2.Multiparametric MRI in Active Surveillance of Prostate Cancer: An Overview and a Practical Approach
Chau Hung LEE ; Teck Wei TAN ; Cher Heng TAN
Korean Journal of Radiology 2021;22(7):1087-1099
MRI has become important for the detection of prostate cancer. MRI-guided biopsy is superior to conventional systematic biopsy in patients suspected with prostate cancer. MRI is also increasingly used for monitoring patients with low-risk prostate cancer during active surveillance. It improves patient selection for active surveillance at diagnosis, although its role during follow-up is unclear. We aim to review existing evidence and propose a practical approach for incorporating MRI into active surveillance protocols.
3.Multiparametric MRI in Active Surveillance of Prostate Cancer: An Overview and a Practical Approach
Chau Hung LEE ; Teck Wei TAN ; Cher Heng TAN
Korean Journal of Radiology 2021;22(7):1087-1099
MRI has become important for the detection of prostate cancer. MRI-guided biopsy is superior to conventional systematic biopsy in patients suspected with prostate cancer. MRI is also increasingly used for monitoring patients with low-risk prostate cancer during active surveillance. It improves patient selection for active surveillance at diagnosis, although its role during follow-up is unclear. We aim to review existing evidence and propose a practical approach for incorporating MRI into active surveillance protocols.
4.Magnetic Resonance Elastography and Other Magnetic Resonance Imaging Techniques in Chronic Liver Disease: Current Status and Future Directions.
Cher Heng TAN ; Sudhakar Kundapur VENKATESH
Gut and Liver 2016;10(5):672-686
Recent advances in the noninvasive imaging of chronic liver disease have led to improvements in diagnosis, particularly with magnetic resonance imaging (MRI). A comprehensive evaluation of the liver may be performed with the quantification of the degree of hepatic steatosis, liver iron concentration, and liver fibrosis. In addition, MRI of the liver may be used to identify complications of cirrhosis, including portal hypertension, ascites, and the development of hepatocellular carcinoma. In this review article, we discuss the state of the art techniques in liver MRI, namely, magnetic resonance elastography, hepatobiliary phase MRI, and liver fat and iron quantification MRI. The use of these advanced techniques in the management of chronic liver diseases, including non-alcoholic fatty liver disease, will be elaborated.
Ascites
;
Carcinoma, Hepatocellular
;
Diagnosis
;
Elasticity Imaging Techniques*
;
Fatty Liver
;
Fibrosis
;
Hypertension, Portal
;
Iron
;
Liver Cirrhosis
;
Liver Diseases*
;
Liver*
;
Magnetic Resonance Imaging*
;
Non-alcoholic Fatty Liver Disease
7.Water as neutral oral contrast agent in abdominopelvic CT: comparing effectiveness with Gastrografin in the same patient
Chau Hung Lee ; Han Zi Gu ; Balamurugan A Vellayappan ; Cher Heng Tan
The Medical Journal of Malaysia 2016;71(6):322-327
Introduction: Positive oral contrast is no longer deemed
necessary for abdominopelvic computed tomography (CT)
scans. Studies have shown water to be an equally effective
oral contrast agent. However, to our knowledge no study has
compared effectiveness between gastrografin and water in
the same patient, which will provide a more objective
evaluation of the two oral contrast agents. We aim to make a
head-to-head comparison of water as neutral oral contrast
(OC) against gastrografin as positive OC for abdominopelvic
CT scans in the same patient.
Methods: A retrospective review of 206 abdominopelvic CT
scans of 103 patients was performed. The scans were
reviewed in consensus by two blinded radiologists. The
ability to visualise each abdominopelvic organ, contrastassociated
artefacts and small bowel wall delineation, was
qualitatively scored on a 5-point scale. Each patient had two
sets of scores, one with water and another with gastrografin
as OC. Paired scores from the two OCs were evaluated by
Wilcoxon signed rank test to determine any significant
difference in performance between the two OCs for
visualisation of abdominopelvic anatomy on CT.
