Baseline Computed Tomography Scan Research Articles

Impact of computed tomography screening for lung cancer on participants in a randomized controlled trial (NELSON trial)

Computed tomography (CT) screening is an important new tool for the early detection of lung cancer. In the current study, the authors assessed the discomfort associated with CT scanning and the subsequent wait for results and health-related quality of life (HRQoL) over time. A total of 351 participants in the Dutch-Belgian randomized controlled trial for lung cancer screening in high-risk subjects (the NELSON trial) who had an appointment for a baseline CT scan were asked to complete questionnaires regarding their experienced discomfort and HRQoL before, 1 day after, and approximately 6 months after the CT scan. HRQoL was measured as generic HRQoL (12-item Short Form [SF-12] and EuroQol questionnaire [EQ-5D]), generic anxiety (State-Trait Anxiety Inventory [STAI-6]), and lung cancer-specific distress (Impact of Event Scale [IES]). Approximately 76.9% of the participants completed all 3 questionnaires. Approximately 87% to 99% of participants reported experiencing no discomfort related to the CT scan. The median SF-12, EQ-5D, STAI-6, and IES scores did not appear to change relevantly over time. Approximately 46.0% and 51.3%, respectively, of the participants reported discomfort in connection with having to wait for the results of the CT scan and dreading those results. These patients had relevantly higher STAI-6 and IES scores (P < .01) (unfavorable) at all 3 assessments. The current evaluation of the potential adverse effects of CT screening for lung cancer on HRQoL demonstrated no negative effects. However, waiting for the CT scan results was reported to be discomforting by approximately half of the participants. Minimizing the waiting time for the test results is therefore recommended.

Progression of Traumatic Intracerebral Hemorrhage: A Prospective Observational Study

ABSTRACT Preliminary evidence has shown that intracerebral hemorrhages, either spontaneous (sICH) or traumatic (tICH) often expand over time. An association between hemorrhage expansion and clinical outcomes has been described for sICH. The intent of this prospective, observational study was to characterize the temporal profile of hemorrhage progression, as measured by serial computed tomography (CT) scanning, with the aim of better understanding the natural course of hemorrhage progression in tICH. There was also a desire to document the baseline adverse event (AE) profile in this patient group. An important motive for performing this study was to set the stage for subsequent studies that will examine the role of a new systemic hemostatic agent in tICH. Subjects were enrolled if they had tICH lesions of at least 2 mL on a baseline CT scan obtained within 6 h of a head injury. CT scans were repeated at 24 and 72 h. Clinical outcomes and pre-defined AEs were documented. The data showed that 51% of the subjects demonstrated an increase in tICH volume, and that most of the increase occurred early. In addition, larger hematomas exhibited the greatest expansion. Thromboembolic complications were identified in 13% of subjects. This study demonstrates that tICH expansion between the baseline and 24-h CT scans occurred in approximately half of the subjects. The earlier after injury that the initial CT scan is obtained, the greater is the likelihood that the hematoma will expand on subsequent scans. The time frame during which hemorrhagic expansion occurs provides an opportunity for early intervention to limit a process with adverse prognostic implications.

Intravenous Recombinant Tissue Plasminogen Activator Improves Arterial Recanalization Rates and Reduces Infarct Volumes in Patients With Hyperdense Artery Sign on Baseline Computed Tomography

We sought to evaluate arterial recanalization as measured by changes in the presence of hyperdense artery sign (HAS) on initial and 24-hour computed tomography scans in patients treated with recombinant tissue plasminogen activator (rt-PA) or placebo, and to assess the effect of rt-PA on patient outcomes in this population. Patients in the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Trial composed the study group. We determined the percentage of patients with HAS in rt-PA- and placebo-treated groups who had persistence (HAS +/+) or resolution (HAS +/-) of HAS on 24-hour computed tomography, and compared outcomes in those with resolution or persistence of the sign in these treatment groups. Baseline HAS occurred in 79 of 604 eligible patients (13%). The two treatment groups were similar, although patients treated with rt-PA were significantly older. Of the 79 patients with HAS on baseline computed tomography scan, 14 of 37 (38%) treated with rt-PA had resolution of HAS at 24 hours compared with 7 of 42 (17%) treated with placebo (P = .03). Infarct volumes at 24 hours were significantly smaller in patients treated with rt-PA with resolution of the sign, compared with those who had persistence of the sign (P = .004). In our analysis, functional outcomes were not significantly improved based on resolution of HAS in either treatment group. There were 4 symptomatic ICHs in the rt-PA-treated group with HAS as compared with two in the placebo-treated group. Among patients with HAS at baseline in the NINDS rt-PA Stroke Trial, intravenous rt-PA increased recanalization as measured by resolution of HAS and reduced infarct volumes at 24 hours.

