a 3 year old girl initially presented at an outside institution with  bruising  on her left shoulder at 3 months of age . she was diagnosed with an infantile hemangioma , which did not respond to subsequent standard treatment consisting of six laser therapy treatments and 8 months of propranolol .
continued enlargement of the lesion involving her left shoulder , with worsening pain , prompted presentation to our institution for further evaluation .
magnetic resonance imaging ( mri ) was performed to evaluate for an underlying vascular malformation ( vm ) .
this showed multiple small foci of t2 hyperintensity isolated to the dermis , with no underlying vm present ( figure 1 ) .
the mri results led to a dermatology consultation and subsequent skin biopsy , with pathology showing kaposiform hemangioendothelioma .
follow - up consultation 3 years later noted decreased size of the left shoulder lesion with resolution of pain . a 26 year old male runner with long - standing anterior right knee pain for the preceding 7 years was initially evaluated in a sports medicine clinic and diagnosed with patellofemoral pain syndrome and mild lateral patellar maltracking .
an mri , performed to assess cartilaginous structures of the right knee , showed a partially intra - articular venous vm along the medial aspect of the right knee joint ( figure 2a and b ) with no arterial involvement .
the patient s pain reached a point where he could hardly get out of bed to put clothes on , or walk to the freezer to get ice to put on the knee .
sclero - therapy was offered and subsequently performed during three serial sessions . during the first sclerotherapy ( figure 2c ) , 10 cc of sodium tetradecyl sulfate 3% ( sotradecol ; angiodynamics , inc . ,
latham , ny , usa ) was mixed , using foam technique , and injected into the lesion , avoiding a component involving the weight - bearing articular surface to avoid potential development of secondary osteoarthritis .
foam technique involves mixing the solution back and forth between two syringes attached to a three - way stopcock .
the second sclerotherapy , 5 months later , utilized 10 cc of sotradecol distributed amongst three separate areas of the vm . a follow - up mri
a third sclerotherapy was performed 4 months after the second for residual pain , using 2 cc of sotradecol with immediate stasis of venous flow after injection . at a 3-month follow - up appointment following the third sclerotherapy ,
the patient noted entering a military officer training program and being able to run 3.2 km ( 2 miles ) twice weekly , pain - free .
a 34 year old man was initially diagnosed with a left forearm vm at 14 years of age .
multiple courses of treatment including surgical resection and endovascular sclerotherapy ensued , following a typical complex recurrent and indolent course for a vm .
he presented to our institution with constant pain in his left forearm , requiring scheduled narcotic pain medication .
an mri was performed , which showed a low - flow vm with a clear nidus in the interosseous membrane region of the distal forearm ( figure 3a , and b ) .
a pre - sclerotherapy diagnostic ultrasound of the region depicted suitable percutaneous access of the vm .
subsequent nidus - targeted treatment with endovascular sclerotherapy ( figure 3c ) using ultrasound for access , markedly improved symptoms after three serial treatments . during the first sclerotherapy
finger compression was used to occlude the deep communicating perforator veins to induce stasis in the vm , which was treated with 4 cc of sotradecol . during the second sclerotherapy
5 months later , the existing vm was much smaller than during the prior treatment .
again , the communicating perforator veins were manually occluded and sclerotherapy using 4 cc of sotradecol was performed .
a third sclerotherapy a few months later utilized 4 cc of sotradecol . following the sclerotherapy treatments ,
a follow - up mri depicted substantially decreased size of the vm ( figure 3d ) . also , the patient noted he no longer required scheduled narcotic pain medication . a 27-year - old woman , diagnosed at age 6 with a right hand vm , presented to our institution for further management with increased discomfort , and concern for risk of rebleeding given newly increased distention of her right hand veins . she had four different operations in the past to control a significant spontaneous bleeding episode , with minimal to no improvement in pain symptoms .
a compression garment had been tried only intermittently in the past , with some relief .
a time - resolved magnetic resonance angiography ( mra ) was performed to further characterize the vm , which depicted a high - flow vm ( figure 4 ) with arterial supply from superficial palmar arch branches of both the ulnar and radial artery .
however , given the substantial risk of collateral damage to adjacent nerves , skin , and muscle and potential loss of limb function , the patient elected for more consistent use of a compression garment prior to more invasive management .
