1.Telomerase activity: a potential marker of bladder transitional cell carcinoma in bladder washes.
Seung Choul YANG ; Dong Hyeon LEE ; Sung Joon HONG ; Byung Ha CHUNG ; Isaac Yi KIM
Yonsei Medical Journal 1997;38(3):155-159
The enzyme telomerase maintains a constant telomere length in immortalized cells, allowing unlimited cell proliferation. Almost all cancer cells express telomerase activity. However, little data is available regarding the role of telomerase activity in the detection of bladder cancer with a bladder wash specimen. We detected telomerase activity in a bladder wash specimen of bladder cancer and normal tissues, and compared them with final pathologic diagnosis. Twenty-three patients with transitional cell carcinoma (TCC) of the bladder were enrolled in our study. A bladder wash specimen was obtained before transurethral resection of the bladder (TURB) and normal and cancer tissues from the same patients during TURB. Telomerase activity was analyzed in each specimen a using telomeric repeat amplification protocol (TRAP) assay based on polymerase chain reaction (PCR) technique. Cytologic diagnosis was performed using Papanicolaou's stain with cytocentrifuged cytology preparation. We observed telomerase activity in 95.7% (22/23) of bath cancer tissues and bladder wash specimens; only one case did not express telomerase activity. Telomerase activity was undetected in all normal tissues except one, which was obtained from a patient with carcinoma in situ. A total of 69.6% (16/23) of wash specimens were positive in cytopathologic diagnosis. The accuracy of cytopathologic diagnosis in pathologic grade 2 or 3 was relatively high (83.3%, 15/18). However, in five cases of grade 1 TCC only 20% (1/5) of cytologic diagnosis was positive whereas the telomerase activity of wash specimens was detected in 80% (4/5). Our data demonstrates that not only the majority of human bladder cancer tissues, but also the bladder wash specimens obtained from patients with TCC, expressed telomerase activity. It indicates that telomerase activity may be a reliable marker in detecting bladder cancer especially in cases with a low grade that bladder wash cytology can miss.
Aged
;
Aged, 80 and over
;
Bladder Neoplasms/enzymology*
;
Carcinoma, Transitional Cell/metabolism*
;
Female
;
Human
;
Irrigation
;
Male
;
Middle Age
;
Telomerase/metabolism*
;
Tumor Markers, Biological
2.Current Trends in Glioblastoma Multiforme Treatment: Radiation Therapy and Immune Checkpoint Inhibitors.
Sarah NICHOLAS ; Dimitris MATHIOS ; Jacob RUZEVICK ; Christopher JACKSON ; Isaac YANG ; Michael LIM
Brain Tumor Research and Treatment 2013;1(1):2-8
Glioblastoma multiforme (GBM) is the most common primary brain cancer. Even with aggressive combination therapy, the median life expectancy for patients with GBM remains approximately 14 months. In order to improve the outcomes of patients with GBM, the development of newer treatments is critical. The concept of using the immune system as a therapeutic option has been suggested for several decades; by harnessing the body's adaptive immune mechanisms, immunotherapy could provide a durable and targeted treatment against cancer. However, many cancers, including GBM, have developed mechanisms that protect tumor cells from being recognized and eliminated by the immune system. For new immunotherapeutic regimens to be successful, overcoming immunosuppression via immune checkpoint signaling should be taken into consideration.
Brain Neoplasms
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Glioblastoma*
;
Humans
;
Immune System
;
Immunosuppression
;
Immunotherapy
;
Life Expectancy
;
Radiosurgery
3.Impact of Human Immunodeficiency Virus in the Pathogenesis and Outcome of Patients with Glioblastoma Multiforme.
Winward CHOY ; Carlito LAGMAN ; Seung J LEE ; Timothy T BUI ; Michael SAFAEE ; Isaac YANG
Brain Tumor Research and Treatment 2016;4(2):77-86
BACKGROUND: Improvement in antiviral therapies have been accompanied by an increased frequency of non-Acquired Immune Deficiency Syndrome (AIDS) defining malignancies, such as glioblastoma multiforme. Here, we investigated all reported cases of human immunodeficiency virus (HIV)-positive patients with glioblastoma and evaluated their clinical outcomes. A comprehensive review of the molecular pathogenetic mechanisms underlying glioblastoma development in the setting of HIV/AIDS is provided. METHODS: We performed a PubMed search using keywords “HIV glioma” AND “glioblastoma,” and “AIDS glioma” AND “glioblastoma.” Case reports and series describing HIV-positive patients with glioblastoma (histologically-proven World Health Organization grade IV astrocytoma) and reporting on HAART treatment status, clinical follow-up, and overall survival (OS), were included for the purposes of quantitative synthesis. Patients without clinical follow-up data or OS were excluded. Remaining articles were assessed for data extraction eligibility. RESULTS: A total of 17 patients met our inclusion criteria. Of these patients, 14 (82.4%) were male and 3 (17.6%) were female, with a mean age of 39.5±9.2 years (range 19–60 years). Average CD4 count at diagnosis of glioblastoma was 358.9±193.4 cells/mm3. Tumor progression rather than AIDS-associated complications dictated patient survival. There was a trend towards increased median survival with HAART treatment (12.0 vs 7.5 months, p=0.10) CONCLUSION: Our data suggests that HAART is associated with improved survival in patients with HIV-associated glioblastoma, although the precise mechanisms underlying this improvement remain unclear.
