Consecutive Computed Tomography Scans Research Articles

Glucose variations and their impact on the treatment response in advanced colorectal cancer

Introduction: Serum glucose is commonly associated with a bad clinical prognosis in many diseases, including colorectal cancer (CRC). However, the real impact of glucose variation (GV) on the treatment and prognosis of CRC patients is unknown. Due to the absence of information, this study aimed to correlate GV and treatment response in advanced CRC. Materials and Methods: Thirty-eight CRC patients with stage III and IV disease were studied. The selected ones were those who have had two consecutive computed-tomography scans and more than one serum glucose (SG) test between the CT scans, which left 19 people of the original group. Results: The mean age of the 19 analyzed subjects was 58.6 years SD=18.26; CI 95% 50.9 - 71.0. Most of the patients were men (59%), with Wilt-Type KRAS mutation (63.2%), without metastasis (71%) and at a clinical stage III (73.3%). No statistically significant value was found (p=0.126) between GV and treatment response in advanced CRC patients. Conclusion: These findings cannot indicate a direct association between GV and treatment response in advanced CRC patient, but open space for evaluation of new methods of handling glucose variations in attempt to get a better understanding about how glucose may influence the CRC prognosis.

Relation Between Epicardial Fat and Subclinical Atherosclerosis in Asymptomatic Individuals

Excessive quantity of epicardial adipose tissue (EAT) is considered a risk factor for coronary artery disease (CAD). There are limited data, however, on the relationship between the quality of EAT and CAD. We investigated the association between the density and volume of EAT and subclinical CAD defined by positive coronary artery calcification (CAC), using computed tomography (CT). We reviewed 609 consecutive CT scans of patients with a mild to moderate risk for CAD to assess the EAT volume, which was measured manually by tracing the parietal pericardial sac on axial images. Fat density was recorded in mean Hounsfield units (HU), and CAC was measured using the Agatston method. The mean patients' age was 50±11 years, and 393 (64.5%) were men. Overall, CAC was present in 135 (22%) patients, of whom 97 (72%) were men and 38 (28%) were women. The mean EAT volume and density were 65±27 cm and -87.0±3.4 HU, respectively. Patients with CAC had significantly higher EAT volume (74±27 vs. 62±26 cm, P<0.001) and lower EAT density (-88±3 vs. -87±3.4 HU, P<0.001) compared with patients without CAC. Multivariate regression analysis showed that both EAT density (hazard ratio, 0.879; 95% confidence interval, 0.817-0.946; P=0.001) and EAT volume >100 cm (hazard ratio, 1.693; 95% confidence interval, 1.256-2.999; P=0.029) predicted the presence of CAC. Both the quality and quantity of EAT derived from noncontrast CT scan predict subclinical CAD, with lower density and higher volume of epicardial fat associated with higher CACs.

Involvement of the proximal radial ulnar joint in partial radial head fractures: a novel three-dimensional computed tomography scan evaluation method.

Partial radial head fractures (PRHF) can involve the proximal radioulnar joint (PRUJ) or be restricted to the 'safe zone' (SZ) during forearm rotation. The objective of the present study was to develop an assessment method for PRUJ involvement in radial head fractures using axial computed tomography (CT) scans. The area of the radial head in contact with the PRUJ zone was identified, and defined on 18 cadaveric elbows CT scans; the quantitative relationship between PRUJ zone and radial tuberosity was established. Then, four evaluators validated it on PRHF CT scan axial views, classifying the fractures as involving the PRUJ or not. Using the radial tuberosity as the 0° of a 360° circle, the SZ was within 108° to 212° clockwise for a right elbow and counter clockwise for the left elbow. Fifty-five consecutive (30 men, 25 women, mean age of 49 years) partial radial head fracture CT scans were classified: four in the SZ only, three in the PRUJ zone and 48 in both the PRUJ and SZ. The kappa for the inter- and intra-observer agreement was 0.517 and 0.881, respectively. Ninety-three percent of partial radial head fractures will involve the PRUJ and the geometric model developed allows their classification, potentially helping surgeons decide on optimal treatment. Retrospective basic science study. Level III: anatomic study, imaging.

