Richard Kent Sanders

North canyon Medical Center · Radiology

Nothronychus was a large, derived therizinosaur from the Upper Cretaceous of Utah and New Mexico. The genus is known from elements that have been referred to single individuals. Therizinosaurs were unusual maniraptoran theropods close to the origin of birds. The axial skeleton is extensively pneumatized, but CT scans reveal an apneumatic synsacrum....

Poposaurus gracilis is a bipedal pseudosuchian archosaur that has been poorly understood since the discovery of the holotype fragmentary partial postcranial skeleton in 1915. Poposaurus. gracilis is a member of Poposauroidea, an unusually morphologically divergent clade of pseudosuchians containing taxa that are bipedal, quadrupedal, toothed, edent...

The soft-tissue reconstruction and associated osteology of the North American therizinosaurian Nothronychus mckinleyi is updated. The cranial nerve topology is revised, bringing it more in line with coelurosaurs. The trunk of the trigeminal nerve is very short, with an incompletely intracranial trigeminal ganglion, an ophthalmic branch diverging an...

Multiple anatomic markers have been used to number the lumbar spine when complete spine imaging is unavailable. In this review, we discussed the current methods of spine numbering and reviewed a recently validated neuroanatomic method of spine numbering that uses the MR imaging of lumbosacral plexus anatomy for localization. This method is promisin...

The common snapping turtle (Chelydra serpentina) is a well studied and broadly distributed member of Testudines; however, very little is known concerning developmental anomalies and soft tissue pathologies of turtles and other reptiles. Here, we present an unusual case of unilateral pulmonary aplasia, asymmetrical carapacial kyphosis, and mild scol...

Background and purpose: Multiple methods have been used to determine the lumbar vertebral level on MR imaging, particularly when full spine imaging is unavailable. Because postmortem studies show 95% accuracy of numbering the lumbar vertebral bodies by counting the lumbar nerve roots, attention to lumbar nerve morphology on axial MR imaging can pr...

Die Neuroarthropathie der Wirbelsäule oder Charcot-Wirbelsäule ist eine progredient verlaufende, destruierende Gelenkerkrankung, die nach Verlust der neuroprotektiven Sensibilität und der propriozeptiven Reflexe auftritt. Die klinische Diagnose ist wegen der unterschiedlich langen Zeit zwischen der initialen neurologischen Schädigung und dem Auftre...

Spinal neuroarthropathy (SNA), or Charcot spine, is a progressive destructive arthropathy occurring after loss of neuroprotective sensation and proprioceptive reflexes. Clinical diagnosis is difficult because of the variable length to presentation after initial neurologic damage and the limited symptoms given preexisting neurologic deficits. SNA is...

Pigmented villonodular synovitis (PVNS) is an uncommon, benign, but locally aggressive lesion characterized most commonly by synovial proliferation of the appendicular large joints, but occasionally involving a bursa or the tendon sheath. PVNS of the spine is rare, typically involving the posterior elements. The lytic radiographic appearance and fl...

Objective: To determine whether exercise on alternative terrain affects the development of the digital cushion and bony structures of the bovine foot. Animals: 20 weaned bull calves. Procedures: Two-month-old calves were randomly allocated to an exercise or control group. For 4 months, the control group was maintained in grass paddocks, and th...

Aim: To develop and demonstrate the efficacy of a computed tomography arthrography (CTA) protocol for the hip that enables accurate three-dimensional reconstructions of cartilage and excellent visualization of the acetabular labrum. Materials and methods: Ninety-three subjects were imaged (104 scans); 68 subjects with abnormal anatomy, 11 patien...

Lameness negatively affects the well-being and economic productivity of beef and dairy cattle. It has been reported that the prevalence of lameness in dairy herds is nearly 20% for primiparous cows and almost 50% for multiparous cows. Hence, evaluation, development, and implementation of better management protocols are necessary to produce replacem...

Symptomatic venous malformation (VM) of muscle in adults is rare and usually presents in childhood or adolescence as the individual is growing. We describe an atypical presentation of a malformation affecting the gastrocnemius muscle asymmetrically with onset in adulthood, which created a diagnostic challenge. Electromyography (EMG) and muscle biop...

