Transcript of Imaging of adrenal masses
- 1. Presentor: Dr Kusum Pathania Moderator: Dr Jyoti Arora
IMAGING OF ADRENAL MASSES
- 2. Adrenal Gland The adrenal gland is named for its location
adjacent to the kidneys: ad-renal Also known as suprarenal glands
Characteristic inverted Y, V, or T shape Pair of important
endocrine glands situated on the posterior abdominal wall over the
upper pole of the kidneys behind the peritoneum. Each gland is
enclosed in the perirenal fascia and each have a body and two limbs
-medial and lateral.
- 3. HISTOLOGY ADRENAL CORTEX-90% of adrenal three zones 1.Zona
glomerulosa-outer most 10-15% Secretes mineralocorticoids
(aldosterone) 2.Zona fasciculata-80% - secretes cortisol 3.Zona
reticulata-5-10% - secretes androgens
- 4. ADRENAL MEDULLA- 10% of adrenal made up of chromaffin cells,
secretes-EPINEPHRINE or NOREPINEPHRINE Partof sympathetic autonomic
nervous system.
- 5. VASCULAR SUPPLY: Arterial supply : inferior phrenic artery
superiorly. aorta medially . renal artery inferiorlly Venous
drainage : Right side: drain to IVC . Left side : drain to left
adrenal vein or directly to IVC. Lymphatics : Para-aortic and
paracaval lymph nodes.
- 6. Normal gland CT Right adrenal gland : superior to right
kidney, medial to right lobe of liver, lateral to crus of right
hemidiaphragm, posterior to IVC. Shape : elongated comma lying in
crease between liver and crus of diaphragm.
- 7. ngt
- 8. Normal gland CT Left adrenal gland : superior to and
anterior to upper pole of kidney in triangle formed by left lateral
margin of aorta, posterior surface of body and tail of pancreas and
upper pole of left kidney.
- 9. Normal CT measurements: Length - 4-6cm Width -2-3cm . Each
limb normally measures 5mm in width and the body should measure
8-10mm in width Criteria for Enlargement: Length >6cm AP
diameter > 3cm Limb thickness > 6mm Thickness more than
adjacent crus.
- 10. PURPOSE : Overview of adrenal disease and their imaging
appearance. Current concept of differentiating a benign from
malignant adrenal mass with particular attention to CT and MRI.
Present an imaging alogrithm for characterizing an adrenal
mass.
- 11. IMAGING MODALITIES : Ultrasound Computed tomography
Magnetic resonance imaging Nuclear medicine imaging
- 12. ULTRASOUND : Primarily reserved for use in pediatric
population because of lack of ionising radiation and small body
habitus of children. Right adrenal best evaluated from midaxillary
and anterior axillary line . Liver provide acoustic window. Left
adrenal evaluated from posterior or mid axillary approach. No
suitable acoustic window for left so completely evaluated in 80% of
people.
- 13. CT Routine CT protocol for adrenal imaging NCCT abdomen
CECT abdomen (70 secs delay) Delayed scan (after 15 minutes)
Computed tomography (CT) is the imaging modality of choice for
evaluating adrenal glands morphology and masses associated with it.
High resolution CT of upper abdomen, using 1-3mm thick slices to
reduce the volume averaging, is most accurate technique for
indentifying adrenal lesions. Contrast-enhanced CT and delayed
images help in further characterization of the lesions. 100-150ml
of contrast is injected at a rate of 3mlper second and images are
aquired at 70sec and 15 min after contrast injection.
