were produced by casting liquid devil's tongue jelly using silicone molds. Sets of 20 phantoms were created with the following volumes: 20 mL, 40 mL, 60 mL, 80 mL, and 100 mL. Three focal lesions were created by injecting 0.5 mL of warm agar solution stained with red, blue, and green ink into each phantom model. The focal lesions were verified by ultrasonography. The systematic randomized biopsy protocols consisted of 12, 14, 16, 18, and 20 biopsy cores. The diagnostic yield of the multiple systematic biopsy protocols was compared. RESULTS: The overall detection rates of each model set were 93.3% for 20 mL, 88.3% for 40 mL, 71.7% for 60 mL, 43.3% for 80 mL, and 30.0% for 100 mL. Statistically significant differences in the detection rate were found between 40 mL and 60 mL and between 60 mL and 80 mL. No statistically significant increase in the detection rate was observed within a given volume set even when the number of core biopsies increased from 12 to 20. CONCLUSION: The diagnostic yield of systematic randomized biopsies is inversely proportional to the phantom volume.

Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography

OBJECTIVE: To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. MATERIALS AND METHODS: This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. RESULTS: The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. CONCLUSION: The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

Effects of Whole-Body Vibration on the Improvement of Balance, Gait and Activities of Daily Living in Patients with Subacute Stroke

OBJECTIVE: The purpose of this study was to investigate the effects of whole-body vibration on the improvement of functional performance in subacute stroke patients. METHODS: Twenty subacute stroke patients were equally randomized to either a vibration or a control group and received 4-week conventional rehabilitation therapy and standing exercise. During the standing exercise, the vibration group received 10-minute whole-body vibration and the control group performed standing exercise without vibration. Outcome variable included the Korean version of Berg Balance Scale (BBS), the manual muscle test (MMT) of the paretic knee extensor, Modified Ashworth Scale (MAS) of the paretic ankle plantar flexor spasticity, Functional Ambulation Category (FAC), and the Korean version of Modified Barthel Index (MBI) before and after 4-week intervention. RESULTS: After the 4-week intervention, the difference in BBS between groups was significant, which was significantly larger in the vibration group than in the control group. Significant differences in FAC and MBI were also observed between groups. The change of the FAC, total MBI, and mobility MBI were significantly higher in the vibration group than in the control group. MMT and MAS did not show significant difference after intervention between groups. Differences in BBS were strongly positively correlated with FAC and mobility MBI, and were moderately correlated with both of total MBI and self-care MBI. CONCLUSION: Additional whole-body vibration intervention may efficiently improve balance control and ambulation in subacute stroke patients.

Clinical Usefulness of Unenhanced Computed Tomography in Patients with Acute Pyelonephritis

BACKGROUND: Unenhanced computed tomography (UCT) may be useful for evaluating acute pyelonephritis; however, no study has compared UCT with enhanced computed tomography (ECT) as a diagnostic tool. We evaluated a clinical usefulness of UCT versus ECT in acute pyelonephritis (APN). METHODS: We reviewed the clinical and radiological data from 183 APN-suspected patients who underwent UCT and ECT simultaneously at emergency room (ER) over a two-year period. Demographic, clinical parameters and computed tomography (CT) parameters of 149 patients were compared. RESULTS: The average patient age was 61.2 (± 10) years: 31 patients were men. Ninety-nine (66.4%) patients showed stones (18.7%), perinephric infiltration (56%), swelling (21%), and hydronephrosis (6.7%) on UCT. Seventeen patients (11.4%) had an atypical clinical course, requiring additional tests for accurate diagnosis. In 7 patients UCT and ECT results did not differ; in 10 patients, the diagnosis changed on ECT. On ECT, 112/149 (75.2%) patients had stones (16.7%), perinephric infiltrations (57%), swelling (21%), and hydronephrosis (6.7%); 62.5% showed parenchymal involvement: 34 (22.8%) patients had no abnormal ECT findings. APN CT findings are similar on stone, perinephric infiltration, swelling and hydronephrosis on both CTs. Twelve patients (8.0%) had an abnormal ECT finding, i.e., low-grade (1 and 2) parenchymal involvement. Six (4%) patients developed contrast-induced acute kidney injury within 2 days after ECT. CONCLUSION: We demonstrate that UCT is not inferior to ECT as an initial tool for evaluating APN for screening nephrolithiasis and hydronephrosis without the risk of contrast-induced acute kidney injury (CIAKI). However, patients with an atypical clinical course may still need ECT.

