Các dấu hiệu MRI u mô mềm

Các dấu hiệu MRI u mô mềm Jeff Stevens, MD Ricardo Garza-Gongora, MD Linda Parman, MD Connie So, MD https://dps2016.rsna.org/exhibit/?exhibit=MK252-ED-X Mở đầu • Soft tissue tumors of the extremities are commonly encountered, though remain a challenging diagnosis • • While radiography and CT still serve a vital role in the evaluation of soft tissue tumors, MRI, with its improved soft tissue contrast, often provides much greater detail of these lesions • • A specific diagnosis often remains unobtainable • – A correct histological diagnosis is only reached in one-third of cases • • Still, certain soft tissue tumors have specific characteristics or “signatures” which are highly suggestive and occasionally diagnostic of a certain histological diagnosis precluding the need for biopsy Điểm • To briefly discuss technical considerations important in MR evaluation of soft tissue tumors • • To provide a radiologic depiction of certain soft tissue tumors which demonstrate specific MR signal characteristics or “signatures”, which may allow for diagnosis without biopsy • • In most cases, a specific diagnosis is not obtainable by imaging alone This exhibit will also provide a systematic approach to narrow the differential diagnosis for those lesions which remain indeterminate Lưu ý kỹ thuật T1 and T2 sequences are the base sequences in evaluation a soft tissue mass T2FS - highlight areas of increased signal intensity (SI)/edema within or around the mass T1FS – used to further evaluate lesions demonstrating T1 hyperintensity Post-contrast imaging often required for evaluation of mass lesions These are often performed with T1 weighting and fat saturation Lưu ý kỹ thuật Trường khảo sát Mặt cắt Tiêm thuốc tương phản • Large FOV used when needing to establish the presence of a lesion Sacrifices spatial resolution • • Preferred small FOV targeting the lesion • Axial plane used to determine compartmental anatomy and presence/extent of invasion of adjacent structures • Lesions should be imaged in at least two longitudinal planes –this depends on area of interest • Sagittal with anterior or posterior masses and coronal with medial or lateral masses • Used to delineate cystic from solid masses • Plays important role in targeting soft tissue nodules in cystic or hemorrhagic lesions • Enhancement cannot reliably distinguish benign or malignant lesions Đặc điểm tín hiệu Điểm • Fat T1 tăng tín hiệu • Methemoglobin • Proteinaceous Material • Melanin T2 giảm tín hiệu • Calcification • Hemosiderin • Fibrosis T2 tăng tín hiệu Includes cysts and “cyst-like” lesions, which can be both benign and malignant Further characterized following administration of IV gadolinium Lưu đồ: Tổn thương tăng tín hiệu T1 • Methemoglobin (Hematoma) Xóa mỡ? Khơng • Melanin (Melanoma) có Đóng vơi? Khơng có Phleboliths? Hemangioma • Proteinaceous Fluid (Abscess, Ganglion, Epidermal Inclusion Cyst) Đóng vơi/cốt hóa vùng Viêm cốt hóa • Lipoma (or lipoma variants) • Well-differentiated liposarcoma • Hemangioma • Other fat-containing lesion Tăng tín hiệu T1 Khơng có xóa mỡ Substances which demonstrate T1 shortening but not lose SI following fat suppression include proteinaceous fluid, methemoglobin, and melanin T1 T1 FS Two lesions, one of which is T1 hyperintense without significant fat suppression This represents methemoglobin in hematomas Differing signal intensity of these lesions is related to different ages of blood products Tăng tín hiệu T1 Khơng có xóa mỡ T1 T1 FS T1 FS+ Gd Axial MR images demonstrate a (ruptured) epidermal inclusion cyst within the dorsal subcutaneous tissues near the olecranon Mass demonstrates slightly increased T1 