Mm In Axial Diameter Research Articles

Bronchoscopic Evaluation of a Steerable Needle for Simulated Tumor Targets in the Lung Periphery: A Feasibility Study (Bullseye)

Background: Peripheral bronchoscopy is often performed to biopsy peripheral pulmonary lesions. Despite technological advancements to improve reach and access to the lung periphery, the diagnostic yield of peripheral bronchoscopy has been inconsistent, and challenging, particularly for lesions that are adjacent to peripheral bronchi. Current biopsy instruments are reliant on the catheter or scope to align properly with targeted lesions. Objectives: This study evaluates the feasibility of using a steerable biopsy needle to gain access to peripheral tumor targets in a cadaveric model. Methods: Simulated tumor targets 10–30 mm in axial diameter were placed into human cadavers. Bronchoscopy was performed using a 4.2 mm OD flexible bronchoscope, CT-anatomic correlation, and multi-planar fluoroscopy for lesion localization. Once at the targeted location, a steerable needle was deployed and the needle position was determined to be in the central zone, peripheral zone, or outside of the lesion by cone beam CT imaging. If the needle position was within the lesion, a fiducial marker was deployed to mark the needle position, and the needle was articulated and/or rotated in an attempt to place another fiducial marker into a different location within the same lesion. If the needle was outside of the lesion, the bronchoscopist was provided with two additional attempts to gain access to the lesion. Results: Fifteen tumor targets were placed with a mean lesion size of 20.4 mm. The majority of lesions were located in the upper lobes. One fiducial marker was placed in 93.3% of lesions and a second fiducial marker was successfully placed in 80% of lesions. A fiducial marker was placed within the central zone in 60% of lesions. Conclusion: The steerable needle was successfully placed within 93% of targeted lesions 10–30 mm in diameter in a cadaveric model, with the ability steer the instrument into another portion of the lesion in 80% of cases. The ability to steer and control needle positioning toward and within peripheral lesions may complement existing catheter and scope technology during peripheral diagnostic procedures.

Left Pyelic Bifidity and Ectopic Ureteral Superolateral Intravesical Homolateral Ectopic Junction Revealed by a Urinary Calculus Apropos of a Case at the Pasteur Clinic

Introduction: Malformations of the excretory tract are abnormalities due to a disorder of embryogenesis. According to some authors, their frequency varies from 0.30 to 5.25 per 1000. The aim of this study was to highlight the CT uroscan aspect of pyelic bifidity with intravesical ureteral ectopic junction revealed by a urinary calculus and to explain the interest of CT uroscan in the management of urinary pathologies. Result: We report the observation of a 37-year-old overweight patient with a body mass index equal to 28, a history of surgery and extracorporeal litho-thipsis dating back 10 years. He was referred to the Imaging Department in the context of renal colic. The uroscanner made it possible to highlight a left pyelic bifidity associated with an ectopic abutment of the left ureter on the superolateral wall of the bladder, a calculation in the left ectopic ureteral meatus measured at 4 mm in axial diameter. He noted upstream of these lesions, a uretero-pyelo-calicielle dilation on double homolateral pyelon. On late cuts, a slight delay in left renal excretion was noted. The right kidney was also the site of a hyperdense calculation of 1257 HU density and measured 4 mm in transverse diameter with a non-obstructive appearance. Due to a lack of means, our patient was subjected to oral medication, hygiene and dietary rules and rigorous monitoring. Conclusion: At the end of this study, the uroscanner is presented as the reference examination to better explore urinary pathologies. At the same time, it makes it possible to carry out a study of the organs surrounding the urinary tract. Always think about the association of several urinary pathologies each time you see a patient for renal colic.

Accuracy of a Robotic Endoscopic System in Cadaver Models with Simulated Tumor Targets: ACCESS Study

Background: Bronchoscopy for the diagnosis of peripheral pulmonary lesions continues to present clinical challenges, despite increasing experience using newer guided techniques. Robotic bronchoscopic platforms have been developed to potentially improve diagnostic yields. Previous studies in cadaver models have demonstrated increased reach into the lung periphery using robotic systems compared to similarly sized conventional bronchoscopes, although the clinical impact of additional reach is unclear. Objectives: This study was performed to evaluate the performance of a robotic bronchoscopic system’s ability to reach and access artificial tumor targets simulating peripheral nodules in human cadaveric lungs. Methods: Artificial tumor targets sized 10–30 mm in axial diameter were implanted into 8 human cadavers. CT scans were performed prior to procedures and all cadavers were intubated and mechanically ventilated. Electromagnetic navigation, radial probe endobronchial ultrasound, and fluoroscopy were used for all procedures. Robotic-assisted bronchoscopy was performed on each cadaver by an individual bronchoscopist to localize and biopsy peripheral lesions. Results: Sixty-seven nodules were evaluated in 8 cadavers. The mean nodule size was 20.4 mm. The overall diagnostic yield was 65/67 (97%) and there was no statistical difference in diagnostic yield for lesions <20 mm compared with lesions measuring 21–30 mm, the presence of a concentric or eccentric radial ultrasound image, or relative distance from the pleura. Conclusions: The robotic bronchoscopic system was successful at biopsying 97% of peripheral pulmonary lesions 10–30 mm in size in human cadavers. These findings support further exploration of this technology in prospective clinical trials in live human subjects.

