Anatomic Sequence Research Articles

Whole-body MRI in oncology: can a single anatomic T2 Dixon sequence replace the combination of T1 and STIR sequences to detect skeletal metastasis and myeloma?

ObjectivesTo compare the diagnostic accuracy of a single T2 Dixon sequence to the combination T1+STIR as anatomical sequences used for detecting tumoral bone marrow lesions in whole-body MRI (WB-MRI) examinations.MethodsBetween January 2019 and January 2020, seventy-two consecutive patients (55 men, 17 women, median age = 66 years) with solid (prostate, breast, neuroendocrine) cancers at high risk of metastasis or proven multiple myeloma (MM) prospectively underwent a WB-MRI examination including coronal T1, STIR, T2 Dixon and axial diffusion-weighted imaging sequences. Two radiologists independently assessed the combination of T1+STIR sequences and the fat+water reconstructions from the T2 Dixon sequence. The reference standard was established by consensus reading of WB-MRI and concurrent imaging available at baseline and at 6 months. Repeatability and reproducibility of MRI scores (presence and semi-quantitative count of lesions), image quality (SNR: signal-to-noise, CNR: contrast-to-noise, CRR: contrast-to-reference ratios), and diagnostic characteristics (Se: sensitivity, Sp: specificity, Acc: accuracy) were assessed per-skeletal region and per-patient.ResultsRepeatability and reproducibility were at least good regardless of the score, region, and protocol (0.67 ≤ AC1 ≤ 0.98). CRR was higher on T2 Dixon fat compared to T1 (p < 0.0001) and on T2 Dixon water compared to STIR (p = 0.0128). In the per-patient analysis, Acc of the T2 Dixon fat+water was higher than that of T1+STIR for the senior reader (Acc = +0.027 [+0.025; +0.029], p < 0.0001) and lower for the junior reader (Acc = −0.029 [−0.031; −0.027], p < 0.0001).ConclusionsA single T2 Dixon sequence with fat+water reconstructions offers similar reproducibility and diagnostic accuracy as the recommended combination of T1+STIR sequences and can be used for skeletal screening in oncology, allowing significant time-saving.Key Points• Replacement of the standard anatomic T1 + STIR WB-MRI protocol by a single T2 Dixon sequence drastically shortens the examination time without loss of diagnostic accuracy.• A protocol based on fat + water reconstructions from a single T2 Dixon sequence offers similar inter-reader agreement and a higher contrast-to-reference ratio for detecting lesions compared to the standard T1 + STIR protocol.• Differences in the accuracy between the two protocols are marginal (+ 3% in favor of the T2 Dixon with the senior reader; −3% against the T2 Dixon with the junior reader).

The Importance of Body Part Labeling to Enable Enterprise Imaging: A HIMSS-SIIM Enterprise Imaging Community Collaborative White Paper

In order for enterprise imaging to be successful across a multitude of specialties, systems, and sites, standards are essential to categorize and classify imaging data. The HIMSS-SIIM Enterprise Imaging Community believes that the Digital Imaging Communications in Medicine (DICOM) Anatomic Region Sequence, or its equivalent in other data standards, is a vital data element for this role, when populated with standard coded values. We believe that labeling images with standard Anatomic Region Sequence codes will enhance the user’s ability to consume data, facilitate interoperability, and allow greater control of privacy. Image consumption—when a user views a patient’s images, he or she often wants to see relevant comparison images of the same lesion or anatomic region for the same patient automatically presented. Relevant comparison images may have been acquired from a variety of modalities and specialties. The Anatomic Region Sequence data element provides a basis to allow for efficient comparison in both instances. Interoperability—as patients move between health care systems, it is important to minimize friction for data transfer. Health care providers and facilities need to be able to consume and review the increasingly large and complex volume of data efficiently. The use of Anatomic Region Sequence, or its equivalent, populated with standard values enables seamless interoperability of imaging data regardless of whether images are used within a site or across different sites and systems. Privacy—as more visible light photographs are integrated into electronic systems, it becomes apparent that some images may need to be sequestered. Although additional work is needed to protect sensitive images, standard coded values in Anatomic Region Sequence support the identification of potentially sensitive images, enable facilities to create access control policies, and can be used as an interim surrogate for more sophisticated rule-based or attribute-based access control mechanisms. To satisfy such use cases, the HIMSS-SIIM Enterprise Imaging Community encourages the use of a pre-existing body part ontology. Through this white paper, we will identify potential challenges in employing this standard and provide potential solutions for these challenges.

