PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2643142

Normal thymus in infancy: sonographic characteristics.

B K Han·D S Babcock·A E Oestreich
View original source ↗Export metadata ↓

Abstract

A prospective sonographic study of the normal thymus in 56 infants was performed to determine the shape, extent, and echogenicity of normal thymic tissue. The thymus had either a triangular or teardrop shape on longitudinal scans and a trapezoidal or bilobate shape on transverse scans. Typically, the thymus was located anterior to the great vessels and extended down to the upper portion of the heart (in one infant, to the diaphragm). It extended up into the lower cervical area in five infants. The great vessels--including the superior vena cava, aorta, and the pulmonary artery--were well imaged through the thymus. In six infants the thymus encircled the left innominate vein. The echogenicity of the thymus was homogeneous, similar to that of the liver and spleen. The intensity of thymic echogenicity was less than that of the liver, spleen, and thyroid gland. This study demonstrates that the thymus has a characteristic sonographic appearance and can be easily identified.

Explore related subjects

Child, PreschoolFemaleHumansInfantInfant, NewbornMaleReference ValuesThymus GlandUltrasonographyCase ReportsJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B K Han, D S Babcock, A E Oestreich. 1989. Normal thymus in infancy: sonographic characteristics.. https://doi.org/10.1148/radiology.170.2.2643142

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Safety of a quadrivalent meningococcal conjugate vaccine (MenACYW-TT) administered concomitantly with routine pediatric vaccines in healthy infants and toddlers in USA and Puerto Rico: Results from a Phase III, randomized, active-controlled study.

MenACYW-TT, a quadrivalent meningococcal tetanus toxoid-conjugate vaccine, is approved for prevention of invasive meningococcal disease in infants ≥ 6 weeks of age in the USA. This Phase III study (NCT03673462; September 17, 2018 - March 16, 2023) evaluated the safety of MenACYW-TT compared with a licensed quadrivalent meningococcal oligosaccharide diphtheria CRM197-conjugate vaccine (MenACWY-CRM) when administered concomitantly with routine pediatric vaccines in healthy infants and toddlers in a four-dose series (3+1 schedule). Participants were randomized 3:1 to receive MenACYW-TT (Group 1; n = 2080) or MenACWY-CRM (Group 2; n = 697) at 2, 4, 6, and 12 months of age, with concomitant administration of routine pediatric vaccines (DTaP5-IPV/Hib, PCV13, rotavirus, hepatitis B, MMR, and varicella vaccines). Safety assessments included immediate unsolicited adverse events within 30 minutes post-vaccination, solicited injection site and systemic reactions within 7d, unsolicited AEs within 30d, serious adverse events (SAEs) including adverse events of special interest (AESIs), and medically attended adverse events (MAAEs) throughout the study. MenACYW-TT and MenACWY-CRM were overall well tolerated, and safety profiles were comparable. Solicited injection site reactions occurred in 84.9% and 84.6% of participants in Groups 1 and 2, respectively; solicited systemic reactions in 87.1% and 88.2%, respectively. During the entire study, 5.2% in Group 1 and 3.0% in Group 2 experienced at least one SAE; 0.9% and 0.1%, respectively, reported at least one AESI. Three deaths occurred in Group 1. All SAEs, AESIs, and deaths were unrelated to study vaccines. This study supports the safety profile of MenACYW-TT in infants and toddlers aged ≥ 6 weeks.Study registration: Clinicaltrials.gov: NCT03673462; EudraCT: 2019-004459-35.

Child, Preschool↗
PubMed2026

Two new cases of fragile X syndrome without CGG triplet expansion. Clinical-molecular characterization and review of the literature.

Fragile X syndrome (FXS) is classically caused by CGG repeat expansion in the FMR1 gene leading to gene silencing. We describe two unrelated patients with clinical features consistent with FXS but harbouring distinct molecular mechanisms. The first patient had a pathogenic intronic variant in FMR1, predicted to impair protein function, and no repeat expansion. The second patient carried a complete deletion of the FMR1 gene, resulting in loss of gene expression. Both individuals presented with developmental delay, intellectual disability, and behavioural manifestations typical of FXS. These cases expand the causal heterogeneity underlying a clinically recognizable phenotype. They reinforce the concept that comprehensive molecular testing beyond repeat expansion analysis is mandatory in individuals with a strong clinical suspicion of FXS, in absence of a typical CGG triplet expansion.

Child, Preschool↗
PubMed2026

Unveiling clinical and genetic landscapes of MMA and CBS: insights from whole exome sequencing in a tertiary care setting.

BACKGROUND: MMA and CBS deficiency are rare autosomal recessive metabolic disorders caused by defects in cobalamin metabolism and cystathionine-beta-synthase activity, respectively. Advanced molecular genetic techniques, have become essential for diagnosing these conditions. This study aimed to analyze the genetic variations in three MMA and four CBS deficiency cases using WES and correlate the findings with clinical, biochemical, and treatment outcomes. METHODS: Clinical evaluation, biochemical testing, neuroimaging, and WES were performed. WES data were analyzed using the reference genome GRCh37, and variants were classified according to ACMG guidelines. Treatment outcomes were monitored for three months post-intervention. RESULTS: In MMA cases, a homozygous pathogenic variant (c.394 C > T, p.Arg132Ter) in MMACHC was identified in all three patients. Biochemical abnormalities included methylmalonic aciduria, elevated homocysteine, and megaloblastic anemia. Hydroxycobalamin therapy improved behavioral, cognitive, and dermatological symptoms, though residual neuropathy persisted in one case. In CBS deficiency, pathogenic variants in CBS (c.992 C > T, p.Ala331Val; c.862 G > A, p.Ala288Thr; c.700 G > A, p.Asp234Asn) were identified. Clinical features included developmental delayed milestones, lens dislocation, and vascular complications. Treatment outcomes varied based on early diagnosis and compliance. CONCLUSION: This study highlights the importance of newborn screening program with WES in diagnosing and managing MMA and CBS deficiency, facilitating early intervention, improving clinical outcomes, and supporting precision medicine approaches. IMPACT: Early newborn screening and diagnosis are critical for effective treatment and improved patient outcomes. Novel clinical and pathogenic variants will expand the current understanding of these disorders. WES enhances the diagnostic precision for MMA and CBS deficiency, facilitating timely intervention and superior clinical management. Accurate and early detection of treatable IEMs through NBS can significantly reduce disease burden and healthcare costs.

Child, Preschool↗