Michael B. Nielsen

Prognostic Implications of Nonobstructive Coronary Plaques in Patients With Non–ST-Segment Elevation Myocardial Infarction: A Multidetector Computed Tomography Study

OBJECTIVESnWe sought to determine whether the amount of noncalcified plaque (NCP) in nonobstructive coronary lesions as detected by multidetector computed tomography (MDCT) was a predictor of future coronary events.nnnBACKGROUNDnPatients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) frequently have multiple coronary plaques, which may be detected with MDCT.nnnMETHODSnWe included 312 consecutive patients presenting with NSTEMI, who underwent 64-slice MDCT coronary angiography and coronary artery calcium scoring before invasive coronary angiography. All patients were treated according to current guidelines based on an invasive treatment approach. Quantitative measurements of plaque composition and volume were performed by MDCT in all nonobstructive coronary lesions. The endpoint was cardiac death, acute coronary syndrome, or symptom-driven revascularization.nnnRESULTSnAfter a median follow-up of 16 months, 23 patients had suffered a cardiac event. Age, male sex, and diabetes mellitus were all associated with an increasing amount of NCP. In a multivariate regression analysis for events, the total amount of NCP in nonobstructive lesions was independently associated with an increased hazard ratio (1.18/100-mm(3) plaque volume increase, p = 0.01). Contrary to this, neither Agatston score nor the amount of calcium in nonobstructive lesions was associated with an increased risk.nnnCONCLUSIONSnMultidetector computed tomography plaque imaging identified patients at increased risk of recurrent coronary events after NSTEMI by measuring the total amount of NCP in nonobstructive lesions. The amount of calcified plaque was not associated with an increased risk.

Key players in pancreatic cancer-stroma interaction: Cancer-associated fibroblasts, endothelial and inflammatory cells

Pancreatic cancer (PC) is the most aggressive type of common cancers, and in 2014, nearly 40000 patients died from the disease in the United States. Pancreatic ductal adenocarcinoma, which accounts for the majority of PC cases, is characterized by an intense stromal desmoplastic reaction surrounding the cancer cells. Cancer-associated fibroblasts (CAFs) are the main effector cells in the desmoplastic reaction, and pancreatic stellate cells are the most important source of CAFs. However, other important components of the PC stroma are inflammatory cells and endothelial cells. The aim of this review is to describe the complex interplay between PC cells and the cellular and non-cellular components of the tumour stroma. Published data have indicated that the desmoplastic stroma protects PC cells against chemotherapy and radiation therapy and that it might promote the proliferation and migration of PC cells. However, in animal studies, experimental depletion of the desmoplastic stroma and CAFs has led to more aggressive cancers. Hence, the precise role of the tumour stroma in PC remains to be elucidated. However, it is likely that a context-dependent therapeutic modification, rather than pure depletion, of the PC stroma holds potential for the development of new treatment strategies for PC patients.

Real-Time Image Fusion Involving Diagnostic Ultrasound

OBJECTIVEnThe aim of our article is to give an overview of the current and future possibilities of real-time image fusion involving ultrasound. We present a review of the existing English-language peer-reviewed literature assessing this technique, which covers technical solutions (for ultrasound and endoscopic ultrasound), image fusion in several anatomic regions, and electromagnetic needle tracking.nnnCONCLUSIONnThe recent progress of real-time ultrasound in image fusion may provide several new possibilities, including diagnosis, treatment, and follow-up of oncologic patients.

In vivo validation of a blood vector velocity estimator with MR angiography

Conventional Doppler methods for blood velocity estimation only estimate the velocity component along the ultrasound beam direction. This implies that a Doppler angle under examination close to 90deg results in unreliable information about the true blood direction and blood velocity. The novel method transverse oscillation (TO), which combines estimates of the axial and the transverse velocity components in the scan plane, makes it possible to estimate the vector velocity of the blood regardless of the Doppler angle. The present study evaluates the TO method with magnetic resonance phase contrast angiography (MRA) by comparing in vivo measurements of stroke volume. Eleven healthy volunteers were included in this prospective study. From the obtained data sets recorded with the 2 modalities, vector velocity sequences were constructed and stroke volume calculated. Angle of insonation was approximately 90deg for TO measurements. The correlation between the stroke volume estimated by TO and MRA was 0.91 (p<0.01) with the equation for the line of regression: MRA=1.1ldrTO-0.4. A Bland-Altman plot was additionally constructed where the mean difference was 0.2 ml with limits of agreement at -1.4 ml and 1.9 ml. The results indicate that reliable vector velocity estimates can be obtained in vivo using the presented angle-independent 2-D vector velocity method. The TO method can be a useful alternative to conventional Doppler systems by avoiding the angle artifact, thus giving quantitative velocity information.

