3D-MR vs. 3D-CT of the shoulder in patients with glenohumeral instability.

OBJECTIVE: To determine whether 3D-MR osseous reformats of the shoulder are equivalent to 3D-CT osseous reformats in patients with glenohumeral instability. MATERIALS AND METHODS: Patients with glenohumeral instability, who were to be imaged with both CT and MRI, were prospectively selected. CT and MR were performed within 24 h of one another on 12 shoulders. Each MR study included an axial 3D isotropic VIBE sequence. The image data from the isotropic VIBE sequence were post-processed using subtraction and 3D software. CT data were post-processed using 3D software. The following measurements were obtained for both 3D-CT and 3D-MR post-processed images: height and width of the humeral head and glenoid, Hill-Sachs size and percent humeral head loss (if present), size of glenoid bone loss and percent glenoid bone loss (if present). Paired t-tests and two one-sided tests for equivalence were used to assess the differences between imaging modalities and equivalence. RESULTS: The measurement differences from the 3D-CT and 3D-MR post-processed images were not statistically significant. The measurement differences for humeral height, glenoid height and glenoid width were borderline statistically significant; however, using any adjustment for multiple comparisons, this failed to be significant. Using an equivalence margin of 1 mm for measurements and 1.5% for percent bone loss, the 3D-MR and 3D-CT post-processed images were equivalent. CONCLUSION: Three-dimensional-MR osseous models of the shoulder using a 3D isotropic VIBE sequence were equivalent to 3D-CT osseous models, and the differences between modalities were not statistically significant.

Imaging techniques in chronic thromboembolic pulmonary hypertension.

PURPOSE OF REVIEW: Chronic thromboembolic pulmonary hypertension (CTEPH) can affect up to 4-5% of patients with acute pulmonary embolism. It is likely an underdiagnosed entity. Misdiagnosis is common because patients often present with nonspecific symptoms of pulmonary hypertension. Early diagnosis may help improve the outcome, as CTEPH is potentially curable with pulmonary thromboendarterectomy (PEA). Imaging is central to an accurate diagnosis, and for assessing correctly the technical feasibility of PEA. This review examines the findings of various imaging techniques in CTEPH and their contribution in the diagnostic and therapeutic evaluation of the disease. RECENT FINDINGS: Ventilation-perfusion scintigraphy remains a sensitive method for excluding CTEPH. Multidetector computed tomography angiography (MDCTA) depicts directly changes of CTEPH, provides a surgical 'road map', and should be used for the diagnostic assessment of all suitable patients with pulmonary arterial hypertension. In many centers, the role of conventional pulmonary angiography is gradually being replaced by cross-sectional methods. MRI has a role in preoperative and postoperative assessment of right ventricular function and can depict vascular abnormalities up to segmental level. SUMMARY: MDCTA in combination with MRI represent the main techniques for the diagnosis and management of CTEPH. Newer techniques such as dual spectrum computed tomography may further improve preoperative and postoperative assessment of CTEPH patients.

Comparative manifestations and diagnostic accuracy of high-resolution computed tomography in usual interstitial pneumonia and nonspecific interstitial pneumonia.

PURPOSE OF REVIEW: Of the idiopathic interstitial pneumonias, the differentiation between idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonitis (NSIP) raises considerable diagnostic challenges, as their clinical presentations share many overlapping features. IPF is a fibrosing pneumonia of unknown cause, showing a histologic pattern of usual interstitial pneumonia (UIP), and has a poorer prognosis than does NSIP. This review examines whether the radiographic features of IFP and NSIP as assessed by high-resolution computed tomography (HRCT) can be used to distinguish between these two entities. RECENT FINDINGS: The diagnostic accuracy of HRCT for UIP and NSIP has been reported to be approximately 70% in various studies. Disagreement between the HRCT diagnosis and the histologic diagnosis occurs in approximately one-third of the cases. The predominant feature of honeycombing on HRCT yields a specificity of approximately 95% and sensitivity of approximately 40% for UIP. In contrast, a predominant feature of ground glass opacities (GGOs) gives a sensitivity of approximately 95% and specificity of approximately 40% for NSIP. SUMMARY: The finding of honeycombing as the predominant HRCT feature suggests the diagnosis of UIP and may exclude the need for biopsy. Predominant features of GGOs are not specific enough to distinguish between NSIP and UIP.