Whole-brain voxel-based analysis of diffusion tensor MRI parameters in patients with primary open angle glaucoma and correlation with clinical glaucoma stage

Glaucoma is the second leading cause of blindness worldwide. The purpose of this study is to identify areas of neurodegeneration in glaucoma utilizing 3 T magnetic resonance (MR) diffusion tensor imaging (DTI) parameters with whole-brain voxel-based analysis (VBA) and determine whether these parameters correlate with disease severity. Twenty-five glaucoma patients and 25 age-matched healthy volunteers were prospectively examined. Clinical glaucoma severity was assessed utilizing static threshold visual field parameters. All subjects underwent 3 T MRI utilizing a DTI sequence (repetition time/echo time 13,000/68.9 ms, maximal b value 800 s/mm(2) along 30 directions) and an anatomic sequence to provide structural information. All data sets were processed by VBA. Brain fractional anisotropy, mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were compared in the two groups. Correlation between DTI parameters and glaucoma stage were determined. The bilateral optic radiations and chiasma of glaucoma patients demonstrated statistically significantly lower fractional anisotropy (p < 0.05). Optic radiation RD was similarly decreased in glaucoma patients (p < 0.05). There were no statistically significant differences noted in MD or AD between the two groups (p > 0.05). Optic chiasm fractional anisotropy values were negatively correlated with glaucoma stage (r = -0.53, p < 0.05) and optic radiation RD values positively correlated (left r = 0.45, p < 0.05; right = 0.38, p = 0.06). DTI parameters fractional anisotropy and RD are altered in the optic chiasm and radiations of glaucoma patients. As fractional anisotropy and RD also correlate with glaucoma stage, these values could serve as potential noninvasive markers of disease severity.

A novel advanced design of the hip joint wear simulator

Researches on development of an advanced design of the hip joint wear simulator, which meets the demands of standard ISO/DIS 14242 on angular movement waveforms and waveform of the loading cycle possessing the minimum complexity, sufficient reliability, “cleanliness” of test environment and flexibility in readjustment depending on requirements of trials have been executed. Also units of the developed simulator satisfy necessary performances of their durability and rigidity for maintenance of requirements of the specified standard at realization of constructive decisions with minimum expenses at cost. Modification of the improved base simulator is executed. Modification consists of providing angular displacements FE, AA and IOR, three independent electromechanical axes consisting of the step-by-step motor with a reducer and a drive with a toothed belt are used. The simulator contains two blocks including four test stations each, wherein three stations are mobile, and other one is stationary for trial on soak. The anatomic Euler sequence set of rotations FE→AA→IOR is provided in a simulator. For depreciation of the device (up to 25% on each block) its modification when IOR-movement is applied due to rotation of a spherical femoral head around a moving vertical axis by means of the rotary lever placed parallel to the longitudinal FE-axis and having a sliding contact throughout the test with motionless guide, put on the simulator frame foundation, can be used. It is found that its modification gives very high accuracy of duplication of the mentioned IOR-movement profile both according to standard ISO 14242, and for walking gait of the person. For the first time electromechanical axes that can reliably provide recurrence of the loading cycle profile (with sharp peaks), presented in ISO 14242, at frequency 1 Hz are applied for creation of loading in a simulator, that is technically not able to execute the existing pneumatic drives. The developed design of a simulator allows: to test friction pairs according to the requirement of the Customer under any test protocol; to execute perfection and development of new methods of processing of perspective materials of hip prosthesis friction pairs; to pass in further for prediction of a resource of hip prosthesis friction pair on the basis of perfection of mathematical simulation methods of wear process. Experience of designing and manufacturing of the specified simulator will allow developing simulators further for trials in spine, artificial limbs of various extremities, artificial joints and implants.

