Non-Cardiovascular Findings on CMR

Marty Smith M.D.Marty Smith M.D.Instructor in Radiology

Beth Israel Deaconess Medical Center

Harvard Medical School

Boston, MA

A major teaching hospital of Harvard Medical School

Objectives

• Review data for incidental non-cardiovascular findings (NCF) in cross-sectional cardiac imaging

• Approach to non-cardiovascular structures on CMR imaging

• Overview of common lesions and their expected appearance on CMR

What is covered?

Imaged volume – Base of Neck → Kidneys

Base of Neck - Thyroid, parathyroid, trachea, esophagus, muscles, vertebral bodies, lymph nodes, nerves, fat

Thorax Thyroid Mediastinum – thymus, trachea & bronchi, esophagus,

vertebral bodies, spinal canal, lymph nodes, nerves, fat Lungs and pleura Chest wall – bones, muscles, lymph nodes, nerves, fat Breasts Diaphragm

What is covered?

Abdomen Liver Gall bladder and bile ducts Pancreas Kidneys Adrenal Glands Spleen Stomach Bowel and Mesentery Vertebral column, nerves, spinal canal, paravertebral

musculature, fat, fascia, & lymph nodes

Background: Non-Cardiac Findings

Dewey M, et al. Non-cardiac findings on coronary computed tomography and magnetic resonance imaging. Eur Radiol 2007 Feb 1; [Epub ahead of print].

• 108 consecutive patients suspected of having CAD who had CTA & MRA

• Significant NCF → clinical or radiology F/U

• CT – 5 (5%) significant non-cardiac findings

PE, pleural effusion, sarcoid, HH, & pulmonary nodule

• MRI – 2 (2%) significant non-cardiac findings Pleural effusion & sarcoid – both seen on CT

Non-Cardiac Findings

Conclusion: Incidental NCF are common; images should be analyzed by radiologists to ensure findings not missed & unnecessary follow-up avoided.

Dewey at al. Eur Radiol 2007

Of 108 pts.

Non-Cardiac Findings on Cardiac CT

• Cardiac MDCT in 503 pts1 346 new NCF in 292 pts (58.1%) 114 pts (22.7%) had clinically significant findings

4 cases of malignancy (0.8%). 49 lung nodules <1cm (12 > 1cm), 8 aortic,17 pleural effs

• Cardiac MDCT in 166 pts, suspected CAD2

NCF in 41 pts (24.7%), major (4.8%)

• EBCT in 1326 pts for coronary Ca2+ scoring3

NCF requiring f/u in 103 pts (7.8%)

• EBCT in 1812 consecutive pts4

NCF in 630 (35%); 50 (2.8%) f/u imaging1 Onuma Y, et al. J Am Coll Cardiol 2006 2 Haller S, et al. AJR Am J Roentgenol; 20063 Horton KM, et al. Circulation 2002 4 Hunold P, et al. Eur Heart J 2001

Summary for CT:

• NCF in 24-58%

• NCF needing f/u in 2-23%

• Classification criteria variable

BIDMC CMR Experience – Part I

• 1534 clinical CMR reports reviewed 2002-061

• 129 NCF in 116 (8.2%) studies 55 “major” findings in 50 (3.3%) studies

lymphadenopathy - 22 (1.4%) lung abnormalities - 19 (1.2%) mediastinal masses - 6 (0.4%) breast lesions - 4 (0.3%), ascites - 3 (0.2%), soft tissue

masses - 1 (0.1%)

74 “minor” findings in 70 (4.6%) studies pleural effusions, liver lesions, renal cysts, HH,

diaphragmatic abnormalities, splenic abnormalities, paraspinal lipomas, & anomalous vasculature

• NCF mean age 54 vs 49 w/o (p <0.001)

1 Chan PG, etal. JACC 2009

BIDMC CMR Experience – Part II

• 495 clinical CMR exams in 2006 reviewed for NCF by radiologist w/o prior readings

• NCF classification Benign (gynecomastia, simple cyst) Indeterminate (pleural effusion, liver & renal lesions) Worrisome (lung nodules)

• Follow-up of indeterminate & worrisome NCF using Careweb New vs known abnormality What follow-up performed

Results: NCF Prevalence

• 295 NCF in 212 / 495 (43%) studies 144 Benign: 123 / 495 (25%) studies 137 Indeterminate: 105 / 495 (21%) studies 14 Worrisome: 14 / 495 ( 3%) studies

Benign: Gynecomastia (41), HH (22), Renal Cyst (17), Liver cyst/hemangioma (16), Scoliosis (11), Mediastinal LAN <1.5 cm (10), Other (27)

Indeterminate:Pleural effusion (29), Renal lesion (27), Atelectasis (11), Mediastinal LAN >1.5 cm (11), Lung consolidation (7), Big HH (6), Liver lesion (6), Other (40)

