Medicexchange.com News

Posts Tagged ‘Computed Tomography’

Dynamic CT-based stress myocardial perfusion imaging is plausible for  hemodynamically significant coronary artery stenosis.

 

The medical research was contributed by Fabian Bamberg, MD, MPH; Alexander Becker, MD; Florian Schwarz, MD; Roy P. Marcus, BS; Martin Greif, MD; Franz von Ziegler, MD; Ron Blankstein, MD, MPH; Udo Hoffmann, MD, MPH; Wieland H. Sommer, MD; Verena S. Hoffmann, PhD; Thorsten R. C. Johnson, MD; Hans-Christoph R. Becker, MD; Bernd J. Wintersperger, MD; Maximilian F. Reiser, MD and Konstantin Nikolaou, MD from the Departments of Clinical Radiology and Cardiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich, Germany; Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Mass; Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Mass; and Institute of Biomedical Epidemiology, Ludwig-Maximilians University, Munich, Germany.

The research objective was to determine possibility of CT-based dynamic myocardial perfusion imaging for hemodynamically important coronary artery stenosis, as determined with fractional flow reserve. (Courtesy: RSNA)

Subjects with known coronary artery disease passed through electrocardiographically stirred dynamic stress myocardial perfusion imaging (MPI).

Fractional flow reserve was measured with a luminal narrowing of 50%–85% (within main coronary arteries).

Calculated myocardial blood flow was gathered from CT images through parametric deconvolution for segments; was associated to hemodynamically substantial coronary artery stenosis with fractional flow reserve (0.75 or less) in a blinded manner.

Traditional estimates of diagnostic precision were obtained, and logistic regression analysis was put in use for discriminatory power analysis.

About 33 subjects finished the study procedure; diagnostic precision of CT for anatomically vital stenosis (coronary artery) was high; low for hemodynamically considerable stenosis.

Through with gauged myocardial blood blow, 43% coronary lesions were marked as not hemodynamically important, which considerably increased positive predictive value to 78%; the existence of a coronary artery stenosis with comparable myocardial blood flow less than 75 mL/100 mL/min had a high risk for hemodynamic significance.

Conclusion: dynamic CT-based stress myocardial perfusion imaging is feasible for hemodynamically significant coronary artery stenosis.

CT scans for appendicitis has soared across the U.S. among children and adults; increased use of X-rays has raised grave concern in the healthcare market: a study report

 

Appendicitis is an inflammation/rubor of the vermiform/cecal appendix; grave intricacies can result out of ruptured appendix.

Computed tomography is most precise for appendicitis but higher radiation compared to conventional X-ray is a worrisome factor, according to a study published in the Annals of Emergency Medicine.

The percentage of CT scan for appendicitis in the U.S. emergency rooms shot up to 69% (in 2006), from 6% in 1996, the study corroborates.

Most of opt for combination medical imaging; ultrasound is another feasible alternative over CT, as it does not expose patient to radiation.

More personalized approach with doctor-patients at emergency rooms, on symptoms and histories were found beneficial, than relying solely on diagnostic imaging, to manage their conditions.

Performance of CT for appendicitis is required to be explored fully, for more sensible use.

While CT scans have been proved well to slash death rate by 20% of lung cancer in the US – who might, and under what conditions remain the matter of discussion, for current and ex-smokers.

 

Radiology/hospital practices across USA are up high on the technology, despite of intense discord over wide usage, and of who all should go for CT scans, for lung cancer. US is high on death toll due to lung cancer, study suggests. (Courtesy: The Washington Post)

The course was touched-off by a Federal study that found imaging some heavy and ex-smokers could bring down death rate amongst them, associated to lung cancer.

Supporters of the CT scan say, it would bring down death rate, and people at risk should be scanned, and payers should be willing for them, in conference with doctors.

On the other, critics feel screening millions will lay in a wave of false alarms with people, which provoke expensive, grave and needless follow-up examinations/biopsies and surgeries.

In comparison to the combined death rate of colon, breast and prostate cancers, more than 157,000 Americans die of lung cancers, every year, study corroborates, as it is difficult to treat and is often diagnosed late.

More than 100 million current and ex-smokers are at high risk of lung cancer, in the US; many are apt due to family history, or exposure to asbestos and radon.

Unlike 2D images by conventional chest x-rays, 3D images of the lungs through with CT scanners demonstrate precisely for small tumors and related.

Last November, the National Cancer Institute declared about ceasing $250 million National Lung Screening Trial that was examining the approach in 53,500 men and women in 33 sites across the United States, when CT scans proved feasible to slash death rate by 20%, in contrast to chest x-rays. Who might benefit from CT scan, and under what conditions remain a matter of discussion, though many hospitals do CT imaging.