Prevalence and Functional Implication of Silent Coronary Artery Disease in Marathon Runners Over 40 Years of Age: The MATCH-40 Study.

BACKGROUND: Marathon participation is becoming increasingly popular among individuals ≥40 years of age. Little is known about the prevalence of subclinical coronary artery disease (CAD) and corresponding ischemia in this patient population. The study objectives are: (1) to characterize the prevalence of silent CAD in marathoners ≥ 40 years old using cardiac computed tomography angiography (CCT); and (2) if subclinical CAD was detected, to determine the functional significance of occult lesions by stress echocardiography (SE). METHODS: Marathoners aged ≥ 40 years who completed a full marathon between 2018 and 2019 were recruited to undergo a prospective CCT. Coronary artery stenosis was graded as zero, mild (1%-49%), moderate (50%-69%), or severe (> 70%). All study participants diagnosed with mild-to-severe atherosclerotic CAD on CCT further underwent functional imaging with exercise treadmill SE. RESULTS: A total of 65 individuals (53 ± 7 years, 65% males, 24 ± 3 kg/m2) underwent a prospective CCT within 12 months of marathon completion. Of the total study population, 13 participants (20%) were diagnosed with CAD, of whom 10 (77%) had mild disease, 1 (8%) had moderate disease, and 2 (15%) had severe disease by CCT. Despite the identification of subclinical CAD on CCT, none of the 13 patients had any evidence of inducible ischemia on SE. CONCLUSIONS: This is the first study to incorporate both CCT and SE in the evaluation of subclinical CAD in marathoners ≥40 years old. Although the overall prevalence of anatomic CAD was 20%, there was no evidence of functional ischemia in this highly competitive cohort.

CONTEXTE: Les marathons ont gagné en popularité auprès des individus âgés de 40 ans ou plus. On en sait toutefois peu sur la prévalence de la coronaropathie subclinique et de l'ischémie qui lui est associée dans cette population de patients. L'étude visait à 1) caractériser la prévalence de la coronaropathie silencieuse chez les marathoniens âgés de 40 ans ou plus à l'aide d'une angiographie cardiaque par tomodensitométrie (ACTDM) si une coronaropathie subclinique était détectée, à déterminer l'importance fonctionnelle des lésions occultes par une échocardiographie d'effort (EE). MÉTHODOLOGIE: Des marathoniens âgés de 40 ans ou plus ayant réalisé un marathon entre 2018 et 2019 ont été recrutés et soumis à une ACTDM prospective. Les sténoses des artères coronaires étaient classées selon une échelle allant de zéro, légère (1 à 49 %), modérée (50 à 69 %) à sévère (> 70 %). Tous les participants à l'étude ayant reçu un diagnostic de coronaropathie athéroscléreuse légère à sévère à la suite de l'ACTDM ont été soumis à une imagerie fonctionnelle avec EE sur tapis roulant. RÉSULTATS: Au total, 65 sujets (53 ± 7 ans, 65 % d'hommes, 24 ± 3 kg/m2) ont été soumis à une ACTDM prospective dans un délai de 12 mois à la suite de leur dernier marathon. Dans l'ensemble de la population à l'étude, 13 participants (20 %) ont reçu un diagnostic de coronaropathie; 10 (77 %) présentaient une maladie bénigne, 1 (8 %) présentait une maladie modérée et 2 (15 %) présentaient une maladie sévère selon l'ACTDM. Même si une coronaropathie subclinique a été diagnostiquée lors de l'ACTDM, aucun des 13 patients ne présentait de signe d'ischémie inductible à l'EE. CONCLUSIONS: Il s'agit de la première étude à utiliser l'ACTDM et l'EE pour évaluer la présence d'une coronaropathie chez des marathoniens âgés de 40 ou plus. Même si la prévalence globale de la coronaropathie anatomique était de 20 %, il n'y avait aucun signe d'ischémie fonctionnelle au sein de cette cohorte hautement compétitive.