Three-dimensional anal endosonography may improve staging of anal cancer compared with two-dimensional endosonography.

PURPOSEThree-dimensional (3-D) endosonography is a new method of staging anal carcinoma that has not yet been validated in comparison with two-dimensional (2-D) endosonography, the latter using only a single scan plane. The aim of this study was to investigate the differences between the two endosonographic techniques.METHODSThirty patients with an endosonographically detectable anal tumor were examined with a 10 MHz rotating endoprobe. Cross-sectional images of the anal sphincters were stored on a 3-D system during retraction of the endoprobe through the anal canal. Afterwards, any projection could be reconstructed. Cross-sectional images (2-D) were compared with reconstructed projections (3-D) according to five parameters concerning tumor spread and presence of regional lymph nodes. In this study, a scale of 0 to 5 points on critical issues was used; ideally, the results should be identical in 2-D and 3-D endosonography.RESULTSThe 3-D method detected a median of 5 diagnostic findings, compared with a median of 4 findings with the 2-D method (P = 0.001). In eight patients the lateral tumor margin was visualized only by 3-D endosonography. The median number of lymph nodes visualized in 3-D was 1 (range, 0-13), in 2-D the median number was 0 (range, 0-6), P = 0.002.CONCLUSIONSUse of 3-D endosonography in patients with anal carcinoma improves detection of perirectal lymph nodes and may improve that of tumor invasion, compared with 2-D endosonography. This may affect local tumor staging and thus planning of treatment. A study with histopathologic correlation is needed to verify this endosonographic study.

A Comparative Study of Strain and Shear-Wave Elastography in an Elasticity Phantom

OBJECTIVE. The purpose of this study was to assess the diagnostic accuracy of strain and shear-wave elastography for determining targets of varying stiffness in a phantom. The effect of target diameter on elastographic assessments and the effect of depth on shear-wave velocity were also investigated. MATERIALS AND METHODS. We examined 20 targets of varying diameters (2.5-16.7 mm) and stiffnesses (8, 14, 45, and 80 kPa) with a 4-9-MHz linear-array transducer. Targets were evaluated 10 times with three different methods-shear-wave elastography, strain ratio, and strain histogram analysis-yielding 600 evaluations. AUCs were calculated for data divided between different stiffnesses. A 1.5-6-MHz curved-array transducer was used to assess the effect of depth (3.5 vs 6 cm) on shear-wave elastography in 80 scans. Mixed model analysis was performed to assess the effect of target diameter and depth. RESULTS. Strain ratio and strain histogram AUCs were higher than the shear-wave velocity AUC (p < 0.001) in data divided as 80 versus 45, 14, and 8 kPa. In data divided as 80 and 45 versus 14 and 8 kPa, the methods were equal (p = 0.959 and p = 1.000, respectively). Strain ratios were superior (p = 0.030), whereas strain histograms were not significantly better (p = 0.083) than shear-wave elastography in data divided as 80, 45, and 14 versus 8 kPa. Target diameter had an effect on all three methods (p = 0.001). Depth had an effect on shear-wave velocity (p = 0.001). CONCLUSION. The ability to discern different target stiffnesses varies between shear-wave and strain elastography. Target diameter affected all methods. Shear-wave elastography is affected by target depth.

Three-Dimensional Anal Endosonography May Improve Detection of Recurrent Anal Cancer

PurposeIn our center since 2001, follow-up examination has included three-dimensional endosonography in all patients with suspicion of local recurrence of anal cancer. This study was designed to investigate whether three-dimensional endosonography surpassed two-dimensional endosonography as a diagnostic tool for patients with suspected local recurrence.MethodsThis prospective study included 38 consecutive patients who have had anal carcinoma and were investigated using three-dimensional endosonography in combination with anoscopy and digital rectal examination at Rigshospitalet from July 2001 to January 2005 under suspicion of local recurrence. All endosonographic examinations—two-dimensional, three-dimensional, and three-dimensional in combination with anoscopy and digital rectal examination—were evaluated by blinded observers. The observers scored each examination according to a five-point scale in which a score from 1 to 3 was regarded as benign endosonographic findings and a score from 4 to 5 was regarded as malignant endosonographic findings. The endosonographic diagnosis for each examination was compared with histologic evaluation or when no biopsy had been taken with a follow-up period of at least six months. If a patient showed no signs of local recurrence in the follow-up period, no local recurrence was considered to be present at the time of the investigation.ResultsThe sensitivity was 1.0 for three-dimensional endosonography in combination with palpation, 0.86 for three-dimensional endosonography alone, and 0.57 for two-dimensional endosonography. The differences between two-dimensional endosonography and three-dimensional endosonography alone as well as two-dimensional endosonography and three-dimensional endosonography + anoscopy and digital rectal examination both reached significance with P values <0.05.ConclusionsThis study indicates that three-dimensional endosonography surpasses two-dimensional endosonography in the evaluation of patients with suspicion of local recurrence of anal cancer especially in combination with anoscopy and digital rectal examination.

