2.Evaluation of imaging performance of major image guidance systems
Chan MF* ; Yang J ; Song Y ; Burman C ; Chan P ; Li S
Biomedical Imaging and Intervention Journal 2011;7(2):1-7
Purpose: The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in
image-guided radiation therapy (IGRT) were evaluated.
Materials and methods: The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and
Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image
quality including image noise, uniformity, density accuracy, spatial resolution, contrast linearity, and contrast resolution.
The measurement results were analysed using in-house image analysis software. Reproducibility, position correction,
and geometric accuracy were also evaluated with markers in a smaller alignment phantom. The performance evaluation
compared volumetric image properties from these four systems with those from a conventional diagnostic CT (CCT).
Results: It was shown that the linearity of the two kV CBCT was fairly consistent with CCT. The Elekta CBCT
with half-circle 27-cm FOV had higher CT numbers than the other three systems. The image noises of the Elekta kV
CBCT, Siemens MV CBCT, and Tomotherapy fan-beam CT (FBCT) are about 2-4 times higher than that of the Varian
CBCT. The spatial resolutions of two kV CBCTs and two MV CBCTs were 8-11 lp/cm and 3-5 lp/cm, respectively.
Conclusion: Elekta CBCT provided a faster image reconstruction and low dose per scan for half-circle scanning.
Varian CBCT had relatively lower image noise. Tomotherapy FBCT had the best uniformity.
4.Scanning laser polarimetry in pulmonary tuberculosis patients on chemotherapy.
Wilson W T TANG ; Jimmy S M LAI ; Clement C Y THAM ; Kam-Keung CHAN ; Kin-Sang CHAN
Annals of the Academy of Medicine, Singapore 2006;35(6):395-399
INTRODUCTIONThe aim of this study was to analyse the thickness of the retinal nerve fibre layer (RNFL) of pulmonary tuberculosis patients on ethambutol and isoniazid.
MATERIALS AND METHODSThis was a prospective cohort study where patients with newly diagnosed pulmonary tuberculosis requiring chemotherapy, including ethambutol and isoniazid, were imaged using scanning laser polarimetry. Their mean baseline RNFL thickness and various scanning laser polarimetry parameters of both eyes were measured 2 weeks after the commencement of chemotherapy. The measurements were repeated at 3 months and 6 months after treatment. The various parameters of the baseline and the follow-up measurements were compared using paired sample t-test with Bonferroni correction.
RESULTSTwenty-four patients (16 males and 8 females; mean age, 51.0 +/- 17.6 years) were recruited. There was no statistically significant difference between the baseline and the follow-up measurements in RNFL thickness and all other scanning laser polarimetry parameters.
CONCLUSIONIn this cohort of subjects, there was no subclinical change in RNFL thickness detected by scanning laser polarimetry in pulmonary tuberculosis patients on chemotherapy, including ethambutol and isoniazid, after 6 months of treatment.
Adult ; Aged ; Aged, 80 and over ; Antitubercular Agents ; adverse effects ; therapeutic use ; Diagnostic Techniques, Ophthalmological ; Ethambutol ; adverse effects ; therapeutic use ; Female ; Humans ; Isoniazid ; adverse effects ; therapeutic use ; Lasers ; Male ; Middle Aged ; Prospective Studies ; Retinal Diseases ; chemically induced ; diagnosis ; Tuberculosis, Pulmonary ; drug therapy
5.Evaluation and treatment of facial feminization surgery: part I. forehead, orbits, eyebrows, eyes, and nose
Brian N. DANG ; Allison C. HU ; Anthony A. BERTRAND ; Candace H. CHAN ; Nirbhay S. JAIN ; Miles J. PFAFF ; James C. LEE ; Justine C. LEE
Archives of Plastic Surgery 2021;48(5):503-510
Facial feminization surgery (FFS) incorporates aesthetic and craniofacial surgical principles and techniques to feminize masculine facial features and facilitate gender transitioning. A detailed understanding of the defining male and female facial characteristics is essential for success. In this first part of a two-part series, we discuss key aspects of the general preoperative consultation that should be considered when evaluating the prospective facial feminization patient. Assessment of the forehead, orbits, hairline, eyebrows, eyes, and nose and the associated procedures, including scalp advancement, supraorbital rim reduction, setback of the anterior table of the frontal sinus, rhinoplasty, and soft tissue modifications of the upper and midface are discussed. In the second part of this series, bony manipulation of the midface, mandible, and chin, as well as soft tissue modification of the nasolabial complex and chondrolaryngoplasty are discussed. Finally, a review of the literature on patient-reported outcomes in this population following FFS is provided.