a 3 year old girl initially presented at an outside institution with  bruising  on her left shoulder at 3 months of age . she was diagnosed with an infantile hemangioma , which did not respond to subsequent standard treatment consisting of six laser therapy treatments and 8 months of propranolol .
continued enlargement of the lesion involving her left shoulder , with worsening pain , prompted presentation to our institution for further evaluation .
magnetic resonance imaging ( mri ) was performed to evaluate for an underlying vascular malformation ( vm ) .
this showed multiple small foci of t2 hyperintensity isolated to the dermis , with no underlying vm present ( figure 1 ) .
the mri results led to a dermatology consultation and subsequent skin biopsy , with pathology showing kaposiform hemangioendothelioma .
follow - up consultation 3 years later noted decreased size of the left shoulder lesion with resolution of pain .
a 26 year old male runner with long - standing anterior right knee pain for the preceding 7 years was initially evaluated in a sports medicine clinic and diagnosed with patellofemoral pain syndrome and mild lateral patellar maltracking .
an mri , performed to assess cartilaginous structures of the right knee , showed a partially intra - articular venous vm along the medial aspect of the right knee joint ( figure 2a and b ) with no arterial involvement .
the patient s pain reached a point where he could hardly get out of bed to put clothes on , or walk to the freezer to get ice to put on the knee .
sclero - therapy was offered and subsequently performed during three serial sessions . during the first sclerotherapy ( figure 2c ) , 10 cc of sodium tetradecyl sulfate 3% ( sotradecol ; angiodynamics , inc . ,
latham , ny , usa ) was mixed , using foam technique , and injected into the lesion , avoiding a component involving the weight - bearing articular surface to avoid potential development of secondary osteoarthritis .
foam technique involves mixing the solution back and forth between two syringes attached to a three - way stopcock .
the second sclerotherapy , 5 months later , utilized 10 cc of sotradecol distributed amongst three separate areas of the vm . a follow - up mri after the second sclerotherapy depicted reduced size of the vm ( figure 2d ) .
a third sclerotherapy was performed 4 months after the second for residual pain , using 2 cc of sotradecol with immediate stasis of venous flow after injection . at a 3-month follow - up appointment following the third sclerotherapy ,
the patient noted entering a military officer training program and being able to run 3.2 km ( 2 miles ) twice weekly , pain - free .
a 34 year old man was initially diagnosed with a left forearm vm at 14 years of age .
multiple courses of treatment including surgical resection and endovascular sclerotherapy ensued , following a typical complex recurrent and indolent course for a vm .
he presented to our institution with constant pain in his left forearm , requiring scheduled narcotic pain medication .
an mri was performed , which showed a low - flow vm with a clear nidus in the interosseous membrane region of the distal forearm ( figure 3a , and b ) .
a pre - sclerotherapy diagnostic ultrasound of the region depicted suitable percutaneous access of the vm .
subsequent nidus - targeted treatment with endovascular sclerotherapy ( figure 3c ) using ultrasound for access , markedly improved symptoms after three serial treatments . during the first sclerotherapy
finger compression was used to occlude the deep communicating perforator veins to induce stasis in the vm , which was treated with 4 cc of sotradecol . during the second sclerotherapy 5 months later , the existing vm was much smaller than during the prior treatment .
again , the communicating perforator veins were manually occluded and sclerotherapy using 4 cc of sotradecol was performed .
a third sclerotherapy a few months later utilized 4 cc of sotradecol . following the sclerotherapy treatments ,
a follow - up mri depicted substantially decreased size of the vm ( figure 3d ) . also , the patient noted he no longer required scheduled narcotic pain medication .
a 27-year - old woman , diagnosed at age 6 with a right hand vm , presented to our institution for further management with increased discomfort , and concern for risk of rebleeding given newly increased distention of her right hand veins .
she had four different operations in the past to control a significant spontaneous bleeding episode , with minimal to no improvement in pain symptoms .
a compression garment had been tried only intermittently in the past , with some relief .
a time - resolved magnetic resonance angiography ( mra ) was performed to further characterize the vm , which depicted a high - flow vm ( figure 4 ) with arterial supply from superficial palmar arch branches of both the ulnar and radial artery .