Acute Hemorrhagic Stroke: rFVIIa Is Not Effective

Intracerebral hemorrhage accounts for about 15% of strokes. No effective treatment is available for these events (unlike for thrombotic strokes), but use of recombinant activated factor VII (rFVIIa) has shown promise in early trials. To further assess this agent, researchers conducted the Factor Seven for Acute Hemorrhagic Stroke (FAST) trial, a randomized, double-blind, placebo-controlled trial involving 122 institutions in 22 countries. Patients received either placebo or rFVIIa (20 μg/kg or 80 μg/kg) within 1 hour after the baseline computed tomography scan and …

Investigating the low‐dose limits of multidetector CT in lung nodule surveillance

The purpose of this study was to evaluate the factors limiting nodule detection in thoracic computed tomography (CT) and to determine whether prior knowledge of nodule size and attenuation, available from a baseline CT study, influences the minimum radiation dose at which nodule surveillance CT scans can be performed while maintaining current levels of nodule detectability. Multiple nodules varying in attenuation (-509 to + 110 HU) and diameter (1.6 to 9.5 mm) were layered in random and ordered sequences within 2 lung cylinders made of Rando lung material and suspended within a custom-built CT phantom. Multiple CT scans were performed at varying kVp (120, 100, and 80), mA (200, 150, 100, 50, 20, and 10), and beam collimation (5, 2.5, and 1.25 mm) on a four-row multidetector scanner (Lightspeed, General Electric, Milwaukee, WI) using 0.8 s gantry rotation. The corresponding range of radiation dose over which images were acquired was 0.3-26.4 mGy. Nine observers independently performed three specific tasks, namely: (1) To detect a 3.2 mm nodule of 23 HU; (2) To detect 3.2 mm nodules of varying attenuation (-509 to -154 HU); and (3) To detect nodules varying in size (1.6-9 mm) and attenuation (-509 to 110 HU). A two-alternative forced-choice test was used in order to determine the limits of nodule detection in terms of the proportion of correct responses (Pcorr, related to the area under the ROC curve) as a summary metric of observer performance. The radiation dose levels for detection of 99% of nodules in each task were as follows: Task 1 (1 mGy); Task 2 (5 mGy); and Task 3 (7 mGy). The corresponding interobserver confidence limits were 1, 5, and 10 mGy for Tasks 1, 2, and 3, respectively. There was a fivefold increase in the radiation dose required for detection of lower-density nodules (Tasks 1 to 2). Absence of prior knowledge of the nodule size and density (Task 3) corresponds to a significant increase in the minimum required radiation dose. Significant image degradation and reduction in observer performance for all tasks occur at a dose of < or = 1 mGy. It is concluded that the size and attenuation of a nodule strongly influence the radiation dose required for confident evaluation with a minimum threshold value of 1-2 mGy (minimum dose CT). A prior knowledge of nodule size and attenuation is available from the baseline CT scan and is an important consideration in minimizing the radiation exposure required for nodule detection with surveillance CT.

Facial diplegia revealing ventriculoperitoneal shunt failure in a patient with Crouzon syndrome

The authors report on the case of a 15-year-old boy with Crouzon syndrome (CS) who presented with headache and facial diplegia. He had undergone several craniofacial interventions and a posterior fossa decompression for tonsillar herniation caused by the CS. A ventriculoperitoneal (VP) shunt had been inserted for hydrocephalus. Emergency computed tomography (CT) disclosed slight dilation of the ventricular cavities compared with their appearance on a baseline CT scan. Magnetic resonance imaging showed a deformed brainstem but no compression at the occipital foramen; there was no apparent explanation for the facial diplegia. The neuroophthalmological examination revealed neither papilledema nor oculomotor palsy. Electromyography confirmed incomplete peripheral facial diplegia. The patient underwent emergency shunt revision, during which complete obstruction of the ventricular catheter and severe cerebrospinal fluid hypertension were found. After surgery, cranial hypertension symptoms completely resolved and the facial diplegia improved slowly with a persistent and incomplete right superior facial palsy. Cranial 3D CT scanning reconstructions and brain magnetic resonance imaging demonstrated severe petrous bone distortion that could have been responsible for direct stretching injuries on the facial nerves at the level of the internal acoustic meatus. The present case represents the first reported occurrence of VP shunt failure as revealed by a facial palsy; the authors discuss the pathophysiology of facial palsy in intracranial hypertension.