Acquired Immunodeficiency Syndrome
;
Antiretroviral Therapy, Highly Active
;
CD4 Lymphocyte Count
;
Diagnosis
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Female
;
Follow-Up Studies
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Glioblastoma*
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HIV*
;
Humans*
;
Male
;
World Health Organization
4.A Case Series of DuraMatrix-Onlay® Plus in Cranial Surgery Is Associated With a Low Complication Profile
Mahlet MEKONNEN ; Gabrielle HOVIS ; Natalie MAHGEREFTEH ; Anubhav CHANDLA ; Yelena MALKHASYAN ; Ashley B. ZHANG ; Isaac YANG
Brain Tumor Research and Treatment 2023;11(4):232-238
Background:
DuraMatrix-Onlay® Plus is a collagen dura membrane derived from purified bovine Achilles tendon. The matrix provides a scaffold for collagen synthesis and is intended to be used as an onlay without the need for dural sutures. The study aims to describe our experience with 33 consecutive patients who underwent a duraplasty procedure using the novel DuraMatrix-Onlay® Plus collagen dura membrane.
Methods:
This is a retrospective case series of 33 patients who underwent a duraplasty proce-dure at a single academic hospital in Los Angeles, CA, USA between May 2016 and March 2017. The primary outcome was the incidence rate of cerebrospinal fluid (CSF) leak. Secondary outcomes included rates of patient infection, dural substitute complication, and removal.
Results:
Thirty-three patients underwent a duraplasty procedure using the DuraMatrix-Onlay® Plus material. The average age of the patients was 41.12±7.34 years (range 2–75 years). There were 18 (54.5%) females and 15 (45.5%) males. The majority of procedures were elective operations for the resection of a lesion (n=19, 58%), and the average graft size was 17.69±4.73 cm2 . At an average follow-up of 3 months, there were no postoperative CSF leaks. The rates of patient infection, dural substitute complication, and removal were 6%, 6%, and 3%, respectively.
Conclusion
DuraMatrix-Onlay® Plus is associated with a low rate of postoperative CSF leakage and an acceptable complication profile. This result supports the use of collagen matrices for dural closure in general neurosurgical procedures.
5.Characteristics and Treatments of Large Cystic Brain Metastasis: Radiosurgery and Stereotactic Aspiration.
Moinay KIM ; Stephanie CHEOK ; Lawrance K CHUNG ; Nolan UNG ; Kimberly THILL ; Brittany VOTH ; Do Hoon KWON ; Jeong Hoon KIM ; Chang Jin KIM ; Stephen TENN ; Percy LEE ; Isaac YANG
Brain Tumor Research and Treatment 2015;3(1):1-7
Brain metastasis represents one of the most common causes of intracranial tumors in adults, and the incidence of brain metastasis continues to rise due to the increasing survival of cancer patients. Yet, the development of cystic brain metastasis remains a relatively rare occurrence. In this review, we describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes.
Adult
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Brain*
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Drainage
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Humans
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Incidence
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Necrosis
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Neoplasm Metastasis*
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Radiosurgery*
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Survival Rate
6.Genomic and Molecular Characterization of Brain Tumors in Asian and Non-Asian Patients of Los Angeles: A Single Institution Analysis.
Courtney DUONG ; Thien NGUYEN ; John P SHEPPARD ; Vera ONG ; Lawrance K CHUNG ; Daniel T NAGASAWA ; Isaac YANG
Brain Tumor Research and Treatment 2017;5(2):64-69
BACKGROUND: Worldwide, approximately 2% of new cancers are of the brain. Five-year survival rates among brain cancer patients have been reported as a little over a third. Differences in clinical outcomes between brain tumor patients of different races remain poorly understood. METHODS: A retrospective chart review was performed on brain tumor resection patients≥18 years old. Demographics, treatment variables, and survival outcomes were collected. Primary outcomes were length of stay, recurrence rate, progression-free survival (PFS), and overall survival (OS). RESULTS: A total of 452 patients were included in analysis. Females and males had nearly a 1:1 ratio (n=242 and n=220, respectively). Mean age was 54.8 years (SD: 14.5 range: 18–90). Females composed 69% (n=48) of Asian patients; males constituted 31% (n=22). Mean age of the Asian patients was 55.9 years (SD: 14.6 range: 26–89). Asian-only cohort tumor pathologies included glioblastoma (GBM) (n=14), high-grade glioma (n=7), low-grade glioma (n=4), meningioma (n=38), and metastases (n=7). Of the 185 meningioma patients, non-Asian patients comprised 79% of the group (n=146). Of the 65 GBM patients in total, non-Asian patients made up 89% of the GBM cohort (n=58). There were no statistically significant differences between these groups of both cohorts in recurrence (p=0.1580 and p=0.6294, respectively), PFS (p=0.9662 and p=0.4048, respectively), or OS (p=0.3711 and p=0.8183, respectively). CONCLUSION: Studies evaluating the survival between patients of different racial backgrounds against several tumor varieties are rare. Patients of certain racial backgrounds may need additional consideration when being attended to despite the same mutational composition as their counterparts. Repeated studies using national databases may yield more conclusive results.
