Imaging Non-Specific Wrist Pain: Interobserver Agreement and Diagnostic Accuracy of SPECT/CT,MRI, CT,Bone Scan and Plain Radiographs

Purpose

Chronic hand and wrist pain is a common clinical issue for orthopaedic surgeons and rheumatologists. The purpose of this study was 1. To analyze the interobserver agreement of SPECT/CT, MRI, CT, bone scan and plain radiographs in patients with non-specific pain of the hand and wrist, and 2. to assess the diagnostic accuracy of these imaging methods in this selected patient population.

Materials and Methods

Thirty-two consecutive patients with non-specific pain of the hand or wrist were evaluated retrospectively. All patients had been imaged by plain radiographs, planar early-phase imaging (bone scan), late-phase imaging (SPECT/CT including bone scan and CT), and MRI. Two experienced and two inexperienced readers analyzed the images with a standardized read-out protocol. Reading criteria were lesion detection and localisation, type and etiology of the underlying pathology. Diagnostic accuracy and interobserver agreement were determined for all readers and imaging modalities.

Results

The most accurate modality for experienced readers was SPECT/CT (accuracy 77%), followed by MRI (56%). The best performing, though little accurate modality for inexperienced readers was also SPECT/CT (44%), followed by MRI and bone scan (38% each). The interobserver agreement of experienced readers was generally high in SPECT/CT concerning lesion detection (kappa 0.93, MRI 0.72), localisation (kappa 0.91, MRI 0.75) and etiology (kappa 0.85, MRI 0.74), while MRI yielded better results on typification of lesions (kappa 0.75, SPECT/CT 0.69). There was poor agreement between experienced and inexperienced readers in SPECT/CT and MRI.

Conclusions

SPECT/CT proved to be the most helpful imaging modality in patients with non-specific wrist pain. The method was found reliable, providing high interobserver agreement, being outperformed by MRI only concerning the typification of lesions. We believe it is beneficial to integrate SPECT/CT into the diagnostic imaging algorithm of chronic wrist pain.     

Early experience with computed tomographic angiography in microsurgical reconstruction

Preoperative angiography is frequently used in the planning of microsurgical reconstruction. However, several potentially devastating complications can result from angiography, including arterial occlusion and pseudoaneurysm. Computed tomographic angiography is a relatively new technique that can provide detailed information about vascular anatomy as well as soft and bony tissue without the risks of traditional angiography. In addition, three-dimensional image reconstruction uniquely demonstrates anatomical relationships among blood vessels, bones, and soft tissue. Fourteen computed tomographic angiograms were obtained in 10 patients undergoing microsurgical reconstruction of the head and neck, lower extremity, or upper extremity. The average patient age was 46.9 years (range, 22 to 67 years). Charges related to the computed tomographic procedure were compared with those of conventional preoperative imaging for microsurgical repair. At our institution, the average computed tomographic angiogram charge was 1140 US dollars, whereas the average charge for traditional arteriography was 3900 US dollars. When compared with intraoperative evaluation, computed tomographic angiograms demonstrated clinically relevant surgical anatomy. No complications were noted for the radiographic procedure or after free flap reconstruction. Computed tomographic angiography provides high-resolution, three-dimensional arterial, venous, and soft-tissue imaging without the risks of traditional angiogram and at a lower cost.     

Case Report: Thunderclap headache and reversible segmental cerebral vasoconstriction associated with use of oxymetazoline nasal spray

