Computer Assisted Tomography

Imaging of Usual and Unusual Complication of Rotator Cuff Repair Several complications may be encountered after rotator cuff (RC) repair. A thorough knowledge of surgical interventions, normal postoperative findings, and postoperative complications is crucial to provide a timely diagnosis, improving the clinical outcome of patients. Postoperative complications may involve RC, implanted device, osteochondral tissue, surgical-site infection, peripheral nerves, soft tissues, and vascular structures. In this review, we discuss the usual and unusual complications detectable after RC repair.

An Ancillary Sign in the Diagnosis of Bankart and Bankart Variants in Patients With Glenohumeral Instability on Nonarthrographic Magnetic Resonance Imaging: Preglenoid Fat Thickness Objective We investigated whether preglenoid fat thickness can be used as an ancillary sign for preliminary diagnosis of Bankart and its variants on nonarthrographic magnetic resonance imaging. Materials and Methods Sixty-eight anterior dislocation patients were included in this retrospective study. Forty-eight patients with Bankart and its variants, as detected by arthroscopy and magnetic resonance arthrography, were included in the study group. The study group was divided into osseous Bankart, labral Bankart, Perthes, and anterior labroligamentous periosteal sleeve avulsion subgroups. Twenty patients with no detected labral pathologies by arthroscopy and magnetic resonance arthrography were included in the control group. In these patients, preglenoid fat tissue thickness at the anteroinferior portion was measured at the level of the glenoid tubercle. Thickness of preglenoid fat tissue was compared between groups with different labral pathologies and those with normal labrum. Results The preglenoid fat tissue thickness was 2.65 ± 1.05 mm in the control group and 0.90 ± 0.59 mm in the study group (P < 0.0001). Patients with preglenoid fat tissue thinner than 1.6 mm showed a significantly increased likelihood of having Bankart and its variants in receiver operating characteristic analysis (sensitivity of 95.8% and specificity of 85%). There was no significant difference in preglenoid fat tissue thickness between the subgroups of the study group (osseous Bankart, labral Bankart, Perthes, and anterior labroligamentous periosteal sleeve avulsion). Conclusion Preglenoid fat tissue measurement can be used as an ancillary sign in the diagnosis of Bankart and Bankart variants in glenohumeral instability patients.

Comparison of Cone-Beam Computed Tomography and Multislice Computed Tomography in the Assessment of Extremity Fractures Objectives The aims of this study were to evaluate the agreement between cone-beam computed tomography (CBCT) and multislice computed tomography for the characterization of extremity fractures and to compare image quality, radiation dose, and patient tolerance. Methods Thirty-six patients with suspected fracture affecting distal extremities or who required preoperative fracture assessment were enrolled prospectively. Each patient underwent CBCT and multislice computed tomography the same day. Both examinations were evaluated independently twice by 2 trained radiologists using the Müller AO classification for fracture characterization. Results Cohen κ coefficient for agreement between the imaging techniques was almost perfect for fracture characterization, κ = 0.94 [95% confidence interval, 0.91–0.98]. There was substantial to almost perfect agreement for secondary findings. Cone-beam computed tomography was well tolerated and significantly less irradiant and had better subjective image. Conclusions An excellent agreement between both imaging techniques was found. This confirms the ability of CBCT to assess fractures and its potential in the management of patients with distal limb trauma.

Dual-Energy Computed Tomography in Loosening of Revision Hip Prosthesis: A Comparison Between MARS and non-MARS Images Purpose The aim of the study was to assess potential endoprosthesis loosening in patients after revision total hip arthroplasty, based on monochromatic dual-energy computed tomography (DECT) images obtained with and without metal artifact reduction software (MARS) and comparison with the clinical examination and hip function. Materials and Methods Twenty-five consecutive patients underwent DECT examinations. Two monochromatic data sets were generated: with MARS (75-keV MARS) and without MARS (140-keV non-MARS) and evaluated for signs of loosening, using a dedicated radiological score. The Harris Hip Score (HHS) was used to evaluate patients' hip function. Results The mean radiological score for loosening in the non-MARS group was 16.2, in the MARS group 17.0 and was significantly higher (P < 0.001). Radiological loosening evaluation in non-MARS images correlated with the HHS score (ρ = 0.43, P = 0.03), whereas there was no correlation between MARS images and HHS (ρ = 0.15, P = 0.47). New MARS-related artifacts, which hinder implant-bone interface evaluation, were found in 75-keV MARS images ("pseudo-loosening" in 33 of 34 prostheses, "ground-glass blurring" in 20 of 32). Conclusions High-energy monochromatic DECT images are superior to low-energy DECT MARS images in assessment of the potential loosening and correlate better with the clinical examination outcomes. For revision total hip arthroplasty evaluation, 2 data sets should be assessed inseparably because of extra artifacts in MARS images.