Results: There was significantly better delineation of
duodenal wall (p<0.001) and overall visualisation of the
duodenum (p=0.011) using water as OC compared to
gastrografin. No statistically significant differences were
demonstrated between water and gastrografin for
visualisation of the rest of the abdominopelvic organs, walldelineation
of the rest small bowel and contrast-associated
artefacts.
Conclusions: Water can be used in place of gastrografin as
oral contrast in abdominopelvic CT without compromising
visualization of abdominopelvic organs.
8.It is Time to Incorporate Artificial Intelligence in Radiology Residency Programs
Korean Journal of Radiology 2023;24(3):177-179
With the surge of interest in the development and application of artificial intelligence (AI) in radiology, we propose that know-how on the development and clinical evaluation of AI models needs to be incorporated in radiologist training curricula to prepare our specialty to lead in the new era of radiology practice augmented by AI.
9.Prevention and Management of Adverse Reactions Induced by Iodinated Contrast Media.
Yi Wei WU ; Kheng Song LEOW ; Yujin ZHU ; Cher Heng TAN
Annals of the Academy of Medicine, Singapore 2016;45(4):157-164
Iodinated radiocontrast media (IRCM) is widely used in current clinical practice. Although IRCM is generally safe, serious adverse drug reactions (ADRs) may still occur. IRCM-induced ADRs may be subdivided into chemotoxic and hypersensitivity reactions. Several factors have been shown to be associated with an increased risk of ADRs, including previous contrast media reactions, history of asthma and allergic disease, etc. Contrast media with lower osmolality is generally recommended for at-risk patients to prevent ADRs. Current premedication prophylaxis in at-risk patients may reduce the risk of ADRs. However, there is still a lack of consensus on the prophylactic role of premedication. Contrast-induced nephropathy (CIN) is another component of IRCM-related ADRs. Hydration remains the mainstay of CIN prophylaxis in at-risk patients. Despite several preventive measures, ADRs may still occur. Treatment strategies for potential contrast reactions are also summarised in this article. This article summarises the pathophysiology, epidemiology and risk factors of ADRs with emphasis on prevention and treatment strategies. This will allow readers to understand the rationale behind appropriate patient preparation for diagnostic imaging involving IRCM.
Acute Kidney Injury
;
chemically induced
;
prevention & control
;
therapy
;
Contrast Media
;
adverse effects
;
Drug Hypersensitivity
;
etiology
;
prevention & control
;
therapy
;
Drug-Related Side Effects and Adverse Reactions
;
etiology
;
prevention & control
;
therapy
;
Fluid Therapy
;
Humans
;
Iodine Radioisotopes
;
adverse effects
10.Clinics in diagnostic imaging (143). Perianal mucinous adenocarcinoma arising from chronic fistula-in-ano.
Chia Ming HO ; Cher Heng TAN ; Bernard Chi-Shern HO
Singapore medical journal 2012;53(12):843-quiz p. 849
We report a case of mucinous adenocarcinoma arising in the perianal soft tissue in association with chronic fistula-in-ano in a 43-year-old man who had a relapse of perianal pain and bloody discharge after six years of defaulted follow-up. He underwent magnetic resonance (MR) and computed tomography imaging with correct identification of the disease entity on imaging. Mesh-like septations and an enhancing solid component with high diffusion-weighted imaging (DWI) and intermediate apparent diffusion coefficient signals were observed. He underwent abdominoperineal resection of the tumour but succumbed due to postoperative complications. Literature on the MR imaging features of this tumour remains scarce. We highlight the MR imaging features, including those seen on DWI, which were useful in making the correct diagnosis. Though uncommon, this would be an important condition to recognise since assessment of fistula-in-ano by MR imaging is considered to be the standard of care in current clinical practice. The clinical features of this entity are also briefly discussed.
Adenocarcinoma, Mucinous
;
complications
;
diagnosis
;
Adult
;
Anus Neoplasms
;
complications
;
diagnosis
;
Chronic Disease
;
Diagnosis, Differential
;
Diffusion Magnetic Resonance Imaging
;
Humans
;
Male
;
Rectal Fistula
;
complications
;
diagnosis
;
Tomography, X-Ray Computed