Successful management of brain abscess and paradoxical embolization caused by huge pulmonary arteriovenous malformation: a case report / 中国医师杂志

Objective:The purpose of this case report is to improve the understanding of pulmonary arteriovenous malformation (PAVM) and its related complications by reviewing case data and literature.Methods:A case of huge PAVM complicated with brain abscess and paradoxical embolization of liver, spleen and kidney is reported, and then we summarize its clinical characteristics, diagnosis and treatment, and review the relevant references.Results:Brain abscess and paradoxical embolization are the most common complications of PAVM. The diagnosis and process of this patient was timely and clear. The patient received interventional embolization for PAVM and achieved good results.Conclusions:PAVM can cause brain abscess and paradoxical embolization. We should be vigilant to avoid missed diagnosis and misdiagnosis.

Power Doppler Ultrasound Findings of Renal Infarct after Experimental Renal Artery Occlusion: Comparison withSpiral CT

PURPOSE: To evaluate the efficacy of power Doppler ultrasonography (PDUS) in depicting renal infarction inrabbits during experimental renal segmental arterial occlusion, and to compare the results with those of CTscanning. MATERIALS AND METHODS: In 28 rabbits weighing 2.5-4kg, the segmental renal artery was occluded throughthe left main renal artery by embolization with Ivalon (Nycomed, Paris, France). Power Doppler ultrasonography andspiral CT scanning were performed before and at 2, 5, 8, 15, and 24 hours, and 3 and 7 days after occlusion of thesegmental renal artery. The location of infarcted areas and collaterals, as seen on PDUS and CT scans, wasevaluated by two radiologists. RESULTS: In all cases, as seen on power Doppler ultrasonography, infaretedareas-when compared with normal parenchyma, clearly demonstrated wedge-shaped perfusion defects in the kidney. Thelocation of the lesion closely corresponded to the location seen during CT scanning. After renal arterialocclusion, transiently congested capsular arteries, which were named 'capsular sign', were seen in 63% ofrabbits in the two and five-hour groups. No significant cortical rim sign was demonstrated on power Dopplerultrasonography, though it was noted on spiral CT at 15 and 24 hours, and 3 and 7 days after renal arterialocclusion. CONCLUSION: Power Doppler ultrasonography was useful for the diagnosis of renal infarction. Congestedcapsular artery seen in the early stage of renal infarction might be a characteristic finding of this condition,as seen on power Doppler ultrasonography.

MR Imaging Findings of Renal Infarction Induced by Renal Artery Ligation in Rabbits: The Usefulness of Diffusion-weighted Imaging

PURPOSE: To assess the usefulness of diffusion-weighted imaging(DWI) in evaluating serial parenchymal changesin renal infarction induced by renal artery ligation, by comparing this with the conventional spin echo techniqueand correlating the results with the histopathological findings. MATERIALS AND METHODS: In 22 rabbits, renalinfarction was induced by ligation of the renal artery. Spin-echo T1-weighted imaging(T1WI), turbo spin-echo(TSE)T2-weighted imaging(T2WI), and DWI were performed, using a 1.5-T superconductive unit, at 30 minutes, 1 hour, 2,3, 6, 12 and 24 hours, and 2, 3, 7 and 20 days after left renal artery ligation. Changes in signal intensity onT1WI, T2WI, and DWI were correlated with histopathologic findings. RESULTS: On MR images obtained 30 minutesafter ligation, the signal intensity of affected kidney was not significantly different from that of contralateralkidney, as seen on T1WI and T2WI, but was noticeably higher on DWI. On T2WI, the signal intensity ratio(SIR) wasslightly higher over time from 30 minutes to 2 days after ligation, and then decreased slightly. The SIR on DWIincreased abruptly at 30 minutes, remained high until 12 hours, and then fell, returning to close to the normalrange at between 2 and 3 days. It fell further, below the normal range, until 20 days after ligation. The mainhistopathologic findings after ligation were congestion and swelling of renal tubules (1-6 hours after ligation),degeneration and necrosis of renal tubules (12 hours - 2 days), coagulation necrosis of renal tubules(3 days),collection of cellular debris between renal tubules (7 days), and proliferation of fibroblast between renaltubules (20 days). CONCLUSION: Diffusion-weighted imaging is useful for the detection of hyperacute renalinfarction, and the apparent diffusion coefficient may provide additional information concerning its evolution.

Efficacy of Renal Artery Embolization with 50% Acetic Acid in Rabbits, and Pathologic Findings

PURPOSE: To evaluate the embolic effect and pathologic change in the kidney after infusion of 50% acetic acidin the renal artery. MATERIALS AND METHODS: Five kidneys were embolized with 50% acetic acid mixed with saline(group A) and five were embolized with 50% acetic acid mixed with contrast medium (group B). Four rabbits(2 fromgroup A and 2 from group B) were sacrificed during the first day and the remaining six, 28 days afterembolization. To determine the effect of embolization and pathologic findings, the two groups were compared. RESULTS: Complete occlusion of the renal artery was observed in both groups; histologic findings indicatingtubular necrosis and blood clots within the renal artery were noted one day after embolization. After four weeks,complete necrosis of the renal arterial wall and tubular cells had occurred. The procedures required forembolization were easier in group B because the extent of embolization could be controlled by fluoroscopy. CONCLUSION: At 50% dilution after mixing with contrast medium, the embolie effect of acetic acid isperfect;because the embolic material is visualised the procedure was easier to control than embolization withalcohol. acetic acid can, threrfore, be used as an effective embolic agent in renal artery embolization.

The Diagnostic Value of Contrast-Enhanced CT in Acute Bilateral Renal Cortical Necrosis: A Case Report

Acute renal cortical necrosis in which there is destruction of the renal cortex and sparing of the renalmedulla, is a relatively rare cause of acute renal failure. A definitive diagnosis of acute renal corticalnecrosis is based on renal biopsy, but on CT(computed tomography) the rather specific contrast-enhanced appearance of acute renal cortical necrosis has been described. As renal biopsy is not available, contrast-enhanced CT is auseful, noninvasive investigate modality for the early diagnosis of acute renal cortical necrosis. We report the characteristic CT findings of acute renal cortical necrosis in a patient with acute renal failure following anoperation for abdominal trauma.