CT Scan Hematoma Volume: A Surrogate Endpoint for the Effect of Treatment in Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) represents approximately 15% of all strokes, with no approved therapeutic interventions available. The 30-day mortality rate is 35 to 50% and only 10 to 20% of survivors regain functional independence. Previous studies have indicated that substantial increase in hematoma volume occurs within the first hours after ICH onset. These studies also indicated that hematoma volume expansion is associated with neurological deterioration and was a critical determinant of 30-day mortality. Early interventions directed at reducing hematoma expansion would be of considerable value. However, no validated measurements exist to directly translate the impact of hematoma volume on clinical outcomes. Changes in hematoma volume as determined by computed tomography (CT) scan is a potential surrogate endpoint for clinical outcomes. A recent randomized, double-blind, parallel-group, placebo-controlled clinical trial (399 patients) evaluated the use of rFVIIa (recombinant activated coagulation Factor VII) to reduce expansion of ICH hematoma volume, also determined the inter- and intrareader variability of CT scan measurements. In addition, assessments of clinical outcomes (modified Rankin Score, mRS) and mortality were conducted. A baseline CT scan was performed within 3 hours after symptom onset. Placebo or rFVIIa was administered within 1 hour after the baseline scan. CT scans were repeated at 24 hours and 72 hours post-treatment. Inter-reader and intrareader variability was assessed by comparison of ICH volumes measured on CT images by two independent neuroradiologists, masked to treatment. A meta-analysis conducted on a hemostatic treatment–naive ICH patient population pooled from four studies (N = 218) demonstrated that hematoma volume was an independent determinant of mortality (p

Functional status and use of healthcare facilities in long-term survivors of transient ischaemic attack or minor ischaemic stroke

Background: Stroke may have a major effect on survivors and on the healthcare system. Aims: To study the functional status and use of healthcare facilities in long-term survivors of a...

Investigation of Gamma Knife image registration errors resulting from misalignment between the patient and the imaging axis

The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comfort. Results equally apply to magnetic resonance imaging. Seven 0.5 mm diameter CT-visible spheres were rigidly mounted to a string tied tightly at each end to diagonally opposite posts attached to a Leksell stereotactic frame. A standard CT fiducial box was applied to the frame in the usual clinical manner. A baseline CT scan (1 mm slice thickness) was obtained with the fiducial box perfectly aligned with the scanner axis. After localization of the image set, the (x,y,z) coordinate of the center of each sphere was recorded. Repeat CT scans with varying fiducial box misalignments with the imaging axis were subsequently obtained. The mean difference between the base line and the respective coordinates in misaligned geometries was approximately 0.2 mm (sigma=0.2 mm), well within the accuracy of the image sets and the delivery of radiosurgery with the Gamma Knife.

Importance of Early Ischemic Computed Tomography Changes Using ASPECTS in NINDS rtPA Stroke Study

The importance of early ischemic change (EIC) on baseline computed tomography (CT) in the decision to thrombolyze the patient with acute ischemic stroke has been controversial. ASPECTS is a semiquantitative scale that scores the extent of EIC within the middle cerebral artery territory. We examined whether ASPECTS could be a treatment modifier by systematically reviewing the CT scans in the NINDS rtPA Stroke Study. Six hundred eight of the 624 CT scans were available and of sufficient quality. One of 2 teams (n=3 each) of expert ASPECTS readers evaluated each scan for an ASPECTS value using a consensus score approach. Each team was blind to all clinical information except symptom side and blind to follow-up imaging and outcome information. ASPECTS values were stratified before analysis. Multivariable logistic regression was used to determine if an ASPECTS by treatment interaction existed on treatment response, outcome, and intracerebral hemorrhage risk. A total of 57.2% (348 of 608) of scans showed EIC with an ASPECTS <10. ASPECTS dichotomized into 8 to 10 and <8 did not have a treatment-modifying effect on good outcome but showed a trend to lower mortality at 90 days with tPA (relative risk 0.67, 95% confidence interval 0.41 to 1.06, P=0.10). ASPECTS 8 to 10 were associated with a trend to larger benefit of tPA with a number needed to treat (NNT) of 5 versus ASPECTS 3 to 7 with a NNT of 8. There was no evidence of treatment effect modification by the baseline ASPECTS value in the NINDS rtPA Stroke Study. Therefore, exclusion of patients for thrombolysis within 3 hours of symptom onset based on EIC is not supported by our data. There is a trend to reduced mortality and increased benefit to rtPA if the baseline CT scan is favorable (ASPECTS >7).