Value of the Cinematic Rendering From Volumetric Computed Tomography Data in Evaluating the Relationship Between Deep Soft Tissue Sarcomas of the Extremities and Adjacent Major Vessels: A Preliminary Study Objective The aim of the study was to assess the value of cinematic rendering (CR) from volumetric computed tomography data in evaluating the relationship between deep soft tissue sarcomas (STSs) of the extremities and the adjacent major vessels. Methods Preoperative contrast-enhanced axial imaging (CEAI) in the arterial phase with three-dimensional volume rendering (VR) and CR of contrast-enhanced computed tomography were used to assess adjacent vascular invasion in 43 cases of deep STSs of the extremities. The imaging assessments were compared with surgical findings and interpreted as negative (no vascular invasion) or positive (vascular invasion was present). Intrareader and interreader agreement were assessed using Cohen κ statistics. The diagnostic performance of CEAI, VR, and CR was evaluated by receiver operating curve analysis and compared using the DeLong test. Results Thirty-four and nine cases were classified as negative and positive, respectively, in surgery. Intrareader agreement values for the CEAI, VR, and CR assessments were all excellent (0.984, 0.934, and 0.914, respectively), whereas the interreader agreement for CEAI assessments was greater than that for VR and CR (0.969 vs 0.804 and 0.761). Cinematic rendering showed lower accuracy (0.698), sensitivity (0.778), specificity (0.676), positive predictive values (0.389), and negative predictive values (0.920) for vascular invasion diagnosis than CEAI or VR; the accuracy, sensitivity, specificity, positive predictive values, and negative predictive values increased to 0.767, 0.889, 0.735, 0.471, and 0.962 for both CEAI and VR. The results were not statistically significant (all P > 0.05). Conclusions Cinematic rendering has the potential to be used to evaluate vascular invasion in cases of deep STSs of the extremities, but it should be used alongside the traditional methods such as CEAI.

Kinematic Analysis of the Distal Radioulnar Joint in Asymptomatic Wrists Using 4-Dimensional Computed Tomography–Motion Pattern and Interreader Reliability Purpose The aim of this study was to determine the normal measurement values and interobserver performance of the distal radioulnar joint during wrist pronation-supination using 4-dimensional computed tomography (CT). Methods Four-dimensional CT examinations were performed on the asymptomatic contralateral wrists of 10 patients with unilateral chronic wrist pain. Measurements were conducted using the modified radioulnar (mRU) line and epicenter (Epi) methods. Volar subluxation of the ulnar head was demonstrated with negative values. Wilcoxon rank sum test was used to determine the measurement changes. Interobserver agreements were assessed using interclass correlation coefficients. Results In pronation, mRU line measurements (median, 0.09; interquartile range, 0–0.15) were significantly larger than in supination (median, −0.1; interquartile range, −0.18 to 0; P = 0.008).The Epi measurements were not significantly different in pronation (median, 0.03; interquartile range, 0.01–0.07) and supination (median, 0.06; interquartile range, 0.01–0.1; P = 0.799). There was an excellent inter-observer agreement between the two readers using mRU and Epi methods in pronation (0.982, 0.898), midpoint (0.994, 0.827) and supination (0.989, 0.972) positions, respectively. Conclusions Using 4-dimensional CT examination, distal radioulnar joint kinematics in asymptomatic wrists demonstrate excellent interobserver agreements with increased volar ulnar subluxation with supination as detected using mRU, but not the Epi method.

Computed Tomography Angiography and Magnetic Resonance Angiography of Congenital Anomalies of Pulmonary Veins We aimed to review computed tomography and magnetic resonance angiography of congenital anomalies of pulmonary veins. Total anomalous pulmonary venous return shows all pulmonary veins drain abnormally in another site rather than left atrium. Imaging can detect anomalous veins either supracardiac, infracardiac, or mixed. Partial anomalous pulmonary venous return shows some pulmonary vein have abnormal drainage that well delineated with computed tomography angiography. Scimitar syndrome is a type of partial anomalous pulmonary venous return where the pulmonary veins of the right lung drain infracardiac and is associated with right lung hypoplasia and dextrocardia. Pseudoscimitar show anomalous vein that takes a tortuous course and drains into the left atrium producing a false-positive scimitar sign. Cor triatriatum shows septum divide left atrium with proximal chamber receives blood flow from the pulmonary veins. Levoatriocardinal vein is an anomalous connection between the left atrium and anomalous vein from systemic venous system that is embryo logically derived from the cardinal veins. Computed tomography angiography can detect pulmonary vein stenosis, atresia, hypoplasia, and varix. Imaging is important for intimal diagnosis and detects the anomalous vessels and its connection, presence of stenosis, and associated other congenital cardiac anomalies. Also, it is a great role in assessment of patients after surgery.

