Assessment of low-dose paranasal sinus CT imaging using a new deep learning image reconstruction technique in children compared to adaptive statistical iterative reconstruction V (ASiR-V).

PURPOSE: To compare the effects of deep learning image reconstruction (DLIR) and adaptive statistical iterative reconstruction V (ASiR-V) on image quality in low-dose computed tomography (CT) of paranasal sinuses in children. METHODS: Low-dose CT scans of the paranasal sinuses in 25 pediatric patients were retrospectively evaluated. The raw data were reconstructed with three levels of DLIR (high, H; medium, M; and low, L), filtered back projection (FBP), and ASiR-V (30% and 50%). Image noise was measured in both soft tissue and bone windows, and the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of the images were calculated. Subjective image quality at the ethmoid sinus and nasal cavity levels of the six groups of reconstructed images was assessed by two doctors using a five-point Likert scale in a double-blind manner. RESULTS: The patients' mean dose-length product and effective dose were 36.65 ± 2.44 mGy·cm and 0.17 ± 0.03 mSv, respectively. (1) Objective evaluation: 1. Soft tissue window: The difference among groups in each parameter was significant (P < 0.05). Pairwise comparisons showed that the H group' s parameters were significantly better (P < 0.05) than those of the 50% post-ASiR-V group. 2. Bone window: No significant between-group differences were found in the noise of the petrous portion of the temporal bone or its SNR or in the noise of the pterygoid processes of the sphenoids or their SNRs (P > 0.05). Significant differences were observed in the background noise and CNR (P < 0.05). As the DLIR intensity increased, image noise decreased and the CNR improved. The H group exhibited the best image quality. (2) Subjective evaluation: Scores for images of the ethmoid sinuses were not significantly different among groups (P > 0.05). Scores for images of the nasal cavity were significantly different among groups (P < 0.05) and were ranked in descending order as follows: H, M, L, 50% post-ASiR-V, 30% post-ASiR-V, and FBP. CONCLUSION: DLIR was superior to FBP and post-ASiR-V in low-dose CT scans of pediatric paranasal sinuses. At high intensity (H), DLIR provided the best reconstruction effects.

[Release of gastrocnemius aponeurosis and suture of the Achilles tendon end scar tissue managing the chronic Achilles tendon rupture].

OBJECTIVE: To investigate the clinical effect of scar tissue suture at the broken end of Achilles tendon after gastrocnemius aponeurosis release in the treatment of chronic Achilles tendon rupture. METHODS: The clinical data of 17 patients with old achilles tendon rupture treated from January 2017 to December 2019 were analyzed retrospectively, including 15 males and 2 females, aged 26 to 53 years with an average of (35.2±11.6) years old, and the time from injury to operation was 37 to 92 days with an average of (49.3±13.3) days. Myerson's classification included 6 cases of typeⅡ and 11 cases of typeⅢ. The defect of the broken end of Achilles tendon was 2 to 5 cm with an average of(4.1±1.5) cm after partial scar tissue was removed. All patients were treated with gastrocnemius aponeurosis, appropriate excision of scar tissue at the broken end of Achilles tendon and direct suture. The continuity and healing of Achilles tendon were evaluated by color Doppler ultrasound 3 months after operation. The ankle plantar flexor strength was measured by ankle plantar flexor strength tester before operation and 1 year after operation. American Orthopaedic Foot and Ankle Society ankle hindfoot score (AOFAS) and Achilles tendon rupture score were used before operation and 1 year after operation Achilles tendon total fracture score (ATRS) was used to evaluate the clinical rehabilitation of Achilles tendon rupture. RESULTS: All patients were followed up for 12 to 18 months with an average of(13.6±1.8) months. The surgical incision healed in stageⅠ. Color Doppler ultrasound showed good continuity of Achilles tendon, local Achilles tendon slightly thickened and irregular fiber direction. The ankle plantar flexor force (92.2±3.9) N at 1 year after operation was significantly higher than that before operation (29.5±4.2) N (P<0.05);One year after operation, the AOFAS(91.20±3.30) was significantly higher than that before operation (42.20±4.40)(P<0.05);the ATRS (90.70±3.00) was significantly higher than that before operation(40.00±2.90)(P<0.05). CONCLUSION: The gastrocnemius aponeurosis release combined with scar suture of Achilles tendon end is an effective technique for the treatment of chronic Achilles tendon rupture, avoid injury to hallux flexor longus or flexor digitorum longus, with the plantar flexor muscle strength of the ankle was recovered well, is an effective method to treat chronic Achilles tendon rupture.