Radiological imaging in pneumonia: recent innovations.

PURPOSE OF REVIEW: Pneumonia is one of the major infectious diseases responsible for significant morbidity and mortality throughout the world. Radiological imaging plays a prominent role in the evaluation and treatment of patients with pneumonia. This paper reviews recent innovations in the radiologic diagnosis and management of suspected pulmonary infections. RECENT FINDINGS: Chest radiography is the most commonly used imaging tool in pneumonias because of availability and an excellent cost-benefit ratio. Computed tomography is mandatory in unresolved cases or when complications of pneumonia are suspected. A specific radiologic pattern can suggest a diagnosis in many cases. Bacterial pneumonias are classified into four main groups: community-acquired, aspiration, healthcare-associated and hospital-acquired pneumonia. The radiographic patterns of community-acquired pneumonia may be variable and are often related to the causative agent. Aspiration pneumonia involves the lower lobes with bilateral multicentric opacities. The radiographic patterns of healthcare-associated and hospital-acquired pneumonia are variable, most commonly showing diffuse multifocal involvement and pleural effusion. SUMMARY: Combination of pattern recognition with knowledge of the clinical setting is the best approach to the radiologic interpretation of pneumonia. Radiological imaging will narrow the differential diagnosis of direct additional diagnostic measures and serve as an ideal tool for follow-up examinations.

Is HRCT the best way to diagnose idiopathic interstitial fibrosis?

PURPOSE OF REVIEW: High-resolution computed tomography (HRCT) has been the major advance in the diagnosis of idiopathic interstitial pneumonias in the last two decades. In diffuse lung diseases, HRCT now has a central role in routine diagnostic evaluation, and a major impact on the utility of other diagnostic tests, especially bronchoalveolar lavage and surgical lung biopsy. RECENT FINDINGS: Numerous published studies have evaluated the accuracy of HRCT. The clinical information was not always utilized to generate a noninvasive diagnosis, however. Despite failure to identify idiopathic pulmonary fibrosis on HRCT in a significant minority of cases, given compatible clinical data, characteristic HRCT appearances justify noninvasive diagnosis in most patients. The limitations of the published studies highlight importance of integrating HRCT data with baseline clinical information and, in selected cases, histopathologic findings. SUMMARY: When HRCT and clinical findings are both typical of an individual diffuse lung disease, i.e. 'pathognomonic', it is generally appropriate to institute management based on a confident noninvasive diagnosis. When clinical and HRCT data are divergent, or when HRCT features are 'indeterminate', however, histologic evaluation continues to play an essential role. Integration of histology with radiologic and clinical data is the best way to formulate the final diagnosis in these cases.

Variable ventilation improves perioperative lung function in patients undergoing abdominal aortic aneurysmectomy.

BACKGROUND: Optimizing perioperative mechanical ventilation remains a significant clinical challenge. Experimental models indicate that "noisy" or variable ventilation (VV)--return of physiologic variability to respiratory rate and tidal volume--improves lung function compared with monotonous control mode ventilation (CV). VV was compared with CV in patients undergoing abdominal aortic aneurysmectomy, a patient group known to be at risk of deteriorating lung function perioperatively. METHODS: After baseline measurements under general anesthesia (CV with a tidal volume of 10 ml/kg and a respiratory rate of 10 breaths/min), patients were randomized to continue CV or switch to VV (computer control of the ventilator at the same minute ventilation but with 376 combinations of respiratory rate and tidal volume). Lung function was measured hourly for the next 6 h during surgery and recovery. RESULTS: Forty-one patients for aneurysmectomy were studied. The characteristics of the patients in the two groups were similar. Repeated-measures analysis of variance (group x time interaction) revealed greater arterial oxygen partial pressure (P = 0.011), lower arterial carbon dioxide partial pressure (P = 0.012), lower dead space ventilation (P = 0.011), increased compliance (P = 0.049), and lower mean peak inspiratory pressure (P = 0.013) with VV. CONCLUSIONS: The VV mode of ventilation significantly improved lung function over CV in patients undergoing abdominal aortic aneurysmectomy.