Circulatory Stasis or Thrombus in Left Atrial Appendage, An Easy Diagnostic Solution Objective The purpose of this study was to assess the diagnostic performance of prone position cardiac multidetector computed tomography (MDCT) in the detection of left atrial appendage (LAA) thrombi and to make differentiate between thrombus and circulatory stasis using transesophageal echocardiography (TEE) as the criterion-standard imaging modality. Methods From December 2014 to April 2016, 53 consecutive patients were admitted to the hospital because of circulatory stasis or/and thrombus. All patients underwent prone-position MDCT and TEE. Prone-position MDCT and TEE sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Results For the MDCT scan in the prone position, the sensitivity, specificity, positive predictive value, and negative predictive value results were 100%, 100%, 100%, and 100%, respectively. Conclusions Multidetector computed tomography scanning in the prone position differentiates circulatory stasis and LAA thrombus, is clinically useful for detecting and ruling out LAA thrombus, and may be an alternative to TEE as a diagnostic tool.

Cardiovascular Magnetic Resonance Provides Evidence of Abnormal Myocardial Strain and Primary Cardiomyopathy in Marfan syndrome Objective Marfan syndrome is an autosomal-dominant genetic disorder caused by mutations in the fibrillin-1 gene. The condition is a connective tissue disease that frequently involves the cardiovascular system. The existence of a primary cardiomyopathy in Marfan syndrome, however, is controversial. The aims of this study were to investigate the prevalence of left ventricular dysfunction with both transthoracic echocardiography and cardiovascular magnetic resonance (CMR) in a cohort of Marfan syndrome patients and to investigate patterns of myocardial strain across the cohort. Methods We used an institutional database to identify all patients with a firm diagnosis of Marfan syndrome based on Ghent criteria. Inclusion required left ventricular ejection fraction (LVEF) to have been measured by both CMR and transthoracic echocardiography within 12 months of each other. Normal LVEF was defined as a value of >55% when measured by CMR. Velocity vector imaging was used to measure left ventricular longitudinal strain patterns by application of feature tracking to cine magnetic resonance images. Results were compared with data from 20 age-matched control subjects. Results Sixty-nine Marfan syndrome patients met the inclusion criteria. The mean age was 35.4 ± 15.0 years, and 56.5% were male. The mean LVEF was 59.0% ± 7.0% by CMR and 59.1% ± 5.8% by echo. One-fifth of Marfan syndrome patients (15/69; 21.7%) had reduced function with LVEF ≤55% by CMR, but only 5 of these were identified by echo. Furthermore, echo identified 5 Marfan syndrome patients as having reduced LVEF in the presence of a normal LVEF by CMR. Some Marfan syndrome patients had abnormal longitudinal strain patterns even with LVEF within the reference range. Conclusions These data provide support for a primary cardiomyopathy in some Marfan syndrome patients. Cardiovascular magnetic resonance is more sensitive than echo for identifying cases with mild systolic dysfunction. Strain analysis may be more sensitive than simple LVEF assessment for identifying at-risk individuals.

Does the Tube Voltage Affect the Characterization of Coronary Plaques on 100- and 120-kVp Computed Tomography Scans Objective The aim of this study was to compare the diagnostic performance of 100- and 120-kVp coronary computed tomography (CT) angiography (CCTA) scans for the identification of coronary plaque components. Methods We included 116 patients with coronary plaques who underwent CCTA and integrated backscatter intravascular ultrasound studies. On 100-kVp scans, we observed 24 fibrous and 24 fatty/fibrofatty plaques; on 120-kVp scans, we noted 27 fibrous and 41 fatty/fibrofatty plaques. We compared the fibrous and the fatty/fibrofatty plaques, the CT number of the coronary lumen, and the radiation dose on scans obtained at 100 and 120 kVp. We also compared the area under the receiver operating characteristic (ROC) curve of the coronary plaques on 100- and 120-kVp scans with their ROC curves on integrated backscatter intravascular ultrasound images. Results The mean CT numbers of fatty and fatty/fibrofatty plaques were 5.71 ± 36.5 and 76.6 ± 33.7 Hounsfield units (HU), respectively, on 100-kVp scans; on 120-kVp scans, they were 13.9 ± 29.4 and 54.5 ± 22.3 HU, respectively. The CT number of the coronary lumen was 323.1 ± 81.2 HU, and the radiation dose was 563.7 ± 81.2 mGy-cm on 100-kVp scans; these values were 279.3 ± 61.8 HU and 819.1 ± 115.1 mGy-cm on 120-kVp scans. The results of ROC curve analysis identified 30.5 HU as the optimal diagnostic cutoff value for 100-kVp scans (area under the curve = 0.93, 95% confidence interval = 0.87–0.99, sensitivity = 95.8%, specificity = 78.9%); for 120-kVp plaque images, the optimal cutoff was 37.4 HU (area under the curve = 0.87, 95% confidence interval = 0.79–0.96, sensitivity = 82.1%, specificity = 85.7%). Conclusions For the discrimination of coronary plaque components, the diagnostic performance of 100- and 120-kVp CCTA scans is comparable.

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182

6948891480

alsfakia@gmail.com