The repeatability of computed tomography lung volume measurements: Comparisons in healthy subjects, patients with obstructive lung disease, and patients with restrictive lung disease.

In this study, we examined the repeatability of computed tomography (CT) lung volume measurements in healthy individuals and patients with obstructive and restrictive lung diseases. To do this, we retrospectively enrolled 200 healthy individuals (group 1), 100 patients with obstructive lung disease (group 2), and 100 patients with restrictive lung disease (group 3) who underwent two consecutive chest CT scans within a 1-year period. The CT lung volume was measured using a threshold-based, three-dimensional auto-segmentation technique at a default range from –200 to –1024 HU. The within-subject standard deviation, repeatability coefficient, within-subject coefficient variability, and intraclass correlation coefficient were evaluated. No significant differences were identified between the two consecutive CT lung volume measurements in any of the groups (p> 0.05). The within-subject standard deviations for groups 1, 2, and 3 were 441.1, 387.0, and 288.6, respectively, while the repeatability coefficients were 1222.6, 1072.6, and 800.1, respectively. The within-subject coefficient variabilities for groups 1, 2, and 3 were 0.097, 0.083, and 0.090, respectively, while the intraclass correlation coefficients were 0.818, 0.881, and 0.910, respectively. The two CT lung volume measurements showed excellent agreement in healthy individuals and patients with obstructive or restrictive lung disease. However, the repeatability was lower in healthy individuals than it was in patients with lung diseases.

Radioanatomic Study of the Greater Palatine Canal Relevant to Endoscopic Endonasal Surgical Landmarks.

Objective A radioanatomic study of surgically relevant variations in the greater palatine canal (GPC) on computed tomography (CT) was performed to determine susceptibility during endoscopic endonasal procedures. Study Design Blinded radioanatomic analysis. Setting Tertiary university hospital. Subjects and Methods Fifty consecutive paranasal CT scans (100 sides) were analyzed. Measurements were standardized to landmarks such as the inferior turbinate (IT) and floor of the nasal cavity (FNC) to assess variability and vulnerability of the nerve. Measurements included (1) incidence of maxillary sinus pneumatization posterior to the GPC, (2) distance from the posterior wall of the maxillary sinus to the GPC at the IT and FNC, (3) width of bone containing the GPC, (4) incidence of medial GPC dehiscence, and (5) angle of the GPC extending from the IT to FNC. Results Ninety-one percent of maxillary sinuses were pneumatized posterior to the GPC. The distance from the posterior wall of the maxillary sinus to the GPC was 2.8 ± 1.7 mm (range, -2.3 to 5.9) at the posterior attachment of the IT and 4.1 ± 3.1 mm (range, -6.3 to 11.9) at the FNC. The width of bone containing the GPC was 3.3 ± 1.3 mm (range, 1-8.9), and the medial bony GPC was dehiscent in 38% of cases. In the sagittal plane, the angle of the GPC between the IT and the FNC was 31.9 ± 6.9 degrees (range, 10.8-45). Conclusion The GPC has considerable anatomic variability relative to important surgical landmarks in endoscopic procedures. Preoperative review of CTs to assess vulnerability may prevent postoperative complications.

Computer-aided Detection Fidelity of Pulmonary Nodules in Chest Radiograph.