6.Evaluation and treatment of facial feminization surgery: part II. lips, midface, mandible, chin, and laryngeal prominence
Brian N. DANG ; Allison C. HU ; Anthony A. BERTRAND ; Candace H. CHAN ; Nirbhay S. JAIN ; Miles J. PFAFF ; James C. LEE ; Justine C. LEE
Archives of Plastic Surgery 2022;49(1):5-11
Facial feminization surgery (FFS) refers to a set of procedures aimed at altering the features of a masculine face to achieve a more feminine appearance. In the second part of this twopart series, assessment and operations involving the midface, mandible, and chin, as well as soft tissue modification of the nasolabial complex and chondrolaryngoplasty, are discussed. Finally, we provide a review of the literature on patient-reported outcomes in this population following FFS and suggest a path forward to optimize care for FFS patients.
7.Evaluation and treatment of facial feminization surgery: part I. forehead, orbits, eyebrows, eyes, and nose
Brian N. DANG ; Allison C. HU ; Anthony A. BERTRAND ; Candace H. CHAN ; Nirbhay S. JAIN ; Miles J. PFAFF ; James C. LEE ; Justine C. LEE
Archives of Plastic Surgery 2021;48(5):503-510
Facial feminization surgery (FFS) incorporates aesthetic and craniofacial surgical principles and techniques to feminize masculine facial features and facilitate gender transitioning. A detailed understanding of the defining male and female facial characteristics is essential for success. In this first part of a two-part series, we discuss key aspects of the general preoperative consultation that should be considered when evaluating the prospective facial feminization patient. Assessment of the forehead, orbits, hairline, eyebrows, eyes, and nose and the associated procedures, including scalp advancement, supraorbital rim reduction, setback of the anterior table of the frontal sinus, rhinoplasty, and soft tissue modifications of the upper and midface are discussed. In the second part of this series, bony manipulation of the midface, mandible, and chin, as well as soft tissue modification of the nasolabial complex and chondrolaryngoplasty are discussed. Finally, a review of the literature on patient-reported outcomes in this population following FFS is provided.
9.Life threatening and occult mediastinal haemorrhage secondary to acquired factor VIII deficiency.
Chieh Suai TAN ; Kenneth P CHAN ; Charles T CHUAH ; Heng Joo NG ; Foong Koon CHEAH ; Felicia S TEO ; Philip C T ENG
Annals of the Academy of Medicine, Singapore 2009;38(3):280-281
Aged
;
Female
;
Hemophilia A
;
complications
;
Hemorrhage
;
etiology
;
Humans
;
Mediastinal Diseases
;
etiology
10.Angioplasty on an infarct-related anomalous right coronary artery arising from posterior coronary sinus.
Man-Hong JIM ; Ryan L Y KO ; Carmen W S CHAN ; Stephen C W CHEUNG ; Wing-Hing CHOW
Annals of the Academy of Medicine, Singapore 2010;39(3):258-260
INTRODUCTIONThe objective of this case report was to illustrate the diagnostic and intervention approach of anomalous right coronary artery (RCA).
CLINICAL PICTUREA 60-year-old man presented with acute inferior myocardial infarction. Cardiac catheterisation revealed an anomalous RCA arising from the posterior coronary sinus as the infarct-related artery.
TREATMENTAd hoc percutaneous coronary intervention with stent implantation was performed using a few technical modifications.
OUTCOMEGood angiographic result was achieved within 90 minutes, with 260 mL of contrast used.
CONCLUSIONA high index of suspicion and logical diagnostic and intervention approach are required for the proper management of anomalous RCA.
Angioplasty, Balloon, Coronary ; Cardiac Catheterization ; methods ; Coronary Angiography ; Coronary Vessel Anomalies ; complications ; diagnostic imaging ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; complications ; surgery