Using gross dissections and computed tomography we studied the lungs of juvenile American alligators (Alligator mississippiensis). Our findings indicate that both the external and internal morphology of the lungs is strikingly similar to the embryonic avian respiratory system (lungs + air sacs). We identified bronchi that we propose are homologous...

Many disarticulated bones from multiple individuals of a primitive therizinosaurian, referred to Falcarius utahensis, were found in the paucispecific Crystal Geyser bonebed in the Lower Cretaceous Cedar Mountain Formation of eastern Utah. To date, more than 2000 specimens from this species have been excavated. Included in this collection are two pa...

A nearly complete skull of Eutretauranosuchus delfsi was uncovered at the upper Jurassic Dry Mesa Dinosaur Quarry in the Brushy Basin Member of the Morrison Formation in western Colorado. It permits an expanded description of the taxon. Like the holotype, from Canyon City, Colorado, the Dry Mesa specimen probably represents a subadult, based on fai...

The lungs of birds move air in only one direction during both inspiration and expiration through most of the tubular gas-exchanging bronchi (parabronchi), whereas in the lungs of mammals and presumably other vertebrates, air moves tidally into and out of terminal gas-exchange structures, which are cul-de-sacs. Unidirectional flow purportedly depend...

The Dry Mesa Dinosaur Quarry in western Colorado is characterized by a high diversity of vertebrate fossils, including pterosaur remains. Most of the pterosaur material has been referred to the species Mesadactylus ornithosphyos. Since its original description, additional material of this pterosaur has been uncovered. The new material includes the...

Abstract All amniotes except birds and mammals have the ability to shunt blood past the lungs, but the physiological function of this ability is poorly understood. We studied the role of the shunt in digestion in juvenile American alligators in the following ways. First, we characterized the shunt in fasting and postprandial animals and found that...

Ligament function and propensity for injury are directly related to regional stresses and strains. However, noninvasive techniques for measurement of strain are currently limited. This study validated the use of Hyperelastic Warping, a deformable image registration technique, for noninvasive strain measurement in the human medial collateral ligamen...

The distal arthrogryposis (DA) syndromes are a distinct group of disorders characterized by contractures of two or more different body areas. More than a decade ago, we revised the classification of DAs and distinguished several new syndromes. This revision has facilitated the identification of five genes (i.e., TNNI2, TNNT3, MYH3, MYH8, and TPM2)...

Injectable hydrogel and porous sponge formulations of Carbylan-GSX, a crosslinked synthetic extracellular matrix (ECM), were used to deliver human demineralized bone matrix (DBM) in a rat femoral defect model. A cortical, full-thickness 5-mm defect was created in two femurs of each rat. Six rats were assigned to each of five experimental groups (th...

A well preserved specimen of the theropod Ceratosaurus from the Upper Jurassic Morrison Formation of western Colorado was recently described and given the name C. magnicornis. The systematics of the genus is outside the scope of the present study but, as a generally accepted basal tetanuran, the braincase was CT scanned to provide a description of...

The radiologic evaluation of the shoulder girdle is an important adjunct to the clinical history and physical examination. Close collaboration between musculoskeletal clinicians and musculoskeletal radiologists improves the diagnostic performance of imaging studies. Technologic advantages, especially in MRI, have improved appreciation of shoulder a...

Osteochondral injuries are an important type of musculoskeletal trauma that can lead to disabling arthritis if not recognized and treated appropriately in the early stages. The anatomic configuration and biomechanical function of a joint are important for understanding its particular pattern of osteochondral injury and the resultant imaging appeara...

Sauroposeidon proteles is a large brachiosaurid sauropod recently described from the Antlers Formation (Aptian-Albian) of southeastern Oklahoma. Sauroposeidon represents the culmination of brachiosaurid trends toward lengthening and lightening the neck, and its cervical vertebrae are characterized by extensive pneumatic structures. The elaboration...

Sauroposeidon proteles, a new brachiosaurid sauropod, is represented by an articulated series of four mid-cervical vertebrae recovered from the Antlers Formation (Aptian–Albian) of southeastern Oklahoma. Most Early Cretaceous North American sauropod material has been referred to Pleurocoelus, a genus which is largely represented by juvenile materia...