Timely screening does save patients, but both risk and harms are associated with the scan; the study found that scans generated false alarms in about 40% of the cases; though imaging saved 88 patients in trial study, about 16 died due to complications associated with follow-up examinations, where 6 did not have cancer, either.

Foremost medical groups have urged physicians to wait until experts cautiously revise the findings; federally funded cost-benefit analysis is in progress. Insurers (inclusive of government’s vital centers for Medicare/Medicaid services) say, they will survey the outcomes of those discussions, prior determining, whether to pay for scans.

It is more significant for physicians to get a feedback from their peers on behavioral changes, than policy makers or insurance agents.

 

A recent study on newly diagnosed cancer patients, showed that coaching doctors can reduce a lot of unnecessary tests.

The study was focused on enhancing healthcare quality and compliance. It was led by Dr. David C. Miller, urologist at the University of Michigan, and is published in the Journal of Urology.

Effective training on current guidelines helped physicians on computed tomography scans and Bone Scans they commanded for low-risk patients when compared to the rate of these tests done at the beginning of the study.

This spared the patients unnecessary cost and exposure to radiation which in itself is a cancer risk.

The study also found that these tests can lead to additional harmless findings which increases the stress of the patients and leads to further tests.

The research team tried to look at diagnostic approach of physicians treating on patients with prostate cancer – early, middle and late stage. They found that many doctors commanded for computed tomography/bone scans even for patients with early stage cancers with improbability of spread.

And one of the reasons is that they do not know the national guidelines.

At the onset, about 28% got bone scans, and 31% low-and-medium-risk cases received CT scans; both the procedures expose patients to radiation. After a study-phase of 16 months and so, CT scans were done only for 16% of cases with low/medium risk spread, and 13% had bone scans.

On the concluding note, Miller said that it is more significant for physicians to get a feedback from their peers on behavioral changes, than policy makers or insurance agents.

(Courtesy: Reuters Health)

Hospitalization rates have taken a negative curve, post CT utilization in emergency departments: study

 

The amount of CT scans in emergency care units have upsurged in recent times, and this has led to fewer hospital admissions; the figures through with a recent study  (Courtesy: Healthcare IT News, HIMSS) suggest that the rate of computed tomography scans have increased about 330% in between year 1996-2007; reduced rate of hospitalization is a good sign for patients.

The study confirms that majority of CT scans in the United States of America are performed in emergency departments, as primary care doctors/physicians refer most of their patients to these, for preliminary tests and examinations, prior hospital admissions.

The usage of computed tomography scan has dramatically increased more amongst older patients, and there is gradual decrease in post process hospitalization. CT utilization took a swift jump from 3.2% to 13.9%, through with the data being analyzed over of patients. As per the figures, the hospitalization rate, post CT scan was 26%, in year 1996; through with the end of year 2007 it started showing the negative trend with half to 12.1% decline in the rate; heavy descent was observed during that phase, with respect to hospital/intensive care unit admissions, post CT utilization.

Greater certainty of diseases have been made possible through with CT scans, and this ensued in to better patient outcomes; emergency departments that used to manage and treat patients that had grave disorders, without diagnostic imaging never served the right purpose for many of the patients. Patients and their family members sometimes urge emergency care doctors for getting imaged/scanned by, for detailed diagnosis, of their health; this ensures better diagnostic approach for disorders that the patients have, for timely treatment and care, and trim down the need for needless hospitalization.

For more on other Healthcare related news, blogs and stories – stay tuned with MedicExchange!

The diagnostic performance of low-dose CT is comparable to standard dose CT, to characterize/analyze appendicitis in young adults.

 

The medical research study was conducted by So Yeon Kim, MD; Kyoung Ho Lee, MD, PhD; Kyuseok Kim, MD, PhD; Tae Yun Kim, MD, PhD; Hye Seung Lee, MD, PhD; Seung-sik Hwang, MD, PhD; Ki Jun Song, PhD; Heung Sik Kang, MD, PhD; Young Hoon Kim, MD, PhD and Joong Eui Rhee, MD, PhD from the Departments of Radiology, Emergency Medicine, Seoul National University, Korea; Department of Social and Preventive Medicine, Inha University School of Medicine, Incheon, Korea; and Department of Biostatistics, Yonsei University College of Medicine, Seoul, Korea.

Appendicitis is an inflammation/rubor of the vermiform/cecal appendix. The research objective was to equate standard and low radiation doses in intravenous, contrast-enhanced abdominal CT scan, for identification of acute appendicitis in young adults.

