Anatomy Recognition Research Articles

Medical diagnostic imaging optimization based on anatomy recognition

Anatomical information is identified from a medical image and/or used for controlling a medical diagnostic imaging system, such as an ultrasound system. To identify anatomical information from a medical image, a processor applies a multi-class classifier. The anatomical information is used to set an imaging parameter of the medical imaging system. The setting or identification may be used in combination or separately.

Development and evaluation of a training program for therapeutic radiographers as a basis for online adaptive radiation therapy for bladder carcinoma

Aims Online adaptive radiotherapy requires a new level of soft tissue anatomy recognition and decision making by therapeutic radiographers at the linear accelerator. We have developed a therapeutic radiographer training workshop encompassing soft tissue matching for an online adaptive protocol for muscle invasive bladder cancer. Our aim is to present the training program, and its evaluation which compares pre and post training staff soft tissue matching and bladder contouring using Cone Beam Computer Tomography (CBCT). Materials and Methods Prior to commencement of an online adaptive bladder protocol, a staff training program for 33 therapeutic radiographers, with a separate ethics approved evaluation component was developed. A multidisciplinary training program over two days was carried out with a total of 11 h of training, covering imaging technology, pelvic anatomy and protocol specific decision making in both practical and theoretical sessions. The evaluation included both pre training and post training testing of staff. Results Pre training and post training, the standard deviations in the contoured bladder between participants in left–right direction were 0.64 vs 0.59 cm, superior–inferior 0.89 vs 0.77 cm and anterior–posterior direction was 0.88 vs 0.52 cm respectively. Similarly the standard deviation in the volume contoured decreased from 40.7 cc pre training to 24.5 cc post training. Time taken in contouring was reduced by the training program (19.8 vs 17.2 min) as was the discrepancy in choice of adaptive radiotherapy plans. The greatest reduction in variations in contouring was seen in staff whose pre training had the largest deviations from the reference radiation oncologist contours. Conclusion A formalized staff training program is feasible, well received by staff and reduces variation in organ matching and contouring. The improvement was particularly noticed in staff who pre training had larger deviations from the reference standard.

Division of the right posterior attachments of the head of the pancreas with a linear stapler during pancreaticoduodenectomy: vascular and oncological considerations based on an anatomical cadaver-based study

Section of the right posterior attachment (RPA) of the pancreatic head from the adventicia of the superior mesenteric artery (SMA) is the last step of pancreaticoduodenectomy. This procedure might be technically demanding, time consuming and potentially dangerous. A method using a stapler has been proposed to simplify this step of the pancreaticoduodenectomy. To evaluate the potential consequences of RPA section using this new method, we used an experimental model of pancreaticoduodenectomy in 20 cadavers. After RPA stapling, the residual areolar tissue located between the staple line and SMA was removed (by sub adventicial dissection) and weighed. This allowed an evaluation of: (1) the theoretical risk of SMA injury and (2) the potential carcinological consequences of using stapling division, in comparison with the lymphadenectomy obtained with the conventional sub-adventicial dissection. A right hepatic artery was accidentaly injured in 10% of cases because of the lack of arterial dissection and arterial anatomy recognition. Forty-three percent of the RPA containing nerves and lymphatics remains in place. Using the stapling technique for RPA division theoretically increases the risk of micro or macroscopically positive margin after surgical resection. The result of this human cadaver-based dissection suggests that the use of the mechanical stapling device for final division of the RPA might increase the risk of SMA injury. The risk of vascular injury has been reported in surgical literature and is confirmed by this study. Such results (10% of accidentaly injury) may not be representative in leaving human patients, thanks to the use of a detectable palpable pulse of the SMA. The latter is important in avoiding vascular injury during RPA division. This study also shows that this new technique may increase the risk of incomplete tumor resection.

Spatial Orientation and Off-Axis Challenges for NOTES

Issues of spatial orientation and off-axis visualization must be addressed to make natural orifice translumenal endoscopic surgery (NOTES) more than a clinical oddity practiced by a highly skilled minority. The issue is the degree of mental work needed to operate with this new modality, with issues of depth perception and anatomy recognition currently making these procedures extremely difficult and unlikely to be practically applied or taught. New instrument designs and clinical tricks combined can dramatically decrease the mental work needed and make this closer to a widely learnable access method. In the long run, computer interfaces may be necessary to resolve some of these human factor issues and make a true universal platform.

Historical Perspectives on Parathyroid Surgery

The field of parathyroid surgery is rich in history. It begins with an obscure publication by a Swedish medical student noting a distinct anatomic entity in the neck adjacent to the thyroid gland; these tiny glands would come to be known as the parathyroid glands. This was followed by the subsequent discovery of their role in calcium metabolism, once the devastating effects of hyperparathyroidism on the bones and kidneys were recognized. The first neck explorations with identification and removal of parathyroid adenomas took place in the early twentieth century. Following the initial parathyroid operations in the United States and Europe, the mid-twentieth century was dominated by extensive investigation into calcium metabolism and the effects of parathyroid hormone and by refinement of techniques in parathyroid surgery. In more recent years, the introduction of sophisticated localization studies and minimally invasive parathyroid operations continues to inspire progress in this unique and fascinating field. In this review, the sequence of events starting with the anatomic recognition of the parathyroid glands and ending with the most recent developments and advances in parathyroid surgery are described.

