scholarly journals High frequency multiphase 4DCT for the detection of parathyroid adenomas, a pictorial essay

2021 ◽  
Author(s):  
Steven Raeymaeckers ◽  
Yannick De Brucker ◽  
Maurizio Tosi ◽  
Nico Buls ◽  
Johan De Mey
Keyword(s):  
Primary Hyperparathyroidism ◽  
Lymph Nodes ◽  
High Frequency ◽  
Type A ◽  
Type A Pattern ◽  
Parathyroid Adenomas ◽  
Pictorial Essay ◽  
The Difference ◽  
Temporary Rise

Abstract 4DCT for the detection of (an) enlarged parathyroid(s) is a commonly performed examination in the management of primary hyperparathyroidism. In our center we introduced a high frequency multiphase 4DCT protocol obtaining 16 phases, including 11 different arterial phases. Exposure to this multiphase 4DCT technique is comparable to that for classic helical 4DCT. In this pictorial essay we reconstructed our multiphase 4DCT series in the manner of a classic helical 4DCT and compare both techniques. We illustrate how multiphase 4DCT may aid in the detection of parathyroid adenomas. We find 17 out of 19 lesions demonstrating a type A pattern of enhancement, therefore suggesting this pattern could be more prevalent than previously thought. Some parathyroid adenomas may be mistaken for enlarged lymph nodes using classic 4DCT whereas high frequency multiphase 4DCT can detect a temporary rise in enhancement, thus suggesting the lesions in question to be of parathyroid origin. Smaller lesions may prove more obvious as the difference in enhancement between parathyroid and thyroid can become more prominent.

scholarly journals Primary hyperparathyroidism in young patients in Russia: high frequency of hyperparathyroidism-jaw tumor syndrome

2017 ◽  
Vol 6 (8) ◽  
pp. 557-565 ◽  
Author(s):  
Elizaveta Mamedova ◽  
Natalya Mokrysheva ◽  
Evgeny Vasilyev ◽  
Vasily Petrov ◽  
Ekaterina Pigarova ◽  
...  
Keyword(s):  
Primary Hyperparathyroidism ◽  
High Frequency ◽  
Multiple Endocrine Neoplasia Type ◽  
Young Patients ◽  
Parathyroid Adenomas ◽  
Next Generation Sequencing Ngs ◽  
Generation Sequencing ◽  
Germline Sequence ◽  
Dependent Probe

Background Primary hyperparathyroidism (PHPT) is a relatively rare disorder among children, adolescents and young adults. Its development at an early age is suspicious for hereditary causes, though the need for routine genetic testing remains controversial. Objective To identify and describe hereditary forms of PHPT in patients with manifestation of the disease under 40 years of age. Design We enrolled 65 patients with PHPT diagnosed before 40 years of age. Ten of them had MEN1 mutation, and PHPT in them was the first manifestation of multiple endocrine neoplasia type 1 syndrome. Methods The other fifty-five patients underwent next-generation sequencing (NGS) of a custom-designed panel of genes, associated with PHPT (MEN1, CASR, CDC73, CDKN1A, CDKN1B, CDKN1C, CDKN2A, CDKN2C, CDKN2D). In cases suspicious for gross CDC73 deletions multiplex ligation-dependent probe amplification was performed. Results NGS revealed six pathogenic or likely pathogenic germline sequence variants: four in CDC73 c.271C>T (p.Arg91*), c.496C>T (p.Gln166*), c.685A>T (p.Arg229*) and c.787C>T (p.Arg263Cys); one in CASR c.3145G>T (p.Glu1049*) and one in MEN1 c.784-9G>A. In two patients, MLPA confirmed gross CDC73 deletions. In total, 44 sporadic and 21 hereditary PHPT cases were identified. Parathyroid carcinomas and atypical parathyroid adenomas were present in 8/65 of young patients, in whom CDC73 mutations were found in 5/8. Conclusions Hereditary forms of PHPT can be identified in up to 1/3 of young patients with manifestation of the disease at <40 years of age. Parathyroid carcinomas or atypical parathyroid adenomas in young patients are frequently associated with CDC73 mutations.