Aim:The most ubiquitous chest diagnostic method is the chest radiograph. A common radiographic finding, quite often incidental, is the nodular pulmonary lesion. The detection of small lesions out of complex parenchymal structure is a daily clinical challenge. In this study, we investigate the efficacy of the computer-aided detection (CAD) software package SoftView™ 2.4A for bone suppression and OnGuard™ 5.2 (Riverain Technologies, Miamisburg, OH, USA) for automated detection of pulmonary nodules in chest radiographs.Subjects and Methods:We retrospectively evaluated a dataset of 100 posteroanterior chest radiographs with pulmonary nodular lesions ranging from 5 to 85 mm. All nodules were confirmed with a consecutive computed tomography scan and histologically classified as 75% malignant. The number of detected lesions by observation in unprocessed images was compared to the number and dignity of CAD-detected lesions in bone-suppressed images (BSIs).Results:SoftView™ BSI does not affect the objective lesion-to-background contrast. OnGuard™ has a stand-alone sensitivity of 62% and specificity of 58% for nodular lesion detection in chest radiographs. The false positive rate is 0.88/image and the false negative (FN) rate is 0.35/image. From the true positive lesions, 20% were proven benign and 80% were malignant. FN lesions were 47% benign and 53% malignant.Conclusion:We conclude that CAD does not qualify for a stand-alone standard of diagnosis. The use of CAD accompanied with a critical radiological assessment of the software suggested pattern appears more realistic. Accordingly, it is essential to focus on studies assessing the quality-time-cost profile of real-time (as opposed to retrospective) CAD implementation in clinical diagnostics.

Infarct Core Expansion on Computed Tomography before and after Intravenous Thrombolysis

PurposeInfarct core can expand rapidly in acute stroke patients receiving intravenous tissue plasminogen activator (IV t-PA). We investigated changes in the extent of infarct core during IV t-PA treatment, and explored the associative factors of this infarct core expansion in patients with proximal artery occlusion.Materials and MethodsWe included patients who were considered for sequential intra-arterial therapy (IAT) due to occlusion of intracranial proximal artery after IV t-PA. Patients who had a baseline Alberta Stroke Program Early Computed Tomography (CT) Score (ASPECTS) ≥6 and who underwent two consecutive CT scans before and shortly after IV t-PA infusion were enrolled. Patients were classified into no, moderate, and marked expansion groups based on decreases in ASPECTS (0–1, 2–3, and ≥4, respectively) on follow-up CT. Collateral status was graded using CT angiography.ResultsOf the 104 patients, 16 (15.4%) patients showed moderate and 13 (12.5%) patients showed marked infarct core expansion on follow-up CT scans obtained at 71.1±19.1 min after baseline CT scan. Sixteen (15.4%) patients had an ASPECTS value <6 on the follow-up CT. None of the patients with marked expansion were independent at 3 months. Univariate analysis and ordinal logistic regression analysis demonstrated that the infarct core expansion was significantly associated with collateral status (p<0.001).ConclusionAmong patients who were considered for IAT after IV t-PA treatment, one out of every seven patients exhibited marked expansion of infarct core on follow-up CT before IAT. These patients tend to have poor collaterals and poor outcomes despite rescue IAT.

Sarcopenia in Advanced Serous Ovarian Cancer.

Cancer cachexia is a paraneoplastic syndrome comprising involuntary weight loss and muscle depletion (sarcopenia). Although weight loss has been associated with poor clinical outcome, there is only limited information on the prevalence and prognostic impact of sarcopenia in ovarian cancer so far. Total skeletal muscle mass was determined by computed tomography image analysis of the third lumbar skeletal muscle cross-sectional area in 128 patients with advanced serous ovarian cancer. Longitudinal change of muscle mass was studied in 209 consecutive computed tomography scans from 43 patients. Association with survival was determined using Cox proportional hazards model. The prevalence of sarcopenia at first diagnosis was 11% (12/105; 95% confidence interval [CI], 6%-20%). Sarcopenic patients had a significantly reduced progression-free (hazard ratio, 2.64; 95% CI, 1.24-5.64; P = 0.012) and overall survival (hazard ratio, 3.17; 95% CI, 1.29-7.80; P = 0.012). On multivariable analysis, these prognostic effects remained significant after adjustment for age, International Federation of Gynecology and Obstetrics stage, and postsurgical residual disease. Longitudinal analyses identified both patients with loss and gain of muscle mass. However, change in muscle mass over time was not associated with survival. Baseline sarcopenia is a prognostic factor in advanced serous ovarian cancer. Identification of sarcopenic patients and early enrollment in physical or nutritional education programs might thus be a feasible way to improve outcome and should be further evaluated in prospective clinical trials.

