Facial abscess. Acute renal failure. A limited examination was performed with only sagittal T1 and coronal STIR sequences as the patient could not tolerate being in the scanner for an extended time. It is also limited by lack of contrast administration.There is a severe, extensive edema and increased T2/STIR signal involving the soft tissues on the left side of the face, centered at the muscles of mastication with inferior extension into the left submandibular region, medially into the left parapharyngeal space as well as laterally into the subcutaneous fat and skin. This process extends superiorly to involve the temporal and infratemporal region. A well-defined component of the abnormality which shows more homogeneous T2-hyperintensity is present just lateral to the left mandibular ramus, deep to the left masseter muscle, and measures in the coronal plane 4.5 cm x 1.6 cm, probably representing an abscess. Associated abnormal left mandibular marrow signal is also seen without gross cortical erosion, which can be reactive or reflective of osteomyelitis. A larger but more heterogeneous fluid collection with gas and signs of loculation is present at the superior extension of the abnormality along the temporalis muscle. This measures coronally 8.2 cm x 2.1 cm. Anteroposteriorly, the abnormality measures at least 4.5 cm. There is no gross underlying skull erosion or definite marrow signal abnormality. A third large and more discrete abnormality is present in the left submandibular region and measures in the coronal plane 4.7 cm x 4.1 cm but is less T2-hyperintense and may reflect phlegmon. Smaller foci of fluid loculation are present within the left lateral and medial pterygoid muscles. The left posterior gland is enlarged and more T2-hyperintense, compared to the right which is probably reactive. Focal T2-hyperintensity that measures 1.5 cm in diameter abuts the inferior aspect of the proximal gland on image #15 of series #801.The deep left parapharyngeal extension is associated with mild-to-moderate narrowing of the pharynx.There is abnormal T2-hyperintensity surrounding the root of the last left maxillary molar which might be the source of the infection. Mucosal thickening and retention cysts are present in the left maxillary sinus. There is also mucosal thickening in the ethmoid and sphenoid sinuses, more on the left. Minimal right maxillary mucosal thickening is associated with focal T2-hypointensity, which may reflect inspissated secretions.While the major cervical carotid flow voids are preserved, the left internal jugular vein patency cannot be assessed.While there is no gross intracranial extension, this study is not designed to assess for that. There is no involvement of the left orbital or preorbital soft tissues. There is a right globe prosthesis. Included brain shows no gross abnormality.
1.This is a limited, noncontrast enhanced examination as described above.2.A severe infiltrative left facial abnormality is most compatible with an infection, with multiple abscesses including the left temporalis/masseter muscles as well as the left lateral and medial pterygoid muscles. The larger fluid locules are in the left temporal region and lateral to the left mandibular ramus deep to the left masseter muscle as described above. Large focal abnormality in the left submandibular region may represent phlegmon rather than a well-formed abscess. More accurate abscess assessment requires intravenous contrast administration but the patient is in acute renal failure.3.The component adjacent to the mandibular ramus is associated with abnormal marrow signal but no cortical erosion. This may reflect a reactive process but may also reflect early osteomyelitis.4.The deep left parapharyngeal extension is associated with mild-to-moderate narrowing of the pharynx.Dr. Monther Qandeel discussed the above findings and recommendations with Dr. Glenda Montague over the phone on on December 15, 2015 at 0851 hours.