OXYMETAZOLINE IS A SYMPATHOMIMETIC amine found in over-the-counter nasal decongestants. We report a case of chronic use of nasal oxymetazoline associated with thunderclap headache due to reversible segmental intracranial vasoconstriction.A 31-year-old woman had sudden onset of global headache at 1 pm when she was resting that she characterized as the “worst of her life,” rating the pain as 10/10. Associated symptoms included nausea, vomiting, sonophobia and photophobia. The headache waxed and waned over the next 4 days, and on day 4 the patient presented to the emergency department in a community hospital. Her blood pressure, findings on neurological examination and initial CT scan were normal. Her past medical history included hiatal hernia, cigarette smoking and remote use of marijuana (she denied any other illicit drugs), and she was taking sertraline, peptobismol, lansoprazole and domperidone. A lumbar puncture revealed normal cerebrospinal fluid with no xanthochromia. The opening pressure in the seated position was 37 cm H₂O. She was transferred to our hospital, and CT venography was performed. It revealed no venous sinus thrombosis, but multifocal vessel irregularities in both the anterior and posterior arterial circulations were observed. Cerebral angiography confirmed focal areas of vasospasm in the internal carotid circulations bilaterally as well as in the vertebrobasilar system (Fig. 1A, B, C). Results of hematologic and serologic investigations were negative for signs of systemic infection, inflammation or vasculitis.Open in a separate windowFig. 1: A: CT angiogram at admission showing axial reformatted images with severe narrowing of the M2 branches of the right middle cerebral artery. B: CT angiogram at admission showing midline sagittal multiplanar reformatted image; done to assess dural sinuses, the image shows multifocal narrowings of the anterior cerebral arteries. C: Right anterior oblique view from a selective cerebral angiogram of the right internal carotid artery showing focal narrowing and dilatation of anterior cerebral artery. D: Follow-up left anterior oblique view from the left carotid artery showing near complete resolution of arteriopathic changes.The patient had been using Afrin, a nasal spray that contains oxymetazoline, regularly for the previous 6 months. Although she was using the medication at recommended daily dosages (2–3 sprays twice daily), she was using it consistently. Two weeks before presentation she had noticed a pattern of headache starting 20 minutes after use of the nasal spray. The index event had occurred immediately after its use.Use of the nasal spray was discontinued. Narcotic analgesics reduced the pain, but the nausea and vomiting responded to ondansetron only. The patient had no improvement in her headache with nimodipine, a calcium-channel antagonist that causes dilatation of arterial smooth muscle. Repeat lumbar puncture was done in the supine position at discharge and demonstrated an opening pressure of 19 cm H₂O. Two weeks after discharge the headache had nearly resolved. A repeat angiogram at 6 weeks showed complete resolution of most areas of arterial narrowing (Fig. 1D).     

Place de la scintigraphie osseuse planaire et TEMP/TDM dans l’exploration des prothèses de hanche douloureuses

Investigation of hip pain in a patient bearing a hip prosthesis is a common indication in Nuclear Medicine departments daily practice. Indeed, morphological cross-sectional imaging devices, such as MDCT and MRI, are often hampered by metallic implants. If planar bone scintigraphy is acknowledged with a high sensitivity, nonetheless, this exam specificity is poor. Since Anger cameras twinned with spiral CT (SPECT/CT) have appeared in the clinical arena, this limited specificity is compensated by the CT threefold input, all at once attenuation correction, localizing and diagnostic tool. Bone SPECT/CT requires that the Nuclear Medicine physician upgrades his knowledge of bone and joint anatomy, CT patterns, but foremost, data merging from SPECT and CT. The aim of this article is to sketch out bone SPECT/CT role and patterning in miscellaneous complications following arthroplasty, explained by pathophysiological mechanisms.     

Bronchovascular responses to intravenous contrast media for helical CT pulmonary angiography

CT angiography is now commonly used for the diagnosis of pulmonary embolism, but the contrast media used for imaging produces various hemodynamic changes. In this study, we investigated the bronchovascular and hemodynamic responses to intravenous iopromide, a non-ionic contrast agent used for pulmonary CT angiograms, in anesthetized, mechanically ventilated sheep (n = 6). Bronchial blood flow and cardiac output were measured with ultrasonic flow probes. Systemic and pulmonary arterial pressures were continuously monitored. Injections of 0.9% NaCl (120 ml over 30 s) or iopromide (300 mg/ml, 120 ml over 30 s) were given in random order in a peripheral vein with an angiogram infuser and hemodynamic changes were determined. After these parameters returned to baseline, the left pulmonary artery (LPA) was occluded with a snare and the animals were allowed to stabilize. Injections of NaCl and iopromide were repeated in random order as before. There were no significant hemodynamic effects with infusion of NaCl. With intact pulmonary vasculature, NaCl and iopromide did not cause significant changes in arterial blood gases, however, cardiac output (QT, L/min), mean systemic and pulmonary arterial pressures (PSA and PPA, Torr) increased and bronchovascular resistance (BVR, Torr x min/ml), decreased. Following LPA ligation, pH and PO2 significantly decreased over baseline, whereas PCO2 increased. After LPA ligation, iopromide produced a greater decrease in BVR as compared with preligation intact pulmonary vasculature. In conclusion, iopromide caused rapid hemodynamic changes and decreased BVR, likely secondary to osmolar stress. Bronchovascular effects were more pronounced after pulmonary arterial occlusion.     

