SA Journal of Radiology - Volume 8, Issue 2, 2004
Volume 8, Issue 2, 2004
A quick guide to safety and compatibility of passive implants and devices in an MR environment : review articleSource: SA Journal of Radiology 8, pp 6 –12 (2004)More Less
An increasing number of patients with metal implants are being referred for magnetic resonance imaging (MRI) investigations. Implants and devices may be divided into two groups, namely active and passive. This article will focus on passive devices. A device is MR-safe when it is used in the MR environment, but presents no additional risk to the patient or other individuals, although the quality of diagnostic information may be affected. MR procedures may be contraindicated due to various interactions between the MR environment and medical devices, which include torque, translational force, heating, induced electrical currents, magnetic field interactions, artefacts, and misrepresentation. Therefore, before deciding whether any object is MRsafe/ compatible, the intended use and the possible retaining mechanisms must be considered.
Source: SA Journal of Radiology 8, pp 13 –17 (2004)More Less
Many different artefacts can occur during magnetic resonance imaging (MRI), some affecting the diagnostic quality, while others may be confused with pathology. An artefact is a feature appearing in an image that is not present in the original object. Artefacts can be classified as patientrelated, signal processing-dependent and hardware (machine)-related.This article presents an overview of MRI artefacts and possible rectifying methods.
Author S.F. OttoSource: SA Journal of Radiology 8, pp 19 –22 (2004)More Less
The progress made in diagnostic and therapeutic medicine has resulted in an increase in the number of malpractice suits brought against medical practitioners. To constitute negligence it must be shown that the conduct of the accused did not measure up to the standard of care the law required of him in the particular circumstances and that he acted with guilt and therefore can be blamed for the deed. This paper describes medical practitioner negligence and reviews relevant cases.
Do dose area product meter measurements reflect radiation doses absorbed by health care workers? : original articleSource: SA Journal of Radiology 8, pp 24 –27 (2004)More Less
This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from the source. The study included the interventional radiologists, radiographers and nurses associated with radiological intervention procedures during the period 1 August 2003 - 31 August 2003. The amount of radiation produced during every procedure was measured by a dose area product meter (DAP) and routinely recorded. The absorbed doses received by health care workers were measured using a thermoluminescent dose meter (TLD). The TLDs were analysed and recorded at the end of each week. Health care workers wore TLDs on the following areas: forehead, thyroid (attached under thyroid guard), and abdomen (worn under lead jacket). A strong positive correlation (r = 0.9, p = 0.0374) was found between the radiographers' head TLD and DAP meter readings. All other correlations between TLD and DAP readings were not statistically significant. Strong positive correlations were found between the TLD readings of the radiologists' and nurses' bodies, the nurses' and radiographers' bodies and the radiologists' and the radiographers' bodies, all of which were statistically significant.
Source: SA Journal of Radiology 8, pp 28 –30 (2004)More Less
We performed an audit to determine the profile of cerebral aneurysms at the Universitas Hospital Bloemfontein, the only government hospital with a vascular suite in the Free State and Northern Cape area. Two hundred and twenty-three government patients, diagnosed with cerebral aneurysms during the period 1 January 2000 to 31 December 2003, were included in the study. Of the 223 patients, 37.2% were male and 62.8% female. The patients' average age was 45.5 years (range 11 - 78 years).Most patients (61.4%) were older than 40 years. The average age for males and females was 41.4 and 46.3 years, respectively, with the females being significantly older (95% CI: 1.7 - 8.2). Most patients had single aneurysms (65.5%). More females (42.9%) had multiple aneurysms compared with the males (20.5%) (95% CI females - males: 9.9 - 33.7%). Of the patients 40 years and younger, 22.1% had multiple aneurysms compared with 42.3% of the patients older than 40 years (95% CI: 7.8 - 31.7%). In our audit the females (when compared with the males) had a clear preponderance for cerebral aneurysms, were significantly older, and had a significant increase in multiplicity with an increase in age.
Endovascular foreign objects retrieved by interventional radiologists at Universitas Hospital : case reportSource: SA Journal of Radiology 8, pp 31 –33 (2004)More Less
During the past 4 years, 15 patients have undergone intravascular removal of foreign bodies - 9 central venous line fragments, 3 guidewires, 2 pacemaker leads and 1 misplaced embolisation coil. Ten foreign bodies (including 2 guidewires, 2 pacemaker leads and 6 central venous catheter fragments) were recovered from the big veins and right heart, 3 (central venous line fragments) from the pulmonary arterial system and 2 (an embolisation coil and a guidewire) from the arterial system. The percutaneous removal of foreign bodies is efficient with few complications. Surgery should only be considered for patients in whom removal attempts with endovascular interventional techniques have failed.
Polycystic liver disease - a disease entity presenting as part of autosomal-dominant polycystic kidney disease : case reportSource: SA Journal of Radiology 8, pp 34 –37 (2004)More Less
A 65-year-old man was referred to the Gastroenterology Department with complaints of longstanding upper abdominal discomfort and hepatomegaly. Ultrasound of the liver revealed a massively enlarged liver with multiple cystic areas. Aspiration of the largest cyst revealed 15 ml of yellow fluid without any organisms or malignant cells.A diagnosis of autosomal-dominant polycystic kidney disease was suspected, but could not initially be confirmed on ultrasound / computed tomography imaging. Magnetic resonance imaging confirmed the multiple hepatic cysts and revealed multiple smaller cysts in both kidneys. Symptomatology subsided after aspiration of the largest cyst and the patient was discharged. The patient has subsequently been followed up and is currently symptom free. The case illustrates the importance of screening for associated kidney disease in patients with polycystic liver disease.
Author S.H. BothaSource: SA Journal of Radiology 8, pp 38 –40 (2004)More Less
Complex regional pain syndrome (CPRS), type 1 is a pain disorder that develops unpredictably and can follow a minor injury. A 12-year-old boy presented with severe pain in the feet and could not walk or stand weight bearing. Normal X-rays showed osteopenic changes and radiolucent lines, which appeared to be stress fractures. Three-phase bone scintigraphy showed no uptake in the left lower leg on the blood pool phase or on the immediate or delayed images. This indicated typical CPRS type 1 in children. The uptake in the right foot was increased and the stress fracture and other illness could not be differentiated. Computed tomography was done to exclude stress fractures. Only osteopenic changes in both calcaneus bones were found and there was no evidence of cortical stress fractures. Magnetic resonance images revealed oedema in the calcaneus and talus bones of both feet. The patient received epidural narcotic infusion with sympathetic blockage for 1 week combined with extensive physiotherapy. The blood pool phase of the bone scan became normal within 2 weeks, and increased uptake in both feet was noticed. The patient was followed up with MRI every 3 months and the bone marrow oedema disappeared after 6 months.