Brain magnetic resonance imaging findings and radiologic review of maple syrup urine disease: Report of three cases.

BACKGROUND: Maple syrup urine disease (MSUD) is a rare autosomal-recessive disorder that affects branched-chain amino acid (BCAA) metabolism and is named after the distinctive sweet odor of affected infants' urine. This disease is characterized by the accumulation of BCAAs and corresponding branched-chain ketoacids of leucine, isoleucine, and valine in the plasma, urine, and cerebrospinal fluid. However, the mechanisms of MSUD-induced brain damage remain poorly defined. The accumulation of BCAAs in the brain inhibits the activity of pyruvate dehydrogenase and α-ketoglutarate, disrupting the citric acid cycle and consequently impacting the synthesis of amino acids, causing cerebral edema and abnormal myelination. CASE SUMMARY: We report three neonates admitted to our hospital with the classic subtype of MSUD. All three patients, with a transient normal period, presented with poor feeding, vomiting, poor weight gain, and increasing lethargy after birth. Laboratory testing revealed metabolic acidosis. The serum tandem mass spectrometry amino acid profile showed elevated plasma levels of BCAAs (leucine, isoleucine, and valine). Brain magnetic resonance imaging (MRI) presented abnormal signals mainly involving the globus pallidus, thalamus, internal capsule, brainstem, and cerebellar white matter, which represent the typical myelinated areas in normal full-term neonates. CONCLUSION: In our patients, MRI showed typical features, in concordance with the available literature. Early detection and timely treatment are very helpful for the prognosis of MSUD patients. Therefore, we discuss the neuroimaging features of MSUD to enhance the knowledge of pediatricians about this disease.

Imaging manifestations of congenital mesoblastic nephroma.

OBJECTIVE: Congenital mesoblastic nephroma (CMN) is a rare renal tumor mainly observed in infants and young children. This study aims to analyze the imaging manifestations of CMN to improve the understanding of the disease. METHODS: The imaging manifestations and clinical records of all pediatric patients with CMN admitted to our hospital over the last 7 years were retrospectively analyzed. The diagnosis of CMN was confirmed by postoperative pathology. All patients underwent computed tomography (CT) scans; 2 patients additionally underwent magnetic resonance imaging (MRI) scans (including one prenatal MRI scan). RESULTS: We evaluated 10 pediatric patients (6 males and 4 females) aged 7 days to 12 months (median age: 4 months) with CMN located on the left kidney in six cases and the right kidney in four cases. The CT imaging manifested as solid lesions (5 cases), solid-cystic lesions with solid predominance (4 cases), or solid-multicystic lesions with cystic predominance (1 case). Enhanced CT showed moderately and heterogeneously enhanced solid component and intracystic septations at the corticomedullary phase that were further enhanced at the nephrographic phase, although their CT values were still lower than those of the renal parenchyma. The "double-layer sign" were seen in 4 cases of classic type of CMN, and the "intratumor pelvis sign" were seen in 9 cases that include 5 classic, 3 cellular and 1 mixed type of CMN. In the 2 patients who underwent MRI, the scans showed solitary masses. The lesions had hypointense signals on the T1WI sequence and isointensity or slightly lower-intensity signals than the surrounding renal parenchyma on the fluid-sensitive sequences, whereas the lesions showed hyperintense signals on the diffusion-weighted imaging (DWI) sequence. CONCLUSIONS: The imaging manifestations of CMN are closely correlated with the pathological subtype and have certain characteristics. The "double-layer sign" was seen with most classic type CMN, and "intratumor pelvis sign" was seen in 90% cases.