signal characteristics relative to muscle Contrast-enhanced T1-weighted MR image shows only minimal peripheral enhancement Lưu đồ: Tổn thương tăng tín hiệu T1 • Methemoglobin (Hematoma) Xóa mỡ? Khơng • Melanin (Melanoma) có Đóng vơi? Khơng có Phleboliths? Hemangioma • Proteinaceous Fluid (Abscess, Ganglion, Epidermal Inclusion Cyst) Đóng vơi/cốt hóa vùng Viêm cốt hóa • Lipoma (or lipoma variants) • Well-differentiated liposarcoma • Hemangioma • Other fat-containing lesion Tăng tín hiệu T1 Có xóa mỡ Most T1 hyperintense lesions which demonstrate fat suppression are lipomas T1 T1 FS Identical to adjacent fat on T1WI Uniform, homogeneous fat suppression on T1FS Tăng tín hiệu T1 Có xóa mỡ Other fat-containing masses include well-differentiated liposarcomas, hemangiomas, and heterotopic ossification Axial and coronal T1-weighted images demonstrate predominately fat SI mass within the musculature of the left upper thigh with additional nodular area of intermediate to low T1 SI Biopsy was consistent with welldifferentiated liposarcoma T1 T1 Lưu đồ: Tổn thương giảm tín hiệu T2 Đóng vơi? Có May contain characteristic calcifications, such as cloudlike paraarticular calcifications in goutor flocculent calcifications in tumoral calcinosis Khơng • Giant Cell Tumor of the Tendon Sheath Hemosiderin? • Plantar Fibroma • Pigmented Villonodular Synovitis • Elastofibroma • Hemorrhagic Mass Nonspecific, but includes benign and malignant lesions, such as: • Post-op scar Mơ xơ Giảm tín hiệu T2 Có đóng vôi T1 T1 FS CT Sagittal T1 and T2FS MR images of the knee demonstrate tumoral calcinosis posterior and inferior to the knee joint Peri-articular masses are hypointense on both T1 and T2 weighted imaging Sagittal CT image better demonstrates the flocculent calcifications seen in tumoral calcinosis Giảm tín hiệu T2 U tế bào khổng lồ bao gân Location can greatly aid lesion characterization of T2 hypointense lesions Notice lesion’s location relative to the flexor tendon of the index finger Low T2 signal intensity in a giant cell tumor of the tendon sheath is due to both hemosiderin and fibrotic components Axial T1WI and sagittal T2WI MR images of the hand demonstrate a GCT of the tendon sheath arising from the flexor tendon of the index finger Giảm tín hiệu T2 Tầm quan trọng vị trí Other T2 hypointense lesions which may be further characterized according to location: • Pigmented Villonodular Synovitis • Elastofibroma • Post-operative Scar • Plantar Fibroma • Dupuytren disease Axial T2-weighted MR image demonstrates pigmented villonodular synovitis (PVNS) arising from the tibiofibular joint Giảm tín hiệu T2 U sợi đàn hồi Axial T1 and STIR images demonstrate a low T1 and predominately low T2 signal intensity mass along the right posterolateral chest wall MR appearance and location are most compatible with an elastofibroma Giảm tín hiệu T2 Fibromatosis Axial T1WI and T2weighted MR images demonstrated homogeneous hypointense T1 and T2 signal in left gluteal fibromatosis Many lesions which demonstrate low T2 signal intensity remain nonspecific Marked low T2 signal intensity in left gluteal fibromatosis Tăng tín hiệu T2 Tổn thương dạng nang Not all lesions that are homogeneously hyperintense on T2 are fluid-filled lesions (i.e cysts, ganglia, and seromas) Myxomatous tumors, peripheral nerve sheath tumors, and even small synovial sarcomas can mimic cyst on T2WI First step in characterization of these T2 hyperintense “cyst-like” lesions is administration of intravenous gadolinium contrast material • Ganglion • Seroma • Abscess • Epidermoid Inclusion Cysts • Bursa Enhancement Pattern of T2 Hyperintense Lesions Không/bắt thuốc viền (Tổn thương lấp đầy