Computed Tomography Pulmonary Angiogram Dynamic Parameter Correlation With Pulmonary Pressure and Pulmonary Hypertension Etiologies.

OBJECTIVE: Pulmonary hypertension (PH) is caused by etiologies that differ in pathophysiology. Patients with undiagnosed PH may have a computed tomography pulmonary angiography (CTPA) scan during workup. Static measurements on computed tomography correlate with PH; however, dynamic parameters have received less attention. We studied the correlation between CTPA dynamic parameters and PH and assessed whether these parameters differ among PH etiologies. We also propose a method for PH screening. METHODS: Patients who underwent right-heart catheterization and CTPA within 45 days of each other were included. Charts were reviewed for presence and etiology of PH. The time it took to reach the CTPA trigger threshold during bolus tracking (TT) was recorded and compared with pulmonary pressure measured on pulmonary artery catheterization. The correlation between TT values and pulmonary pressure was studied, as well as the sensitivity and specificity of TT for PH. RESULTS: Twenty-seven patients with 28 examinations were included. A significant correlation was found between pulmonary pressure and TT, as well as TT and right ventricular decreased function, P < 0.01. Left heart failure showed the longest TT among PH subgroups and significantly longer TT in patients with both PH and right ventricular decreased function. Time to trigger demonstrated a sensitivity range of 75% to 92% and specificity between 56% and 88% for pulmonary pressure of 40 mm Hg or greater. CONCLUSIONS: Dynamic parameters of flow measured on CTPA significantly correlate with pulmonary pressure and can potentially help screen for PH. Left heart failure seems to have the greatest impact on TT among patients with PH.

Identifying the Long-Term Role of Inducible Nitric Oxide Synthase after Contusive Spinal Cord Injury Using a Transgenic Mouse Model.

Inducible nitric oxide synthase (iNOS) is a potent mediator of oxidative stress during neuroinflammation triggered by neurotrauma or neurodegeneration. We previously demonstrated that acute iNOS inhibition attenuated iNOS levels and promoted neuroprotection and functional recovery after spinal cord injury (SCI). The present study investigated the effects of chronic iNOS ablation after SCI using inos-null mice. iNOS-/- knockout and wild-type (WT) control mice underwent a moderate thoracic (T8) contusive SCI. Locomotor function was assessed weekly, using the Basso Mouse Scale (BMS), and at the endpoint (six weeks), by footprint analysis. At the endpoint, the volume of preserved white and gray matter, as well as the number of dorsal column axons and perilesional blood vessels rostral to the injury, were quantified. At weeks two and three after SCI, iNOS-/- mice exhibited a significant locomotor improvement compared to WT controls, although a sustained improvement was not observed during later weeks. At the endpoint, iNOS-/- mice showed significantly less preserved white and gray matter, as well as fewer dorsal column axons and perilesional blood vessels, compared to WT controls. While short-term antagonism of iNOS provides histological and functional benefits, its long-term ablation after SCI may be deleterious, blocking protective or reparative processes important for angiogenesis and tissue preservation.

MR Imaging of the Spine: Urgent and Emergent Indications.

Spinal emergencies and urgent conditions must be recognized early so that the diagnosis can be quickly confirmed and treatment can be instituted to possibly prevent permanent loss of function. The American College of Radiology provides guidelines for recognition of patients presenting with myelopathy or acute low back pain who require further evaluation for suspicion of more serious problems and contribute to appropriate imaging utilization. Spinal emergencies include spinal cord compression secondary to vertebral fracture or space occupying lesion, spinal infection or abscess, vascular or hematologic damage, severe disc herniation, and spinal stenosis.

Endovascular management of renal transplant dysfunction secondary to hemodynamic effects related to ipsilateral femoral arteriovenous graft.

Hemodialysis access options become complex in long-term treatment for patients with renal disease, while awaiting renal transplantation (RT). Once upper extremity sites are exhausted, lower extremities are used. RT is preferably in the contralateral iliac fossa, rarely ipsilateral. In current literature, RT dysfunction secondary to the hemodynamic effects of an ipsilateral femoral arteriovenous graft (AVG) has been rarely described. To our knowledge, AVG ligation is the only published technique for hemodynamic correction of an ipsilateral AVG. We present a simple, potentially reversible endovascular approach to manage the hemodynamic effects of an AVG, without potentially permanently losing future AVG access.

Combining neurotrophin-transduced schwann cells and rolipram to promote functional recovery from subacute spinal cord injury.

Following spinal cord injury (SCI), both an inhibitory environment and lack of intrinsic growth capacity impede axonal regeneration. In a previous study, prevention of cyclic adenosine monophosphate (AMP) hydrolysis by the phosphodiesterase-4 inhibitor rolipram, in combination with Schwann cell (SC) grafts, promoted significant supraspinal and proprioceptive fiber growth and/or sparing and improved locomotion. In another study, transplanted SCs transduced to generate a bifunctional neurotrophin (D15A) led to significant increases in graft SCs and axons, including supraspinal and myelinated axons. Here we studied the growth and myelination of local and supraspinal axons and functional outcome following the combination of rolipram administration and neurotrophin-transduced SC implantation after SCI. Rolipram was administered subcutaneously for 4 weeks immediately after contusion at vertebral T8 (25.0-mm weight drop, MASCIS impactor). GFP or GFP-D15A-transduced SCs were injected into the injury epicenter 1 week after SCI. GFP-D15A SC grafts and GFP SC grafts with rolipram contained significantly more serotonergic fibers compared to GFP SCs. SC myelinated axons were increased significantly in GFP SC with rolipram-treated animals compared to animals receiving SCI alone. Rolipram administered with either GFP or GFP-D15A SCs significantly increased numbers of brain stem-derived axons below the lesion/implant area and improved hindlimb function. Compared to the single treatments, the combination led to the largest SC grafts, the highest numbers of serotonergic fibers in the grafts, and increased numbers of axons from the reticular formation below the lesion/implant area and provided the greatest improvement in hindlimb function. These findings demonstrate the therapeutic potential for a combination therapy involving the maintenance of cyclic AMP levels and neurotrophin-transduced SCs to repair the subacutely injured spinal cord.