Multimodality Imaging in Patients with Secondary Hypertension: With a Focus on Appropriate Imaging Approaches Depending on the Etiologies

Although the causes of hypertension are usually unknown, about 10% of the cases occur secondary to specific etiologies, which are often treatable. Common categories of secondary hypertension include renal parenchymal disease, renovascular stenosis, vascular and endocrinologic disorders. For diseases involving the renal parenchyma and adrenal glands, ultrasonography (US), computed tomography (CT) or magnetic resonance (MR) imaging is recommended. For renovascular stenosis and vascular disorders, Doppler US, conventional or noninvasive (CT or MR) angiography is an appropriate modality. Nuclear imaging can be useful in the differential diagnosis of endocrine causes. Radiologists should understand the role of each imaging modality and its typical findings in various causes of secondary hypertension. This article focuses on appropriate imaging approaches in accordance with the categorized etiologies leading to hypertension.

Focal lesion at the midline of the prostate on transrectal ultrasonography: take it or leave it?

PURPOSE: The purpose of this study was to analyze the detection rate of prostate cancers from targeted biopsy specimens of midline focal lesions and to investigate the ultrasonographic findings to reduce unnecessary additional targeted biopsies. METHODS: Ninety-eight men with midline focal lesions detected on transrectal ultrasonography were enrolled. Additional targeted biopsies for midline focal lesions were performed after 12-core random systematic biopsies. Correlations between the ultrasonographic characteristics of midline focal lesions and the pathologic results were analyzed. RESULTS: Twenty of 98 targeted biopsy cores (20.4%) were positive for malignancy. In a univariate analysis, midline focal lesions without bulging contours (P=0.023), with involved margins (P=0.001), without hypoechoic perilesional rims (P=0.005), and with longer diameters (P=0.005) were statistically significant for cancer detection. In a multivariate analysis, involved margin (P=0.027), having longer diameter (P=0.011) or absence of hypoechoic perilesional rim (P=0.025) made a statistically significant contribution to cancer detection. CONCLUSION: Biopsy of midline focal lesions was not always non-significant in the detection of prostate cancer. Additional targeted biopsies should be considered in cases of midline focal lesions with involved margins but without hypoechoic perilesional rims.

Ultrasound contrast-enhanced study as an imaging biomarker for anti-cancer drug treatment: preliminary study with paclitaxel in a xenograft mouse tumor model (secondary publication)

PURPOSE: The purpose of this study was to assess tumor angiogenesis using contrast-enhanced ultrasonography (CEUS) of human prostate cancer cells (PC3) that were implanted in mice before and after paclitaxel injection. METHODS: Twelve mice were injected with human PC3. The mice were grouped into two groups; one was the paclitaxel-treated group (n=6) and the other was the control group (n=6). Before administering paclitaxel into the peritoneal cavity, baseline CEUS was performed after the administration of 500 μL (1×108 microbubbles) of contrast agent. The area under the curve (AUC) up to 50 seconds after injection was derived from the time-intensity curves. After injection of paclitaxel or saline, CEUS studies were performed at the 1-week follow-up. Changes in tumor volume and the AUC in both two groups were evaluated. After CEUS, the microvessel density (MVD) was compared between the groups. RESULTS: In the paclitaxel-treated group, the AUC from CEUS showed a significant decrease 1-week after paclitaxel administration (P=0.030), even though the tumor volume showed no significant changes (P=0.116). In the control group, there was no significant decrease of the AUC (P=0.173). Pathologically, there was a significant difference in MVD between both groups (P=0.002). CONCLUSION: The AUC from the time intensity curve derived from CEUS showed an early change in response to the anti-cancer drug treatment that preceded the change in tumor size. The findings of CEUS could serve as an imaging biomarker for assessing tumor responses to anti-cancer drug treatment.

