Incidental findings in the skeletal musculature on computed tomography.

OBJECTIVE: The purpose of this study was to analyze intramuscular incidental findings identified on CT in a large patient cohort. METHODS: In the time period from 2010 to 2015, a total of 44,794 patients with several diagnoses were investigated by CT. Only those patients who underwent body CT including the neck, thorax, abdomen and pelvic regions after the i.v. application of a contrast medium were involved in the study. There were 4085 patients. On further analysis, only patients with intramuscular findings (IFs) incidentally detected on CT were included. Osseous or soft-tissue lesions with invasion into the musculature were excluded from the study. Patients with known or clinically suspicious muscle disorders were also excluded. Overall, 639 (15.64% of the 4085 analyzed cases) patients, 253 females and 386 males, with mean age 72.43 ± 12.02 years, were identified. Collected data were evaluated by means of descriptive statistics. RESULTS: In the 639 patients, 917 IFs were identified. More often, several benign disorders were diagnosed (n = 803, 87.6%). There were hernias (33.5%), atrophy of different muscles (22%), lipomas (21%), intramuscular calcifications (8.7%), bursitis (1.2%) and intramuscular bleeding (1.1%). Malignant IFs (n = 114, 12.4%) included intramuscular metastases (11.9%) and lymphomas (0.6%). Most frequently, the identified IFs were localized in the abdominal wall musculature, paravertebral and gluteal muscles. In 657 cases (71.6% of all IFs), the identified muscle findings were not diagnosed by the radiologist who initially assessed the investigation. CONCLUSION: CT can detect different incidental disorders within the skeletal musculature. Most of them were benign. However, malignant lesions can also occur. Therefore, skeletal muscles should be carefully evaluated on CT performed for other reasons. Advances in knowledge: IFs occur in 15.6% of CT investigations. Benign findings represent 87.6% and malignant lesions can be identified in 12.4%.

Radiological findings on irradiation-CT in patients with non metastatic breast cancer.

OBJECTIVE: The aim of this study was to evaluate the number of incidental findings on native CT treatment-planning scans for radiation in breast cancer patients. METHODS: The treatment-planning scans of 382 patients with non-metastatic breast cancer were retrospectively analyzed for additional findings. The planning scan area covered the entire thorax and the upper part of the abdomen. Incidental findings were classified according to their clinical relevance. RESULTS: Overall 892 incidental findings were detected in the CT treatment-planning scans (mean 2.34 findings per patient). Only a small proportion of patients (n = 63, 16.4%) had no finding. Most findings were located in the thorax (683, 76.57%), and 209 findings (23.43%) were abdominal. 79 findings (8.87%) were of major clinical relevance, 232 findings (26.01%) were of moderate clinical relevance and 580 findings (65.02%) were of minor clinical relevance. Most clinically relevant findings were in the thorax (p = 0.006). Abdominal findings were more of significantly minor clinical relevance (p < 0.0001). CONCLUSION: Radiological findings are frequent in native CT treatment-planning scans for radiation of breast cancer patients. Therefore, the radiologist should use this performed sectional image to obtain additional information of the patient. Advances in knowledge: Treatment-planning CT scans can show several radiological findings, namely 2.34 findings per patient. Major clinically relevant findings account for 8.87%.

The frequency of incidental pulmonary embolism in different CT examinations.

OBJECTIVE: Pulmonary embolism (PE) is commonly found in patients with oncologic and non-oncologic disease. The aim of the present study is to assess how frequently suspected, incidental and unreported PE occurs in particular CT examinations. In addition, differences in embolus distribution are to be considered. METHODS: In a retrospective, single-centre study that covered a 5.5-year period, every contrast-enhanced CT examination was reviewed. The study group included 7238 patients with 11,747 CT examinations. A detailed pulmonary artery obstruction index (Mastora score) was used to assess thrombus mass and distribution. RESULTS: PE frequency was 3.9% in oncologic patients and 6.6% in non-oncologic patients. PE was unsuspected in 54% of all PE events. Incidental PE was mostly often found in the following CT examinations: evaluation of acute pulmonary disease and follow-up staging. The thrombus mass was higher in non-oncologic patients than in oncologic patients. Furthermore, the thrombus mass was significantly lower in unsuspected PE than in suspected PE. In addition, the thrombus mass was significantly lower in unreported PE than in incidental PE. CONCLUSION: The radiologist should pay special attention to pulmonary vessels, even when not asked for PE, in the following CT examinations: evaluation of acute pulmonary disease and follow-up staging. ADVANCES IN KNOWLEDGE: Particular CT indications are associated with a high frequency of PE. Whether PE is suspected or not and found or not highly depends on thrombus mass.

Costs associated with evaluation of incidental breast lesions identified on computed tomography.

