Page 423 - Atlas of Small Animal CT and MRI

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Figure 4.3.7 Cryptococcal Mediastinal Granuloma (Feline) MR

(a) DX, LAT (b) T1, SP (c) T2, SP

(d) T2, TP (e) T1+C, SP
3y FS Siamese with a recent history of vomiting, anorexia, and abdominal distension. Pelvic limb paresis has developed within the past
24 hours. A cranial mediastinal mass is detected on survey thoracic radiographs (a). There is a large, irregularly margined cranial medias­
tinal mass that is moderately T1 intense and T2 hyperintense (b–d). The mass mildly and nonuniformly enhances following contrast
administration (e). Large numbers of cryptococcal organisms were detected on a fine‐needle aspiration biopsy sample collected from the
mediastinal mass. A diagnosis of systemic cryptococcosis was confirmed from fungal titers.

Figure 4.3.8 Mycotic Mediastinitis (Canine) CT

(a) CT, TP (b) CT+C, TP (c) CT+C, SP
4y M Rottweiler with a 3‐week history of lethargy, inappetence, and pleural effusion. The dog was initially imaged in dorsal recumbency
(a) to redistribute pleural fluid. The mediastinum is widened and has a heterogeneous pattern of attenuation (a: arrowheads). A contrast‐
enhanced examination performed with the dog in sternal recumbency reveals a widened and irregularly margined cranial mediastinum
with a heterogeneous pattern of enhancement (b: arrowheads). Mediastinal lymphadenopathy is also evident (c: arrow). Pleural fluid is
present in the dependent regions of the pleural space (b: asterisks). Surgical biopsy revealed pyogranulomatous mediastinitis,
lymphadenitis, and pleuropneumonia that were subsequently confirmed to be due to Coccidioides immitis.

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