Intracranial Perishunt Catheter Fluid Collections with Edema, a Sign of Shunt Malfunction: Correlation of CT/MRI and Nuclear Medicine Findings

Fluid collections with edema along the intracranial tract of ventriculoperitoneal shunt catheters in adults are rare and are more frequently seen in children. The imaging appearance of these fluid collections is frequently confusing and presents a diagnostic dilemma. We present 6 cases of adult patients noted to have collections with edema along the tract of ventriculoperitoneal shunt catheters. To our knowledge, there are no previous studies correlating the CT/MR imaging findings with nuclear medicine scans in this entity. We hypothesized that when seen in adults, the imaging findings of a CSF-like fluid collection around the intracranial ventriculoperitoneal shunt catheter on CT/MR imaging may suggest areas of CSF accumulation with interstitial edema. It is important to recognize this rare ventriculoperitoneal shunt complication in adults to prevent misdiagnosis of an abscess or cystic tumor.

Residual Cervical Thymus: A Normal CT Finding That May Be Present Throughout Patients' Lives

BACKGROUND AND PURPOSE

Although the thymus is centered in the mediastinum, often a cervical component can be seen in children and young adults. The frequency of radiologically evident residual cervical thymus in older adults is not known. The purpose of our study was to determine the proportion of adults who have residual cervical thymus visible on contrast-enhanced neck CT.

MATERIALS AND METHODS

We retrospectively identified 700 patients who had undergone contrast-enhanced CT between February 2013 and August 2013. We categorized the patients by decade of life and calculated the proportion in which residual cervical thymic tissue could be detected. The location of the tissue focus, greatest axial diameter, and distance above the manubrium were recorded. A multivariate model was used to determine whether age or sex predicted the likelihood of identifiable cervical thymus, the size of residual thymus, or the distance of residual thymus above the sternum.

RESULTS

Of the 700 patients, 157 (22.4%) had residual cervical thymus. The mean distance of the residual thymus above the manubrium was 13.4 ± 7.26 mm. The mean size of the residual cervical thymus was 12.5 ± 4.11 mm. The frequency of residual thymus decreased exponentially with age. There was a statistically significant relationship between age and the size of the residual cervical thymus (P = .02). Most of the cervical thymic tissue was found in the left paratracheal region.

CONCLUSIONS

Residual cervical thymus may be present at any age, though the frequency decreases with increasing age.

Magnetic resonance imaging findings in chronic inflammatory demyelinating polyneuropathy with intracranial findings and enhancing, thickened cranial and spinal nerves

Chronic inflammatory demyelinating polyneuropathy is a rare autoimmune disorder characterized by chronically progressive or relapsing symmetric sensorimotor involvement. We describe the imaging findings in our patient. Magnetic resonance imaging showed presence of an intracranial white matter lesion and enhancing, thickened cranial and spinal nerves. This disorder has been described very infrequently in the radiology literature.

Mandibular haemophilic pseudotumour containing a fluid-fluid level

Osseous haemophilic pseudotumours are uncommon. Mandibular haemophilic pseudotumours are rare, with only approximately 12 cases reported in the literature to date. We present imaging findings of a histopathologically proven mandibular haemophilic pseudotumour. A fluid-fluid level, hitherto not associated with this condition, is also described.