Tracheal collapse diagnosed by multidetector computed tomography: evaluation of different image analysis methods

ABSTRACT Background: The gold standard for diagnosing excessive tracheal collapse is still evaluation during bronchoscopy. Today, multidetector computed tomography (MDCT) is used to confirm a suspicion of abnormal tracheal collapse. There is no gold standard for computed tomography (CT) image analysis of tracheal collapse. Purpose: To evaluate four different methods for the diagnosis of tracheal collapse using the images obtained through MDCT to help clinicians evaluate the images in daily practice. Objectives: 374 consecutive high-resolution CT scans with full inspiratory and end-expiratory CT scans were retrospectively analyzed. Methods: The images were analyzed in four different ways. The degree of collapse was based on cross-sectional areas of individual locations or volumes of entire regions: (1) 1 cm above the carina, (2) the level of maximal collapse of the trachea, (3) the entire region from the carina to the thoracic inlet, and (4) the trachea and bronchial region as defined by the software. Results: We compared three existing and one new method for image analysis of tracheal collapse by MDCT. The prevalence of tracheal collapse varied from 10.7% to 19.5% in this cohort of patients suffering from mixed lung diseases when using an expiratory collapse of ≥50% as a threshold. The four methods were comparable with highly significant Pearsons correlation coefficients (0.764–0.856). However, the four methods identified different patients with collapse of ≥50%. There was no correlation between symptoms and the degree of collapse. Conclusion: The different methods identify tracheal collapse in different patients. Hence, the diagnosis of excessive tracheal collapse can not rely solely on MDCT images. Generally, there is a poor correlation between symptoms and the degree of collapse in the different methods. However, when using the maximal collapse, there is some correlation with symptoms. When in doubt regarding the diagnosis, further investigations, such as bronchoscopy, should be carried out.

Calculation of an Optic Nerve Injury Risk Profile Before Sphenoid Sinus Surgery.

Our objective was to analyze variations in the optic nerve (ON) course and surrounding structures in an effort to construct an optic nerve injury risk profile before endoscopic intranasal sphenoidal, or endoscopic endonasal transphenoidal, skull-base surgery, and eventually to construct and formulate a common classification by combining the known classes. The authors used computed tomography (CT) toward this end. The authors retrospectively reviewed 200 consecutive CT scans (400 sides) of the paranasal sinuses. The pneumatization of the anterior clinoid process, the relationships of the ONs to the sphenoidal sinuses, and ON dehiscence were evaluated. The authors then created a formula by which risk profiles can be constructed for patients for whom sphenoid or parasellar surgery is planned. Pneumatization of the anterior clinoid process was evident in 28.25%. Dehiscence of the bony wall of the ON was evident in 9.5%. The ON course lay adjacent to the sphenoidal sinus, causing sinus wall indentation, in 23%. Cumulative optic nerve injury risk scoring showed that, radiologically, surgery on 8.5% and 1.5% of sphenoid sinuses described here carried severe or critical risk of ON injury, respectively. Head-and-neck surgeons and neurosurgeons should be aware of variations in ON course. The authors composed an optic nerve injury risk classification category based on the sum of individual weights of each of these classes. Reductions in ON injuries require careful evaluation of potential variant anatomies. Preoperative CT scans must be meticulously reviewed to avoid ON injury.

Indices of Paraspinal Muscles Degeneration: Reliability and Association With Facet Joint Osteoarthritis: Feasibility Study.