however , given the substantial risk of collateral damage to adjacent nerves , skin , and muscle and potential loss of limb function , the patient elected for more consistent use of a compression garment prior to more invasive management .
vms are present at birth and grow as the patient does , demonstrating a normal rate of endothelial turnover .
they may not become apparent until adulthood , once they enlarge enough to be visualized or produce symptoms .
histologically , they encompass a spectrum of lesions that include arterial , capillary , venous , and lymphatic components in various combinations , with the majority consisting of venous - predominant low - flow malformations .
management of vms requires a multidisciplinary approach due to their prolonged and often progressive clinical course .
this typically involves multiple physicians with expertise in internal medicine , pediatric cardiology , dermatology , surgery , psychiatry , and interventional radiology , in order to correctly classify vms and guide long - term treatment .
treatment is mainly guided by patient symptoms and classification of the vm based on low - flow versus high - flow .
additional considerations include patient age , life expectancy , comorbid conditions and progression of symptoms .
severe symptoms such as disabling pain , swelling , functional impairment , ulceration , or severe bleeding often require more invasive treatment , which is typically endovascular treatment with embolization or sclerotherapy versus surgical resection . both treatment approaches complement each other , and are generally palliative rather than curative , requiring much dedication .
low - flow vms , which represent about 90% of vms , can be successfully treated using endovascular sclerotherapy alone .
this involves percutaneous access to the lesion and direct injection of a sclerosing agent , causing precipitation of endothelium proteins via denaturation and dehydration , and ultimately thrombosis and endothelial destruction . maintaining
therefore , one must not obstruct all major venous pathways of the affected extremity with sclerotherapy .
less common high - flow vms , defined as such by containing an arterial component , often require more aggressive treatment secondary to shunting from high - output failure states , which is associated with increased morbidity and mortality .
high - flow vms are typically treated first with transarterial embolization , which involves occlusion of the vascular inflow and/or outflow for primary treatment alone , or as an adjunctive treatment , prior to subsequent sclerotherapy or surgery .
determining pertinent vm characteristics , including classification of high - flow or low - flow , is important prior to intervention .
noninvasive imaging , particularly mri , plays an important role in the characterization of vms .
classification into low - flow or high - flow dynamics provides a useful way to assist the interventional radiologist in planning treatment .
whether dealing with low - flow or high - flow vms , it is important to identify the nidus , which represents the abnormal focus of tortuous vessels at the center of the vm .
there may be multiple nidi in a single lesion . by targeting the nidus during treatment ,
the most direct pathways of blood flow into the malformation are sclerosed and a longer duration of effect is observed .
occasionally , an intervention can stimulate vascular endothelial cells and paradoxically worsen symptoms . therefore targeting treatment to the nidus and thoughtfully limiting damage to adjacent structures
pretreatment imaging also helps to identify the nidus for targeting treatment ( figure 3 ) .
images can depict vm extent and associated involvement of muscle , bone , joints , or subcutaneous tissue that may predispose to complications ( figure 2 ) .
though clinically apparent , the extent of a vm is often underestimated by physical exam alone .
one study revealed that in greater than 75% of cases there was more extensive involvement demonstrated on mri compared to the physical exam and nearly half of those cases resulted in a change in management .
mri also guides therapy further by characterizing vascular inflow and outflow ; determining the number of feeding vessels avoids potential problems with undertreatment of a single vessel when multiple vessels contribute .
while mri is the mainstay of diagnostic imaging assessment of vms , additional imaging modalities may be helpful .
mri techniques have the benefit of excellent soft tissue characterization and lack of ionizing radiation in patients who are often young and require serial follow - up .
risks of mri include safety concerns related to the strong magnetic field , as well as the risk of nephrogenic systemic fibrosis with the use of intravenous gadolinium in patients with chronic kidney disease .
ultrasound provides real - time visualization during intervention for vascular access and real - time arterial and venous flow velocities .
ultrasound is limited by inability to assess deep lesions or those adjacent to bone or air .
computed tomography ( ct ) and ct angiography provides detail using contrast enhancement and allows assessment of calcification or thrombus , in addition to providing complementary imaging information when mr does not provide a clear answer .
ct is limited by exposure to ionizing radiation , and depicts less blood flow information when compared to mr .