The study comprised about 257 patients, suspected of appendicitis that passed through CT with standard/low radiation dose; through with Wilcoxon rank-sum test, Freeman-Halton statistics, and ROC curve analysis the diagnostic performance of CT was recorded and equated by, for appendicitis.

Of 44 standard dose and 55 low radiation dose examinations, one of the abdominal radiologists made primary report, which served as final report; for residual examination, on-call radiologists were requested that submitted over primary reports, and the abdominal radiologists then put forward final reports.

About primary reports – standard and low dose CT groups did not considerably vary in regions under the receiver operating characteristic curve, specificity or sensitivity, for detection of appendicitis; no considerable deviation could be established amongst two groups in confidence level, when diagnosing/debarring appendicitis in preliminary reports; identical results were marked for the final reports. The dose groups even did not substantially vary in terms of subsequent: appendiceal visualization/image, distinctive characterization of appendiceal perforation, sensitivity for substitution method/diagnoses etc.

Conclusion: the diagnostic performance of low dose computed tomography to that of standard-dose CT is comparable, for characterization of appendicitis in young adults.

Orienting troponin measurement to cardiac CT angiography findings is secure, and ensures lessened duration of stay for patients with low-moderate risk of chest pain.

 

The medical research study is done by Arthur Nasis, MBBS, FRACP; Ian T. Meredith, MBBS, PhD, FRACP; Nitesh Nerlekar, MBBS; James D. Cameron, MBBS, MD; Paul R. Antonis, MBBS, FRACP; Philip M. Mottram, MBBS, PhD, FRACP; Michael C. Leung, MBBS, PhD, FRACP; John M. Troupis, MBBS, FRANCR; Marcus Crossett, BAppSci; Anthony G. Kambourakis, MBBS, FACEM; George Braitberg, MBBS, FACEM; Udo Hoffmann, MD, MPH and Sujith K. Seneviratne, MBBS, FRACP from the Monash Cardiovascular Research Centre, Clayton and Southern Health and Monash University Department of Medicine, Melbourne, Australia; Departments of Diagnostic Imaging and Emergency Medicine, Southern Health, Melbourne, Australia; and Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston. (Courtesy: RSNA Journal)

The research objective was to evaluate influence on duration of stay, and rate of major unfavorable cardiovascular cases, of cardiac CT angiography aided algorithm to evaluate subjects that come up to emergency departments with low to moderate chest pain.

203 successive patients with ischemic type chest pain/discomfort were registered for the study; patients were passed initially through cardiac CT angiography, with following treatment decided by recommendation to results at cardiac CT angiography.

Except for patients with severe stenoses, which had to be admitted to the hospital, other without apparent plaque were instantly discharged; subjects with mild-moderate stenoses and nonobstructive plaque were discharged after a negative troponin test (for muscle constriction). Discharged patients were pursued through for a year, and so; more to that, duration of stay and safety results amid these subjects were equated with patients with low-moderate risk of chest pain that submitted over to standard care procedures, without cardiac CT angiography, at emergency department. Bonferroni method was utilized for to equate duration of stay amid groups.

Of the results, subjects that passed through cardiac CT angiography showed the following: except for 31 with severe stenoses, and 65 with no signs of plaque, about 107 patients showed up with nonobstructive plaque. After pursuance, no cases were detected of death/mortality, or of severe coronary symptom; re-admittance rate to the hospital, due to chest pain was more through with standard of care; average emergency department duration of stay was higher with standard of care approach, in comparison to that with cardiac CT angiography.

Conclusion: orienting troponin measurement to cardiac CT angiography results is secure, and facilitates early discharge of subjects/patients with low-moderate risk of chest pain, ensuing in lessened duration of stay.

Degree and constitution of atherosclerotic plaque equated through with coronary CT angiography differ between black and white Americans, with comparatively more calcified disorders in white than black Americans.

 

The medical research study is done by John W. Nance, Jr, MD; Fabian Bamberg, MD, MPH; U. Joseph Schoepf, MD; Doo Kyoung Kang, MD; J. Michael Barraza, Jr, BS; Joseph A. Abro, MA; Gorka Bastarrika, MD, PhD; Gary F. Headden, MD; Philip Costello, MD and Christian Thilo, MD, from the Heart and Vascular Center, Medical University of South Carolina, Charleston, SC; Department of Radiology, University of Munich-Grosshadern Campus, Munich, Germany; Department of Radiology, Ajou University School of Medicine, Suwon, South Korea; Department of Radiology, University of Navarra, Pamplona, Spain; and Department of Cardiology, Klinikum Augsburg, Germany. (Courtesy: RSNA Journal)

The research objective was to utilize coronary CT angiography, for to equate preponderance, degree and composition/constitution of coronary atherosclerotic lesions in white and black Americans, with acute pain in the chest.