A reliability and cross-sectional observational study. To introduce a scoring system for visible fat infiltration in paraspinal muscles; to evaluate intertester and intratester reliability of this system and its relationship with indices of muscle density; to evaluate the association between indices of paraspinal muscle degeneration and facet joint osteoarthritis. Current evidence suggests that the paraspinal muscles degeneration is associated with low back pain, facet joint osteoarthritis, spondylolisthesis, and degenerative disc disease. However, the evaluation of paraspinal muscles on computed tomography is not radiological routine, probably because of absence of simple and reliable indices of paraspinal degeneration. One hundred fifty consecutive computed tomography scans of the lower back (N=75) or abdomen (N=75) were evaluated. Mean radiographic density (in Hounsfield units) and SD of the density of multifidus and erector spinae were evaluated at the L4-L5 spinal level. A new index of muscle degeneration, radiographic density ratio=muscle density/SD of density, was calculated. To evaluate the visible fat infiltration in paraspinal muscles, we proposed a 3-graded scoring system. The prevalence of facet joint osteoarthritis was also evaluated. Intraclass correlation and κ statistics were used to evaluate inter-rater and intra-rater reliability. Logistic regression examined the association between paraspinal muscle indices and facet joint osteoarthritis. Intra-rater reliability for fat infiltration score (κ) ranged between 0.87 and 0.92; inter-rater reliability between 0.70 and 0.81. Intra-rater reliability (intraclass correlation) for mean density of paraspinal muscles ranged between 0.96 and 0.99, inter-rater reliability between 0.95 and 0.99; SD intra-rater reliability ranged between 0.82 and 0.91, inter-rater reliability between 0.80 and 0.89. Significant associations (P<0.01) were found between facet joint osteoarthritis, fat infiltration score, and radiographic density ratio. Two suggested indices of paraspinal muscle degeneration showed excellent reliability and were significantly associated with facet joint osteoarthritis. Additional studies are needed to evaluate the associations with other spinal degeneration features and low back pain.

Magnetic resonance imaging and computed tomography for diagnosing semicircular canal dehiscence.

We investigated the semicircular canal (SC) dehiscence using temporal computed tomography (CT) and magnetic resonance (MR) imaging. We retrospectively reviewed 114 (228 ears) consecutive MR images and CT scans of the temporal bones for dehiscence of the SCs. In the 1.5 Tesla (T) MR imaging, T1 and T2-weighted images were obtained. Dehiscence of the SCs was defined by absence of high attenuation bone coverage on the CT scans, and absence of low-signal bone margins on the MR images. Superior SC dehiscence was detected in 4 (1.8%) ears using CT scans and 5 (2.2%) ears using MR imaging. Posterior SC dehiscence was detected in 4 (1.8%) ears using CT scans and 4 (1.8%) ears using MR imaging. In the non-dehiscent cases, there was hypointense bone coverage between the canal and the cerebrospinal fluid (CSF). However, in the cases of semicircular canal dehiscence, hypointense bone tissue did not appear between the canal and the CSF in the MR imaging. If there is clinical doubt about the presence of SC dehiscence, we recommend that MR imaging be conducted first. When dehiscence is not seen in the MR, a CT examination should be performed. MR imaging is preferred primarily, because it does not contain ionizing radiation.

Variations in arterial supply to the lower lumbar spine.

Several papers examined the vascular anatomy of the lumbosacral region using cadavers with angiography. However, few reports used CT angiography, and discussion on variations of fourth lumbar, fifth lumbar, and lumbar branch of iliolumbar arteries were limited. To clarify the vascular variations around the lower lumbar spine including the lumbosacral region, particularly at the posterior elements, we performed anatomical analysis using computed tomography (CT). Extra-osseous arteries surrounding the lumbar spine including the lumbosacral region were evaluated by two orthopedic surgeons independently, using 323 consecutive abdominal contrast-enhanced multi-planner CT scans that were taken for surgical plans in colon cancer patients. Subjects were 204 men and 119 women, whose ages ranged from 15 to 89years (mean 66.5). Each segmental artery was visible at the L1-4 spinal levels, running from the vertebra through the lamina in 91.0% on the right side, in 90.7% on the left side, while it was visible in 4.6% on the right side, in 8.7% on the left side at the L5 level. The extra-osseous arterial supply to the L5 lamina was basically provided by two vessels on each side. One was mostly derived from the L4 segmental artery (right: 92.6%; left: 92.0%) that was distributed around the superior articular process, the other was derived from the iliolumbar artery (right: 62.9%; left: 55.7%) that was distributed around the inferior articular process through the lamina. There were mainly four combination patterns of those arteries. These combinations, which had been considered as regular patterns in textbooks, were observed in approximately 50% (right: 55.7%; left: 48.6%) of patients. Various distributions of arteries around the lower spine were identified.