Factors Related to the Occurrence of Urinary Tract Infection Following a Urodynamic Study in Patients With Spinal Cord Injury

OBJECTIVE: To analyze the factors related to urinary tract infection (UTI) occurrence after an urodynamic study (UDS) in patients with spinal cord injury (SCI). METHODS: We retrospectively investigated the medical records of 387 patients with SCI who underwent UDS with prophylactic antibiotic therapy between January 2012 and December 2012. Among them, 140 patients met the inclusion criteria and were divided into two groups, UTI and non-UTI. We statistically analyzed the following factors between the two groups: age, sex, level of injury, SCI duration, spinal cord independence measure, non-steroidal anti-inflammatory drug use, diabetes mellitus, the American Spinal Injury Association impairment scale (AIS), lower extremity spasticity, a history of UTI within the past 4 weeks prior to the UDS, symptoms and signs of neurogenic bladder, urination methods, symptoms during the UDS and UDS results. RESULTS: Among the 140 study participants, the UTI group comprised 12 patients and the non-UTI group comprised 128 patients. On univariate analysis, a history of UTI within the past 4 weeks prior to the UDS was significant and previous autonomic dysreflexia before the UDS showed a greater tendency to influence the UTI group. Multivariable logistic regression analysis using these two variables showed that the former variable was significantly associated with UTI and the latter variable was not significantly associated with UTI. CONCLUSION: In patients with SCI, a history of UTI within the past 4 weeks prior to the UDS was a risk factor for UTI after the UDS accompanied by prophylactic antibiotic therapy. Therefore, more careful pre-treatment should be considered when these patients undergo a UDS.

Usefulness of resistive index on spectral Doppler ultrasonography in the detection of renal cell carcinoma in patients with end-stage renal disease

PURPOSE: The aim of this study was to explore the usefulness of the resistive index (RI) on spectral Doppler ultrasonography (US) in the detection of renal cell carcinoma (RCC) in patients with end-stage renal disease (ESRD). METHODS: Seventeen ESRD patients with kidneys in which renal masses were suspected in routine US were subjected. They underwent computed tomography scans and additional Doppler US for the characterization of the detected lesions. All underwent radical nephrectomy with the suspicion of RCC. Fourteen patients finally were included. RI measurements were conducted in the region of the suspected renal mass and the background renal parenchyma. The intraclass correlation coefficient was used to assess the reproducibility of the RI measurement. A paired t-test was used to compare the RI values between the renal mass and the background renal parenchyma (P<0.05). RESULTS: The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma (0.41-0.65 vs. 0.75-0.89; P<0.001). The intrareader reproducibility proved to be excellent and good for the renal masses and the parenchyma, respectively (P<0.001). CONCLUSION: RI on spectral Doppler US is useful in detecting RCC in patients with ESRD. The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma.

Trastuzumab-Conjugated Liposome-Coated Fluorescent Magnetic Nanoparticles to Target Breast Cancer

OBJECTIVE: To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNP@m-SiO2]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNP@m-SiO2]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. MATERIALS AND METHODS: The physiochemical characteristics of Lipo[MNP@m-SiO2] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNP@m-SiO2] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin(R))-conjugated Lipo[MNP@m-SiO2] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. RESULTS: We obtained uniformly-sized and evenly distributed Lipo[MNP@m-SiO2] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNP@m-SiO2] was observed by in vitro fluorescence and MR imaging. CONCLUSION: Trastuzumab-conjugated Lipo[MNP@m-SiO2] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.

The Correlations of Parameters Using Contrast Enhanced Ultrasonography in the Evaluation of Prostate Cancer Angiogenesis

