Performance Of Imaging Studies Research Articles

Performance of imaging studies in patients with suspected appendicitis after stratification with adult appendicitis score

BackgroundDiagnostic scoring is used to stratify patients with suspected appendicitis into three groups: high, intermediate, and low probability of appendicitis. The stratification can be used for selective imaging to avoid the harms of radiation without compromising diagnostic accuracy.The aim was to study how stratification by Adult Appendicitis Score affects diagnostic performance of imaging studies.MethodsAnalysis of 822 patients who underwent diagnostic imaging for suspected appendicitis was made. Adult Appendicitis Score was used to stratify patients into groups of high, intermediate, and low probability of appendicitis. Diagnostic performance of computed tomography (CT) and ultrasound (US) was compared between these patient groups.ResultsAfter scoring, pre-test probability of appendicitis ranged from 9-16% in low probability group to 75-79% in high probability group in patients who underwent US or CT. Post-test probability of appendicitis after positive CT was 99, 91, and 75% in high probability, intermediate probability and low probability groups, respectively, p < 0.001. After positive US the respective probabilities were 95, 91 and 42%, p < 0.001.ConclusionDiagnostic imaging has limited value in patients with low probability of appendicitis according to Adult Appendicitis Score.

Tumors Involving Skin, Soft Tissue and Skeletal Muscle: Benign, Primary Malignant or Metastatic?

Metastatic cancer with invasion of skin, soft tissue and skeletal muscle is not common. Examples presenting as soft tissue masses could sometimes lead to misdiagnosis with delayed or inappropriate management. The purpose of current study was to investigate clinical characteristics in the involvement of metastatic cancer. A total of 1,097 patients complaining of skin or soft tissue masses and/or lesions were retrospectively reviewed from January 2012 to June 2013. Tumors involving skin, soft tissue and skeletal muscle of head and neck, chest wall, abdominal wall, pelvic region, back, upper and lower extremities were included in the study. Fifty-seven (5.2%) patients were recognized as having malignancies on histopathological examination. The most common involvement of malignancy was basal cell carcinoma, followed by cutaneous squamous cell carcinoma, sarcoma and melanoma. The most common anatomical location in skin and soft tissue malignancies was head and neck (52.6% of the malignancies). Four (0.36%) of the malignant group were identified as metastatic cancer with the primary cancer source from lung, liver and tonsil and the most common site was upper extremities. One of them unexpectedly expired during the operation of metastatic tumor excision at the scalp. Discrimination between benign and malignant soft tissue tumors is crucial. Performance of imaging study could assist in the differential diagnosis and the pre-operative risk evaluation of metastatic tumors involving skin, soft tissue and skeletal muscle.

Effect of Labeling Density and Time Post Labeling on Quality of Antibody-Based Super Resolution Microscopy Images.

Super resolution microscopy (SRM) has overcome the historic spatial resolution limit of light microscopy, enabling fluorescence visualization of intracellular structures and multi-protein complexes at the nanometer scale. Using single-molecule localization microscopy, the precise location of a stochastically activated population of photoswitchable fluorophores is determined during the collection of many images to form a single image with resolution of ~10-20 nm, an order of magnitude improvement over conventional microscopy. One of the key factors in achieving such resolution with single-molecule SRM is the ability to accurately locate each fluorophore while it emits photons. Image quality is also related to appropriate labeling density of the entity of interest within the sample. While ease of detection improves as entities are labeled with more fluorophores and have increased fluorescence signal, there is potential to reduce localization precision, and hence resolution, with an increased number of fluorophores that are on at the same time in the same relative vicinity. In the current work, fixed microtubules were antibody labeled using secondary antibodies prepared with a range of Alexa Fluor 647 conjugation ratios to compare image quality of microtubules to the fluorophore labeling density. It was found that image quality changed with both the fluorophore labeling density and time between completion of labeling and performance of imaging study, with certain fluorophore to protein ratios giving optimal imaging results.

