Howarth D M, Lan L, Thomas P A, Allen L W
Department of Nuclear Medicine, John Hunter Hospital, Newcastle, New South Wales, Australia.
J Nucl Med. 1999 Apr;40(4):579-84.
Lung scintigraphy is used widely for diagnosis of pulmonary embolus (PE). Technegas ventilation imaging has many advantages over other methods, but little outcome data exists on this technique. The aims of this study were to better define the role of lung scintigraphy in the management of patients with suspected PE and to evaluate technegas ventilation imaging by following patient outcomes.
A group of 717 out of 834 consecutive patients, referred to a university teaching hospital for lung scintigraphy to confirm or refute the diagnosis of PE, was followed for 18-30 mo to determine clinical outcome. The follow-up endpoints were death as a result of PE, death as a result of hemorrhage after treatment for PE, uncomplicated survival, survival with subsequent PE, nonfatal hemorrhage after treatment for PE and recurrence of PE in treated patients. Ventilation imaging was performed using technegas, and perfusion imaging was performed using intravenous 99mTc macroaggregated albumin. The modified PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) diagnostic criterion was used for interpretation of lung scintigraphy.
Diagnostic results included 3.5% normal studies, 67.4% assessed as low probability for PE, 10% as moderate probability for PE and 19.1% as high probability for PE. A total of 231 patents received therapy with heparin, followed by warfarin, including those receiving anticoagulation therapy for other conditions. Ninety-six percent of patients with normal and low probability studies (n = 508) had good outcomes, 6 patients died as a result of PE and 12 subsequently developed PE. The odds ratio for death by PE in this group was 0.2. Of the 72 moderate probability studies, 39 patients were untreated. In this group there was 1 death due to PE, and PE subsequently developed in 2 patients. None of the remaining 33 treated patients died, but 4 patients experienced bleeding complications. The odds ratio for death by PE in the moderate probability group was 0.7. In those patients with high-probability studies, there were 8 deaths by PE, 6 deaths by hemorrhage, 11 nonfatal hemorrhages and 7 patients who experienced recurrences of PE. The odds ratios in this group were 6 and 10 for death by PE, or death by PE and the treatment of PE, respectively.
The use of the modified PIOPED diagnostic classification is valid for technegas lung scintigraphy. Using technegas, normal/low-probability and high-probability results are highly predictive of respective outcomes. Technegas lung scintigraphy reduces the number of indeterminate studies.
肺闪烁扫描术广泛用于肺栓塞（PE）的诊断。与其他方法相比，锝气体通气成像有许多优点，但关于该技术的结果数据很少。本研究的目的是更好地确定肺闪烁扫描术在疑似PE患者管理中的作用，并通过跟踪患者结果来评估锝气体通气成像。
连续834例因肺闪烁扫描术被转诊至大学教学医院以确诊或排除PE诊断的患者中，选取717例进行了18至30个月的随访以确定临床结果。随访终点包括因PE导致的死亡、PE治疗后因出血导致的死亡、无并发症存活、随后发生PE的存活、PE治疗后的非致命性出血以及治疗患者中PE的复发。通气成像使用锝气体进行，灌注成像使用静脉注射99mTc大颗粒白蛋白进行。采用改良的PIOPED（肺栓塞诊断前瞻性研究）诊断标准来解读肺闪烁扫描结果。
诊断结果包括3.5%的正常检查、67.4%评估为PE低概率、10%为PE中概率以及19.1%为PE高概率。共有231例患者接受了肝素治疗，随后使用华法林，包括因其他情况接受抗凝治疗的患者。正常和低概率检查的患者（n = 508）中96%预后良好，6例患者因PE死亡，12例随后发生PE。该组中因PE死亡的比值比为0.2。在72例中概率检查中，39例患者未接受治疗。该组中有1例因PE死亡，2例随后发生PE。其余33例接受治疗的患者均未死亡，但4例患者出现出血并发症。中概率组中因PE死亡的比值比为0.7。在高概率检查的患者中，有8例因PE死亡，6例因出血死亡，11例非致命性出血，7例患者经历了PE复发。该组中因PE死亡或因PE及PE治疗导致死亡的比值比分别为6和10。
改良的PIOPED诊断分类法对锝气体肺闪烁扫描术有效。使用锝气体时，正常/低概率和高概率结果对各自的结果具有高度预测性。锝气体肺闪烁扫描术减少了不确定检查的数量。