PURPOSE: The purpose of this study is to investigate the correlations of various kinetic parameters derived from the time intensity curve in a xenograft mouse model injected with a prostate cancer model (PC-3 and LNCaP) using an ultrasound contrast agent with histopathologic parameters. MATERIALS AND METHODS: Twenty nude mice were injected with human prostate cancer cells (15 PC-3 and five LNCaP) on their hind limbs. A bolus of 500 microL (1 x 10(8) microbubbles) of second-generation US contrast agent (SonoVue) was injected into the retroorbital vein. The region of interest was drawn over the entire tumor. The time intensity curve was acquired and then fitted to a gamma variate function. The maximal intensity (A), time to peak (Tp), maximal wash-in rate (washin), washout rate (washout), area under the curve up to 50 sec (AUC50), area under the ascending slope (AUC(in)), and area under the descending slope (AUC(out)) were derived from the parameters of the gamma variate fit. Immunohistochemical staining for VEGF and CD31 was performed. Tumor volume, the area percentage of VEGF stained in a field, and the count of CD31 (microvessel density, MVD) positive vessels showed correlation with the parameters from the time intensity curve. RESULTS: No significant differences were observed between the kinetic and histopathological parameters from each group. MVD showed positive correlation with A (r=0.625, p=0.003), washin (r=0.462, p=0.040), AUC50 (r=0.604, p=0.005), and AUC(out) (r=0.587, p=0.007). Positive correlations were also observed between tumor volume and AUC50 (r=0.481, p=0.032), washin (r=0.662, p=0.001), and AUC(out) (r=0.547, p=0.012). Washout showed negative correlations with MVD (r=-0.454, p=0.044) and tumor volume (r=-0.464, p=0.039). The area percentage of VEGF did not show any correlation with calculated data from the curve. CONCLUSION: MVD showed correlations with several of the kinetic parameters. CE-US has the potential for prediction of tumor vascularity in a prostate cancer animal model.

The Selection of the Appropriate Computer Interface Device for Patients With High Cervical Cord Injury

In order to determine the most suitable computer interfaces for patients with high cervical cord injury, we report three cases of applications of special input devices. The first was a 49-year-old patient with neurological level of injury (NLI) C4, American Spinal Injury Association Impairment Scale (ASIA)-A. He could move the cursor by using a webcam-based Camera Mouse. Moreover, clicking the mouse could only be performed by pronation of the forearm on the modified Micro Light Switch. The second case was a 41-year-old patient with NLI C3, ASIA-A. The SmartNav 4AT which responds according to head movements could provide stable performance in clicking and dragging. The third was a 13-year-old patient with NLI C1, ASIA-B. The IntegraMouse enabling clicking and dragging with fine movements of the lips. Selecting the appropriate interface device for patients with high cervical cord injury could be considered an important part of rehabilitation. We expect the standard proposed in this study will be helpful.

Evaluation of Renal Oxygenation in Normal Korean Volunteers Using 3.0 T Blood Oxygen Level-Dependent MRI

PURPOSE: Renal blood oxygen level-dependent (BOLD) MRI has been used in the evaluation of renal oxygenation. We tried to provide the normal R2* value of the human kidney with 3.0 T, and evaluated the differences in R2* values according to gender and location. MATERIALS AND METHODS: Twenty-four healthy volunteers underwent BOLD MRI at 3.0 T. Multi gradient echo-echo planar imaging sequence with seventeen echoes was used. After generation of the T2* map, the R2* was calculated. The statistical differences in R2* values between the cortex and medulla, males and females, and the right and left kidney were analyzed. The regional differences of R2* within the both kidneys were evaluated respectively. RESULTS: BOLD MRI was successful in all participants. No gross artifact interfered with R2* measurement. The mean R2* at 3.0 T was 17.1 +/- 2.60 s-1 in the cortex and 27.7 +/- 4.83 s-1 in the medulla (p < 0.001). The R2* value in the medulla was significantly higher in the male than female volunteers (p = 0.025). There were no statistical differences of R2* according to the side and location in the kidney (p = 0.197). CONCLUSION: Renal BOLD MRI can be efficiently performed with 3.0 T MRI. Renal medullary hypoxia is present in normal volunteers. Our results may be used as reference values in the evaluation of pathologic conditions using BOLD MRI.

In Vitro and In Vivo Imaging of Prostate Cancer Angiogenesis Using Anti-Vascular Endothelial Growth Factor Receptor 2 Antibody-Conjugated Quantum Dot

OBJECTIVE: Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)-conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. MATERIALS AND METHODS: Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with antiVGFR2, to see a specific binding in vitro. Fluorescent cell images were taken by a confocal microscope. The human prostate cancer cells (PC3) were injected to five nude mice on hind limbs to make the xenograft tumor model. QD-antiVEGFR2 antibody complex was injected into the tumor model and fluorescence measurements were performed at 1, 4, 9, 12, 15, and 24 hours after the injection. RESULTS: The specific interaction between HUVECs and QD-antiVEGFR2 antibody was clearly shown in vitro. The in vivo fluorescence image disclosed that there was an increased signal of tumor, 12 hours after the injection of QDs. CONCLUSION: By showing endothelial cells binding with QDs-antiVEGFR2 antibodyand an experimental application of the antibody for VEGFR2 imaging in the prostate cancer xenograft mouse model, we suggests that the antibody-conjugated QDs can be a potential imaging tool for angiogenesis of the cancer.

