patterns of enhancement james g. smirniotopoulos, m.d. professor of radiology and neurology...
Post on 13-Jan-2016
248 Views
Preview:
TRANSCRIPT
Patterns of EnhancementJames G. Smirniotopoulos, M.D.
Professor of Radiology and NeurologyChairman, Department of Radiology Uniformed
Services University of the Health Sciences4301 Jones Bridge Road
Bethesda, MD 20814 USA
Voice: 301-295-3145FAX: 301-295-3893
Email: jsmirnio@usuhs.milVisit us on the WEB at: http://rad.usuhs.mil
DISCLAIMER
The opinions expressed herein are those of the author(s), and are not necessarily representative of the Uniformed Services University of the Health Sciences (USUHS), the Department of Defense (DOD); or the World Health Organization (WHO). Medicine is a constantly changing field, and medical information is subject to frequent correction and revision. Therefore the reader is entirely responsible for verifying the accuracy and relevance of the information contained herein. Portions copyright 1997-2000 James G. Smirniotopoulos, M.D.
CONTRAST ENHANCEMENT
•Vascularity
•Permeability
CONTRAST ENHANCEMENT
•Vascularity–Blood Volume–Blood Flow
•Permeability–Capillary
CONTRAST ENHANCEMENT
• Any change (increase or decrease) in signal (intensity, density, etc.) over the pre-injection (inhalation, etc.) or normal background pattern, that increases the conspicuity of a lesion or makes the anatomy more visible.
CONTRAST ENHANCEMENT
– Fill a cavity (BE, Cystogram, Myelogram)– Inject a Vessel (Angiogram, venogram,
bronchogram– Diffusion (from vessel) into Interstitium
CT w/ Iodine– MR w/Gadolinium– "Bodygram" on XU
CONTRAST ENHANCEMENT
• VASCULAR (intravascular) PHASE(Inc. Blood Flow/Hypervascular)AVM, MENINGIOMA, GBM, ETC.TRUE "LUXURY" PERFUSION HYPEREMIA (TRAUMATIC)
• INTERSTITIAL (extravascular) PHASE (Blood‑brain‑barrier breakdown)Acute inflammation (ms), Neoplasm, Abscess, "granulation" tissue, Ischemia, "luxury" perfusion,Contusion
CONTRAST ENHANCEMENT
Normal Tissue w/o BBB• DURA (falx and tentorium)• (ARACHNOID ?)• CHOROID PLEXUS• PINEAL GLAND (epiphysis)• PITUITARY GLAND (hypophysis)• CTZ (MEDULLA ‑ AREA POSTREMA)
("Circumventricular Organs")
Enhancement vs. Edema
ABNORMAL PERMEABILITY(ABBB)
EDEMA ENHANCEMENT
INCREASED VASCULARITY
CONTRAST ENHANCEMENT -
PhasesVASCULAR BBB
ANGIO(I‑) ++++ ‑
R‑N (Tc+) + (flow) + (static)
C.T. (I‑) + +++
MRI (Gd+) +/‑ +++
CONTRAST ENHANCEMENT
• Morphologic Patterns– HOMOGENEOUS (SOLID)– HETEROGENEOUS (non‑uniform)– RING (unilocular/multilocular)– SERPENTINE ("GYRIFORM")
CONTRAST ENHANCEMENT
• Location– SUPERFICIAL (CORTICAL/GYRAL)– GREY‑WHITE JUNCTION– DEEP WHITE MATTER– PERIVENTRICULAR, EPENDYMAL
CONTRAST ENHANCEMENT
Cortical/Gyriform– Cerebral Ischemia / Infarction– CSF or sub‑pial spread– Meningo‑encephalitis– S.A.H.– Leptomeningeal Malformation (SW)– Meningioangiomatosis (NF2)
CONTRAST ENHANCEMENT
• Ring LesionCircumferential or peripheral/marginalenhancement, surrounding a centralnon‑enhancing region. In turn, this isoften surrounded by a large area of "edema". May Be Unilocular OrMultilocular.
