Chest X-ray:
1. Increased density and widening of superior mediastinum,
   predominant over left side, nature to be determined
   (figure 1).

Multidetector row CT scan of chest with pre- and post-intravenous
 contrast, and with multiplanar reconstruction, maximum-intensity
 projection, and 3D volume rendering:

1. A lobulated big mass with punctate calcifications (figure 2,
   arrows) and mild contrast enhancement (figure 3) in bilateral
   paraspinal regions of posterior mediastinum, predominant over
   left side, neurogenic tumor such as thoracic neuroblastoma may
   be considered until proved otherwise.
2. Suspicious spinal canal invasion by the tumor with mild erosion
   of posterior surfaces of corresponding vertebral bodies in upper
   thoracic spine (figure 3, red arrow).
3. Presence of mass effect of the above tumor with direct
   indentation of left-sided descending aorta (figure 4 and 5,
   yellow arrows) and indirect compression of left bronchus (figure
   4-6, blue arrows) with significant smooth stenosis.
4. Some passive atelectasis in both lungs due to mass effect of
   the tumor.
5. Small subpleural infiltration in both lower lungs, may due to
   chronic inflammatory process.

Impression:
1. Posterior mediastinum tumor, suspicious neurogenic tumor.
2. Suspicious tumor invasion to thoracic spinal canal.

1.5 Tesla MRI of chest (focus on thoracic spine) with
 MR myelography, T2 weighted echo train spin echo, T1 weighted echo
 train spin echo with and without fat saturation, MR diffusion
 imaging, T2/T1 steady-state gradient echo with fat saturation,
 and with intravenous gadolinium-enhancement:

1. A lobulated big long T1 and T2 mass with strong contrast
   enhancement (figure 7, red arrows) and without significant
   restricted water diffusibility (not showed) in bilateral
   paraspinal regions of posterior mediastinum, predominant over
   left side, neurogenic tumor such as thoracic neuroblastoma may
   be considered until proved otherwise.
2. Presence of tumor direct invasion to T1-T5 dilated spinal canal
   through bilateral neuroforamina (figure 7, yellow arrows).
   Mass effect of the tumor with encasement and compression of
   corresponding spinal cord (figure 8, arrows).
   But no detectable signal change or contrast enhancement within
   spinal cord itself.
3. Besides, tumor direct extension to midline posterior back soft
   tissue and left paravertebral back muscles (figure 7, green
   arrows).
4. A 1.1cm ovoid enhancing nodule in right infraspinatus muscle
   over right upper back, suggesting tumor distal metastasis
   (figure 9, red arrows).
5. Some small lymph nodes in bilateral axillae, may due to
   chronic infection.

Impression:
1. Posterior mediastinum tumor, suspicious neurogenic tumor.
2. Tumor invasion to T1-T5 spinal canal with corresponding
   spinal cord compression.
3. Besides tumor direct invasion to left back muscle and distal
   metastasis to right back muscle.