Resilience as a Possible Predictor for Psychological Distress in Chronic Spinal Cord Injured Patients Living in the Community

OBJECTIVE: To investigate whether higher resilience level predicts low levels of psychological distress in chronic SCI patients living in the community. METHOD: Thirty seven patients (mean age 41.5+/-10.9, male : female=28 : 9) with chronic spinal cord injury (duration 8.35+/-7.0 years) living in the community are included, who were hospitalized for annual checkups from November, 2010 to May, 2011. First, their spinal cord injury level, completeness and complications were evaluated. The patients completed questionnaires about their educational status, religion, employment status, marital status, medical and psychological history and also the following questionnaires: Hospital Anxiety and Depression Scale (HADS), Connor-Davidson Resilience Scale (CD-RISC), Alcohol Use Disorders Identification Test-alcohol consumption questions (AUDIT-C) and Health-related quality of life (EQ-5D). The patients were divided into two subgroups: patients with HADS > or =13 are classified as high psychological distress group and others as low psychological distress group. We compared the two groups to find statistically significant differences among the variables. RESULTS: CD-RISC, EQ-5D and employment status are significantly different between two groups (p<0.05). In a forward stepwise regression, we found that EQ-5D had a greater contribution than CD-RISC to the psychological distress level. CONCLUSION: In addition to health-related quality of life, resilience can be suggested as a possible predictor of psychological distress in chronic SCI patients.

Endotracheal intubation using i-gel and a flexible fiber optic bronchoscope: A case report

Most anesthesiologists, at one point or another, are faced with a difficult airway. We came upon an unexpected difficult airway and a failed intubation using a direct laryngoscope and lightwand. At this point, we decided to insert an i-gel which is quick and simple. This allowed us to maintain oxygenation and ventilation. After checking for the location of the laryngeal inlet with a flexible fiber optic bronchoscope, a 5.5 mm internal diameter endotracheal tube was inserted into the trachea over the flexible fiber optic bronchoscope. Finally, a suitable a 7.0 mm internal diameter endotracheal tube was inserted using an exchange catheter technique. With respect to this case, we conclused that the i-gel is a very helpful device for endotracheal intubation in patients with difficult airways.

US Contrast Enhanced Study as an Imaging Biomarker of Anti-cancer Drug Treatment: Preliminary Study with Paclitaxel and a Xenograft Mouse Tumor Model

PURPOSE: We wanted to assess tumor angiogenesis of human prostate cancer cells (PC3) implanted in mice before and after paclitaxel injection via contrast-enhanced ultrasonography (CEUS). MATERIALS AND METHODS: Twelve mice were injected with human prostate cancer cells (PC3) on the back or hind limbs. The mice were grouped into two groups; one was the paclitaxel treated group (n = 6) and the other was the control group, which was treated with normal saline (n = 6). Before injection of paclitaxel into the peritoneal cavity, baseline CEUS was performed by the administration of 500 microl (1x108 microbubbles) of contrast agent. The area under the curve (AUC) up to 50 seconds after contrast injection was derived from the time-intensity curves. After injection of paclitaxel or saline, one week follow up CEUS studies were performed. The changes of the tumor volume and the AUC in both two groups were evaluated. After CEUS, the mice were sacrificed and the microvessel density (MVD) was compared. RESULTS: In the paclitaxel treated group, the AUC from CEUS showed a significant decrease one week after paclitaxel administration (p = 0.03), even though the tumor volume showed no significant changes (p = 0.116). In the control group, there was no significant decrease of the AUC (p = 0.173). Pathologically, there was a significant difference of microvessel density in both groups (p = 0.002). CONCLUSION: The AUC from the time intensity curve derived from CEUS showed early change in response to the anti-cancer drug treatment in advance of a tumor size response. The findings of CEUS could be an imaging biomarker for assessing the tumor response to anti-cancer drug treatment.