Gokce Kaan Atac

Incidence of pulmonary embolism during COPD exacerbation

OBJECTIVE: Because pulmonary embolism (PE) and COPD exacerbation have similar presentations and symptoms, PE can be overlooked in COPD patients. Our objective was to determine the prevalence of PE during COPD exacerbation and to describe the clinical aspects in COPD patients diagnosed with PE. METHODS: This was a prospective study conducted at a university hospital in the city of Ankara, Turkey. We included all COPD patients who were hospitalized due to acute exacerbation of COPD between May of 2011 and May of 2013. All patients underwent clinical risk assessment, arterial blood gas analysis, chest CT angiography, and Doppler ultrasonography of the lower extremities. In addition, we measured D-dimer levels and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels. RESULTS: We included 172 patients with COPD. The prevalence of PE was 29.1%. The patients with pleuritic chest pain, lower limb asymmetry, and high NT-pro-BNP levels were more likely to develop PE, as were those who were obese or immobile. Obesity and lower limb asymmetry were independent predictors of PE during COPD exacerbation (OR = 4.97; 95% CI, 1.775-13.931 and OR = 2.329; 95% CI, 1.127-7.105, respectively). CONCLUSIONS: The prevalence of PE in patients with COPD exacerbation was higher than expected. The association between PE and COPD exacerbation should be considered, especially in patients who are immobile or obese.

Should the cut-off value of D-dimer be elevated to exclude pulmonary embolism in acute exacerbation of COPD?

OBJECTIVE The aim of this study was to evaluate the D-dimer levels in patients with chronic obstructive pulmonary disease (COPD) exacerbation with and without pulmonary embolism (PE) and to attempt to define a new cut-off value for D-dimer to exclude the diagnosis of PE in patients with COPD exacerbation. METHODS This cross-sectional study was performed between the June 2012 and January 2013. The COPD patients who were admitted to the emergency department with acute exacerbation were consecutively included. D-dimer levels were measured upon admission. All patients underwent computed tomography angiography (CTA) and Doppler ultrasonography (US) of the lower extremities. RESULTS A total of 148 patients were enrolled. Fifty-three patients (36%) who did not have PE had higher than normal (>0.5 pg/mL) D-dimer levels. The D-dimer levels of the COPD patients with PE were significantly higher than those of the patients without PE (2.38±2.80 vs. 1.06±1.51 pg/mL) (P<0.001). The cut-off value for D-dimer in diagnosing PE in the COPD patients was 0.95 pg/mL. The area under the receiver operating characteristic (ROC) curve was 0.752±0.040 (95% CI: 0.672-0.831) (P<0.001). CONCLUSIONS This study showed that the D-dimer concentrations of COPD patients who are in the exacerbation period may be higher than normal, even without PE. The cut-off level for D-dimer was 0.95 pg/mL (sensitivity 70%, spesificity 71%) for the exclusion of PE in the patients with COPD exacerbation. The D-dimer cut-off value that is used to exclude PE in patients with acute exacerbation of COPD should be reevaluated to prevent the excessive use of further diagnostic procedures.

Quantative computerized tomography assessment of lung density as a predictor of postoperative pulmonary morbidity in patients with lung cancer