Calcium score reflects the extent/degree of calcium deposits in coronary arteries; cardiac CT for calcium score ensures if the patient is at high risk for a heart attack. In conformance with HIPAA, about 301 subjects, white and black Americans, with mean age of about 55 years, and so, were assessed over their CT angiography data, with cases of severe chest pain.

Artery segments were assessed for existence of subsequent: atherosclerotic plaque/atheroma, plaque constitution, and stenosis/constriction.

Through with threshold oriented algorithm/image segmentation, non-calcified plaque volume was measured by; the existence and degree of atherosclerotic plaque/atheroma were equated amidst groups utilizing regression analysis models; calcium score of 101-400, and above show up for moderate/extensive rate for coronary artery disease.

About the results, though there was no considerable deviation amongst black and white Americans with regard to existence of plaque/stenosis, black Americans had higher prevalence/volume of non-calcified plaque, free of cardiovascular risk factors and diabetes/polygenic disorders.

Conclusion: degree and composition/constitution of atherosclerotic plaque equated through with coronary CT angiography alter amongst black and white Americans, with comparatively more non-calcified cases in black, and more calcified disorder in white Americans; study further is required for to establish if CT plaque depiction can enhance predictive rate of cardiac risk in black Americans.

Enhanced visualization of peripheral/central arteries can be achieved through with low energy pulmonary CT angiography, without considerable reduction in image quality.

 

The medical research study was conducted by Naama R. Bogot, Alexander Fingerle, Dorith Shaham, Izhak Nissenbaum and Jacob Sosna from Departments of Radiology – Hadassah-Hebrew University Medical Center and Shaare Zedek Medical Center (Jerusalem, Israel); University of Michigan Hospitals, Ann Arbor, MI; Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Beth Israel Deaconess Medical Center, Boston, MA.

The medical research objective was to likely equate visualization of peripheral/central pulmonary arteries on concurrently obtained standard and low energy pulmonary CT angiography.

Single source dual layer dual energy MDCT was utilized for to scan 33 successive patients with suspected pulmonary embolism; image noise and attenuation were equated at the segmental and main pulmonary arteries, and signal-to-noise ratios were gauged by;

Independent blind study was performed by radiologists, as they evaluated arterial visibility in agreement, through utilization of maximum intensity projection (MIP) algorithm. Statistical analysis were done through kappa coefficient and non parametric test.

About the results, pulmonary embolism was discovered in about 3 patients; sub-segmental emboli/obstruction and segmental vessel were found merely for low energy images – with enhanced image visualization of segmental arteries. In contrast to standard images, greater amount of subsegmental vessels was observed on low energy MIP restoration; visualization of subsegmental vessels was higher in quality in most of the cases, through low-energy imaging There could be no considerable deviation established in standard against low energy computed tomography images over mean signal-to-noise-ratio.

Conclusion: Enhanced visualization of peripheral/central arteries can be achieved through with low energy pulmonary CT angiography, without considerable reduction in image quality.

The detection rate on nonopacified portal venous MDCT for upper urinary tract tumors is high; with lack of morphological attributes, implicative for urothelial malignancy, ureter with normal appearance can be promising.

 

The medical research was conducted by Max Kupershmidt, Myles Margolis, Hyun-Jung Jang, Christine Massey and Ur Metser from Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women’s College Hospital, University of Toronto; Department of Biostatistics, Princess Margaret Hospital, Toronto, ON, Canada.

The research objective was to evaluate the recognition and negative predictive rate of upper urinary tract tumors in nonopacified urinary tracts on portal venous phase multi-row detector CT.

About 20 patients with upper urinary tract tumors were retroactively studied, and results were evaluated through blind study; reviewers tried to determine if the segments of the tract could be fully examined for presence and absence of tumors; the morphological attributes of tumors were characterized by, viz. urothelial thickening, polypoid mass etc.! The recognition rate of the proximate – upper urinary tract sections was considerably higher than that for distal sections, which were directed away.

The portal venous phase MDCT for tumor detection showed subsequent values: sensitivity – 95%; specificity – 97%; negative predictive value – 100%, in the order. Morphological attributes vital for the existence of tumor were urothelial thickening and discrete polypoid mass. Except for moderate consensus on urothelial thickening, interobserver agreement for all the attributes demonstrated good results.

Conclusion: the recognition rate on nonopacified portal venous MDCT for upper urinary tract tumors is high; with deficiency of morphological attributes, proposing urothelial malignancy, ureter with normal appearance can be satisfactory/assuring.