In-vivo visualisation of the anatomical structures related to the acupuncture points Dai mai and Shen mai by MRI: A single-case pilot study

BackgroundThe concept of acupuncture point localisation in Traditional Chinese Medicine (TCM) is based on millenary practical experience. Modern imaging methods such as PET, MRI and SPECT have been used primary for the investigation of the mechanisms of action of acupuncture. In this pilot single-case study we have evaluated the technical possibilities for in-vivo imaging of the anatomical relations of acupuncture points using state of the art MRI.MethodsPreliminary experiments relating to the quality of acupuncture needles under the setting of MRI were done both with stainless steel and gold needles. In a second step, in-vivo imaging was carried out. A licensed acupuncture practitioner (RM) chose two points belonging to the so-called extraordinary vessels. In 2 sequential, separate procedures, he inserted himself gold acupuncture needles using a neutral technique (known as Ping Bu Ping Xie) into the Dai mai and Shen mai points, i.e. gall bladder 26 and bladder 62. Imaging was done on a Siemens Magnetom Avanto MR scanner using a head array and body coil. Mainly T1-weighted imaging sequences, as routinely used for patient exams, were used to obtain multi-slice images.ResultsIn the preliminary experiments only acupuncture needles made of gold showed enough stability in order to be used for further imaging procedures. Using an onion and a banana as an object, further studies showed that the gold needles produced a void defect that corresponds to the tip of the inserted needle, while at the same time an artefactually increased diameter was observed. The in-vivo experiments showed that the Dai mai point was in relation to the abdominal internal oblique muscle. The Shen mai point artefact showed up close to the longus and brevis peroneal tendons at the fibular malleolus. Side effects related to heating or burning were not observed. Improved anatomical recognition was obtained using 3D-volume rendering techniques.ConclusionThrough an adequate choice of acupuncture material (gold needles) as well as of ideal MRI imaging sequences it has been possible to visualize the anatomical characteristics at the acupuncture points Dai mai and Shen mai in-vivo. At the selected sites the needles showed a relation to tendino-fascial and muscular structures. These anatomical structures fit well into the recently described WOMED concept of lateral tension in which these acupuncture points play a regulatory role.

Improving Surgical Pattern Recognition Through Repetitive Viewing of Video Clips

Previous field studies show that surgery residents and medical students have difficulty recognizing appropriate anatomic cues during laparoscopic surgery, causing delays in procedures and errors. Such observations led to the development of an anatomy recognition training intervention, specifically the use of an ordered set of video clips that show the main steps of a laparoscopic procedure. Each procedural step is shown several times in succession, with each repetition coming from a different surgery, thus exposing the learner to varied anatomy and crucial maneuvers. A factorial experiment with 30 medical students showed that the group using these ordered, perceptual learning modules had a significant increase in scores on questions assessing perceptual knowledge and procedural knowledge, with no corresponding increase for the control group who watched the videos from the same cases but in an unstructured format for the same amount of time (p< 0.05). Neither group showed improvement on strategic or declarative knowledge tests. The study suggests that ordered perceptual learning modules are a potential means for training perceptual and procedural knowledge in an effective, safe, and efficient manner, serving as a complement to other types of training methods that teach physical dexterity, strategic and declarative knowledge.

Controversies concerning the anatomical definition of the conduction tissues.

Conduction across the atrioventricular junctions had long been controversial, with arguments raging as to whether such conduction was myogenic or neurogenic. The landmark study of Tawara in 1906 established the existence of an axis of histologically specialized myocardial cells contained within fibrous sheaths as being responsible for rapid conduction from the atrial to the ventricular myocardium. Keith and Flack then demonstrated that the atrial impulse was generated in the sinus node, with subsequent slowing within the atrioventricular node of Tawara. The detailed reviews of Aschoff and Monckeberg then emphasized the morphological features that permit unequivocal recognition of the nodes, along with rapidly conducting tracts. It is now pertinent that we remember these original criteria for anatomical recognition as we discuss the steps involved in the development of these conducting structures from their embryologic primordiums. In this review, we restate the criteria of Aschoff and Monckeberg, then discuss their relevance to the developmental issues, emphasizing that all myocardial cells have the potential to conduct. The important issues, therefore, are the changes that occur as the heart itself changes from a solitary muscular tube, already possessing the capacity t generate an electrocardiogram, to the four-chambered structure we recognize in postnatal life.

Radiologic Anatomy — A Credit Course for First-Year Medical Students

Diagnostic radiology should assume a more prominent role in medical student education. We have developed a 4-year plan for radiologic education at the University of Florida. The initial step in this plan is a required credit course in radiologic anatomy given in the first semester. Designed to introduce students to various imaging modalities while teaching anatomic recognition, the course combines a lecture series with systematized self-study film packets and self-test packets. These are reinforced by a videotape series and other written materials. Examinations are in practical format utilizing radiographs on viewbox stations. The course provides a foundation for subsequent coursework in diagnostic radiology, including radiologic pathology and clinical radiology. These courses stress how to workup patients and how to use the radiologist as a consultant in patient care. The response to the radiologic anatomy course has been highly favorable.

Quantitative und morphologische Aussagekraft der Spect-Perfusionsuntersuchung bei thorakalen Raumforderungen

The results of planar perfusion scintigraphy, SPECT and CT were evaluated quantitatively and compared with each other in 47 patients with thoracic tumours. SPECT was superior to conventional scintigraphy in respect of morphological information. Quantitative evaluation of the function data derived from SPECT permits a more detailed anatomical recognition of perfusion inhomogeneity due to the tumour and can distinguish between central and peripheral tumour growth. Comparison between CT and SPECT showed good morphological agreement between the two.