OBJECTIVE: The purpose of this study was to calculate the costs associated with the evaluation of breast incidentalomas (BI) identified on CT. METHODS: All CT scans of the thorax performed at the radiological department of the University Hospital of the Martin-Luther-University Halle-Wittenberg between the years 2006 and 2014 were reanalysed retrospectively. 111 patients with BI were identified. The radiological and clinical reports of these cases were examined, and the costs of all further diagnostic procedures performed to clarify the detected BI were calculated. RESULTS: In 31 (27.9%) of the 111 patients, BI were not further investigated. Of the remaining 80 (72.1%) cases of BI, primary breast carcinoma was diagnosed in 10 (12.5%) cases, breast involvement by lymphoma in 7 (8.8%) cases, intramammary metastases in 19 (23.7%) cases and different benign findings in 44 (55.0%) cases. The total costs associated with clarification of BI in our institution (n = 53) amounted to €14,045.71. The costs per BI were €265.01 and per newly identified breast cancer €1560.63. CONCLUSION: Breast lesions incidentally detected on CT should be categorized as major incidental findings because of the high frequency of malignancy. The radiologist should carefully evaluate the breast on CT images and all identified BI should be clarified. The clarification of BI is associated with a low economic burden in comparison with screening programmes for primary breast cancer. ADVANCES IN KNOWLEDGE: The radiologist should carefully evaluate the breast on CT and all identified BI should be clarified. The evaluation of BI is associated with a low economic burden.

Parallel signaling pathways of melatonin in the pancreatic beta-cell.

Previous results demonstrated that melatonin inhibits cAMP production and stimulates IP(3) liberation in rat insulinoma INS1 cells, a model for the pancreatic beta-cell. This study addresses the impact of melatonin on insulin release. Insulin, cAMP and IP(3) levels of INS1 cells in a superfusion system were measured. Initially, forskolin was used to stimulate cAMP and subsequently insulin release. Incubation of forskolin (5 micromol/L)-stimulated cells with melatonin (100 nmol/L) inhibited cAMP and insulin levels (down to 60% of insulin and cAMP release). The G(i)alpha-protein-inhibitor pertussis toxin (PTX) was used to distinguish between the G(i)alpha-dependent cAMP pathway and the G(i)alpha-independent IP(3) pathway. In our experiments we employed a specific stimulation pattern to prove proper inhibition of G(i)alpha-proteins by PTX. In INS1 cells incubated with 250 ng/mL PTX for 24 hr, melatonin was no longer able to inhibit the forskolin-induced cAMP and insulin release. In a study, carbachol was used to stimulate IP(3) and subsequently insulin release. Surprisingly, incubation of carbachol (300 micromol/L)-stimulated cells with melatonin (100 nmol/L) inhibited insulin release (down to 75% of insulin release). Finally, in PTX-incubated INS1 cells, melatonin (100 nmol/L) increased carbachol (300 micromol/L)-induced insulin release (up to 124% of insulin release). In conclusion, we found that the melatonin MT(1)-receptor on pancreatic beta-cells is coupled to parallel signaling pathways, with opposite influences on insulin secretion. The cAMP- and subsequently insulin-inhibiting signaling pathway involves PTX-sensitive G(i)alpha-proteins and is predominant in terms of insulin release.

Melatonin stimulates inositol-1,4,5-trisphosphate and Ca2+ release from INS1 insulinoma cells.

The effects of melatonin in mammalian cells are exerted via specific receptors or are related to its free radical scavenging activity. It has previously been reported that melatonin inhibits insulin secretion in the pancreatic islets of the rat and in rat insulinoma INS1 cells via Gi-protein-coupled MT1 receptors and the cyclic adenosine 3',5'-monophosphate pathway. However, the inositol-1,4,5-trisphosphate (IP3) pathway is involved in the insulin secretory response as well, and the melatonin signal may play a part in its regulation. This paper addresses the involvement of the second messengers IP3 and intracellular Ca2+ ([Ca2+]i) in the signalling cascade of melatonin in the rat insulinoma INS1 cell, a model for the pancreatic beta-cell. For this purpose melatonin at concentrations ranging from 1 to 100 nmol/L, carbachol and the nonselective melatonin receptor antagonist luzindole were used to stimulate INS1 cell batches, followed by an IP3-mass assay and Ca2+ imaging. Molecular biological studies relating to the mRNA of IP3 receptor (IP3R) subtypes and their relative abundance in INS1 cells showed expression of IP3R-1, IP3R-2 and IP3R-3 mRNA. In conclusion, we found that in rat insulinoma INS1 cells there is a dose-dependent stimulation of IP3 release by melatonin, which is accompanied by a likewise transient increase in [Ca2+]i concentrations. The melatonin effect observed mimics carbachol action. It can be abolished by 30 micromol/L luzindole and is sustained in Ca2+-free medium, suggesting a mechanism that includes the depletion of Ca2+ from intracellular stores.