CONTRAST ENHANCEMENT
• Contrast leaks into interstitium from vessels without BBB
• Remains localized within millimeters of where it leaks out
• Not "simple diffusion" but rather "BULK FLOW" at a very slow rate
• (Glacier Not River)
CONTRAST ENHANCEMENT
Diffusion ExperimentSHARK TANK ‑ with volunteer• Flowing Water ‑ rapid movement by "bulk
flow”• Motionless Water ‑ Diffusion (simple
diffusion)• Jell-O, viscous fluid, DB or DT
slow movement by "bulk flow"
CONTRAST ENHANCEMENT
Ring LesionsM ‑ Metastasis, MSA ‑ Abscess (Also Cerebritis)G ‑ Glioblastoma, GranulomaI ‑ Infarct (Esp. Basal Ganglia)C ‑ Contusion (Rare)A ‑ AIDS (Toxo, Etc.)L ‑ Lymphoma (in Aids)
D ‑ Demyelination (Active)R ‑ Resolving Hematoma Radiation Change (Necrosis)
CONTRAST ENHANCEMENT
Ring Lesion Features For Infection• ORGANIZED ABSCESS
thin and uniform wall (3‑7mm.)smooth inner margin does not "fill in" on CT, MR?
• CEREBRITIS (infection w/o organization):variable wall (may be smooth) smooth/variable inner marginoften has "fill‑in" on DDD(w/o fluid level)
CONTRAST ENHANCEMENT-
Abscess• 2 ‑ 4 wks. for ORGANIZED WALL• 2 LAYERS• inner MESENCHYMAL (capillaries,fibroblasts,
collagen)• outer ASTROGLIAL (reactive astrocytes)• WALL facing GM is well formed 3‑5 mm• WALL FACING WM IS THINNER/WEAKER
(Daughter Abscess)Ventricular Spill ("pyocephalus")
CONTRAST ENHANCEMENT
Ring Lesion Features For NeoplasmNECROTIC NEOPLASM:• thick and irregular wall• shaggy inner margin (usually)• may "fill in" heterogeneously on DDDCYSTIC NEOPLASM:• thin wall +/‑ MURAL NODULE• PART OF WALL MAY NOT ENHANCE
– smooth inner margin– uniform fluid enhancement
or FLUID LEVEL
CONTRAST ENHANCEMENT-
HematomaEARLY: Hyperdense, round/oval
Homogeneous mass of RBC's Proportional mass effect for volume Edema "Halo", not spreading
LATER: Iso‑/Hypodense, smaller Reactive capillaries form outside Uniform rim of enhancement May see "vasogenic" edema
CONTRAST ENHANCEMENT- Post-
Operative• RESIDUAL TUMOR
– (left behind)• RECURRENT TUMOR
– (grew back)• INFECTION• NORMAL POSTOPERATIVE CHANGE
– (surgical trauma, healing)• RADIATION Tx.?
CONTRAST ENHANCEMENT - Surgical Change and/or Residual
Neoplasm?• Surgical Enhancement typically after 24‑48
hrs.(scan early!)may last for months
• In the Operative Bed (mixed w/ residual?) and along the Margins of Resection– thin and uniform in brain (CT/MR)
• LINEAR meningeal/dural enhancement on MR (not lumpy-bumpy)
• Small amts. of air, blood (non‑contrast)
References
1. Aoki S, Sasaki Y, Machida T, and Tanioka H. Contrast-Enhanced MR Images in Patients with
Meningioma: Importance of Enhancement of the Dura Adjacent to the Tumor.
AJNR 1990;11935-938.
2. Bourekas EC, Lewin JS, and Lanzieri CF. Case Report: Postcontrast Meningeal MR Enhancement Secondary to Intracranial Hypotension Caused by
Lumbar Puncture. J Comput Assist Tomogr 1995;19(2):299-301.
3. Cairncross JG, Pexman JHW, Rathbone MP, and DelMaestro RF. Postoperative Contrast
Enhancement in Patients with Brain Tumor. Ann Neurol 1985;17570-572.