Are morphologic features of recent small subcortical infarcts related to specific etiologic aspects?

Background:Recent small subcortical infarcts (RSSIs) mostly result from the occlusion of a single, small, brain artery due to intrinsic cerebral small-vessel disease (CSVD). Some RSSIs may be attributable to other causes such as cardiac embolism or large-artery disease, and their association with coexisting CSVD and vascular risk factors may vary with morphological magnetic resonance imaging (MRI) features.Methods:We retrospectively identified all inpatients with a single symptomatic MRI-confirmed RSSI between 2008 and 2013. RSSIs were rated for size, shape, location (i.e. anterior: basal ganglia and centrum semiovale posterior cerebral circulation: thalamus and pons) and MRI signs of concomitant CSVD. In a further step, clinical data, including detailed diagnostic workup and vascular risk factors, were analyzed with regard to RSSI features.Results:Among 335 RSSI patients (mean age 71.1 ± 12.1 years), 131 (39%) RSSIs were >15 mm in axial diameter and 66 (20%) were tubular shaped. Atrial fibrillation (AF) was present in 44 (13.1%) and an ipsilateral vessel stenosis > 50% in 30 (9%) patients. Arterial hypertension and CSVD MRI markers were more frequent in patients with anterior-circulation RSSIs, whereas diabetes was more prevalent in posterior-circulation RSSIs. Larger RSSIs occurred more frequently in the basal ganglia and pons, and the latter were associated with signs of large-artery atherosclerosis. Patients with concomitant AF had no specific MRI profile.Conclusion:Our findings suggest the contribution of different pathophysiological mechanisms to the occurrence of RSSIs in the anterior and posterior cerebral circulation. While there appears to be some general association of larger infarcts in the pons with large-artery disease, we found no pattern suggestive of AF in RSSIs.

Signal Change of Acute Cortical and Juxtacortical Microinfarction on Follow-Up MRI.

Although the clinical importance of cortical microinfarcts has become well-recognized recently, the evolution of cortical microinfarcts on MR imaging is not fully understood. The aim of this study was to examine the temporal changes in acute cortical microinfarcts using susceptibility-weighted imaging and conventional MR imaging. Patients with acute infarcts located in the cortical and/or juxtacortical region measuring ≤10 mm in axial diameter based on diffusion-weighted imaging who had a follow-up 3T MR imaging were retrospectively included in the study. All lesions did not show hypointensity on initial T2*WI. For cortical and/or juxtacortical microinfarcts detected on initial DWI, 2 neuroradiologists evaluated the follow-up MR imaging (T2WI, FLAIR, T2*WI, and SWI) and assessed lesion signal intensities and locations (cortical microinfarcts or microinfarcts with juxtacortical white matter involvement). On initial DWI, 2 radiologists observed 180 cortical and/or juxtacortical microinfarcts in 35 MR imaging examinations in 25 patients; on follow-up, the neuroradiologists identified 29 cortical microinfarcts (16%) on T2WI, 9 (5%) on FLAIR, 4 (2%) on T2*, and 97 (54%) on SWI. All cortical microinfarcts detected with any follow-up MR imaging showed hyperintensity on T2WI/FLAIR and/or hypointensity on T2*WI and SWI. SWI revealed conversion (paramagnetic susceptibility changes) of acute cortical microinfarcts, suggesting that a substantial number of cortical microinfarcts may contain hemorrhagic components.

Small strokes causing severe vertigo: frequency of false-negative MRIs and nonlacunar mechanisms.

Describe characteristics of small strokes causing acute vestibular syndrome (AVS). Ambispective cross-sectional study of patients with AVS (acute vertigo or dizziness, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with at least one stroke risk factor from 1999 to 2011 at a single stroke referral center. Patients underwent nonquantitative HINTS "plus" examination (head impulse, nystagmus, test-of-skew plus hearing), neuroimaging to confirm diagnoses (97% by MRI), and repeat MRI in those with initially normal imaging but clinical signs of a central lesion. We identified patients with diffusion-weighted imaging (DWI) strokes ≤10 mm in axial diameter. Of 190 high-risk AVS presentations (105 strokes), we found small strokes in 15 patients (median age 64 years, range 41-85). The most common vestibular structure infarcted was the inferior cerebellar peduncle (73%); the most common stroke location was the lateral medulla (60%). Focal neurologic signs were present in only 27%. The HINTS "plus" battery identified small strokes with greater sensitivity than early MRI-DWI (100% vs 47%, p < 0.001). False-negative initial MRIs (6-48 hours) were more common with small strokes than large strokes (53% [n = 8/15] vs 7.8% [n = 7/90], p < 0.001). Nonlacunar stroke mechanisms were responsible in 47%, including 6 vertebral artery occlusions or dissections. Small strokes affecting central vestibular projections can present with isolated AVS. The HINTS "plus" hearing battery identifies these patients with greater accuracy than early MRI-DWI, which is falsely negative in half, up to 48 hours after onset. We found nonlacunar mechanisms in half, suggesting greater risk than might otherwise be assumed for patients with such small infarctions.