Major femoral vascular access complications after coronary diagnostic and interventional procedures: A Danish register study☆

BACKGROUNDnVascular access complications after coronary angiography (CAG) and percutaneous coronary intervention (PCI) are known to increase morbidity, prolong hospitalization and raise hospital costs. Therefore, risk factor identification and improvement of safety strategies for vascular management are important. We aimed to assess the incidence of major vascular complications related to femoral access, and to identify potential risk factors.nnnMETHODSnOver a period of six years, 23,870 index procedures (CAG) were performed in two centres, prospectively entered in the database and retrospectively analysed. Data was obtained from the Eastern Danish Heart Registry and cross-matched with data from the Danish Vascular Registry. Index procedures were defined as the first trans-femoral procedure. Demographic, procedural and mortality data, as well as information on access complications requiring surgery within 30 days were collected. Mortality data were collected for minimum 12 months.nnnRESULTSnWe identified 130 (0.54%) access complications requiring surgery; 65 pseudoaneurysms (0.28%), 46 arterial occlusions (0.19%), 15 hematomas (nine groin and six retroperitoneal hematomas) (0.06%), and 4 arterial dissections (0.02%). Risk factors for complications were left sided femoral access (OR 4.11 [2.29-7.37] p<0.001), peripheral arterial disease (PAD) (OR 2.42 [1.48-3.94] p<0.0001) and female sex (OR 2.22 [1.51-3.24] p<0.0001).nnnCONCLUSIONnVascular complications related to femoral access in coronary diagnostic and interventional procedures are low (0.54%). Risk factors were left sided access, PAD, and female sex.

Does bony hip morphology affect the outcome of treatment for patients with adductor-related groin pain? Outcome 10 years after baseline assessment

Background Adductor-related groin pain and bony morphology such as femoroacetabular impingement (FAI) or hip dysplasia can coexist clinically. A previous randomised controlled trial in which athletes with adductor-related groin pain underwent either passive treatment (PT) or active treatment (AT) showed good results in the AT group. The primary purpose of the present study was to evaluate if radiological signs of FAI or hip dysplasia seem to affect the clinical outcome, initially and at 8–12u2005years of follow-up. Methods 47 patients (80%) were available for follow-up. The clinical result was assessed by a standardised clinical outcome combining patient-reported activity, symptoms and physical examination. Anterioposterior pelvic radiographs were obtained and the centre-edge angle of Wiberg, α angle, presence of a crossover sign and Tönnis grade of osteoarthritis were assessed by a blinded observer using a reliable protocol. Results No significant between-group differences regarding the distribution of radiological morphologies were found. There was a decrease over time in clinical outcome in the AT group with α angles >55° compared to those with α angles <55° (p=0.047). In the AT group, there was no significant difference in the distribution of Tönnis grades between hips that had an unchanged or improved outcome compared with hips that had a worse outcome over time (p=0.145). Conclusions No evidence was found that bony hip morphology related to FAI or dysplasia prevents successful outcome of the exercise treatment programme with results lasting 8–12u2005years. The entity of adductor-related groin pain in physically active adults can be treated with AT even in the presence of morphological changes to the hip joint.

The diagnostic value of adding dynamic scintigraphy to standard delayed planar imaging for sentinel node identification in melanoma patients

PurposeThe aim of this study was to compare early dynamic imaging combined with delayed static imaging and single photon emission computed tomography (SPECT)/CT with delayed, planar, static imaging alone for sentinel node (SN) identification in melanoma patients.MethodsThree hundred and seven consecutive melanoma patients referred for SN biopsy (SNB) were examined using combined imaging. Secondary interpretation of only the delayed static images was subsequently performed. In 220 patients (72%), complete surgical and pathological information relating to the SNB was available. The number of SNs identified and number of patients with positive SNs were compared between the two interpretations of the imaging studies and, when available, related to pathology data.ResultsA slightly higher number of SNs (mean 0.12/patient) was identified when interpreting only delayed static images compared to combined imaging. In a direct patient-to-patient comparison, the number of SN(s) identified on the combined vs static images only showed moderate agreement (kappa value 0.56). In 38 patients (17%), positive SNs were identified by the combined procedure compared to 35 (16%) by static imaging only. Thus by static imaging only, tumour-positive SNs were not identified in 3 of 38 patients (8%).ConclusionFor SN identification in melanoma patients, dynamic imaging combined with delayed static imaging and SPECT/CT is superior to delayed static imaging only because the latter is more likely to fail to identify SNs containing metastases.