Utility of Microhemorrhage as a Diagnostic Tool in Distinguishing Vestibular Schwannomas from other Cerebellopontine Angle (CPA) Tumors.

Although a majority of tumors in the Cerebellopontine Angle (CPA) are vestibular schwannomas (VS), other masses can also be seen in the region and differentiation of various CPA tumors, particularly meningiomas can be difficult on imaging alone. Treatment options may vary based on specific pathology of the CPA tumor. In this study, the presence of microhemorrhage (MH) and other imaging features such as size of lesion, cystic features and pattern of IAC extension, were evaluated as a tool in distinguishing VS from other CPA masses. A review of CPA masses in the last 11 years at our institution was performed. All the pathology proven tumors with at least 1 pre-operative MRI were considered for analysis. A T2* GRE or SWI sequence was used to assess presence of MH within the lesion. Pattern of IAC extension ('centric' versus 'eccentric') of tumor was also evaluated. A total of 147 patients were reviewed out of which 102 patients (with T2* GRE or SWI) were included for analysis of MH. 57 patients (56%) had VS as the final histopathological diagnosis and 45 patients (44%) had other types of tumor. A sensitivity of 82% and a specificity of 98% was noted for the presence of MH favoring the diagnosis of VS from other tumors (p < 0.001). All meningiomas with IAC extension (25/31) showed an 'eccentric' pattern of extension into the canal. Visualization of MH and pattern of IAC extension is useful in the differentiation of schwannomas from other CPA masses, particularly meningiomas.

Nosocomial Herpes Encephalitis: rare but treatable with early MR diagnosis.

Nosocomial/hospital acquired herpes encephalitis is rare and is usually undiagnosed in its early phase because of the non-specific clinical picture and low level of clinical and neuroimaging suspicion. There is a paucity of data in radiology literature for this entity, specifically in the settings of surgery and trauma. We describe two cases of nosocomial herpes simplex encephalitis to demonstrate the imaging clues that might lead to an early diagnosis of this disease.

Unusual case of cerebral aspergillosis with clinical and imaging findings mimicking lymphoma.

A 14-year-old female post-transplant patient with a history of post-transplant lymphoproliferative disease/lymphoma presented with fever and lethargy. Computed tomography of the brain demonstrated a hypodense lesion with surrounding edema in the right periventricular region not seen on a routine study performed two weeks earlier. On magnetic resonance imaging (MRI) this lesion was mainly iso-intense to gray matter on T2-weighted (T2W) images and demonstrated peripheral contrast enhancement. Diffusion restriction was seen within most of the lesion including, but not limited to, its periphery. Lesion location and MRI characteristics, particularly on T2W and diffusion sequences, were suggestive of lymphoma. The patient's history of post-transplant lymphoproliferative disorder also supported this diagnosis. However, in view of the patient's immunocompromised state, rapid onset of symptoms, and recent normal CT scan of the brain, infection was also entertained. Biopsy revealed short branching hyphae consistent with aspergillosis. This case is interesting as the MRI restriction pattern and the patient's history were more suggestive of lymphoma, but in reality the lesion represented an evolving aspergillosis abscess. Biopsy was necessary to further proceed with appropriate medical management, which is significantly different for the two entities.

Case report. Unusual presentation of a pancreatic mass in an infant: pancreatic haemangioendotheliomatosis.

Primary pancreatic tumours are extremely rare in children. We report a case of a 5-month-old male with a diffuse invasive tumour of the head of the pancreas. The tumour demonstrated peripancreatic extension into the porta hepatis, which occluded the portal vein and invaded the superior mesenteric artery. It was found to be haemangioendotheliomatosis of the pancreas. Imaging, pathological findings and a brief relevant classification of haemangioma are discussed.

Pulmonary imaging of pandemic influenza H1N1 infection: relationship between clinical presentation and disease burden on chest radiography and CT.