dịch) Bắt thuốc bên (Tổn thương đặc) Myxomatous Tumors: • Myxoid Sarcoma • Intramuscular Myxoma Other: • Synovial Sarcoma • PNST • Necrotic Tumors Tăng tín hiệu T2 không bắt thuốc/bắt thuốc viền Nang hạch T2 FS T1 + Gd Coronal MR images demonstrate a ganglion near the right acromioclavicular joint T2-weighted MR image shows a cyst-like area hyperintense lesion Contrast-enhanced T1-weighted MR image shows no significant enhancement Tăng tín hiệu T2 có bắt thuốc bên U sợi thần kinh Axial MR images demonstrate an oval mass in the posterior thigh, hypointense on T1WI and hyperintense on T2WI Contrast-enhanced T1-weighted MR image shows heterogeneous enhancement Neurofibroma was identified at biopsy Tăng tín hiệu T2 có bắt thuốc bên U nhầy T1 T2 T1 FS + Gd Coronal MR images demonstrate a low T1 and high T2 signal intensity mass in the right subaxillary region Contrast-enhanced T1-weighted MR image shows heterogeneous enhancement Myxomawas identified by pathology Tăng tín hiệu T2 có bắt thuốc bên liposarcoma dạng nhầy Coronal MR images demonstrate mixed-intensity lesion within the region of the left shoulder The most cephalad portion of the lesion is predominately fat with mild complexity Most caudal portion of lesion is hypointense on T1WI and hyperintense on T2WI with enhancing mural nodularity Myxoid Liposarcoma was identified on biopsy Tóm tắt: Xác định đặc điểm tổn thương tín Tổn hiệu Tă theo Tổn thương chứa: thương: ng t n hi ệu T1 Mỡ Methemoglobin Chất giàu protein Melanin Lipoma(or variant), well-differentiated liposarcoma, hemangioma, heterotopic ossification Máu tụ Nang hạch, abscess Melanoma Gi ả m t n hi ệu T2 Tổn thương chứa: Mô xơ Tổn thương: Scar tissue, GCT of tendon sheath, plantar fibroma, elastofibroma, desmoid, fibrosarcoma, lymphoma Cục tophi, đóng vơi loạn dưỡng U đại bào bao gân Đóng vơi đặc Hemosiderin Tă ng tn Tổn thương lấp đầy dịch (bắt hi thuốc viền/không bắt thuốc) ệu U đặc (bắt thuốc bên trong) T2 Tổn thương: Ganglion, seroma,abscess, epidermoid inclusion cyst Tổn thương dạng nhầy, PNST, synovial sarcoma Tài liệu tham khảo • Bermejo A, De Bustamante TD, Martinez A, Carrera R, Zabía E, Manjón P MR imaging in the evaluation of cystic-appearing soft-tissue masses of the extremities Radiographics 2013;33(3):833– 55 • Chan WP Magnetic resonance imaging of soft-tissue tumors of the extremities: A practical approach World Journal of Radiology 2013;5(12):455-459 doi:10.4329/wjr.v5.i12.455 • Kransdorf MJ, Murphey MD Radiologic evaluation of soft-tissue masses: a current perspective Am J Roentgenol 2000; 175:575–587 • Kubiena H, Entner T, Schmidt M, Frey M Peripheral neural sheath tumors (PNST) what a radiologist should know Eur J Radiol 2013;82(1):51–5 doi: 0.1016/j.ejrad.2011.04.037 • Papp DF, Khanna AJ, McCarthy EF, Carrino JA, Farber AJ, Frassica FJ Magnetic resonance imaging of soft-tissue tumors: determinate and indeterminate lesions J Bone Joint Surg Am 2007;89 Suppl 3:103–115 • Wu JS, Hochman MG Soft-tissue tumors and tumorlike lesions: a systematic imaging approach Radiology 2009;253:297–316 ... lesions Đặc điểm tín hi? ?u Điểm • Fat T1 tăng tín hi? ?u • Methemoglobin • Proteinaceous Material • Melanin T2 giảm tín hi? ?u • Calcification • Hemosiderin • Fibrosis T2 tăng tín hi? ?u Includes cysts and... L? ?u ý kỹ thuật T1 and T2 sequences are the base sequences in evaluation a soft tissue mass T2FS - highlight areas of increased signal intensity (SI)/edema within or around the mass T1FS – used... fat-containing lesion Tăng tín hi? ?u T1 Khơng có xóa mỡ Substances which demonstrate T1 shortening but not lose SI following fat suppression include proteinaceous fluid, methemoglobin, and melanin