Sex-Based Differences in Response to Recombinant Tissue Plasminogen Activator in Acute Ischemic Stroke

Women experience worse outcomes after stroke compared with men. Prior work has suggested sex-based differences in coagulation and fibrinolysis markers in subjects with acute stroke. We explored whether sex might modify the effect of recombinant tissue plasminogen activator (rtPA) on outcomes in patients with acute ischemic stroke. Using a combined database including subjects from the National Institute of Neurological Disorders and Stroke (NINDS), Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) A and B, and the Second European Cooperative Acute Stroke Study (ECASS II) trials, we examined 90-day outcomes in patients randomized to rtPA versus placebo by sex. We used logistic regression to control for potential confounders. Among 988 women treated between 0 and 6 hours from symptom onset, patients receiving rtPA were significantly more likely than those receiving placebo to have a modified Rankin Score < or =1 (40.5% versus 30.3%, P<0.0008). Among 1190 men, the trend toward benefit in the overall group did not reach statistical significance (38.5% versus 36.7%, P=0.52). An unadjusted analysis showed that women were significantly more likely to benefit from rtPA compared with men (P=0.04). Controlling for age, baseline National Institutes of Health Stroke Scale, diabetes, symptom onset to treatment time, prior stroke, systolic blood pressure, extent of hypoattenuation on baseline computed tomography scan and several significant interaction terms (including onset to treatment time-by-treatment and systolic blood pressure-by treatment) did not substantially change the strength of the interaction between gender and rtPA treatment (P=0.04). In this pooled analysis of rtPA in acute ischemic stroke, women benefited more than men, and the usual gender difference in outcome favoring men was not observed in the thrombolytic therapy group. For patients presenting at later time intervals, when the risks and benefits of rtPA are more finely balanced, sex may be an important variable to consider for patient selection.

Growth of the thoracic spine in congenital scoliosis after expansion thoracoplasty.

Children with congenital thoracic scoliosis associated with fused ribs with a unilateral unsegmented bar adjacent to convex hemivertebrae will invariably have curve progression without treatment. Surgery has been thought to have a negligible growth-inhibition effect on the thoracic spine in such patients because it has been assumed that the concave side of the curve and the unilateral unsegmented bar do not grow, but we are unaware of any conclusive studies regarding this assumption. The changes in the length of the concave and convex sides, anterior and posterior vertebral edges, posterior arch, and unilateral unsegmented bars of the thoracic spine were measured in the twenty-one children with congenital scoliosis and fused ribs after expansion thoracoplasty had been carried out with use of a vertical, expandable titanium prosthetic rib. Three of these children had undergone posterior spinal fusion previously. Measurements were made with use of a three-dimensional software program that analyzed baseline and follow-up computed tomography scans. The technique was validated through measurement of the thorax of a small female adult cadaver. The patients without spine fusion had an average age of 3.3 years at the time of the baseline computed tomography scan, and the average duration of follow-up was 4.2 years. On the average, these patients showed significant growth (p < 0.0001) of the concave side of the thoracic spine (an increase in length of 7.9 mm/yr, or 7.1%/yr) and the convex side (8.3 mm/yr, or 6.4%/yr) compared with the baseline lengths. There was no significant difference in the increases in length (p = 0.38) between the concave and convex sides. Eleven patients with an unsegmented bar had an average 7.3% increase in the length of the bar (p < 0.0001). In the three children with prior spinal fusion, the increase in length averaged only 4.6 mm/yr (3%/yr) on the concave side of the thoracic spine and 3.7 mm/yr (2.2%/yr) on the convex side; both increases were significant (p < 0.0001). Longitudinal growth of the thoracic spine in a normal child has been estimated to be 0.6 cm/yr between the ages of five and nine years. After expansion thoracoplasty, growth of the thoracic spine was approximately 8 mm/yr in our series of children with congenital scoliosis and fused ribs. After expansion thoracoplasty, both the concave and the convex side of the thoracic spine and unilateral unsegmented bars appeared to grow in these patients. When a thorax is already foreshortened by congenital scoliosis, control of spine deformity with expansion thoracoplasty allows growth of the thoracic spine, and it is likely that the longer thorax provides additional volume for growth of the underlying lungs with probable clinical benefit. Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

4:03 The growth of the thoracic spine in congenital scoliosis after expansion thoracoplasty