The potential for pulmonary involvement among patients presenting with novel swine-origin influenza A (H1N1) is high. To investigate the utility of chest imaging in this setting, we correlated clinical presentation with chest radiographic and CT findings in patients with proven H1N1 cases. Subjects included all patients presenting with laboratory-confirmed H1N1 between 1 May and 10 September 2009 to one of three urban hospitals. Clinical information was gathered retrospectively, including symptoms, possible risk factors, treatment and hospital survival. Imaging studies were re-read for study purposes, and CXR findings compared with CT scans when available. During the study period, 157 patients presented with subsequently proven H1N1 infection. Hospital admission was necessary for 94 (60%) patients, 16 (10%) were admitted to intensive care and 6 (4%) died. An initial CXR, carried out for 123 (78%) patients, was abnormal in only 40 (33%) cases. Factors associated with increased likelihood for radiographic lung abnormalities were dyspnoea (p<0.001), hypoxaemia (p<0.001) and diabetes mellitus (p = 0.023). Chest CT was performed in 21 patients, and 19 (90%) showed consolidation, ground-glass opacity, nodules or a combination of these findings. 4 of 21 patients had negative CXR and positive CT. Compared with CT, plain CXR was less sensitive in detecting H1N1 pulmonary disease among immunocompromised hosts than in other patients (p = 0.0072). A normal CXR is common among patients presenting to the hospital for H1N1-related symptoms without evidence of respiratory difficulties. The CXR may significantly underestimate lung involvement in the setting of immunosuppression.

Kingella kingae spondylodiscitis in a child.

Most osteoarticular infections in children are due to Staphylococcus aureus. In this case, the isolation of Kingella kingae by image guided disc aspiration resulted in modification and optimization of treatment. We take a look at a case of spondylodiscitis in a young child and review some of the current literature with regards to Kingella kingae infections.

Subdural hematomas in infants with benign enlargement of the subarachnoid spaces are not pathognomonic for child abuse.

BACKGROUND AND PURPOSE: Patients who have benign enlargement of the subarachnoid spaces (BESS) have long been suspected of having an increased propensity for subdural hematomas either spontaneously or as a result of accidental injury. Subdural hematomas in infants are often equated with nonaccidental trauma (NAT). A better understanding of the clinical and imaging characteristics of subdural hematomas that occur either spontaneously or as a result of accidental trauma may help distinguish this group of patients from those who suffer subdural hematomas as a result of NAT. The purpose of this study is to describe the clinical and imaging characteristics of subdural hematomas that occur either spontaneously or as a result of accidental injury in infants with BESS. METHODS: We conducted a retrospective review of all patients with BESS complicated by subdural hematomas evaluated at a single institution from 1998 to 2004. Data concerning the patient's clinical presentation, physical findings, imaging, and management are described. RESULTS: During the study period, 7 patients with BESS complicated by subdural hematoma were identified. Their mean age at identification of the subdural hematoma was 7.4 months of age. In 5 cases, there was no recognized trauma before identification of the subdural hematoma. In 3 cases, baseline CT or MR imaging was available, showing prominent subarachnoid spaces without any evidence of subdural hemorrhage. CONCLUSION: Although suspicious for NAT, subdural hematomas can occur in children either spontaneously or as a result of accidental trauma. Caution must be exercised when investigating for NAT based on the sole presence of subdural hematomas, especially in children who are otherwise well and who have BESS.

Spinal hamartoma in a neonate: Unusual presentation and MR imaging findings.

We report an extremely rare case of a congenital spinal cord hamartoma in a male neonate who presented with upper extremity weakness and a port wine stain on the right upper extremity and chest. MR imaging findings are described, and the importance of localizing the lesion in the spinal canal with respect to the dura and its impact on neurosurgical management is stressed.

Use of tongue flap in submucous palatal fibrosis.

Submucous palatal fibrosis invariably leads to trismus due to fibrosis in the retromolar region. Medical lines of treatment are of no use in relieving the trismus once it is established. Various surgical methods, such as excision of fibrous tissue or excision of fibrous tissue with skin grafting, have been suggested, but none of them has been proved to give a lasting cure. We have made use of tongue flaps on either side in cases of trismus due to submucous palatal fibrosis in the retromolar region. Twenty-five cases have been operated upon with this technique and the results are quite encouraging. Regular follow-up for up to three years has shown good results without any complications.