Spectral CT: Current Liver Applications.

Using two different energy levels, dual-energy computed tomography (DECT) allows for material differentiation, improves image quality and iodine conspicuity, and allows researchers the opportunity to determine iodine contrast and radiation dose reduction. Several commercialized platforms with different acquisition techniques are constantly being improved. Furthermore, DECT clinical applications and advantages are continually being reported in a wide range of diseases. We aimed to review the current applications of and challenges in using DECT in the treatment of liver diseases. The greater contrast provided by low-energy reconstructed images and the capability of iodine quantification have been mostly valuable for lesion detection and characterization, accurate staging, treatment response assessment, and thrombi characterization. Material decomposition techniques allow for the non-invasive quantification of fat/iron deposition and fibrosis. Reduced image quality with larger body sizes, cross-vendor and scanner variability, and long reconstruction time are among the limitations of DECT. Promising techniques for improving image quality with lower radiation dose include the deep learning imaging reconstruction method and novel spectral photon-counting computed tomography.

Comparison between Suprapapillary and Transpapillary Uncovered Self-Expandable Metallic Stent Placement for Perihilar Cholangiocarcinoma.

PURPOSE: To compare the effectiveness, adverse events (AEs), stent patency, and patient survival with suprapapillary and transpapillary uncovered self-expandable metallic stent placement for perihilar cholangiocarcinoma. MATERIALS AND METHODS: A single-center retrospective study of 54 patients with inoperable perihilar cholangiocarcinoma who underwent percutaneous transhepatic biliary stent placement between January 1, 2019, and August 31, 2021, was conducted. According to stent location, the patients were classified into 2 groups: suprapapillary (S) and transpapillary (T). Demographic data, Bismuth-Corlette classification, type and location of the stent, laboratory data, postprocedural AEs, procedural success, stent occlusion, reintervention rate, and mortality were compared between the groups. RESULTS: Stent placement was suprapapillary in 13 (24.1%) patients and transpapillary in 41 (75.9%) patients. Mean age was higher in Group T (78 vs 70.5 years; P = .046). Stent occlusion rates were similar in the 2 groups (Group S, 23.8%; Group T, 19.5%), as were AE rates, the most common being cholangitis (Group S, 23.1%; Group T, 24.4%). There were no significant differences in revision rate (Group S, 7.7%; Group T, 12.2%) and 30-day mortality rate (Group S, 15.4%; Group T, 19.5%). Ninety-day mortality rate was statistically significantly higher in Group T (46.3% vs 15.4%; P = .046). Preprocedural bilirubin level was higher in Group T, as were postprocedural leukocyte and C-reactive protein (CRP) levels. CONCLUSIONS: Suprapapillary and transpapillary stent placement procedures were similar in terms of procedural success, occlusion rate, revision rate, postprocedural AEs, and 30-day mortality. Ninety-day mortality rate and postprocedural leukocyte and CRP levels were higher in Group T, although these patients were also older and had higher preprocedural bilirubin levels.

Pros and Cons of Dual-Energy CT Systems: "One Does Not Fit All".

Dual-energy computed tomography (DECT) uses different energy spectrum x-ray beams for differentiating materials with similar attenuation at a certain energy. Compared with single-energy CT, it provides images with better diagnostic performance and a potential reduction of contrast agent and radiation doses. There are different commercially available DECT technologies, with machines that may display two x-ray sources and two detectors, a single source capable of fast switching between two energy levels, a specialized detector capable of acquiring high- and low-energy data sets, and a filter splitting the beam into high- and low-energy beams at the output. Sequential acquisition at different tube voltages is an alternative approach. This narrative review describes the DECT technique using a Q&A format and visual representations. Physical concepts, parameters influencing image quality, postprocessing methods, applicability in daily routine workflow, and radiation considerations are discussed. Differences between scanners are described, regarding design, image quality variabilities, and their advantages and limitations. Additionally, current clinical applications are listed, and future perspectives for spectral CT imaging are addressed. Acknowledging the strengths and weaknesses of different DECT scanners is important, as these could be adapted to each patient, clinical scenario, and financial capability. This technology is undoubtedly valuable and will certainly keep improving.

Evaluation of clinical and functional abnormalities in Pompe disease: Case Report / Avaliação das anomalias clínico-funcionais na doença de Pompe: Relato de Caso

The patient was a 15 year-old girl who turned out at the Physical Therapy Clinic presenting progressiv escoliosis and angle of 50º Coob by X-Ray. She complained of back pain, headache and weakness of shoulder and pelvic girdle. Physical therapy evaluation came across features of delayed motor development and undernourishment, together with generalized muscle weakness (grade = 4) which was observed by the Kendall test. Lung vital capacity was 40.5%. Clinical Changes: studies of the enzymes with acid alpha-glucosidase assay kits used on filter paper and leukocytes showed low enzyme activity, suggesting a late form of the Pompe disease. The molecular studies proved that the patient had amutation associated with late-onset Pompe disease. Acid alpha-glucosidase enzyme assay studies performed in skin fibroblasts showed a reduction of the enzymatic activity of the acid alpha-glucosidase, confirming the previous results. On account of the results, Pompe disease induced important changes inclinical and functional, as well as metabolic changes, decreased strength and muscle action potentially, biomechanical changes in the spine and changes in respiratory capacity. Furthermore, this case of Pompe disease illustrates the importance of adequate physical therapy evaluation as it can be the starting point of investigation of serious conditions such as late onset Pompe disease

Paciente do sexo feminino com 15 anos, apresentou-se na Clínica de Fisioterapia, devido à presença de escoliose progressiva com ângulo de Coob de 50º pelo Raio-X. Apresentou queixa de dor na coluna e na cabeça, fraqueza de cintura escapular e pélvica. Na avaliação fisioterapêutica observou-se um quadro semelhante ao atraso do desenvolvimento motor e desnutrição, com fraqueza muscular generalizada(grau = 4) observada pelo teste de Kendall. Na função pulmonar a capacidade vital apresentou com 40,5%. Estudos enzimáticos com dosagem da alfa-glicosidade ácida em papel-filtro e leucócitos evidenciaram baixa atividade enzimática, sugestivo de forma tardia da doença de Pompe. No estudo molecular, comprovou-se que a paciente possuía mutação associada à forma tardia da doença; estudos enzimáticos da alfa-glicosidase ácida em fibroblastos cultivados a partir de biópsia de pele evidenciaram redução da atividade enzimática da alfa-glicosidase ácida, confirmando estudos enzimáticos prévios. Perante os resultados, a doença de Pompe apresentou alterações clínicas e funcionais importantes como alteração do metabolismo, diminuição de força e do potencial de ação da musculatura, alterações biomecânicas na coluna e na capacidade respiratória. Adicionalmente, o caso ilustra a importância da avaliação fisioterapêutica adequada, pois ele pode ser o ponto de partida da investigação de doenças graves como o presente caso