BACKGROUND The aim of this study was to evaluate the pulmonary reserve of the patients via preoperative quantitative computerized tomography (CT) and to determine if these preoperative quantitative measurements could predict the postoperative pulmonary morbidity. METHODS Fifty patients with lung cancer who underwent lobectomy/segmentectomy were included in the study. Preoperative quantitative CT scans and pulmonary function tests data were evaluated retrospectively. We compare these measurements with postoperative morbidity. RESULTS There were 32 males and 18 females with a mean age of 54.4±13.9 years. Mean total density was -790.6±73.4 HU. The volume of emphysematous lung was (<-900 HU) 885.2±1,378.4 cm(3). Forced expiratory volume in one second (FEV1) (r=-0.494, P=0.02) and diffusion capacity of carbon monoxide (DLCO) (r=-0.643, P<0.001) were found to be correlate with the volume of emphysematous lung. Furthermore FEV1 (r=0.59, P<0.001) and DLCO (r=0.48, P<0.001) were also found to be correlate with mean lung density. Postoperative pulmonary morbidity was significantly higher in patients with lower lung density (P<0.001), larger volume of emphysema (P<0.001) and lower DLCO (P=0.039). A cut-off point of -787.5 HU for lung density showed 86.96% sensitivity and 81.48% specificity for predicting the pulmonary morbidity (kappa =-0.68, P<0.001). Additionally a cut-off point of 5.41% for emphysematous volume showed 84.00% sensitivity and 80.00% specificity for predicting the pulmonary morbidity (kappa =0.64, P<0.001). According to logistic regression analyses emphysematous volume >5.41% (P=0.014) and lung density <-787.5 HU (P=0.009) were independent prognostic factors associated with postoperative pulmonary morbidity. CONCLUSIONS In this study, the patients with a lower lung density than -787.5 HU and a higher volume of emphysema than 5.41% were found to be at increased risk for developing postoperative pulmonary morbidity. More stringent precautions should be taken in those patients that were found to be at high risk to avoid pulmonary complications.

Unintentional irradiation of conceptus by diagnostic imaging examinations in Turkey

Exposure of the fetus to medical radiation sources during the diagnostic procedures without intention is one of the most significant concerns in the medical community. In this study, 45 conventional X-ray and computed tomography (CT) examinations of the women who were unaware of their pregnancy were investigated. Effective doses and fetal doses were calculated for each application by using PCXMC and ImPACT CT scan software. The exposure of abdominal CT and abdominal conventional X-ray examinations was found to be over the literature for both the range and the average values. Average effective dose for abdominal CT examinations was calculated to be ∼3.1 times higher than that in the literature. For abdominal CT and conventional X-ray examinations, the mean fetal doses were found to be ∼3.5 times and ∼5.4 times higher than those in the literature, respectively.

Patient doses from CT examinations in Turkey

PURPOSE We aimed to establish the first diagnostic reference levels (DRLs) for computed tomography (CT) examinations in adult and pediatric patients in Turkey and compare these with international DRLs. METHODS CT performance information and examination parameters (for head, chest, high-resolution CT of the chest [HRCT-chest], abdominal, and pelvic protocols) from 1607 hospitals were collected via a survey. Dose length products and effective doses for standard patient sizes were calculated from the reported volume CT dose index (CTDIvol). RESULTS The median number of protocols reported from the 167 responding hospitals (10% response rate) was 102 across five different age groups. Third quartile CTDIvol values for adult pelvic and all pediatric body protocols were higher than the European Commission standards but were comparable to studies conducted in other countries. CONCLUSION The radiation dose indicators for adult patients were similar to those reported in the literature, except for those associated with head protocols. CT protocol optimization is necessary for adult head and pediatric chest, HRCT-chest, abdominal, and pelvic protocols. The findings from this study are recommended for use as national DRLs in Turkey.

Thymoma type B1 arising in a giant supradiaphragmatic thymolipoma.

Thymolipomas are uncommon tumors of the anterior mediastinum. They may extend into, but rarely stem from, the chest cavity. Furthermore, thymoma arising in a thymolipoma is extremely rare. We report a unique case of thymoma type B1 that originated form a giant thymolipoma located in the chest cavity, which was resected by a lateral thoracotomy in a 23-year-old woman. To our knowledge, this is the first reported case of thymoma type B1 arising within a giant thymolipoma.

Enflamatuvar belirteçlerin negatif apendektomi oranını azaltmadaki rolü: Bilgisayarlı tomografi bulgularına dayanan bir çalışma

