Miyazaki Osamu,  Oguma Eiji,  Nishikawa Masanori,  Tanami Yutaka,  Kitami Masahiro,  Hosokawa Takahiro

Final Pr. ID: Poster #: SCI-026

To assess the size and number of pulmonary lesions in patients with hepatoblastoma
Diagnostic criteria of the PRETEXT (Pretreatment Extent of Disease) staging system for hepatoblastoma states that pulmonary lesions are judged to be metastases if there is one nodule greater than 10mm in diameter, or if among several nodules at least one is greater than 5mm in diameter. Read More

Authors:  Miyazaki Osamu , Oguma Eiji , Nishikawa Masanori , Tanami Yutaka , Kitami Masahiro , Hosokawa Takahiro

Keywords:  hepatoblastoma, lung metastasis, chest CT

Kryger Marc,  Hernandez Alejandra,  Herring Katye,  Riegler Lara,  Hook Marcus,  Daugherty Reza

Final Pr. ID: Poster #: CR-028

A 16 year old boy reporting several months of hip pain, weight-loss, and fatigue presented to our institution after a pelvis radiograph ordered by his family physician showed concerning findings. MR imaging of his pelvis demonstrated a large heterogeneously enhancing mass arising from the right iliac wing causing significant mass effect on the pelvic organs and soft tissues of the buttocks. A percutaneous biopsy confirmed the diagnosis of Ewing sarcoma.
A staging CT of the chest was performed, demonstrating multiple lung metastases. In addition to this finding, there was multifocal bilateral nodular tumor thrombus propagating along multiple subsegmental pulmonary arteries, with a pseudo tree-in-bud morphology. Given their course, these metastatic deposits appeared endovascular in origin. Read More

Authors:  Kryger Marc , Hernandez Alejandra , Herring Katye , Riegler Lara , Hook Marcus , Daugherty Reza

Keywords:  Ewing, Sarcoma, Metastasis

Albers Brittany,  Shah Chetan

Final Pr. ID: Poster #: CR-005

A previously healthy 12 year old female presented with left lower back pain and left thigh numbness. MRI showed a T1 isointense, heterogeneously T2 hyperintense left retroperitoneal mass with extension into the paraspinal muscles and intraspinal extension through the L1-L4 neural foramina. CT and contrast enhanced MRI (CE-MRI) of the lumbar spine and I-123 MIBG scintigraphy were performed. CT did not show any calcifications. MRI showed mildly heterogeneous, avid gadolinium enhancement. The mass was I-123 MIBG avid, without evidence of metastatic disease. Ultrasound guided biopsy yielded ganglion cells and no neuroblasts, suggestive of ganglioneuroma (GN). Partial excision of the retroperitoneal component yielded a 7 x 6 x 3 cm aggregate of tissue, and histopathology confirmed GN.

Follow up CE- MRI at 4, 10, and 16 months after surgery showed stable residual mass. CE-MRI at post op month 23 showed numerous T2 hyperintense enhancing osseous masses in the lumbar spine and sacrum. Residual mass remained stable. A fluoroscopically guided biopsy of a right sacral lesion yielded neuroblastoma. Review of the pathology from the original excision confirmed GN. Whole body I-123 MIBG scintigraphy showed the avid mass and confirmed skeletal metastases.

Ganglioneuromas (GN) are benign tumors of neural origin that exist on a spectrum with ganglioneuroblastoma (GNB) and the frankly malignant neuroblastoma (NB). CT, MR, and nuclear scintigraphy are unreliable for the differentiation of NB/GNB from GN. The most robust imaging feature to identify NB is the presence of distant metastases. Imaging findings that have been proposed as possible distinguishing features are the morphology of the calcifications, early versus delayed gadolinium enhancement, and ADC values. It is a well-known phenomenon that NB may regress into GNB or GN either spontaneously or following treatment with chemotherapy and/or radiation. To our knowledge, only one other case of GN de-differentiating into NB has been reported. Due to the extreme rarity of this case, alternatives must be considered. It is possible that the patient had a bi-phenotypic tumor and the NB component was not sampled initially or that she developed a NB extrinsic to the GN. These alternatives seem unlikely since NB is a rare tumor in 12 year olds, the residual tumor did not change on follow-up imaging, no new primary tumor was seen on recent MIBG, and two years passed prior to the development of metastasis. Read More

Authors:  Albers Brittany , Shah Chetan

Keywords:  Ganglioneuroma, Neuroblastoma, Metastasis

Harreld Julie,  Ayaz Muhammad,  Hillenbrand Claudia,  Loeffler Ralf,  Patay Zoltan

Final Pr. ID: Poster #: EDU-072

Detection of leptomeningeal metastasis (LM) is critical to staging and prognosis of childhood CNS cancers like medulloblastoma and ependymoma. ¹ Though CSF examination is the historical gold standard for diagnosis, technological advances have earned MRI a central role in metastasis detection; recent work finds MRI more predictive of survival than CSF analysis. ^2-4 However, not all sequences are created equal for detection of tumor in the CSF, and pediatric MR imaging presents additional unique challenges such as patient motion, acoustic noise and scan time reduction. In this exhibit, we discuss the strengths and weakness of common sequences for LM detection; technical alternatives for reduction of motion, acoustic noise and scan time; and present a suggested targeted imaging protocol based on current best imaging practice.