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

scholarly journals Extranodal lymphoma of the head and neck: a pictorial essay

2019 ◽  
Vol 52 (4) ◽  
pp. 268-271
Author(s):  
Pinar Gulmez Cakmak ◽  
Gülsüm Akgün Çağlayan ◽  
Furkan Ufuk
Keyword(s):  
Lymph Nodes ◽  
Head And Neck ◽  
Neck Region ◽  
Extranodal Lymphoma ◽  
Imaging Findings ◽  
Head And Neck Region ◽  
Radiological Features ◽  
Extranodal Site ◽  
Pictorial Essay

Abstract Primary extranodal lymphoma is defined as a lymphoma at a solitary extranodal site, with or without involvement of the lymph nodes. The clinical and radiological features of extranodal lymphoma have been documented in recent studies. In this pictorial essay, we reviewed imaging findings of extranodal lymphoma in the head and neck region.

scholarly journals Hyperfine structure in the arc spectrum of cæsium and nuclear rotation

1928 ◽  
Vol 121 (787) ◽  
pp. 432-447 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Nuclear Spin ◽  
High Frequency ◽  
Principal Series ◽  
Very High Frequency ◽  
Nuclear Rotation ◽  
Higher Temperature ◽  
The Difference ◽  
Mechanical Moment ◽  
Very High

The arc spectrum of cæsium was investigated with the object of finding whether any of its lines possessed hyperfine structure, resulting from a nuclear magnetic moment, due to a quantised nuclear spin. The lines belonging to the principal series should, owing to the greater degree of penetration of the electron in the (1 s or 6 1 ) orbit, and the correspondingly greater interaction, show the greatest effect. The lines of the principal series are very easily broadened if the vapour pressure of the metal becomes high, so that great care had to be used in obtaining the spectrum of cæsium at a sufficiently low temperature. The most satisfactory method of excitation was found to be the application by means of external electrodes of a very high frequency alternating current to a tube filled with helium at about 2 mm. pressure containing a small quantity of cæsium. The tube required slight heating to bring out the cæsium lines; without this the helium spectrum was very much stronger than the metallic spectrum. At a very low vapour pressures of cæsium the discharge was blue in colour. Under these conditions the lines of the principal series showed no broadening greater than that due to thermal agitation, but at a slightly higher temperature the colour of the discharge became purple and the lines broadened. The lines belonging to the principal series were found to be very close doublets with very nearly constant frequencies differences. A theory is worked out which explains the origin of these doublets, assuming a nuclear spin of one half quantum; by correlating the difference in the separation of the hyperfine structure doublets in the 1 s — m 2 p 3/2 lines and the 1 s — m 2 p 1/2 lines, it is shown that a ratio of the magnetic to the mechanical moment of the nucleus about twice as great as the corresponding ratio for the electron would account for the observed frequency differences. The spectral notation used throughout is that of Hund. The results are compared with those found for the hyperfine structure of some of the bismuth lines by Back and Goudsmid, and are found to be in satisfactory agreement. A selection principle is found which applies both to the bismuth and the cæsium spectrum.

High-Frequency Quantitative Ultrasound Imaging of Cancerous Lymph Nodes

2009 ◽  
Vol 48 (7) ◽  
pp. 07GK08 ◽  
Author(s):  
Jonathan Mamou ◽  
Alain Coron ◽  
Masaki Hata ◽  
Junji Machi ◽  
Eugene Yanagihara ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Ultrasound Imaging ◽  
Quantitative Ultrasound ◽  
High Frequency

scholarly journals Epitrochlear lymph nodes: Anatomy, clinical aspects, and sonography features. Pictorial essay

2010 ◽  
Vol 13 (4) ◽  
pp. 168-174 ◽  
Author(s):  
O. Catalano ◽  
A. Nunziata ◽  
P.P. Saturnino ◽  
A. Siani
Keyword(s):  
Lymph Nodes ◽  
Clinical Aspects ◽  
Pictorial Essay

Exophoria: clinical features, diagnosis, treatment. The modern view on the problem. Literature review

2021 ◽  
pp. 52-55
Author(s):  
O.A. Lipunova ◽  
◽  
I.L. Plisov ◽  
V.V. Cherhykh ◽  
N.G. Antsiferova ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Type A ◽  
The State ◽  
Type A Pattern ◽  
Direct Gaze ◽  
Modern View ◽  
Convergence Insufficiency ◽  
Horizontal Type ◽  
Type V ◽  
Gaze Position