Basal forebrain atrophy is a presymptomatic marker for Alzheimer's disease

Background Alzheimer's disease (AD) is the most common degenerative neurologic disorder. The onset of symptoms is insidious and follows a long period of progression of an asymptomatic pathology that proceeds in a precise anatomic and temporal sequence. Recent studies with quantitative magnetic resonance imaging techniques have shown the localization of the in vivo pathology of AD and its antecedent, mild cognitive impairment. The objective of the present study was to determine whether a sensitive and reliable marker for the presymptomatic phase of the disorder could be identified by longitudinal analysis of an initially asymptomatic, community-based population. Methods One hundred forty-eight healthy, cognitively normal participants in the Cardiovascular Health Study–Cognition Study had detailed clinical examinations and magnetic resonance imaging scans in 1998–1999 and 2002–2003. Modulated voxel-based morphometry was used to compare regional brain volumes in subjects who remained cognitively normal after 5 to 6 years of follow-up (n = 127) with those who developed probable AD during the same period (n = 21). Results Among normal subjects destined to develop AD, there was significant atrophy in the basal forebrain area as long as 4.5 years before the development of clinical symptoms. When the left hippocampus was also atrophic, the onset of dementia typically occurred earlier than in cases in which the atrophy was confined to basal forebrain. Conclusions Atrophy in the basal forebrain precedes the development of AD in subjects with cognition judged to be normal by neuropsychological testing. The time required to develop dementia appears to be shortened if hippocampal atrophy is also present. These data indicate that atrophy restricted to medial basal forebrain is a biomarker that predicts development of probable AD in asymptomatic elderly subjects.

Intraoperative three-dimensional visualization of the pyramidal tract in a neuronavigation system (PTV) reliably predicts true position of principal motor pathways

Background This prospective study employs anisotropic diffusion-weighted (ADW) magnetic resonance imaging for the integration of individual spatial information concerning the principal motor pathways into the operating room during microneurosurgery in the central region. We hypothesize that the three-dimensional (3-D) visualization of the pyramidal tract position (PTV) in a neuronavigation system based on ADW provides valid information concerning the position and extension of the principal motor pathways. Methods A total of 13 consecutive patients with lesions adjacent to the pyramidal tracts and the central region underwent microneurosurgery with the help of pyramidal tract visualization (PTV). An ADW sequence obtained preoperatively was fused to an anatomic navigation sequence. The 3-D reconstructions of the precentral gyrus (PG), the pyramidal tract, and the tumor were available in a customized neuronavigation system during surgery. Intraoperatively the PG was identified on the basis of the aforementioned data. Electric motorcortex stimulation (CS) was used to directly verify the PG location and indirectly the fiber tract position. Results In 11 cases (92%) the prediction of the principal motor pathways' position was correct. In one case of a meningioma, according to PTV, the tumor was falsely localized postcentrally. In the case of a precentral cavernoma, no motor response could be elicited by cortical stimulation. Conclusion Intraoperative PTV on the basis of ADW provides the neurosurgeon with reliable information concerning the position of the principal motor pathways during intracranial procedures as proved with intraoperative electrophysiological testing. The technique has the potential to reduce operative morbidity. PTV is straightforward and can be adapted to other customized neuronavigation devices.

On the neural correlates of visual perception.