BACKGROUND This study aimed to investigate the role of inflammatory markers in decreasing negative appendectomy rate (NAR) based on their relation with findings of acute appendicitis (AA) on computed tomography (CT). METHODS Ninety-two patients who underwent CT examination with suspected AA were included. We investigated the relation between CT findings of AA and laboratory inflammatory markers and also performed receiver operating characteristic (ROC) analysis to calculate cut-off values of inflammatory markers and CT findings of AA. Appendectomy cases were re-evaluated considering cut-off values to make the operation decision and NAR was recalculated. Chi-squared test was used to compare the actual and recalculated NAR. RESULTS Cut-off values of appendiceal diameter, appendiceal wall thickness, and caecal wall thickness were 7.9, 2, and 2.3 mm, respectively, for the diagnosis of AA. Cut-off values of WBC , NLR, and CRP on ROC analysis were 7.47, 4.06 and 13, respectively, for the diagnosis of AA. When the actual and recalculated NAR (21.9% versus 9.1%) were compared, the difference was found to be almost significant (p=0.058). CONCLUSION Inflammatory markers are not sufficiently powerful on their own to accurately diagnose AA. However, particularly in equivocal cases, proposed cut-off values may be helpful for accurate diagnosis and a lower NAR can be achieved.BACKGROUND This study aimed to investigate the role of inflammatory markers in decreasing negative appendectomy rate (NAR) based on their relation with findings of acute appendicitis (AA) on computed tomography (CT). METHODS Ninety-two patients who underwent CT examination with suspected AA were included. We investigated the relation between CT findings of AA and laboratory inflammatory markers and also performed receiver operating characteristic (ROC) analysis to calculate cut-off values of inflammatory markers and CT findings of AA. Appendectomy cases were re-evaluated considering cut-off values to make the operation decision and NAR was recalculated. Chi-squared test was used to compare the actual and recalculated NAR. RESULTS Cut-off values of appendiceal diameter, appendiceal wall thickness, and caecal wall thickness were 7.9, 2, and 2.3 mm, respectively, for the diagnosis of AA. Cut-off values of WBC , NLR, and CRP on ROC analysis were 7.47, 4.06 and 13, respectively, for the diagnosis of AA. When the actual and recalculated NAR (21.9% versus 9.1%) were compared, the difference was found to be almost significant (p=0.058). CONCLUSION Inflammatory markers are not sufficiently powerful on their own to accurately diagnose AA. However, particularly in equivocal cases, proposed cut-off values may be helpful for accurate diagnosis and a lower NAR can be achieved.

Presence of vascular loops entering internal acoustic channel may increase risk of Sudden sensorineural hearing loss and reduce recovery of these patients.

To analyze whether there is correlation between branching patterns of anterior inferior cerebellar artery/posterior inferior cerebellar artery (AICA/PICA) in cerebellopontine angle (CPA) area, as demonstrated by three‐dimensional fast imaging employing steady‐state acquisition (3D FIESTA) magnetic resonance imaging (MRI) and 1) idiopathic sudden sensorineural hearing loss (ISSNHL) outcomes and 2) recovery of ISSNHL.

Twinkling artifact on color Doppler ultrasound: an advantage or a pitfall?

The twinkling artifact (TA) or color comet-tail artifact is characterized by a rapidly changing mixture of red and blue color Doppler signals. Even though many diseases and clinical conditions have been shown to produce this artifact, its source is not clearly understood yet. The TA may provide additional information to gray-scale ultrasound findings in several clinical situations. However, there may be pitfalls to keep in mind. We must first be aware of the TA to benefit from the advantages and avoid the pitfalls. In this review, we aim to give practicing radiologists an overview of the mechanisms and clinical applications of the TA by illustrating sample cases we have encountered.

Noise reduction in CT perfusion images: A bilateral filter trial

Computed Tomography (CT) perfusion images are acquired in short time period and in order to lower patient radiation dose. Low x-ray photon flux and energy are preferred in such CT exposures. Obtainedimages contain more noise than classical CT images which are usually obtained via using high photon flux and high energy. Perfusion images are used for obtaining functional perfusion maps. Singular value decomposition (SVD) based deconvolution algorithms are mainly used for this purpose. SVD based algorithms are very sensitive to noise because of their intrinsic nature. To denoise perfusion images with noise reduction filters is a very common application in order to obtain functional maps with better image quality to help physician through diagnostic process. In this study, regarding to itssuperior noise reduction and detail preservation capabilities, bilateral filter is chosen for noise reduction. Bilateral filter parameters are optimized via an emprical method on CT perfusion images of suspected acute stroke patiens. Results are evaluated and compared by visual means, peak signal noise ratio, mean square error metrics and region of interes analyses on obtained perfusion maps. It is observed that high magnitude of the present noise is denoised and details containing contrast bolus are preserved.