The prevalence of chondrocalcinosis of the symphysis pubis on CT scan and correlation with calcium pyrophosphate dihydrate crystal deposition disease.

Calcium pyrophosphate dihydrate (CPP) crystal deposition in the articular cartilage can often be seen radiographically as chondrocalcinosis (CC). CPP crystals preferentially deposit in fibrocartilages such as the knee menisci and symphysis pubis (SP). We sought to determine the prevalence of CC in the SP on computed tomography (CT) of the abdomen and pelvis. This retrospective study involved readings on 1070 consecutive CTs of the abdomen and pelvis performed over 3 months in patients over 65 years of age. Medical records of 226 patients found to have CC were reviewed to determine age, gender, documentation of CPPD on problem lists or in medical histories, and whether radiology readings of the CTs mentioned CC. SP CC was identified in 21.1 % (226/1070) of consecutive CT scans with the mean age of CT+ patients being 78.6. Of the 226 patients with SP CC, the observation of CC was documented in only 5.3 % (12/226) of the radiology reports. Of the 12 instances in which the radiology reports mentioned CC, this observation was never (0/12) transmitted to the medical history or problem list. The prevalence of SP CC in patients older than 65 was 21.1 %. Since the majority of CTs of the abdomen and pelvis are not ordered for evaluation of musculoskeletal conditions, this is likely a true prevalence without selection bias. When CC of the SP was present on images, radiologists routinely overlooked or chose not to report CC. Even in the rare instances when it was reported, that information was not added to the medical history or problem list. There are several clinical situations (e.g., acute monoarthritis or atypical osteoarthritis) in which recognizing that a patient has CPP deposition would be useful. Taking the time to review images may yield clinically important findings that are not mentioned anywhere on the patient chart.

Evaluation of Lacrimal Gland Dimensions and Volume in Turkish Population with Computed Tomography.

Computed tomography (CT) is a widespread method for evaluating head and neck pathologies. The lacrimal glands (LGs) are usually visible in routine head and neck CT scans. LG pathologies usually manifests with changes in gland sizes, so it is important to know the normal values of the LG dimensions and volume. The LG sizes may change with age, gender and race. The normal values of LG dimensions and volume in Turkish population was not reported before. The aim of this study was to evaluate the dimensions and volumes of the LGs by CT in a Turkish population. Two hundred seventeen consecutive paranasal CT scans of subjects evaluated retrospectively. Measurements of LG dimensions were performed in axial and coronal paranasal CT images. The LG volume was calculated with Aquarius software by outlining the gland in all consecutive axial images. Four hundred orbits of 200 subjects were included to the study. The mean axial LG length in right and left orbits were 16.2±2.0 mm and 16.0±2.0 mm and the mean axial width of the right and left orbits were 4.1±0.7 mm and 4.0±0.7 mm. The right and left LG mean values for coronal length and width were equal 18.3 ±2.2 mm and 4.1±0.7mm respectively. The mean LG volume was 0.617±0.210 cm(3) in right and 0.597±0.197 cm(3) in the left orbits. There were statistically significant differences in the axial width and volume of the LG according to sides, however there was no significant difference according to gender. Age and LG measurements were negatively correlated. Our study may serve as a guide to determine the average values of the LG measurements in Turkish population and find out the orbital pathologies that involves the LG.

Poorly recognized age-related downward deviation of the inguinal ligament.