Value of CT Enteroclysis in Suspected Small-Bowel Carcinoid Tumors

The purpose of this study was to evaluate the value of CT enteroclysis in depicting small-bowel carcinoid tumors in symptomatic patients with surgical, histologic, or clinical follow-up findings as a reference standard. At our institution, 44 patients with symptoms of suspected gastrointestinal carcinoid tumors underwent CT enteroclysis. Clinical symptoms were as follows: carcinoid syndrome (n = 3), abdominal pain with diarrhea (n = 24), hypervascular liver metastases (n = 7), subileus condition (n = 1), hypervascular peritoneal lesion (n = 3), abnormal ileal stenosis on optical colonoscopy (n = 3), and follow-up extraintestinal carcinoid lesion (n = 3). Positive CT enteroclysis findings were compared with pathology results after surgical procedures (n = 19). Negative examinations were compared with surgery results (n = 3) or clinical follow-up (n = 22). CT enteroclysis findings were positive in 19 patients and negative in 25 patients. The sizes of the carcinoid tumors identified were 5-30 mm in axial diameter. These tumors were depicted as focal nodular lesions located in the small-bowel wall or as intraluminal polypoid masses with marked enhancement. Twenty-two patients underwent only clinical follow-up, with a mean clinical follow-up time of 20 months. The overall sensitivity and specificity of CT enteroclysis in identifying patients with small-bowel carcinoid tumors were 100% and 96.2%, respectively. The negative predictive value of CT enteroclysis was 100% and the positive predictive value, 94.7%. Pathologic findings confirmed small-bowel carcinoid tumors in 18 patients. CT enteroclysis should be considered an excellent tool for the diagnosis of the carcinoid tumor before any surgical procedures.

Histopathologic validation of intracoronary ultrasound imaging.

The purpose of this study was to validate intracoronary ultrasound imaging by correlation with histologic examination. In this in-vitro study of pressure-perfused human coronary arteries, 104 matching intracoronary ultrasound imaging images and histologic cross-sections from 12 hearts were compared to determine the diagnostic accuracy of 30 MHz commercially available intracoronary ultrasound imaging. For lipid deposits, sensitivity was 46% and specificity 97%. The smallest lipid deposit that was visualized measured 0.25 mm in axial diameter on histologic study. For calcific deposits, sensitivity was 77% and specificity 100%. The smallest calcific deposit that was visualized measured 0.25 mm in axial diameter on histologic examination. Atherosclerotic intimal thickening could not be distinguished qualitatively or quantitatively from nonatherosclerotic intimal thickening unless there were localized deposits of lipids or calcium. Intracoronary ultrasound imaging is accurate in detecting lipid and calcium deposits. Intimal thickening in intracoronary ultrasound imaging images does not prove the presence of atherosclerosis.

Sonographische Diagnostik regionärer Halslymphknotenmetastasen bei Patienten mit Kopf-Hals-Malignomen: Sonomorphologische Kriterien und diagnostische Treffsicherheit*

High resolution sonography is generally considered a diagnostic tool with high sensitivity but low specificity in the assessment of cervical lymph node metastases. This study shows, that excellent sonographic results regarding sensitivity and specificity can be achieved, if sonomorphologic parameters, such as size, shape, delineation and type of echo pattern are included in the evaluation. We compared sonomorphology and histology of 82 patients operated for head and neck malignancies. The sonomorphological and histological findings in the largest lymph nodes in all neck areas were compared, and if a definite identification was possible, also in the second largest ones. Virtually, all longitudinal nodes of any size and practically all oval nodes of an axial diameter of up to 20 mm were found to be free of metastases, whereas 80% of round nodes with an axial diameter of up to 20 mm and practically all round and oval nodes exceeding 20 mm in axial diameter as well as irregularly shaped, poorly delineated and structurally inhomogeneous nodes demonstrated metastatic disease. On the basis of these results we have established the following criteria for the assessment of cervical lymph node metastases: All findings demonstrating longitudinal nodes of any size and oval nodes less than 20 mm in axial diameter are to be considered sonographically negative, whereas findings in which oval nodes exceeding 20 mm in axial diameter, as well as round, irregularly shaped, poorly delineated or inhomogeneous lymph nodes are found to be classified malignant. Of 58 sonographically positive neck areas, 54 were found to be malignant on histological examination, while 23 of 24 sonographically negative areas corresponded with histologically benign findings.(ABSTRACT TRUNCATED AT 250 WORDS)