Worrisome: Lung nodules (11), Aortic dissection (1), Aortic ulcer (1), Mediastinal mass (1)

Results: NCF Detection & F/U

• 105 / 295 (36%) NCF listed in clinical report Benign (21%), Indeterminate (50%), Worrisome (50%)

• 11 NCF in reports missed by reviewer

• 65 NCF in 52 pts needed f/u → performed on 25 (38%)*

• Of NCF reported, 22 needed f/u → performed on 12 (55%)**

* No online medical record information currently available for pts with 16 findings

** No online medical record information currently available for pts with 7 findings

Known Follow-up

Management changing findings in 11 pts: • Lung cancer (2)

• Pulmonary nodule requiring further follow-up (2)

• Typical pulmonary carcinoid

• Cryptogenic organizing pneumonitis (COP)

• Multifocal pneumonia secondary to newly diagnosed AML

• Mediastinal lymphadenopathy requiring further follow-up

• Breast implant rupture

• Obstructed atrophic kidney

• New AAA (previously repaired but with recurrence)

Results: Radiologist’s Presence

• Radiologist at joint read-out – 384/495 (78%) scans

• 42% (95/228) of NCF reported when radiologist at joint readout

• 15% (10/67) of NCF reported when radiologist read remotely (p<0.01)

Results: Sequences

• Scouts showed NCF 186/295 (63%)

• T1W FSE showed NCF 176/295 (60%)

• Only 12 (4%) NCF not visualized on one of these sequences 10 benign, 2 indeterminate)

CMR Sequences

CMR Sequence Overview

• Abdomen & base of neck FFE scouts Limited coverage by other sequences

• Thorax – Potentially all sequences Most → T1-w TSE, FFE scouts, B-FFE cines Other T1-w imaging

T1-w TSE FS Post gado T1-w TSE, T1-w IR GRE, T1-w SPGR

T2-w imaging T2-w TSE dark blood Fat suppressed T2-w → SPIR, STIR

FFE Scouts

• Limited soft tissue lesion detection & characterization

• Large inter-slice gap, low resolution

• Contrast based on T2/T1 ratio Bright = Fluid or fat Not bright = Soft tissue, some complex fluid

• Motion insensitive Shape & margin with well defined lesions Internal structures of cysts

• B-FFE and TFE similar for NC lesions

TSE T1

• True T1-weighted sequence with IR blood suppression

Bright – fat, hemorrhage, protein, some flow, some Ca2+

Dark – Simple fluid, most Ca2+, air In-between – most masses

• Cover from top of liver to above arch Excellent for anatomy Best look at mediastinum, breasts, chest wall, lungs

• Navigator problematic around diaphragm

• More helpful when combined with T1 FS

FFE & TSE T1

FFE

T

1

Bright Not Bright

Bright

Not

Bright

• Most commonly see lesions on T1 & FFE

Fat, Hemorrhage

Hemorrhage, Protein

Cyst Soft Tissue

Other T1 Weighted Sequences

• T1-w TSE with fat saturation Identify fatty lesions definitively Increased conspicuity of T1 bright lesions

• Post gadolinium – Tissues vs fluids (inflammation, atelectasis, infarcts) T1-w TSE → less conspicuity of enhancement T1-w FS SPGR → usu. early; best for enhancement T1-w IR GRE → Delayed; caveat of IR Subtractions helpful for intrinsic T1 bright lesions

T2 Weighted Imaging

• T2-w TSE – True T2-w sequence

• STIR –T1-w & T2-w; good fat suppression

• SPIR – True T2-w; less homogeneous fat suppression

• Bright on FFE & T2-w TSE Cysts, hemangiomas, fat, some hemorrhage

• Mildly bright on T2-w TSE → Usu. concerning

• Increased brightness with SPIR, STIR Fibrous tumors (eg, breast ca) still dark

T2-w TSE

SPIR

Big Picture

• Brighter lesion on FFE, T1-w TSE, or T2-w TSE → More likely it’s benign Look for subtle nodularity, esp. with hemorrhage

• No gadolinium → f/u imaging or not? Well seen, sharp margin, homogeneously bright on FFE

or T2-w TSE, not bright on T1-w TSE → Benign → Stop Except breast

Not well seen, irregular margin, heterogeneous, bright on T1(& not fat), not bright on T2-w TSE → f/u imaging

• Enhancement → Usu. f/u imaging for further characterization or diagnostic procedure

Big Picture

• Need to look separately for NCF

• Develop a system

• If you aren’t looking for it, you won’t see it

• Symmetry is your friend

• Use cross referencing tools

• The only thing better than your MR . . . is an old MR (or CT)

Lesions by Location

Mediastinum Diversion

Old Radiology

• Anterior Mediastinum – posterior to sternum, anterior to trachea & posterior aspect of heart thymus, lymph nodes, nerves, fat

