Phim ban đầu đơn giản để hiển thị sỏi thận hoặc ureteric. Tương phản trung bình là tiêm tĩnh mạch, tập trung ở thận và bài tiết. - Nephrogram pha - thận được vạch ra - quan sát vị trí, kích thước | 218 Chapter 11 Imaging Techniques and Clinical Investigations Intravenous urogram An initial plain film to show renal or ureteric stones. Contrast medium is injected intravenously concentrated in the kidney and excreted. Nephrogram phase kidneys are outlined observe position size shape filling defects . tumour Excretion phase renal pelvis renal papillae may be lost from chronic pyelonephritis papillary necrosis calyces blunted from hydronephrosis pelviureteric obstruction large pelvis normal ureters Ureters observe position displaced by other pathology size dilated from obstruction or recent infection irregularities may be contractions and need to be checked in sequential films Neurological investigations Electroencephalogram Approximately 22 electrodes are applied to the scalp in standard positions and cerebral electrical activity is amplified and are marked normal variations and differences between awake and sleep. Main uses Epilepsy primary generalized epilepsy generalized spike and slow-wave discharges partial epilepsy focal spikes Disorders of consciousness or coma encephalopathy encephalitis dementia The main value of this technique is in showing episodes of abnormal waves compatible with epilepsy. Large normal variation makes interpretation difficult. Neurological Investigations 219 Lumbar puncture A needle is introduced between the lumbar vertebrae Fig. 1 through the dura into the subarachnoid space and cerebrospinal fluid is obtained for examination. Normal cerebrospinal fluid is completely clear. The major diagnostic value of this technique is in subarachnoid haemorrhage uniformly red whereas blood from a traumatic tap is in the first specimen xanthochromia yellow stain from haemoglobin breakdown meningitis pyogenic turbid fluid white cells organisms on culture low glucose and raised protein raised pressure may indicate a tumour Myelogram Inject contrast medium into cerebrospinal fluid in subarachnoid space to demonstrate thoracic .