conventional angiography provides the concomitant treatment possibility , while it is limited by its invasive nature , projection format , and exposure to ionizing radiation . at our institution , we begin our vm mri exams with fat suppressed t2-weighted sequences in the axial plane to document vm location for subsequent time - resolved contrast - enhanced images .
then , we inject a gadolinium - based contrast material , usually the blood pool agent gadofosveset trisodium ( ablavar ; lantheus medical imaging , north billerica , ma , usa ) and acquire time - resolved contrast - enhanced mra images . in the extremities , we typically use specialized receiver coils and the cartesian acquisition with projection - like reconstruction ( capr ) technique , which allows creation of both time - resolved three - dimensional ( 3d ) datasets and time - of - arrival maps that depict flow information on a single image ( figures 3b and 4c ) .
capr is a 3d gradient echo sequence that uses elliptical centric sampling , two - dimensional ( 2d ) homodyne reconstruction , view - sharing , and 2d sensitivity - encoding .
clinical advantages of capr include images with both high temporal resolution that allows visualization and clear distinction of arterial and venous phases and high spatial resolution ( 1 mm isotropic ) that allows sharp depiction of small branching vessels .
time - of - arrival maps allow a depiction of the vm on a single image , which patients generally find helpful for understanding subsequent treatment planning and management .
time - resolved mra using capr technique has been shown to demonstrate flow characteristics to guide treatment .
other time - resolved techniques can be used as well , with or without view - sharing .
we typically use non - view - shared , multiphase , breath - hold , 2d accelerated mra when imaging the abdomen or pelvis and view - shared techniques , such as capr , in the extremities .
finally , delayed post - contrast t1-weighted fat - suppressed high - resolution gradient echo images are acquired in the blood pool phase .
these are useful to document the extent of prior ablation or treatment , assess for venous thrombus or outflow obstruction , and further assess soft tissue extent .
our studies were performed on a 3.0-t ge scanner platform system ( ge healthcare , waukesha , wi , usa ) .
this included mri depicting lack of an actual underlying vm leading to skin biopsy , and the correct diagnosis and treatment ( figure 1 ) ; mri depicting the full extent of the underlying vm in relation to sensitive structures , therefore limiting sclerotherapy to safe regions and avoiding possible secondary osteoarthritis ( figure 2 ) ; mri depicting a clear single nidus of the vm , which was targeted for subsequent sclerotherapy ( figure 3 ) ; and mri confirming the high - flow nature of a vm ( figure 4 ) , with endovascular embolization and sclerotherapy offered , but ultimately managed conservatively with compression garment given the clinical setting .
these are only a subset of the advantages pretreatment imaging can provide for these complex vascular lesions .
additional benefits have been described previously , and include determining the focal versus diffuse nature of a vm which may therefore require multiple treatment sessions ; fully characterizing both the superficial and deep venous system drainage of an extremity to ensure adequate residual drainage following treatment , particularly in patients with klippel 
trnaunay syndrome with abnormal underlying venous systems ; and defining the vm connection with the deep venous system to determine the risk of deep venous thrombosis following sclerotherapy .
peripheral vms are complex vascular lesions that consist of a variety of combinations of arterial , capillary , venous , and/or lymphatic vessels .
pretreatment imaging , primarily with mri , provides valuable information prior to intervention in order to make the proper diagnosis , determine lesion extent , identify the nidus , and classify flow dynamics into low - flow or high - flow to guide subsequent treatment .
in particular , imaging with mri and time - resolved mra provides both high spatial and temporal resolution allowing for precise lesion characterization and treatment planning .
 peripheral vascular malformations ( vms ) are complex and diverse vascular lesions which require individualized pretreatment planning . 
 pretreatment imaging using various modalities , especially magnetic resonance imaging and time - resolved magnetic resonance angiography , is a valuable tool for classifying peripheral vms to allow proper diagnosis , demonstrate complete extent , identify the nidus , and distinguish between low - flow and high - flow dynamics that determines the treatment approach . 
 we discuss pretreatment imaging findings in four patients with peripheral vms and how diagnostic imaging helped guide management . 
Case reports
Case 1
Case 2
Case 3
Case 4
Discussion
Conclusion