1.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
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Fluid Therapy
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Humans
;
Iodine Radioisotopes
;
adverse effects
2.Renal-related adverse effects of intravenous contrast media in computed tomography.
Kheng Song LEOW ; Yi Wei WU ; Cher Heng TAN
Singapore medical journal 2015;56(4):186-193
Renal-related adverse effects of intravascular contrast media (CM) include contrast-induced nephropathy in computed tomography and angiography. While large retrospective studies have been published, the exact pathogenesis of this condition is still unknown. We review the main international guidelines, including the American College of Radiology white paper and the guidelines of European Society of Urogenital Radiology, Royal College of Radiologists and Canadian Association of Radiologists, as well as their references, regarding this subject. We present a simplified, concise approach to renal-related adverse effects of CM, taking into consideration the basis for each recommendation in these published guidelines. This will allow the reader to better understand the rationale behind appropriate patient preparation for cross-sectional imaging.
Angiography
;
methods
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Contrast Media
;
adverse effects
;
Drug-Related Side Effects and Adverse Reactions
;
Humans
;
Kidney Diseases
;
chemically induced
;
Tomography, X-Ray Computed
;
methods
3.Clinics in diagnostic imaging (196). Complete PCL tear.
Kheng Song LEOW ; Poh Lye Paul SEE
Singapore medical journal 2019;60(6):286-290
A 21-year-old man presented with left knee pain and instability that persisted three months after a road traffic accident. Physical examination revealed a positive posterior drawer test. Anterior drawer and pivot tests were negative. Magnetic resonance imaging of the knee demonstrated a complete tear of the posterior cruciate ligament (PCL). Recognition of the normal and injured appearances of the PCL is useful to aid the reader in the detection and characterisation of PCL injuries. Isolated acute PCL tears are usually managed conservatively. However, an active search for associated injuries is essential, as their presence may upstage the patients for surgical management.
4.Clinics in diagnostic imaging (203). Focal infarction of the falciform ligament fatty appendage.
Julian Sau Lian CHIENG ; Kheng Song LEOW ; Tze Chwan LIM
Singapore medical journal 2020;61(1):15-18
A 56-year-old man presented to the emergency department with acute upper abdominal pain and mild leucocytosis. The pain was not relieved by intravenous analgesia. Computed tomography of the abdomen and pelvis demonstrated a focal area of fat stranding with a thin peripheral rim of high attenuation and a punctate central hyperdense dot in the vicinity of the falciform ligament. The diagnosis of focal infarction of the falciform ligament fatty appendage was made based on the imaging findings. The patient responded well to conservative management and was discharged for outpatient follow-up. Focal infarction of the falciform ligament fatty appendage is extremely rare and can mimic various causes of acute abdomen that require emergency surgery. Hence, correct radiological diagnosis is essential to avoid unnecessary surgical intervention. We herein discuss the similarities and differences with other common companion cases such as epiploic appendagitis and omental infarction.