Purpose of study: Children with congenital thoracic scoliosis associated with fused ribs with unilateral unsegmented bars adjacent to convex hemivertebra will invariably have curve progression without treatment. The growth inhibition effects on the thoracic spine by surgery is said to be neglectable, because it is assumed that the concave side of such curves and the unilateral unsegmented bars do not grow, but we are unaware of any conclusive studies regarding this assumption.Methods used: We measured the change in length of the thoracic spine on the concave, convex, anterior and posterior vertebral edges and the anterior surface of the posterior arch in 21 children (13 male, 8 female) with congenital scoliosis treated through expansion thoracoplasty by titanium rib prosthesis. Eleven unilateral unsegmented bars were also measured in 10 patients. Three of these children had undergone posterior spinal fusion before titanium rib implantation. Measurements were obtained using a three-dimensional software program (Vitrea 2, Vital Images, Inc, Minneapolis, MN), assessing baseline computed tomography (CT) scans and the latest follow-up scans. The technique was validated through measurement of a small female adult cadaver thorax.of findings: The average age at the baseline CT scan was 3.3 years, the average follow-up time 4.2 years (range, 1.8 to 6.2 years). An average of 7.6 prosthesis expansion surgeries (range, 1 to 16) were performed within the follow-up time. All patients on average showed significant growth (p<.0001) of the concave side of the thoracic spine (7.9 mm increase in length per year, 7.1% increase per year) and the convex side (8.3 mm increase in length per year, 6.4% increase per year) with no significant difference (p=.38) between sides. Unilateral unsegmented bars showed an average of 7.3% increase in length (p<.0001). Younger children showed more growth than older ones. In the three children with prior spinal fusion, the increase in length of the concave side of the thoracic spine was only 2.2 mm/year (2%/year) and the convex side 2.2 mm/year (3%/year), but both increases were significant (p<.0001). There was no correlation between the numbers of expansion surgeries and spinal growth.Relationship between findings and existing knowledge: Our findings suggest that thoracic unilateral unsegmented bars, thought incapable of growth in past literature, can grow when expansion thoracoplasty is performed. Continuing growth of the thoracic spine in such patients will likely result in a longer thorax, providing additional volume for growth of the underlying lungs with probable clinical benefit.Overall significance of findings: In children with congenital scoliosis treated through expansion thoracoplasty by titanium rib prosthesis, both concave and convex sides of the thoracic spine and unilateral unsegmented bars grow, allowing the thoracic spine to grow in length. Our results also suggest that younger children with prior spine fusion have less growth of the thoracic spine than children without spine fusions.Disclosures: Device or drug: Vertical Expandable Prosthetic Titanium Rib (VEPTR). Status: investigational.Conflict of interest: Robert Campbell, Jr., grant research from National Organization of Rare Disorders, FDA; Robert Campbell, Jr., Royalties, Synthes Spine Co.

Lack of clinical significance of early ischemic changes on computed tomography in acute stroke.

The prevalence and clinical significance of early ischemic changes (EICs) on baseline computed tomography (CT) scan of the head obtained within 3 hours of ischemic stroke are not established. To determine the frequency and significance of EIC on baseline head CT scans in the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA (recombinant tissue plasminogen activator) Stroke Trial. The original study, a randomized controlled trial, took place from January 1991 through October 1994 at 43 sites, during which CT images were obtained within 3 hours of symptom onset and prior to the initiation of rt-PA or placebo. For the current analysis, detailed reevaluation was undertaken after October 1994 of all baseline head CT scans with clinical data available pretreatment (blinded to treatment arm). Of 624 patients enrolled in the trial, baseline CT scans were retrieved and reviewed for 616 (99%). Frequency of EICs on baseline CT scans; association of EIC with other baseline variables; effect of EICs on deterioration at 24 hours (>/=4 points increase from the baseline National Institutes of Health Stroke Scale [NIHSS] score); clinical outcome (measured by 4 clinical scales) at 3 months, CT lesion volume at 3 months, death at 90 days; and symptomatic intracranial hemorrhage (ICH) within 36 hours of treatment. The prevalence of EIC on baseline CT in the combined rt-PA and placebo groups was 31% (n = 194). The EIC was significantly associated with baseline NIHSS score (rho = 0.23; P<.001) and time from stroke onset to baseline CT scan (rho = 0.11; P =.007). After adjusting for baseline variables, there was no EIC x treatment interaction detected for any clinical outcome, including deterioration at 24 hours, 4 clinical scales, lesion volume, and death at 90 days (P>/=.25), implying that EIC is unlikely to affect response to rt-PA treatment. After adjusting for NIHSS score (an independent predictor of ICH), no EIC association with symptomatic ICH at 36 hours was detected in the group treated with rt-PA (P>/=.22). Our analysis suggests that EICs are prevalent within 3 hours of stroke onset and correlate with stroke severity. However, EICs are not independently associated with increased risk of adverse outcome after rt-PA treatment. Patients treated with rt-PA did better whether or not they had EICs, suggesting that EICs on CT scan are not critical to the decision to treat otherwise eligible patients with rt-PA within 3 hours of stroke onset.