Browsing by Author "Al-Muhanna, Afnan"

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Gadolinium retention after contrast-enhanced magnetic resonance imaging: A narrative review
(2022) Al-Muhanna, Afnan
Over the past five years, several studies have reported deposition and retention of gadolinium in the brain after administration of gadolinium-based contrast agents (GBCAs) during radiological procedures. Patients with renal insufficiency cannot filter gadolinium efficiently; however, gadolinium is also retained in the brain of some adults and pediatrics with no renal impairment. In the literature, data is mostly available from retrospective magnetic resonance imaging (MRI) studies, where gadolinium deposition may be indirectly measured by evaluating changes in T1 signal intensity in the brain tissues, particularly in the deep gray matter such as the dentate nucleus and/or globus pallidus. Many pathological studies have reported a direct correlation between T1 signal changes and gadolinium deposition in human and animal autopsy specimens, which raised concerns on the use of GBCAs, particularly with linear chelators. The association between gadolinium accumulation and occurrence of physical and neurological side effects or neurotoxic damage has not yet been conclusively demonstrated. Studies have also observed that gadolinium is deposited in the extracranial tissues, such as the liver, skin, and bone, of patients with normal kidney function. This narrative review describes the effects of different types of GBCAs in relation to gadolinium deposition, evaluates current evidence on gadolinium deposition in various tissues of the human body, and summarizes the current recommendations regarding the use of GBCAs.
Radiological patterns in sickle cell disease patients with acute chest syndrome: Are there age-related differences?
(2019) Al-Sharydah, Abdulaziz; Alshahrani, Mohammed; Aldhaferi, Bander; Al-Muhanna, Afnan; Al-Thani, Hanadi
Background: Acute chest syndrome is a major cause of pulmonary disease and mortality in sickle cell disease patients. Its diagnosis can be delayed due to differing imaging patterns between children and adults. Objective: The purpose of this study was to describe the pulmonary and extrapulmonary imaging findings in sickle cell disease patients with acute chest syndrome and determine differences in findings between adult and pediatric patients. Patients and Methods: This retrospective study analyzed the data of all sickle cell disease patients who were admitted with a diagnosis of acute chest syndrome to King Fahd Hospital of the University, Al Khobar, Saudi Arabia, between January and June 2015 (n = 150). After grouping the patients into adults and pediatrics, the pulmonary and extrapulmonary characteristics were identified and the digital radiography, computed tomography and laboratory findings were compared. Results: A total of 116 patients with 163 acute chest syndrome episodes met the inclusion criteria, of which 69 (60%) were adults. In both adult and pediatric patients, the most frequent pulmonary finding was consolidation of the lung parenchyma. The right lung was most frequently involved: the lower lobe in adult patients and the middle lobe in pediatric patients. In addition, pleural effusion was observed in both age groups. Extrapulmonary radiological findings, such as avascular necrosis and cardiomegaly, were significantly more common in adult patients than in pediatric patients (P < 0.05). Compared with adults, pediatric patients had significantly lower hemoglobin levels (P = 0.001) and oxygen tension fraction in arterial blood (P = 0.007). Conclusions: Pediatric and adult sickle cell disease patients with acute chest syndrome typically exhibited similar pulmonary characteristics, whereas extrapulmonary findings were more prominent in adult patients. Furthermore, low levels of hemoglobin and oxygen tension fraction were dependent predictors of acute chest syndrome.