Prolonged viral shedding in feces of pediatric patients with coronavirus disease 2019.

OBJECTIVE: To determine the dynamic changes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory and fecal specimens in children with coronavirus disease 2019 (COVID-19). METHODS: From January 17, 2020 to February 23, 2020, three paediatric cases of COVID-19 were reported in Qingdao, Shandong Province, China. Epidemiological, clinical, laboratory, and radiological characteristics and treatment data were collected. Patients were followed up to March 10, 2020, and dynamic profiles of nucleic acid testing results in throat swabs and fecal specimens were closely monitored. RESULTS: Clearance of SARS-CoV-2 in respiratory tract occurred within two weeks after abatement of fever, whereas viral RNA remained detectable in stools of pediatric patients for longer than 4 weeks. Two children had fecal SARS-CoV-2 undetectable 20 days after throat swabs showing negative, while that of another child lagged behind for 8 days. CONCLUSIONS: SARS-CoV-2 may exist in children's gastrointestinal tract for a longer time than respiratory system. Persistent shedding of SARS-CoV-2 in stools of infected children raises the possibility that the virus might be transmitted through contaminated fomites. Massive efforts should be made at all levels to prevent spreading of the infection among children after reopening of kindergartens and schools.

New insights into the fungal community from the raw genomic sequence data of fig wasp Ceratosolen solmsi.

BACKGROUND: To date, biologists have discovered a large amount of valuable information from assembled genomes, but the abundant microbial data that is hidden in the raw genomic sequence data of plants and animals is usually ignored. In this study, the richness and composition of fungal community were determined in the raw genomic sequence data of Ceratosolen solmsi (RGSD-CS). RESULTS: To avoid the interference from sequences of C. solmsi, the unmapped raw data (about 17.1%) was obtained by excluding the assembled genome of C. solmsi from RGSD-CS. Comparing two fungal reference datasets, internal transcribed spacer (ITS) and large ribosomal subunit (LSU) of rRNA, the ITS dataset discovered a more diverse fungal community and was therefore selected as the reference dataset for evaluating the fungal community based on the unmapped raw data. The threshold of 95% sequence identity revealed many more matched fungal reads and fungal richness in the unmapped raw data than those by identities above 95%. Based on the threshold of 95% sequence identity, the fungal community of RGSD-CS was primarily composed of Saccharomycetes (88.4%) and two other classes (Agaricomycetes and Sordariomycetes, 8.3% in total). Compared with the fungal community of other reported fig wasps, Agaricomycetes and Eurotiomycetes were found to be unique to C. solmsi. In addition, the ratio of total fungal reads to RGSD-CS was estimated to be at least 4.8 × 10(-3), which indicated that a large amount of fungal data was contained in RGSD-CS. However, rarefaction measure indicated that a deeper sequencing coverage with RGSD-CS was required to discover the entire fungal community of C. solmsi. CONCLUSION: This study investigated the richness and composition of fungal community in RGSD-CS and provided new insights into the efficient study of microbial diversity using raw genomic sequence data.

Isolated lymphoma of the optic nerve, chiasm and tract: A case report.

The current study reports the case of a 68-year-old, previously healthy female who presented with progressive visual impairment leading to blindness bilaterally. Brain imaging features were suggestive of malignant glioma of the anterior visual pathway. Postoperative examination indicated a diagnosis of diffuse malignant lymphoma type B. As no evidence of extracranial lymphoma was observed, the final diagnosis was primary central nervous system lymphoma (PCNSL). Following treatment with surgery and radiotherapy, the patient's symptoms went into remission. At a follow-up examination 12 months after diagnosis, the patient demonstrated no evidence of recurrence. To the best of our knowledge, PCNSL isolated to the optic chiasm has been reported only three times in immunocompetent patients. Therefore, the present case of the lymphoma involving the optic nerve, optic chiasm and optic tract in an immunocompetent patient is unusual. The present case emphasizes the importance of considering the diagnosis of lymphoma in this setting.