With visual examples, we will discuss:
1. Signal characteristics of LM and role of complementary sequences for detection
2. Optimizing scan planes and slice thickness for tumor/metastasis location and patient size
3. Strengths and weaknesses of T1 FLAIR, SE, FSE/TSE, gradient echo and ultrafast spoiled gradient echo (VIBE/FAME/LAVA/THRIVE) sequences in terms of time, resolution, SNR and CSF artifact
4. Utility and optimization of post-contrast FLAIR, DWI, TrueFISP/bSSFP, and subtraction images for metastasis detection
5. Reducing imaging time: targeted sequences, k-space undersampling (HASTE, partial Fourier imaging), parallel imaging
6. Reducing acoustic noise: lowering bandwidth, longer echo spacing, modified gradient wave forms, alternate encoding (PETRA, SWIFT, zero-TE)
7. Reducing motion artifact: 2D vs. 3D, non-Cartesian acquisition schemes, motion correction

References:
1. Engelhard HH, Corsten LA. Cancer Treat Res 2005;125:71-85
2. Maroldi R, Ambrosi C, Farina D. Eur Radiol 2005;15:617-626
3. Pang J, Banerjee A, Tihan T. Journal of neuro-oncology 2008;87:97-102
4. Terterov S, Krieger MD, Bowen I, et al. J Neurosurg Pediatr 2010;6:131-136

Figure: Spine imaging at 3 Tesla. (a) Axial post-contrast T1-weighted VIBE images reconstructed at 3mm/0 gap show leptomeningeal metastasis to excellent advantage, without CSF pulsation artifact which obscures the same metastasis on axial (b) T1 TSE (3mm/0.3mm gap) with contrast. Metastasis was confirmed by CSF analysis. Read More

Authors:  Harreld Julie , Ayaz Muhammad , Hillenbrand Claudia , Loeffler Ralf , Patay Zoltan

Keywords:  Brain tumor, MRI, metastasis

Gagnon Marie-helene,  Wallace Andrew,  Yedururi Sireesha,  Khanna Geetika

Final Pr. ID: Poster #: EDU-077

Pulmonary metastases typically present as well-circumscribed, solid nodules of variable size in most pediatric malignancies. Hematogeneous metastases tend to have a basilar and peripheral predilection. Atypical patterns of pulmonary metastases can however occur and lack of recognition can result in understaging or delay in diagnosis. The purpose of this poster is to review the imaging findings of atypical pulmonary metastatic disease in children. Cases from two large tertiary care institutions will be used for illustration.
Atypical pulmonary metastatic patterns include: 1. Dilated and beaded peripheral pulmonary vessels secondary to intravascular metastatic disease (e.g. osteosarcoma). Though central tumor embolus or tumor thrombus is easy to recognize, certain tumors such as osteosarcoma can cause intravascular metastatic disease in peripheral pulmonary arteries which has a characteristic imaging appearance and can mimic a "tree-in-bud" pattern. 2. Interstial thickening secondary to lymphangitic spread of tumor (e.g. lymphoma, renal medullary carcinoma, adenocarcinomas in children). This can be seen with or without mediastinal lymphadenopathy and is characterized by nodular septal line thickening. 3. Miliary pulmonary nodules (e.g. papillary thyroid cancer). Papillary thyroid carcinoma, the most common pediatric thyroid malignancy, can present with innumerable tiny pulmonary nodules which maybe mistaken for an infectious etiology secondary to indolent course. 4. Cavitary pulmonary masses (e.g. sarcomas). Cavitary nodules maybe seen at presentation in certain sarcomas or as a consequence of therapy induced central necrosis. 5. Calcified nodules (e.g. osteosarcomas) which can be mistaken for granulomas. 6. Nodules from hypervascular tumors can show hemorrhagic halos (e.g. angiosarcoma, choriocarcinomas). 7. Endobronchial metastasis can present with persistent segmental/lobar collapse.
An awareness of the spectrum of imaging findings of atypical pulmonary metastases along with their histopathologic correlates will allow the radiologist to make an accurate diagnosis. Read More

Authors:  Gagnon Marie-helene , Wallace Andrew , Yedururi Sireesha , Khanna Geetika

Keywords:  Metastasis, Tumor thrombus, lymphangitic