- 14. MRI MRI of the adrenals is the modality of choice for
further characterization of adrenal lesions. MR parameters should
include T1-and T2-weighted sequences along with chemical shift
imaging. T1 weighted signal show normal adrenal as low signal
against high signal fat. Most tumor show high signal on T2W and low
signal on T1W image. Contrast enhanced dynamic MRI used in d/d of
adenoma, metastasis, granulomas and pheochromocytoma Chemical shift
MR used in d/d of adenoma and metastasis: adenoma high lipid
content
- 15. (a)T1-weighted breath-hold. MR image demonstrates a normal
left adrenal gland (arrow). (b)T2 weighted MR image. Normal gland
MRI
- 16. NUCLEAR MEDICINE IMAGING FDG PET. I-131MIBG
In-111Octreotide
- 17. Adrenal masses A. Neoplasm B. Other mass lesion 1. Cortical
1. Granuloma a. adenoma a. tuberculosis b. carcinoma b.
histoplasmosis 2. Medullary c. blastomycosis a. pheochromocytoma 2.
Bilateral hyperplasia b. neuroblastoma 3. Cyst c. ganglioneuroma a.
endothelial (45%) 3. Stromal b pseudocyst (39%) a. lipoma c.
epithelial (9%) b. myelolipoma d. parasitic (hydatid) 4. Metastasis
4. Hematoma
- 18. ADRENAL DISEASES GROUP I : Adrenal disease with normal
function. GROUP II : Adrenal Hyper-functional disease. GROUP III:
Adrenal insufficiency.
- 19. GROUP I : ADRENAL DISEASE WITH NORMAL FUNCTION: Most of
these are incidentally detected as adrenal masses. Include :
nonfunctional adrenal adenoma or carcinoma, metastasis , lymphoma ,
myelolipoma , adrenal cyst.
- 20. INCIDENTALLY DISCOVERED ADRENAL MASSES: Common incidental
discoveries on CT, MRI, FDG- PET. Adrenal incidentaloma lesions 20
HU) Enhancement with contrast Delayed contrast washout (10 min)
Absolute contrast washout < 60% Isointensity or slightly less
intense than liver T-1 , high to intermediate intensity T-2 MRI
(represent water increase)
- 61. Left adrenal metastases in a 74-year-old man with lung
cancer. (a) T1- weighted in-phase MR image demonstrates a left
adrenal mass (arrow). (b) T1-weighted out-of-phase MR image shows
no significant signal loss in the adrenal gland compared with that
of the spleen. The mass is either a metastasis or atypical adenoma,
and biopsy was recommended.
- 62. MYELOLIPOMA: Benign tumor of the cortex comprised of both
mature fat and hematopoeitic cells. AGE=5Th to 6Th decade SEX=M=F
C/F----asymptomatic/mass effect Imaging appearance may vary acc to
histological component.
- 63. USG----- 1.SIZE---- capillary AGE50-70yrs SEXF:M=2:1
C/Fasymptomatic
- 97. Most characteristic are phleboliths and presence of
vascular lakes. Centripetal enhancement is less characteristic than
in hepatic hemangioma
- 98. Imaging findings X-raycalcifications (64%)---similar to
phleboliths USG no-specific app, heterogenous lesion often
large>10cm is seen.
- 99. NCCT----well- delienated hypoattenuating heterogenous mass
+ necrotic areas CECT----periph. pools of contrast (vasc. lakes)
fill- in phenomenon less freq.- necrosis/hge/ fibrosis
- 100. MRI---- T-1-heter. Low signal, periph. persistent
enhancement in delayed images. T-2-high signal.
- 101. Conclusion Most adrenal masses are incidentalomas and
amongst them, adenomas are most common, which can be functioning or
non- functioning. Some adrenal masses may have pathognomonic CT
features such as myelolipoma, cysts, lipid-rich adenomas and
malignant masses but most incidentalomas have nonspecific
morphologic features. Most adrenal adenomas are lipid-rich and can
be correctly diagnosed on chemical-shift MR imaging or unenhanced
CT. Most lipid-poor adenomas can be accurately characterized on
delayed enhanced CT. In patients with a primary extraadrenal
neoplasm and no other evidence of distant metastatic disease,
noninvasive imaging can reduce the necessity for percutaneous
adrenal mass biopsy in most patients by confirming presence of
adenoma. Percutaneous biopsy can be limited to larger masses whose
imaging studies are not specific & do not indicate an
adenoma.