Neurological findings suggest that the human striate cortex (V1) is an indispensable component of a neural substratum subserving static achromatic form perception in its own right and not simply as a central distributor of retinally derived information to extrastriate visual areas. This view is further supported by physiological evidence in primates that the finest-grained conjoined representation of spatial detail and retinotopic localization that underlies phenomenal visual experience for local brightness discriminations is selectively represented at cortical levels by the activity of certain neurons in V1. However, at first glance, support for these ideas would appear to be undermined by incontrovertible neurological evidence (visual hemineglect and the simultanagnosias) and recent psychophysical results on 'crowding' that confirm that activation of neurons in V1 may, at times, be insufficient to generate a percept. Moreover, a recent proposal suggests that neural correlates of visual awareness must project directly to those in executive space, thus automatically excluding V1 from a related perceptual space because V1 lacks such direct projections. Both sets of concerns are, however, resolved within the context of adaptive resonance theories. Recursive loops, linking the dorsal lateral geniculate nucleus (LGN) through successive cortical visual areas to the temporal lobe by means of a series of ascending and descending pathways, provide a neuronal substratum at each level within a modular framework for mutually consistent descriptions of sensory data. At steady state, such networks obviate the necessity that neural correlates of visual experience project directly to those in executive space because a neural phenomenal perceptual space subserving form vision is continuously updated by information from an object recognition space equivalent to that destined to reach executive space. Within this framework, activity in V1 may engender percepts that accompany figure-ground segregations only when dynamic incongruities are resolved both within and between ascending and descending streams. Synchronous neuronal activity on a short timescale within and across cortical areas, proposed and sometimes observed as perceptual correlates, may also serve as a marker that a steady state has been achieved, which, in turn, may be a requirement for the longer time constants that accompany the emergence and stability of perceptual states compared to the faster dynamics of adapting networks and the still faster dynamics of individual action potentials. Finally, the same consensus of neuronal activity across ascending and descending pathways linking multiple cortical areas that in anatomic sequence subserve phenomenal visual experiences and object recognition may underlie the normal unity of conscious experience.

Congenital clefts of the nose: principles of surgical management.

Congenital clefts of the nose are rare and highly variable. Because there are few examples, standard methods for treatment do not exist. Therefore each patient must be evaluated and managed individually with respect to anatomic elements, timing, and sequence of reconstruction.

Lesions of the thoracic aorta and its arch branches simulating neoplasm

Abnormal radiographic densities in the midportion of the chest are most commonly caused by neoplasms, cysts, or inflammatory disease. However, vascular lesions may present an identical x-ray appearance, with no distinguishing clinical history or physical findings. The cardiothoracic surgeon must be aware of this similarity in order to ensure the most appropriate diagnostic and therapeutic approach. In our experience, the most frequent problem in differential diagnosis is a lesion of the thoracic aorta or its arch branches simulating neoplasm. Nine such cases are presented, with pertinent conventional radiographs angiograms, and computed tomographic (CT) scans. These are considered in anatomic sequence: (1) ruptured sinus of Valsalva aneurysm; (2) ascending aortic aneurysm; (3) tortuosity or aneurysm of the innominate and subclavian arteries; (4) transverse arch aneurysm; (5) pseudocoarctation; and (6) descending aortic aneurysm. Such vascular lesions must be considered early in the evaluation of any juxta-aortic chest density, particularly if the patient is hypertensive and has other manifestations of atherosclerosis. Angiography and computed tomography establish the diagnosis in most instances, although both are less reliable when thrombus fills all or part of an aneurysm. If these methods fail to establish a vascular origin, the possibility of neoplasm is pursued. When neither a vascular nor neoplastic origin can be proved, surgical exploration is indicated in the otherwise good-risk patient.

Central and peripheral rewarming patterns in postoperative cardiac patients.

Central and peripheral temperature patterns in rewarming cardiac surgery patients have been studied by thermistor and infrared scanning techniques. These studies were combined with comprehensive patient monitoring records in a series of five patients. Evidence that thermoregulation, cardiac output, and drug action strongly affect the rewarming patterns could be substantiated for this limited series. In general an anatomic sequence of rewarming occurs in which the toes rewarm before the entire foot. Patterns of rewarming at the fingers and hands were similar to those at the toes. There was interpatient variation in the detailed temporal-spatial re-warming pattern of the digits. Blood flow rates to the toe were computed in accordance with the temperature data and were substantiated by venous occlusion plethysmography.

Sporogony of the swine Coccidium Eimeria debliecki Douwes, 1921.

SYNOPSIS. A pure strain of Eimeria debliecki isolated from a single oocyst in parasite free pigs was used thruout the study. Oocysts were allowed to sporulate at 3 constant temperatures, 20, 25, and 30 C, and the sporulation process was examined at 12‐hour intervals. A detailed description of the anatomic sequence of sporulation at 20 C is given and illustrated with photomicrographs and line drawings. The sporocysts and sporozoites are also described.