Continuous arterial spin labeling perfusion magnetic resonance imaging findings in postpartum vasculopathy

Postpartum vasculopathy (PPV) is a rare heterogeneous nonatherosclerotic vasculopathy that occurs in the puerperium. It occurs spontaneously but may be triggered by vasoconstrictor substances. The angiographic findings vary and include narrowing of the intracranial arteries and vasospasm. The angiographic findings and the occurrence of ischemic infarcts suggest that cerebral blood flow (CBF) is impaired in PPV. The purpose of this study is to determine CBF in patients with PPV. The authors conducted a case study of 3 patients with clinical and laboratory criteria for PPV examined during a 2-year period. Clinical examination, computed tomography imaging, structural magnetic resonance imaging (MRI), cerebral angiography, and continuous arterial spin labeling perfusion (CASL-PI) MRI were performed in all patients. Mean global CBF was determined, and perfusion maps were visually inspected. The CBF values and perfusion maps were correlated with the clinical symptoms and the neuroimaging findings. Three women were studied (22, 34, and 36 years old). The median time of presentation was 4 days postpartum. One presented with intracranial hemorrhage and diffuse arterial narrowing, the other 2 with stroke-like lesions, encephalopathy, and segmental narrowing mainly in the posterior circulation. CASL-PI was performed within 1 week of symptom onset in all 3 patients. Global mean CBF values were 51.8, 39.3, and 41.8 cc/100 g/min. Although global CBF was mildly diminished, it was above ischemic levels. Visual inspection of the CASL-PI perfusion maps did not reveal areas of focal hypoperfusion or hyperperfusion. In this series of patients with PPV, CBF was close to normal. Although angiography often reveals diffuse arterial narrowing, the CBF values encountered in this study do not support a state of generalized or focal oligoemia. Vasomotor tone may change intermittently in patients with PPV.