Imaging of Oncologic Emergencies: What Every Radiologist Should Know

Acute life-threatening conditions in oncology patients may develop either because of underlying malignancy or as a complication from treatment. Oncologic emergencies can be categorized as metabolic, hematologic, and structural conditions. Metabolic and hematologic emergencies are mainly diagnosed on the basis of clinical and laboratory findings. Structural pathologic conditions that result in bleeding, mechanical compression, or obstruction to the hollow organs, such as the trachea and bowel loops, may first be suspected because of clinical findings, including decreasing hematocrit levels, difficulty in breathing, and abdominal pain; however, performance of imaging studies is critical for timely diagnosis and management. Life-threatening conditions of the central nervous system (such as cerebral herniation, carcinomatous meningitis, and spinal cord compression), thoracic emergent conditions (such as central airway obstruction, esophagorespiratory fistula, massive hemoptysis, pulmonary embolism, superior vena cava syndrome, and pericardial tamponade), and abdominopelvic emergencies (such as uncontrolled intraabdominal hemorrhage, bowel obstruction, intestinal perforation, bowel ischemia, intussusception, and urinary tract obstruction) can be definitively diagnosed on the basis of projectional or cross-sectional imaging findings in appropriate clinical scenarios. Select emergent conditions in cancer patients related to chemotherapy and radiation treatment, as well as iatrogenic emergencies secondary to either surgery or placement of central venous catheters, may also demonstrate characteristic findings at imaging studies. In addition, interventional procedures are of great help in the treatment of acute superior vena cava syndrome, massive hemoptysis, and uncontrolled intraabdominal hemorrhage. Radiologists should be aware of these select, "not to be missed" imaging findings of oncologic emergencies to make an accurate, timely diagnosis and provide appropriate patient care.

Rhinosinusitis in autologous and allogeneic bone marrow transplantation: a retrospective study on the performance of imaging studies on severity and prognostic evaluation

The objective of this work was to evaluate the diagnostic and prognostic performance of a traditional imaging staging system for rhinosinusitis in the bone marrow transplantation (BMT) scenario. A retrospective cohort study was carried out at a bone marrow transplantation referral center involving subjects who underwent allogeneic or autologous BMT from September 1st 2005 to September 31st 2007 and later evolved with rhinosinusitis during the BMT inpatient period. Patients who had a previous history of sinusal disease or otolaryngologic surgery were excluded from the study. Data concerning mortality, the treatment of rhinosinusitis and BMT outcomes were extracted from medical files. The collected parameters were compared to the Lund-Mackay tomographic staging system score which was calculated based on available tomography films of each patient. A total of 85 BMT were performed and 23 allogeneic and 14 autologous (43.5%) BMT patients evolved with rhinosinusitis during transplantation. A significant association with LMS was found for the absolute neutrophil count (ANC), with a higher ANC (>500/mm3) correlating with a higher LMS (Mean LMS for lower ANC 6.08 and higher ANC 9.71 points, p<0.05). Need for surgical management and post-BMT admissions, the resolution of the rhinosinusitis and overall mortality had no significant correlation with LMS. Patients with less than 500 neutrophils/mm3 are known to be prone to more severe infections, but paradoxically showed lower LMS when developing rhinosinusitis. However, there were no differences in the main outcomes between those with higher and lower LMS. This would possibly lead to an equivocal assumption of a less severe disease. Severely neutropenic patients are probably not able to mount an effective inflammatory response capable of inducing significant tomographic abnormalities. So, this imaging study would not be able to adequately evaluate the extent of sinusal involvement. We thus conclude that LMS is not an adequate staging system to evaluate the severity of BMT sinusal disease. Rev. Bras. Hematol. Hemoter.

Reoperative parathyroid surgery

Reoperative parathyroid surgery can be technically challenging and exposes the patient to a higher risk of complications than initial parathyroidectomy. Initial surgical failure can be avoided by thorough, bilateral exploration by an experienced parathyroid surgeon or by the use of intraoperative parathyroid hormone (PTH) monitoring if a limited exploration is planned. Before undertaking a reoperation for hyperparathyroidism the patient must be fully reevaluated including a reassessment of the need for surgery, a review of all previous surgical and pathology reports, and the performance of imaging studies to identify the location of the missing gland. An understanding of parathyroid embryology and anatomy helps identify possible locations of missing glands. The specific surgical approach is dictated by the anticipated location of the abnormal gland. Intraoperative PTH monitoring can limit the extent of reoperative surgery. Recurrent laryngeal nerve monitoring can help decrease the risk of complications.