PET Scan

TECHNIQUE: Approximately 1 hour following F-18 FDG tracer injection, F-18 FDG

PET images were acquired from the base of the skull through the proximal thighs.

Noncontrast low-dose CT imaging skull base and neck, chest, abdomen, pelvis and

proximal thighs was acquired and used for F-18 FDG PET attenuation correction

and for anatomic correlation, but is not of diagnostic image quality.

FINDINGS:

F-18 FDG PET Imaging: Reference data includes a volume of right hepatic lobe

parenchyma which contains maximum SUVs of 3.6 and mean SUVs of 2.4. Superior

vena cava mediastinal blood pool SUVs are up to 2.1.

The posterior left lung subpleural pulmonary nodule measuring 0.9 x 1.2 cm

(image 107, series 2) is mildly hypermetabolic containing SUVs up to 2.4.

The previously seen very large hypermetabolic left lower lobe lung mass is no

longer present. The unenhanced CT imaging findings are compatible with interval

left lower lobe lobectomy surgery.

There is again evidence of extensive right neck surgery and photopenia of the

cervical vertebral bone marrow compatible with prior radiation therapy.

There is a very extensive very hypermetabolic skeletal metastatic pattern, with

very hypermetabolic lesions too numerous to individually describe. They involve

sites in the cervical spine, multiple thoracic vertebrae, bilateral rib

contours, all of the lumbar vertebrae and multiple sites in the pelvis and

metabolically active lesions in both proximal femurs. Examples include:

1. An osteolytic lesion in the central and right aspect of T8 vertebral body

contains SUVs up to 12.4.

2. A slightly leftward expansile osteolytic lesion the left side of L2

vertebra, measuring about 2.3 x 2.8 cm (image 168, series 3) contains SUVs up to

9.9.

3. The extensive osteolytic lesion in the S1 sacral body and left alum (image

210, series 3) contains SUVs up to 11.0.

4. Right femoral intertrochanteric proximal metaphyseal lesion contains SUVs up

to 6.8.

No additional soft tissues including lymph nodes stations detectable

hypermetabolic lesions are identified. All other sites of F-18 FDG tracer uptake

between the skull base and thighs are explainable by expected physiologic

processes including some F-18 FDG tracer localization in the left ventricular

posterolateral wall myocardium, moderate nonfocal bowel-related F-18 FDG

localization coursing through the abdomen and pelvis and evidence of excretion

of F-18 FDG tracer by the kidneys and ureter into the urinary bladder.

Other low-dose anatomic correlation CT imaging findings:

Noisy low-dose images of the brain show areas of what appear to be vasogenic

edema in the right cerebral hemisphere, involving the inferior frontal lobe

region, the frontoparietal region and especially the inferolateral right

temporal lobe. There is reduced F-18 FDG metabolic activity in the large area of

right temporal lobe radiolucency.

No metabolically active enlarged cervical lymph nodes are identified. Extensive

right neck tissue loss and numerous surgical clips also seen in the right

thoracic inlet are again noted.

The multiple osteolytic rib and thoracic spine lesions seen previously are again

noted. No additional new pulmonary nodule. The heart size is normal. No enlarged

mediastinal or hilar lymph nodes are identified and there is no evidence of

enlarged axillary lymph nodes.

The unenhanced appearance of the liver is not remarkable. The spleen size is

within normal limits measuring 11.0 cm transaxial dimension. Neither adrenal

gland contains a mass. Unenhanced appearance of the pancreas and kidneys is

unremarkable. There are no metabolically active enlarged retroperitoneal or

pelvic lymph nodes.

There is a small hiatal hernia sac. The stomach otherwise is unremarkable. Small

bowel loops are normal caliber. The colon is not remarkable.

The urinary bladder contains a small amount of fluid. The prostate gland has

dystrophic calcifications. The seminal vesicles appear symmetric.

Extensive osteolytic lesions in multiple lumbar vertebrae and in both sides of

the pelvis are noted.

IMPRESSION:

1. Previously seen large hypermetabolic left lower lobe mass is no longer

present, evidence of interval left lower lobe resection.

2. Evidence of very extensive hypermetabolic, osteolytic skeletal metastatic

pattern.

3. The small left inferoposterior lung subpleural pulmonary nodule also is

detectably metabolically active, compatible with a soft tissue metastasis.

4. Other incidental findings are similar to that seen previously.