A 41-year-old Hispanic man with altered mental status, later found to be HIV positive with a CD4 count of 135
What is your diagnosis?
A. CNS tuberculomas
B. Primary CNS lymphoma
C. Metastases
D. Cerebral toxoplasmosis
A
B
C
The answer is Cerebral Toxoplasmosis
Cerebral toxoplasmosis and lymphoma are the 2 most common ring-enhancing lesions found in patients with HIV/AIDs.
Toxoplasmosis typically presents as multiple ring-enhancing lesions with an eccentric enhancing nodule, also known as the target sign (B, arrows).
Lesions most commonly occur in the basal ganglia and thalami and result in significant surrounding vasogenic edema (A).
Hemorrhage can occur within the lesions, resulting in susceptibility on T2* sequences (C, arrow).
Lymphoma, on the other hand, is more likely to be a solitary ring-enhancing periventricular lesion with ependymal spread.
中文版：
西班牙裔男性，41歲，精神狀態異常，之後發現HIV陽性，CD4計數135
診斷？
A. 中樞神經系統結核瘤
B. 原發中樞神經系統淋巴瘤
C. 轉移瘤
D. 腦弓形蟲病
診斷為：腦弓形蟲病
HIV患者腦內環形強化病變中最常見的兩種為腦弓形蟲病和淋巴瘤。
腦弓形蟲病典型表現為多發病變，環形強化，可見偏心性強化結節，又稱「靶徵」（B，箭頭）。
好發於基底節區、丘腦，常合併嚴重血管源性水腫（A）。
病變內可合併出血，T2*序列呈磁敏感效應（C，箭頭）。
而淋巴瘤好發於腦室旁，通常為單發環形強化，可沿室管膜播散。
From AJNR Classic Case