4. Cañellas AR, López MC, Isern EG, and Gaerín XM. Postcontrast Dural MR Enhancement and Acute CSF
Intracranial Hypotension. J Comput Assist Tomogr 1995;19(6):1008-1009.
5. Chamberlain MC, Sandy AD, Press GA.
Leptomeningeal metastasis: a comparison of gadolinium-enhanced MR and contrast-enhanced CT
of the brain. Neurology 1990;40:435-8.
6. DeLaPaz RL. Advances in brain tumor diagnostic imaging. Curr Opin Neurol 1995;8:430-6.
7. Gado M, Phelps M, Coleman R. An extravascular component of contrast enhancement in cranial
computed tomography. Radiology 1975;177:589-3.
8. Gupta S, Gupta RK, Banerjee D, Gujral RB. Problems with the dural tail sign. Neuroradiology
1993;35:541-2.
9. Kramer R, Janetos G, Perlstein G. An approach to contrast enhancement in computed tomography of
the brain. Radiol 1975;16:641-7.
10. Laohaprasit V, Silbergeld DL, Ojemann GA, Eskridge JM, and Winn HR. Postoperative CT
Contrast Enhancement Following Lobectomy for Epilepsy.
J Neurosurg 1990;73392-395.
11. Latchaw RE, Gold LHA, and Torrije EJ. A protocol for the use of contrast enhancement in cranial
computed tomography. Radiology 1978;126681-687.
12. Messina AV. Computed Tomography: Contrast Enhancement in Resolving Intracerebral
Hemorrhage. Am J Roentgenol 1976;1271050-1052.
13. Mittl Jr. RL and Yousem DM. Frequency of Unexplained Meningeal Enhancement in the Brain
after Lumbar Puncture. AJNR Am J Neuroradiol 1994;15633-638.
14. Nagele T, Petersen D, Klose U, Grodd W, Opitz H, Voigt K. The dural tail adjacent to meningiomas
studied by dynamic contrast-enhanced MRI: a comparison with histopathology. Neuroradiology
1994;36:303-7.
15. Paakko E, Patronal N, Schellinger D. Meningeal Gd-DTPA enhancement in patients with
malignances. J of computer assisted tomography 1990;14:542-6.
16. Phillips M, Ryals T, Kambhu S, Yuh W. Neoplastic vs inflammatory meningeal enhancement with Gd-DTPA. J of computer assisted tomography
1990;24:536-41.
17. Pullicino P and Kendall BE. Contrast Enhancement in Ischaemic Lesions.
Neuroradiol 1980;19235-239.
18. Senegor M. Prominent meningeal tail sign in a patient with a metastatic tumor. Neurosurg
1991;29:294-6.
19. Steinhoff H, Aviles C. Contrast enhancement response of intracranial neoplasms: its validity for
the differential diagnosis of tumors in CT, in Lanksch, W, Kazner E. (eds): Cranial conputerized tomography. New york, springre-Verlag 1976;151-
61.
20. Tien RD, Yang PJ, Chu PK. Dural tail sign: a specific MR sign for meningioma? J Comput Assist
Tomogr 1991;15:64-6.
21. Tokumaru A, O'uchi T, Eguchi T, Kawamoto S, Kokubo T, Suzuki M, and Kameda T. Prominent
Meningeal Enhancement Adjacent to Meingioma on Gd-DTPA-enhanced MR Images: Histopathologic
Correlation. Radiology 1990;175431-433.
22. Tokumaru A, O'uchi T, Eguchi T, Kawmoto S, Kokubo T, Suzuki M, Kameda T. Prominent
meningeal enhancement adjacent to meningioma on go-DTPA-enhanced MR Images. Histopathologic
Correlation. Radiology 1990;175:431-3.
23. Wilms G, Lammens M, Marchal G, Demaerel P, Verplancke J, Van Calenbergh J, Goffin J, Plets C, and Baert AL. Prominent Dural Enhancement Adjacent to Nonmeningiomatous Malignant Lesions on Contrast
Enhanced MR Images. AJNR Am J Neuroradiol 1991;12761-764.
top related