Asian Continental Ancestry Group*
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Biomarkers
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Brain Neoplasms*
;
Brain*
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Cohort Studies
;
Continental Population Groups
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Demography
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Disease-Free Survival
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Female
;
Glioblastoma
;
Glioma
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Humans
;
Length of Stay
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Male
;
Meningioma
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Neoplasm Metastasis
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Pathology
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Recurrence
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Retrospective Studies
;
Survival Rate
7.Diagnostic Role of Prostate Resection in the Elderly Patients Who Experience Significant Co-Morbidity with a High Clinical Suspicion of Prostate Cancer.
Ho Won KANG ; Jin Bak YANG ; Whi An KWON ; Young Suk LEE ; Won Tae KIM ; Yong June KIM ; Seok Joong YUN ; Sang Cheol LEE ; Isaac Yi KIM ; Wun Jae KIM
Journal of Korean Medical Science 2013;28(12):1796-1800
The necessity of routine prostate biopsy prior to transurethral resection of the prostate (TURP) in elderly comorbid patients with a high prostate specific antigen (PSA) level remains controversial. We assessed the role of TURP in prostate cancer diagnosis in these individuals. A total of 197 patients underwent TURP in conjunction with prostatic needle biopsy. Pathologic reviews of specimens of TUR chips and biopsy cores were analyzed. Overall, prostate cancer (CaP) was detected in 114 patients (57.6%). Ninety-eight cancers (86%) were detected with TURP and biopsy, and seven cancers (6.1%) with only TURP. The Gleason score of a TUR-specimen was identical to that of the biopsy-core in 43.9% of cases. Variables associated with diagnostic accuracy in the TUR-specimens included the prebiopsy PSA level, prostate specific antigen density (PSAD), and the Gleason score in biopsy cores. In patients with a PSA level and a PSAD that was greater than 15.4 ng/mL and 0.69 ng/mL/g, respectively, 100% of the cancers were detected in the TUR-specimens. Our results suggest that a prostatic biopsy might be omitted prior to TURP in elderly patients with significant co-morbidity and levels for PSA of >15.4 ng/mL.
Aged
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Aged, 80 and over
;
Area Under Curve
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Biopsy, Needle
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Comorbidity
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Humans
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Male
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Neoplasm Grading
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Prostate/*surgery
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Prostate-Specific Antigen/*blood
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Prostatic Neoplasms/*diagnosis/epidemiology/*pathology/surgery
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ROC Curve
;
Transurethral Resection of Prostate
8.Systematic Analysis of Clinical Outcomes Following Stereotactic Radiosurgery for Central Neurocytoma.
Timothy T BUI ; Carlito LAGMAN ; Lawrance K CHUNG ; Stephen TENN ; Percy LEE ; Robert K CHIN ; Tania KAPREALIAN ; Isaac YANG
Brain Tumor Research and Treatment 2017;5(1):10-15
Central neurocytoma (CN) typically presents as an intraventricular mass causing obstructive hydrocephalus. The first line of treatment is surgical resection with adjuvant conventional radiotherapy. Stereotactic radiosurgery (SRS) was proposed as an alternative therapy for CN because of its lower risk profile. The objective of this systematic analysis is to assess the efficacy of SRS for CN. A systematic analysis for CN treated with SRS was conducted in PubMed. Baseline patient characteristics and outcomes data were extracted. Heterogeneity and publication bias were also assessed. Univariate and multivariate linear regressions were used to test for correlations to the primary outcome: local control (LC). The estimated cumulative rate of LC was 92.2% (95% confidence interval: 86.5-95.7%, p<0.001). Mean follow-up time was 62.4 months (range 3-149 months). Heterogeneity and publication bias were insignificant. The univariate linear regression models for both mean tumor volume and mean dose were significantly correlated with improved LC (p<0.001). Our data suggests that SRS may be an effective and safe therapy for CN. However, the rarity of CN still limits the efficacy of a quantitative analysis. Future multi-institutional, randomized trials of CN patients should be considered to further elucidate this therapy.