Purpose. Create a summary classification of exophoria. To propose an optimal algorithm for optometric and surgical methods of treatment. A modern view of the problem. It is optimal to subdivide exophoria according to the state of the vergent-duction balance into divergence excess, basic exophoria, convergence insufficiency, divergence pseudo-excess, lateral gaze incomitance. By the degree of compensation for compensated, subcompensated, uncompensated, decompensated. In combination with alphabetic pattern for exophoria without pattern, exophoria in combination with horizontal type A pattern, exophoria in combination with vertical type A pattern, exophoria in combination with horizontal type V pattern, exophoria in combination with vertical type V pattern. Features of optimal optical and prismatic correction depend on the state of the vergent-duction balance. In cases of exophoria without pattern surgical treatment is carried out during the transition from a state of subcompensation to non-compensation. In case of exophoria with horizontal-type alphabetical pattern, combined horizontal-transpositional surgery is optimal: elimination of exophoria, the protocol is based on the amount of deviation in the direct gaze position; elimination of the pattern, the protocol is based on vertical transposition of muscles of horizontal action. In cases of exophoria with vertical-type pattern, it is necessary to perform staged vertical-horizontal surgery: stage 1 – elimination of vertical heterotropy in adduction; stage 2 – elimination of exophoria (the protocol is based on the amount of deviation in the direct gaze position). Conclusions. The treatment protocol should be based on a reliably diagnosed diagnosis and consists at the pre-surgical stage in the optimal optical and prismatic correction, the appointment of orthopto-diplopto-prismatic treatment. The effectiveness of treatment is assessed by the dynamics of the disease: the magnitude of exodeviation and the stage of compensation. The protocol of surgical treatment must be reasonable and timely. Key words: exophoria, divergence excess, convergence insufficiency, basic exotropia, lateral gaze incomitance, alphabet pattern.

Detection of parathyroid adenomas with 4DCT: Towards a true four-dimensional technique

2021 ◽  
Author(s):  
Steven Raeymaeckers ◽  
Yannick De Brucker ◽  
Tim Vanderhasselt ◽  
Nico Buls ◽  
Johan De Mey
Keyword(s):  
Primary Hyperparathyroidism ◽  
Thyroid Tissue ◽  
Motion Artifacts ◽  
P Value ◽  
Normal Thyroid Tissue ◽  
Dose Length Product ◽  
Normal Thyroid ◽  
Parathyroid Adenomas ◽  
Parathyroid Lesions ◽  
Over Time

Abstract Background. 4DCT is a commonly performed examination in the management of primary hyperparathyroidism, combining three-dimensional imaging with enhancement over time as the fourth dimension. We propose a novel technique consisting of 16 different contrast phases, instead of three or four different phases. The main aim of this study was to see if this protocol allows for the detection of parathyroid adenomas within dose limits. Our secondary aim was examining the enhancement of parathyroid lesions over time.Methods. For this prospective study, we included 15 patients with primary hyperparathyroidism prior to surgery. We obtain a 4DCT with 16 different phases: an unenhanced phase followed by 11 consecutive arterial phases and 4 venous phases. Centered on the thyroid, continuous axial scanning is performed over a fixed 8cm or 16cm coverage volume after start of contrast administration.Results. In all patients an enlarged parathyroid can be demonstrated, mean lesion size is 13.6mm. Mean peak arterial peak enhancement for parathyroid lesions is 384 HU compared to 333 HU for the normal thyroid. No statistical difference could be found. Time to peak (TTP) is significantly earlier for parathyroid adenomas compared to normal thyroid tissue: 30.8s versus 32.3s (p value 0.008). Mean Slope of Increase (MSI) of the enhancement curve is significantly steeper compared to normal thyroid tissue: 29.8% versus 22.2% (p value 0.012). Mean dose length product was 890.7 mGy.cm with a calculated effective dose of 6.7 mSv.Conclusion. We propose a feasible 4DCT scanning-protocol for the detection of parathyroid adenomas. We manage to obtain a multitude of phases, allowing for a dynamic evaluation within an acceptable exposure range when compared to classic helical 4DCT. Our 4DCT protocol may allow for a better visualization of the pattern of enhancement of parathyroid lesions, as enhancement over time curves can be drawn. This way wash-in and wash-out of contrast in suspected lesions can be readily demonstrated. Motion artifacts are less problematic as multiple phases are available.

Sign in / Sign up

Export Citation Format

Share Document