• Middle Mediastinum – b/w anterior & posterior mediastinum trachea & bronchi, esophagus, lymph nodes, nerves, fat

• Posterior Mediastinum – b/w posterior chest wall & 1 cm behind anterior margin of vertebral column vertebral bodies, spinal canal, lymph nodes, nerves, fat

Cross Sectional Mediastinum

• Differential based on tissue where mass arises

• If not possible, then localize by region Supraaortic mediastinum (superior mediastinum) Prevascular space, Anterior cardiophrenic angles Pretracheal & subcarinal spaces, AP window Paraesophageal or azygoesophageal recess Paravertebral

• Caveat: Be sure it is from the mediastinum Deep to vessels → Definitely Broad Base, smooth margin; not spiculated or irregular

Lymph Nodes

• Every site in mediastinum• Lymphoma, Mets, Sarcoid, Granulomatous Infxn• Pattern can be important

Symmetric bilateral hilar & paratracheal – likely sarcoid Prevascular nodal mass – Hodgkin’s Lymphoma > NHL Unilateral hilar +/- paratracheal – Lung > other mets Posterior mediastinum – Lymphoma (NHL) vs mets Cardiophrenic angle – Mets vs lymphoma

• Intermediate T1, bright T2, enhancement Necrosis – Mets, lymphoma (NHL) ,Tb, fungus Ca2+ – Granulomatous infxn, sarcoid; treated lymphoma

Hodgkin’s Lymphoma

Sarcoid

RCC Mets

Chloroma

Thyroid Lesions

• Supraaortic Mediastinum Can extend into prevascular space, around trachea

• Goiter Bland Goiter – Low SI T1-wi & intermediate SI T2-wi Multinodular Goiter – Heterogeneous on T1-wi & T2-wi

• Thyroid Cancer Can be invasive, but usually notCarcinoma in multinodular goiter – 7.5 %MRI can not definitively differentiate benign & malignant

Thymus & Thymic Masses

• Prevascular Space • Normal thymus

Fat proportion increases with age → harder to see Intermediate on T1-w, bright on T2-w; margins important;

interdigitating fat

• Thymic rebound – stress (chemo, burns)• Thymoma – # 1 adult 1° mediastinal tumor

Variable; homogeneous, cystic, nodules; invasion

• Thymolipoma; thymic cyst, carcinoma, carcinoid; lymphoma, mets

Normal Thymus

T1-w TSE

SPIR

Foregut Cysts

• Bronchogenic – Most common Any location – 50% subcarinal, 20% paratracheal Rounded, smooth, sharply defined (imperctible wall) Fluid contents variable

• Pericardial 90% touch diaphragm, 65%R 35%L cardiophrenic angle Usually simple fluid, sometimes hemorrhage

• Esophageal duplication

• Neurenteric Associated vertebral anomaly

Germ Cell Tumors

• Anterior Mediastinal Mass (prevascular)

• More in young adults; 80% benign

• Teratomas All germinal layers Cysts, fat (Fat-fluid levels), Ca2+, soft tissue

• Seminomas Men; most common malignant GCT; homogeneous

• Nonseminomatous GCT Rare, heterogeneous

Hernias

• Hiatal Sliding (most common), Paraesophageal, Mixed

• Bochdalek Posterolateral and left more common Retroperitoneal fat, rarely kidney or liver

• Morgagni Anteromedial Omental fat (Pseudomass), Transverse Colon

• Traumatic Diaphragmatic Small at inception → grow latently

Esophagus

• Thickening Esophagitis, Barrett’s, cancer

• Mass Leiomyoma, lipoma, cancer

Paravertebral Region

• Neurogenic Tumors Nerve Sheath (Schwannomas), sypmathetic ganglia

tumors, paragangliomas Commonly bright on T2, avidly enhancing

• Thoracic Spine abnormalities Fractures, Malalignment, DDD, Hemangiomas, Tumors

• Meningoceles and nerve sleeve cysts

• Extramedullary hematopoesis Multiple bilateral paravertebral tumors, hyperenhance

• Nodes are still most common

Vertebral Hemangioma

Lungs

• All new nodules & masses* need Chest CT Lung cancer can be round, spiculated, infiltrative Multiple – Mets, granulomatous dz, sarcoid, septic emboli

• Atelectasis common dependently; should enhance Non-dependent consolidation → obstruction, other cause

• Pneumonia Non-dependent or patchy, filled airways, Hypoenhancement

• Pulmonary Edema Usu. symmetric; Sometimes difficult to diff from pneumonia

• Pulmonary Infarcts Peripheral wedge shaped, hypoenhancement & necrosis

• Fibrosis (sarcoid, XRT, CTD, Amiodarone)

Carcinoid

LLL Pneumonia & Right Effusion

Pulmonary Infarct

Pleura

• Pleural effusions Simple vs exudative vs hemorrhagic Associated pleural thickening and enhancement Loculation, empyema

