Neoplastic cauda equina syndrome: a neuroimaging-based review.

Cauda equina syndrome refers to dysfunction of the cauda equina, the collection of ventral and dorsal lumbar, sacral and coccygeal nerve roots that surround the filum terminale. This most commonly occurs as a result of compression by a herniated lumbosacral disc. However, the syndrome may also complicate metastatic cancer or a primary neoplasm within or infiltrating the spinal canal. An accurate and timely diagnosis is critical to avoid irreversible loss of neurological function. The clinician and radiologist must therefore be aware of the many possible causes to guide timely management. Here we review the diverse neoplastic causes affecting the cauda equina nerve roots from a neuroimaging-based perspective. We divide them by location into intramedullary neoplasms at the conus (such as astrocytoma), intradural-extramedullary neoplasms (such as schwannoma and leptomeningeal metastases) and extradural neoplasms (such as spinal metastases from systemic neoplasms). We also discuss the clinical features associated with cauda equina tumours, with special focus on cauda equina syndrome.

Impact of Original and Artificially Improved Artificial Intelligence-based Computer-aided Diagnosis on Breast US Interpretation.

OBJECTIVE: For breast US interpretation, to assess impact of computer-aided diagnosis (CADx) in original mode or with improved sensitivity or specificity. METHODS: In this IRB approved protocol, orthogonal-paired US images of 319 lesions identified on screening, including 88 (27.6%) cancers (median 7 mm, range 1-34 mm), were reviewed by 9 breast imaging radiologists. Each observer provided BI-RADS assessments (2, 3, 4A, 4B, 4C, 5) before and after CADx in a mode-balanced design: mode 1, original CADx (outputs benign, probably benign, suspicious, or malignant); mode 2, artificially-high-sensitivity CADx (benign or malignant); and mode 3, artificially-high-specificity CADx (benign or malignant). Area under the receiver operating characteristic curve (AUC) was estimated under each modality and for standalone CADx outputs. Multi-reader analysis accounted for inter-reader variability and correlation between same-lesion assessments. RESULTS: AUC of standalone CADx was 0.77 (95% CI: 0.72-0.83). For mode 1, average reader AUC was 0.82 (range 0.76-0.84) without CADx and not significantly changed with CADx. In high-sensitivity mode, all observers' AUCs increased: average AUC 0.83 (range 0.78-0.86) before CADx increased to 0.88 (range 0.84-0.90), P < 0.001. In high-specificity mode, all observers' AUCs increased: average AUC 0.82 (range 0.76-0.84) before CADx increased to 0.89 (range 0.87-0.92), P < 0.0001. Radiologists responded more frequently to malignant CADx cues in high-specificity mode (42.7% vs 23.2% mode 1, and 27.0% mode 2, P = 0.008). CONCLUSION: Original CADx did not substantially impact radiologists' interpretations. Radiologists showed improved performance and were more responsive when CADx produced fewer false-positive malignant cues.

Responses of thoracic spinal interneurons to vestibular stimulation.

Vestibular influences on outflow from the spinal cord are largely mediated via spinal interneurons, although few studies have recorded interneuronal activity during labyrinthine stimulation. The present study determined the responses of upper thoracic interneurons of decerebrate cats to electrical stimulation of the vestibular nerve or natural stimulation of otolith organs and the anterior and posterior semicircular canals using rotations in vertical planes. A majority of thoracic interneurons (74/102) responded to vestibular nerve stimulation at median latencies of 6.5 ms (minimum of approximately 3 ms), suggesting that labyrinthine inputs were relayed to these neurons through trisynaptic and longer pathways. Thoracic interneuronal responses to vertical rotations were similar to those of graviceptors such as otolith organs, and a wide array of tilt directions preferentially activated different cells. Such responses were distinct from those of cells in the cervical and lumbar enlargements, which are mainly elicited by ear-down tilts and are synchronous with stimulus position when low rotational frequencies are delivered, but tend to be in phase with stimulus velocity when high frequencies are employed. The dynamic properties of thoracic interneuronal responses to tilts were instead similar to those of thoracic motoneurons and sympathetic preganglionic neurons. However, the preferred tilt directions of the interneurons were more heterogeneous than thoracic spinal outputs, showing that the outputs do not simply reflect an addition of local interneuronal activity.

A Rare Triad of Giant Occipital Encephalocele with Lipomyelomeningocele, Tetralogy of Fallot, and Situs Inversus.

Giant encephalocele is an uncommon congenital anomaly with very few published reports available in the English literature. Tetralogy of Fallot associated with situs inversus is also infrequently reported. To our knowledge there are no published reports of an association between giant encephalocele and Tetralogy of Fallot. The additional finding of situs inversus results in a rare pathologic triad, not heretofore described.

Bronchial artery embolization for malignant hemoptysis: a single institutional experience.

OBJECTIVE: To assess the effectiveness of bronchial artery embolization (BAE) in patients with malignant hemoptysis. METHODS: An IRB-approved retrospective study at our academic institution was conducted on all patients treated by BAE for hemoptysis from lung malignancy. Outcome and safety measures were documented according to Society of Interventional Radiology (SIR) practice guidelines. RESULTS: A total of 26 patients (13 male, 13 female) with lung malignancy underwent BAE for hemoptysis from 2003-2013. Histologic analysis revealed 80% (21/26) of cases were from primary lung malignancies, while the remaining 20% (4/26) represented metastatic disease. Sixty-five percent (17/26) of patients underwent bronchoscopy prior to BAE. Follow-up ranged from 2 to 1,909 days, with average of 155 days. Technical success was achieved in 77% of patients (20/26). Clinical success rate was 75% (15/20). Eighty-five percent of embolized patients (17/20) were treated with particles, 15% (3/20) with gelfoam, and 20% (4/20) with coils. Single-vessel embolization was performed in 70% (14/20), two-vessel in 20% (4/20), and multiple vessels in 10% (2/20). No complications were reported. Six-month all-cause mortality of treated cases was 55% (11/20) with an in-hospital mortality of 25% (5/20). Ten percent (2/20) had remote re-bleeding events beyond 6 months. Statistically significant predictors of mortality were intubation status, hemoglobin/hematocrit at presentation, and thrombocytopenia. CONCLUSIONS: BAE is a safe and useful treatment for clinically significant hemoptysis in patients with primary or metastatic lung masses despite high overall mortality. Intubation status, low hemoglobin/hematocrit, and thrombocytopenia may represent clinical predictors of short term mortality following BAE. ADVANCES IN KNOWLEDGE: Most patients undergoing BAE for malignant hemoptysis achieve high clinical success despite suffering a high mortality from underlying disease.

PET/CT artifacts.

There are several artifacts encountered in positron emission tomography/computed tomographic (PET/CT) imaging, including attenuation correction (AC) artifacts associated with using CT for AC. Several artifacts can mimic a 2-deoxy-2-[18F] fluoro-d-glucose (FDG) avid malignant lesions and therefore recognition of these artifacts is clinically relevant. Our goal was to identify and characterize these artifacts and also discuss some protocol variables that may affect image quality in PET/CT.