ORIGINAL ARTICLE A new approach for simple radioisotope cisternography examination in cerebrospinal fluid leakage detection Hiromitsu Hoshino 1,2 • Tetsuya Higuchi 2 • Arifudin Achmad 2 • Ayako Taketomi-Takahashi 2 • Hiroya Fujimaki 3 • Yoshito Tsushima 2 Received: 25 August 2015 / Accepted: 11 September 2015 / Published online: 14 October 2015 Ó The Japanese Society of Nuclear Medicine 2015 Abstract Objective We developed a new quantitative interpretation technique of radioisotope cisternography (RIC) for the diagnosis of spontaneous cerebrospinal fluid hypovolemia (SCH). Methods RIC studies performed for suspected SCH were evaluated. 111 In-DTPA RIC images were taken at 0, 1, 3, 6, and 24-h after radioisotope injection following the current protocol. Regions of interest (ROI) were selected on 3-h images to include brain, spine, bladder or the whole body. The accumulative radioactivity counts were calculated for quantitative analysis. Final diagnoses of SCH were estab- lished based on the diagnostic criteria recently proposed by Schievink and colleagues. Results Thirty-five patients were focused on. Twenty-one (60.0 %) patients were diagnosed as having SCH according to the Schievink criteria. On the 3-h images, direct cere- brospinal fluid leakage sign was detected in nine of 21 SCH patients (42.9 %), as well as three patients with suspected iatrogenic leakage. Compared to non-SCH patients, SCH patients showed higher bladder accumulation at 3-h images (P = 0.0002), and higher brain clearance between the 6- and 24-h images (P \ 0.0001). In particular, the 24-h brain clearance was more conclusive for the diagnosis than 24-h whole cistern clearance. The combination of direct sign and 24-h brain accumulation resulted in 100 % of accuracy in the 32 patients in whom iatrogenic leakage was not observed. 1- and 6-h images did not provide any additional information in any patients. Conclusions A new simple ROI setting method, in which only the 3-h whole body and 24-h brain images were necessary, was sufficient to diagnose SCH. Keywords Spontaneous cerebrospinal fluid hypovolemia Á Radioisotope cisternography Á Quantitative analysis Á Simple radioisotope cisternography examination protocol Background Spontaneous cerebrospinal fluid hypovolemia (SCH) caused by spontaneous leaks of cerebrospinal fluid (CSF) is characterized by prominent orthostatic headache associated with neck stiffness, tinnitus, hypoacusia, and often photo- phobia and nausea [1–10]. SCH is an important headache etiology particularly in young and middle-aged individuals, but an initial misdiagnosis such as migraine, tension headache, or viral meningitis, is common [4]. Brain magnetic resonance (MR) imaging may show characteristic features of SCH, including subdural fluid collections, enhancement of the pachymeninges, engorge- ment of venous structures, pituitary hyperemia, and sag- ging of the brain [4, 9]. Nonetheless, even in a patient whose spinal CSF leak is confirmed by contrast-enhanced computed tomography (CT) myelography, brain MR imaging may show no abnormal findings [11]. CT myel- ography of the entire spine combined with or without MR myelography has been shown to be useful in detecting & Tetsuya Higuchi tetsuyah92md@gmail.com 1 Department of Radiology, Japan Red Cross Society Maebashi Hospital, 3-21-36 Asahi, Maebashi, Gunma, Japan 2 Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma 371-8511, Japan 3 Department of Neurosurgery, Japan Red Cross Society Maebashi Hospital, 3-21-36 Asahi, Maebashi, Gunma, Japan 123 Ann Nucl Med (2016) 30:40–48 DOI 10.1007/s12149-015-1030-2