Abdominal MRI

Julia Geiger

Learning objectives

Standard MRI-protocol

No special examinations: MR-Urography, MRCP, MR enterography

Things to consider

Most common pediatric abdominal tumors

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What is important?

Sedation / general anesthesia in younger children

Motion reduction and correctionPROPELLER techniquerespiratory triggeringnavigator pulsefast sequences (drawback low SNR)

Coil selection to address body size

SNR optimization (appropriate sequences and coils, longer acquisition time for compensation of low SNR)

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Which sequences do you need?

Basic protocol MRI abdomen:

Coronal STIR (isotropic imaging)Coronal T1Transversal T2 fatsat (PROPELLER)Transversal T1

Protocols should include:

Transversal DWIContrast-enhanced T1 fatsatwith dynamic imaging, multiplanar(check GFR)

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Typical abdominal masses in children

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• Most common extracranialtumor

• frequently metastatic at diagnosis

• Most common renal tumor• known as Wilms tumor• frequently asymptomatic

Nephroblastoma Neuroblastoma

3 yo boyPainless belly swelling

Echo-inhomogeneous tumorwith cysts/necrotic areas andhemorrhages

pseudocapsule, inhomogeneous signalnecroses, hemorrhageleft kidney with «claw sign»

3 yo boyAbdominal MRI for tumor origin, charcterisation, extent andmetastases

T2 STIR T1 T1 Gad fatsat

3 yo boyMultiplanar sequences including contrast and dwi

T2 fatsat

T1 Gad fatsat

dwi

ADC

Tumor extention in renal veinIVC not affected

3 yo boyMRI enables vessel assessment

T2 fatsat

T1 Gad fatsat

Nephroblastoma

Dumba et al. Cancer Imag 2015

NephroblastomaStaging

Claw sign!

4 yo boyAbdominal swelling, no pain, no dysuria

T1 dyn. Gad fatsat T1 Gad fatsat

Vessel displacement

4 yo boyAbdominal swelling, no pain, no dysuria

T2 fatsat T1

T1 Gad fatsat

DWI ADC

Nephroblastoma = Wilms tumor

• Primitive metanephritic blastema• Most common abdominal tumor 1-8 years• Risc factors: nephroblastomatosis, trisomy 13, 18,

Beckwith Wiedemann syndrome, WT1 and WR2 associated

Imaging:• Large, heterogeneous tumor• Vessel displacement, renal vein and

IVC infiltration• «Claw sign» may be helpful• Lung metastases up to 20% at diagnosis

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Typical abdominal masses in children

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2 yo girlReduced general stateAbdominal MRI for tumor origin, charcterisation, extent andmetastases

T2 STIR T2 STIR

heterogeneous signalhemorrhagesmetastasesvessel encasementexceeding midline

2 yo girl

T2 fatsat T1

DWI ADC

Neuroblastomaarising from adrenal gland

3 yo boyabdominal pain, palpable mass in lower abdomen

3 yo boysonography as first line modality

calcifications

3 yo boyAbdominal MRI for tumor origin, charcterisation, extent andmetastases

Neuroforaminal infiltration

T2 fatsat

T2 STIR

T1 Gad fatsat

Neuroblastomaarising from sympathetic chain

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Whole body MRIcoronal STIR

no metastases

MIBG scintigraphy

no metastases, intense MIBG uptakein the pelvic tumor

What information does the pediatric oncologist need from the radiologist?

1. diagnosis neuroblastoma?

2. vital organs or anatomical structures?

3. complete resection possible?

4. stage of the disease?

5. baseline information for response assessments during therapy

5 month old girlhepatomegaly, restless

5 month old girl

inhomogeneous liver

primary liver tumor vs.Metastases?

Metastastic neuroblastomaOrigin?

T2 STIR T2 STIR

liver and bone marrow metastases

Metastastic neuroblastomaOrigin?

T2 fatsat T1 Gad fatsat

DWI ADC

Neuroblastoma

• Sympathetic chain primitive neural crest cells• Location adrenal vs. extraadrenal retroperitoneum

• often sporadic, partially syndrome-related• heterogeneity of tumor, highly variable prognosis• n-MYC oncogene high risk group

Imaging:• Image-defined risk factors: vessel displacement and

encasement, intraspinal extension, tracheal compression…

• calcifications (90%)• >50% metastases at diagnosis• include whole-body MRI!

Neuroblastoma vs. Wilms Tumor

Dumba et al. Cancer Imaging 2015

Sono, MRI, CTSono, MRI, CTMIBG-Scintigraphy99mTc-ScintigraphyFDG-PET/CT/MRIGa-68 DOTATATE

Take home messages

Take home messages

Abdominal MRI

• appropriate MRI sequences and equipment

• for tumor characterisation, location, extent and staging

• differential diagnosis

• baseline examination, treatment planning and monitoring

• interdisciplinary discussion

• biopsy