Brain Neoplasms
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Follow-Up Studies
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Humans
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Hydrocephalus
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Linear Models
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Neurocytoma*
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Particle Accelerators
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Population Characteristics
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Publication Bias
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Radiosurgery*
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Radiotherapy
;
Tumor Burden
9.Racial Differences in Hospital Stays among Patients Undergoing Craniotomy for Tumour Resection at a Single Academic Hospital
John P SHEPPARD ; Carlito LAGMAN ; Prasanth ROMIYO ; Thien NGUYEN ; Daniel AZZAM ; Yasmine ALKHALID ; Courtney DUONG ; Isaac YANG
Brain Tumor Research and Treatment 2019;7(2):122-131
BACKGROUND: Racial differences in American patients undergoing brain tumour surgery remain poorly characterized within urban medical centres. Our objective was to assess racial differences in operative brain tumour patients at a single academic hospital in Los Angeles, California. METHODS: We reviewed medical records of adult patients undergoing craniotomy for tumour resection from March 2013 to January 2017 at UCLA Medical Centre. Patients were categorized as Asian, Hispanic, Black, or White. Racial cohorts were matched on demographic variables for comparisons. Our primary outcome was post-operative length of stay (LOS). Secondary outcomes included hospital mortality and discharge disposition. RESULTS: In this study, 462 patients identified as Asian (15.1%), Hispanic (8.7%), Black (3.9%), or White (72.3%). After cohort matching, non-White patients had elevated risk of prolonged LOS [odds ratio (OR)=2.62 (1.44, 4.76)]. No differences were observed in hospital mortality or non-routine discharge. Longer LOS was positively correlated with non-routine discharge [r(pb) (458)=0.41, p<0.001]. Black patients with government insurance had average LOS 2.84 days shorter than Black patients with private insurance (p=0.04). Among Hispanics, government insurance was associated with non-routine discharge [OR=4.93 (1.03, 24.00)]. CONCLUSION: Racial differences manifested as extended LOS for non-White patients, with comparable rates of hospital mortality and non-routine discharge across races. Prolonged LOS loosely reflected complicated clinical course with greater risk of adverse discharge disposition. Private insurance coverage predicted markedly lower risk of non-routine discharge for Hispanic patients, and LOS of three additional days among Black patients. Further research is needed to elucidate the basis of these differences.
Adult
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Asian Continental Ancestry Group
;
Brain
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Brain Neoplasms
;
California
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Cohort Studies
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Continental Population Groups
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Craniotomy
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Hispanic Americans
;
Hospital Mortality
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Humans
;
Insurance
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Insurance Coverage
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Length of Stay
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Medical Records
;
Socioeconomic Factors
10.Risk of Brain Tumor Induction from Pediatric Head CT Procedures: A Systematic Literature Review.
John P SHEPPARD ; Thien NGUYEN ; Yasmine ALKHALID ; Joel S BECKETT ; Noriko SALAMON ; Isaac YANG
Brain Tumor Research and Treatment 2018;6(1):1-7
Head computed tomography (CT) is instrumental for managing patients of all ages. However, its low dose radiation may pose a low but non-zero risk of tumor induction in pediatric patients. Here, we present a systematic literature review on the estimated incidence of brain tumor induction from head CT exams performed on children and adolescents. MEDLINE was searched using an electronic protocol and bibliographic searches to identify articles related to CT, cancer, and epidemiology or risk assessment. Sixteen studies that predicted or measured head CT-related neoplasm incidence or mortality were identified and reviewed. Epidemiological studies consistently cited increased tumor incidence in pediatric patients (ages 0–18) exposed to head CTs. Excess relative risk of new brain tumor averaged 1.29 (95% confidence interval, 0.66–1.93) for pediatric patients exposed to one or more head CTs. Tumor incidence increased with number of pediatric head CTs in a dose-dependent manner, with measurable excess incidence even after a single scan. Converging evidence from epidemiological studies supported a small excess risk of brain tumor incidence after even a single CT exam in pediatric patients. However, refined epidemiological methods are needed to control for confounding variables that may contribute to reverse causation, such as patients with pre-existing cancer or cancer susceptibility. CT remains an invaluable technology that should be utilized so long as there is clinical indication for the study and the radiation dose is as small as reasonably achievable.
Adolescent
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Brain Neoplasms*
;
Brain*
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Child
;
Confounding Factors (Epidemiology)
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Epidemiologic Methods
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Epidemiologic Studies
;
Epidemiology
;
Head*
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Humans
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Incidence
;
Mortality
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Patient Safety
;
Pediatrics
;
Radiometry
;
Risk Assessment
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Tomography, X-Ray Computed