• Plaques - Asbestos

• Masses Metastases – Lung, Breast

Usually associated with effusion

Fibrous Tumors of the Pleura Malignant Mesothelioma

Chest Wall

• Bones Metastases Primary Benign > Primary Malignant

• Fat Lipoma, Low Grade Liposarcoma

• Muscle Atrophy, Edema Intramuscular Lipomas Mets > Sarcomas

• Subcutaneous and Dermis Sebaceous cysts most common

IntramuscularLipoma

Breasts

• Simple Cysts Must be FFE +/- T2 Bright and T1 dark, no enhancement → still

confirm with Ultrasound

• Proteinaceous / Hemorrhagic Cysts → US• Fibroadenoma

Well circumscribed, T1 dark, usu. T2 bright, progressive enhancement → mammogram & US

• Breast Cancer Not always spiculated; also can be in cysts T1 dark and usu. TSE T2 dark, mildly bright STIR/SPIR Variable enhancement, but usu peak 90-180 sec. Any concern → Mammogram & US +/- MRI

• Only Fat containing lesions do not need workup

Liver• Cysts – most common

Smooth margin, round or oval, bright FFE +/- T2, dark T1, no enhancement → Benign

Other than thin septation, any complexity → F/U MRI

• Hemangiomas – second most Similar to cyst in shape & on FFE, T1, T2, but enhance

Flash fill or peripheral discontinuous → filling centripetally

• Any non cyst-like lesion → f/u MRI Focal Nodular Hyperplasia (FNH) – Most common mass Primary Malignancies – HCC and Cholangio Ca Metastases – Colon, Gastric, Pancreaticobiliary, Lung, Breast,

Melanoma

• Diffuse Dz – Cirrhosis, Fatty, Hemachromatosis

RCC Mets

Hemochromatosis

Cirrhosis

Hemosiderosis

Gall Bladder

• Gall Stones – very common Round or faceted filling defects in GB Usu. dark on all sequences; can be bright on T1-w

• Polyps – common Hard to diff. from adherent gall stones w/o contrast

• Adenomyomatosis – common Usu. Fundal, wall thickening, can have T2-bright foci

• GB wall edema – uncommon Usu. liver dysfxn; if not T2-bright ? Chronic cholecystitis

• GB Cancer – rare Any GB mass requires work-up

Kidney

• Cysts – most common Smooth margin, round or oval, bright FFE +/- T2, dark

T1, no enhancement → Benign Other than thin septation, any complexity → F/U

If hemorrhagic or clearly nodules → MRI

• Masses All potential masses (heterogeneous, not bright FFE or

T2, not dark T1) need F/U Renal Cell > Transitional Cell

• Hydronephrosis – Partial or Complete• Renal Atrophy, Agenesis

Parapelvic Cyst

Sag Right Sag Left

Spleen

• Splenomegaly, Splenules, No spleen - Common

• Hemangiomas Just like liver for the most part

• False Cysts Post traumatic or infarct Can be hemorrhagic and calcify

• Epithelial Cysts, Lymphangioma -rare

• Metastases – uncommon

Splenectomy post trauma Splenosis

Splenic Cyst – Rim Calcification

Final Thoughts

• Surprising No Adrenal Lesions No Pancreatic cysts or lesions No upper abdominal nodes No real bone lesions

• Not surprising No bowel or stomach lesions (motion) No mesenteric masses Minimal unknown cancers

ReferencesChan PG, Rofsky NM, Yeon SB, Hauser TH, Appelbaum E, Smith MP,

Manning WJ. Non-cardiac pathology on clinical cardiac magnetic resonance imaging. Accepted for publication in JACC Cardiovascular Imaging 2009.

Dewey M, Schnapauff D, Teige F, Hamm B. Non-cardiac findings on coronary computed tomography and magnetic resonance imaging. Eur Radiol 2007 Feb 1; [Epub ahead of print].

Onuma Y, Tanabe K, Nakazawa G et al. Noncardiac findings in cardiac imaging with multidetector computed tomography. J Am Coll Cardiol 2006; 48:402–406.

Haller S, Kaiser C, Buser P, Bongartz G, Bremerich J. Coronary artery imaging with contrast-enhanced MDCT: extracardiac findings. AJR Am J Roentgenol; 2006; 187:105–110

Horton KM, Post WS, Blumenthal RS, Fishman EK. Prevalence of significant noncardiac findings on electron-beam computed tomography coronary artery calcium screening examinations. Circulation 2002; 106:532–534

Hunold P, Schmermund A, Seibel RM, Gronemeyer DH, Erbel R. Prevalence and clinical significance of accidental findings in electron-beam tomographic scans for coronary artery calcification. Eur Heart J 2001; 22:1748–1758