| Objective: To investigate the feasibility of susceptibility weightedimaging (SWI) in the diagnosis and differential diagnosis of musculoskeletaltumors and cystic lesions.Material and Methods: A total of116cases of bone and soft tissuetumors and cystic lesions which were proved surgically or pathologically from2010to2011in our hospital were studied prospectively, including51benignneoplasms,46malignant tumors and19cystic lesions. MRI with axial plane,sagittal plane and (or) coronal plane(T1WI and STIR)and SWI wereperformed in all patients, of whom87were given CT and X ray,4only CT,and25only X ray. After observing the hypointensity signal in the lesions ofthe SWI, in combination with the synthetic analysis of X ray, CT, MRI, andmIP and PHASE of SWI, we removed the hypointensity signal in the lesionscaused by apparent calcification, ossification, residue bone, fiber space, andveins. Then, we defined the left hypointensity signal as the hypointensitysignal of blood products. Afterwards, the cases were grouped according to theexistence of blood products-dominant hypointensity signal, the amount, themorphology, the distribution, and the volume in the lesion. Chi-squared testwas used to observe whether there was any difference in the proportion of thebenign tumors, the malignant tumors, and the cystic lesions. Finally, SWIfeatures of the cases over5were summed up.Results: Of all the116cases,113showed hypointensity signal (97.4%),21showed apparent calcification, ossification, and residue bone,23showedexplicit veins, and17showed explicit fiber space. With the hypointensitysignal mentioned above eliminated,100cases contained bloodproducts-dominant hypointensity signal (86.2%), among which the benign, malignant tumors and cystic lesions accounted for92.2%,84.8%, and73.7%respectively, with no statistical significance.As to the proportion of the blood products-dominant hypointensity signalin the lesion volume, there existed significant difference between the benignand malignant tumors, with the former mainly gathered in the limit of＜2/3,while the latter mainly in the limit of≤1/3. There was no significant differencebetween the cystic lesions and benign and malignant tumors.In the benign tumors,51.1%of the blood products-dominanthypointensity signal accounted for≤1/3of the lesion volume,29.8%accounted for1/3～2/3, and19.1%accounted for≥2/3.In the malignant tumors,94.9%of the blood products-dominanthypointensity signal accounted for≤1/3and5.1%accounted for1/3～2/3.In the cystic lesions,85.7%of the blood products-dominant hypointensitysignal accounted for≤1/3of the lesion volume and14.3%accounted for1/3～2/3.In terms of the blood products-dominant hypointensity signal, thereexisted statistical significance between the benign and malignant tumors, withthe former dotlike&patch, and the latter dotlike or dotlike&patch. Therewas no significant difference between benign and malignant tumors, orbetween malignant tumors and cystic lesions.Among the benign tumors,10.6%of the blood products-dominanthypointensity signal presented dotlike and another10.6patch,61.7%dotlike＆patch, and17.0%dotlike＆linear＆patch.Among the malignant tumors,20.5%presented dotlike,64.1%patch,2.6%dotlike＆linear, and12.8%dotlike＆linear＆patch.Among the cystic lesions,42.9%presented dotlike,14.3%patch,35.7%dotlike＆patch, and7.1%dotlike＆linear.In the aspect of the distribution of blood products-dominant hypointensitysignal, there existed difference between benign and malignant tumors andcystic lesions, with the signal distributed mainly in the periphery in the latter. There was no significant difference between benign and malignant tumors,with signal largely distributed in the center＆transition＆periphery.In the benign tumors,4.3%of the signal distributed in the periphery,6.4%in the center＆transition,2.1%in the center＆periphery,6.4%intransition＆periphery, and80.9%in the center＆transition＆periphery.In the malignant tumors,7.7%of the signal distributed in the center,2.6%in the transition,12.8%in the periphery,15.4%in transition＆periphery, and48.7%in the center＆transition＆periphery.In the cystic lesions,78.6%of the signal distributed in the periphery, and21.4%in the center＆transition＆periphery.As the amount of the signal is concerned, there was no significantdifference among the three groups, with multiplicity of all three: benigntumors97.9%, malignant97.4%, and cystic lesions93.8%. The characteristicSWI displays of the tumors are as follows:Giant cell tumors were in the end of bones, with bone destructionexpansion and massive multiple patch hypointensity signal in the lesions.Hemangioma presented with pervasive lump-like or earthworm-likehypointensity signal in the tumors.Neurilemmoma presented with cystic and multiple hypointensity signaland nerve bundle-tumor partial connection.Osteosarcoma presented with radial hypointensity signal perpendicular tothe bone.Baker cyst presented with fairly even hyperintensity signal with clearborder, and the cystic wall with dotlike&patch hypointensity signal.Conclusion: The prevalence of blood products-dominant hypointensitysignal in the muscular-system tumors and tumor-like lesions is86.2%, with nosignificant difference between benign and malignant tumors. Blood productsaccount for more in the benign tumors than in the malignant ones, with theformer in the limit of＜2/3, while the latter in the≤1/3. As far as thedistribution is concerned, the blood products are mainly in the walls in thecystic lesions, while largely inside the tumor in the benign and malignant tumors. In the aspect of morphology, the blood products are mainly dotlike ordotlike&patch in the cystic lesions, while largely dotlike&patch in thebenign and malignant tumors. In terms of amount, there shows no significantdifference among the three groups.To sum up, SWI can be applied in the respect of identifying the featuresof some lesions and in differential diagnosis of some disorders. |
PDF Full Text Request