Objective:To determine factors affecting actual inguinal ligament course in live human subjects.Introduction and hypothesis:Although the expected inguinal ligament course is supposedly a straight line extending from anterior superior iliac spine to pubic tubercle, the actual inguinal ligament course is frequently depicted a priori by a downward bowing dotted line. There are no studies in a live subject supporting this assumption. We hypothesized this assumption is indeed valid and is related to among other factors a lifelong effect of gravity and lax abdominal musculature on the inguinal ligament course.Methods:We retrospectively reviewed 54 consecutive computed tomography scans of the abdomen and pelvis randomly distributed across all age groups. Actual inguinal ligament course was visualized by reconstructing images using Terracon software. Vertical distance from the lowest point of actual inguinal ligament course to the expected inguinal ligament course was measured. We used multiple linear regression analysis to study the correlation between degree of inguinal ligament deviation and several variables.Results:Actual inguinal ligament course was below the expected inguinal ligament course in 52 of 54 patients. The mean deviation was 8.2 ± 5.9 mm. Advanced age was significantly associated with greater downward bowing of the inguinal ligament (p = 0.001).Conclusion:Actual inguinal ligament course is often well below the expected inguinal ligament course; this downward bowing of the inguinal ligament is especially pronounced with advancing age. Operators need to be mindful as this downward bowing can lead to supra-inguinal sticks causing vascular complications.

Isolated free intra-abdominal fluid on CT in blunt trauma: The continued diagnostic dilemma

PurposeThe clinical significance of isolated free fluid (FF) without solid organ injury on computed tomography (CT) continues to pose significant dilemma in the management of patients with blunt abdominal trauma (BAT). MethodsWe reviewed the incidence of FF and the clinical outcome amongst patients with blunt abdominal trauma in a metropolitan trauma service in South Africa. We performed a retrospective study of 121 consecutive CT scans over a period of 12 months to determine the incidence of isolated FF and the clinical outcome of patients managed in a large metropolitan trauma service. ResultsOf the 121 CTs, FF was identified in 36 patients (30%). Seven patients (6%) had isolated FF. Of the 29 patients who had free fluid and associated organ injuries, 33 organ injuries were identified. 86% (25/29) of all 29 patients had a single organ injury and 14% had multiple organ injuries. There were 26 solid organ injuries and 7 hollow organ injuries. The 33 organs injured were: spleen, 12; liver, 8; kidney, 5; pancreas, 2; small bowel, 4; duodenum, 1. Six (21%) patients required operative management for small bowel perforations in 4 cases and pancreatic tail injury in 2 cases. All 7 patients with isolated FF were initially observed, and 3 (43%) were eventually subjected to operative intervention. They were found to have an intra-peritoneal bladder rupture in 1 case, a non-expanding zone 3 haematoma in 1 case, and a negative laparotomy in 1 case. Four (57%) patients were successfully managed without surgical interventions. ConclusionsIsolated FF is uncommon and the clinical significance remains unclear. Provided that reliable serial physical examination can be performed by experienced surgeons, an initial non-operative approach should be considered.

CT-based morphometric analysis of C1 laminar dimensions: C1 translaminar screw fixation is a feasible technique for salvage of atlantoaxial fusions.

Background:Translaminar screw fixation has become an alternative in the fixation of the axial and subaxial cervical spine. We report utilization of this approach in the atlas as a salvage technique for atlantoaxial stabilization when C1 lateral mass screws are precluded. To assess the feasibility of translaminar fixation at the atlas, we have characterized the dimensions of the C1 lamina in the general adult population using computed tomography (CT)-based morphometry.Methods:A 46-year-old male with symptomatic atlantoaxial instability secondary to os odontoideum underwent bilateral C1 and C2 translaminar screw/rod fixation as C1 lateral mass fixation was precluded by an anomalous vertebral artery. The follow-up evaluation 2½ years postoperatively revealed an asymptomatic patient without recurrent neck/shoulder pain or clinical signs of instability. To better assess the feasibility of utilizing this approach in the general population, we retrospectively analyzed 502 consecutive cervical CT scans performed over a 3-month period in patients aged over 18 years at a single institution. Measurements of C1 bicortical diameter, bilateral laminar length, height, and angulation were performed. Laminar and screw dimensions were compared to assess instrumentation feasibility.Results:Review of CT imaging found that 75.9% of C1 lamina had a sufficient bicortical diameter, and 63.7% of C1 lamina had sufficient height to accept bilateral translaminar screw placement.Conclusions:CT-based measurement of atlas morphology in the general population revealed that a majority of C1 lamina had sufficient dimensions to accept translaminar screw placement. Although these screws appear to be a feasible alternative when lateral mass screws are precluded, further research is required to determine if they provide comparable fixation strength versus traditional instrumentation methods.

Evaluation of 126 Consecutive Stereotactic Procedures: Brain Biopsy, Diagnostic Yield, Accuracy, Non-Diagnostic Results, Complications and Follow-up.

A retrospective analysis of 126 consecutive computed tomography (CT)-guided, frame-based stereotactic procedures in 121 patients is presented to evaluate the diagnostic yield, accuracy, complications, management of non-diagnostic cases and followup. The medical records of the identified patients were investigated retrospectively. Age, sex, surgical procedures, histopathological diagnosis, diagnostic yield, accuracy, complications, management of non-diagnostic cases and follow-up were analyzed in 121 consecutive patients. Stereotactic procedures were performed by the author by using Leksell's stereotactic system, and stereotactic biopsies were conducted under local anesthesia except for those patients who were not able to tolerate this treatment. These patients had control CT scans two hours after the operation. Patient age ranged from 2 to 82 years (mean 48 years). Stereotactic biopsy was performed in 112 patients. Cyst and abscess aspiration, intracystic catheter replacement and tumor resection with stereotactic craniotomy were among the other procedures. The diagnostic yield was 93%, and the histological accuracy was 63% with no mortality. Craniotomy and hematoma evacuation were required in two cases. The patients were followed up from one month to 17 years. Frame-based stereotactic biopsy is a safe and efficacious method with acceptable complications. Experience is important, but not sufficient for preventing complications and performing procedures accurately. Necrosis and gliosis are the most common non-diagnostic findings. Empirical treatment with presumptive diagnoses based on clinical and radiological findings and close clinical follow-up may not affect patients adversely. The follow-up of patients through examination and imaging is important to allow the revision of treatment when necessary.

Effect of CT contrast on volumetric arc therapy planning (RapidArc and helical tomotherapy) for head and neck cancer

The objectives of the study were to evaluate the effect of intravenous contrast in the dosimetry of helical tomotherapy and RapidArc treatment for head and neck cancer and determine if it is acceptable during the computed tomography (CT) simulation to acquire only CT with contrast for treatment planning of head and neck cancer. Overall, 5 patients with head and neck cancer (4 men and 1 woman) treated on helical tomotherapy were analyzed retrospectively. For each patient, 2 consecutive CT scans were performed. The first CT set was scanned before the contrast injection and secondary study set was scanned 45 seconds after contrast. The 2 CTs were autoregistered using the same Digital Imaging and Communications in Medicine coordinates. Tomotherapy and RapidArc plans were generated on 1 CT data set and subsequently copied to the second CT set. Dose calculation was performed, and dose difference was analyzed to evaluate the influence of intravenous contrast media. The dose matrix used for comparison included mean, minimum and maximum doses of planning target volume (PTV), PTV dose coverage, and V45Gy, V30Gy, and V20Gy organ doses. Treatment planning on contrasted images generally showed a lower dose to both organs and target than plans on noncontrasted images. The doses for the points of interest placed in the organs and target rarely changed more than 2% in any patient. In conclusion, treatment planning using a contrasted image had insignificant effect on the dose to the organs and targets. In our opinion, only CT with contrast needs to be acquired during the CT simulation for head and neck cancer. Dose calculations performed on contrasted images can potentially underestimate the delivery dose slightly. However, the errors of planning on a contrasted image should not affect the result in clinically significant way.