Development and application of a multimodal contrast agent for SPECT/CT hybrid imaging

Hybrid or multimodality imaging is often applied in order to take advantage of the unique and complementary strengths of individual imaging modalities. This hybrid noninvasive imaging approach can provide critical information about anatomical structure in combination with physiological function or targeted molecular signals. While recent advances in software image fusion techniques and hybrid imaging systems have enabled efficient multimodal imaging, accessing the full potential of this technique requires development of a new toolbox of multimodal contrast agents that enhance the imaging process. Toward that goal, we report the development of a hybrid probe for both single photon emission computed tomography (SPECT) and X-ray computed tomography (CT) imaging that facilitates high-sensitivity SPECT and high spatial resolution CT imaging. In this work, we report the synthesis and evaluation of a novel intravascular, multimodal dendrimer-based contrast agent for use in preclinical SPECT/CT hybrid imaging systems. This multimodal agent offers a long intravascular residence time (t(1/2) = 43 min) and sufficient contrast-to-noise for effective serial intravascular and blood pool imaging with both SPECT and CT. The colocalization of the dendritic nuclear and X-ray contrasts offers the potential to facilitate image analysis and quantification by enabling correction for SPECT attenuation and partial volume errors at specified times with the higher resolution anatomic information provided by the circulating CT contrast. This may allow absolute quantification of intramyocardial blood volume and blood flow and may enable the ability to visualize active molecular targeting following clearance from the blood.     

CT检查中造影剂不良反应的预防、处理及对影像学检查 的影响分析

目的：在CT 等医学影像检查过程中,常需要应用造影剂。在造影剂的使用常常发生不良反应,掌握不良反应的发生率,减少 或减轻患者的不良反应,能够使CT 增强扫描顺利进行,提高检查安全性。方法：搜集我院2011 年10 月至2012 年9 月间的1500 例CT 造影增强检查患者,包括冠状动脉CT 血管成像（冠脉CTA）、头部CT 血管成像（头CTA）、肝脏增强、泌尿系三维成像 （CTU）以及双下肢血管成像（双下肢CTA）,进行造影剂的不良反应类型、造影剂药物剂量、注射速度等统计分析,总结造成不良 反应发生的因素及处理方法。结果：不良反应的类型包括发热、呕吐、荨麻疹、面色潮红、局部疼痛、流泪、血压下降、喉头水肿、休 克等。使用非离子型造影剂出现不良反应者85 例,占5.67 %。其中轻度反应65 例,占4. 33%;中度反应16 例,占1.06%;重度4 例,占0. 27 %。结论：在CT 增强扫描过程中,造影剂的用量及注射速度与不良反应的发生有相关性。ＣＴ 检查过程总应该认真 执行操作流程,密切观察病人情况,积极防治,正确处理,将造影剂不良反应降低到最低程度,使患者更加安全。     

Hemichorea caused by nonketotic hyperosmolar state: A case report and review of the literature

Our report involves a case of hemichorea caused by the nonketotic hyperosmolar state. We have analyzed the clinical data and relevant features of a patient who presented herself to the Affiliated Hospital of Xuzhou Medical University. The patient had unilateral involuntary movements for 1?month. We discovered that her blood glucose levels were very high. The patient underwent computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA), indicating right basal ganglia lesion. Control of the patient’s blood glucose plus supportive treatment resulted in a significant improvement of her clinical state.     

Focus: Rare Disease: A Case of Spinal Infectious Osteomyelitis Versus Gout: Advanced Imaging with Dual Energy CT

A 67-year-old male presented to the hospital for lower back pain and left lower extremity radiculopathy. Although the patient was afebrile and white blood cell count was normal, MRI was concerning for discitis/osteomyelitis at L4-L5. Subsequently, the patient developed a right knee joint effusion and underwent an arthrocentesis that was notable for the presence of urate crystals. A systemic urate crystal arthropathy was proposed as a potential etiology for the patient’s back pain and radiculopathy. Dual energy CT of the lumbar spine was performed, a technique which determines material composition by comparing the photon attenuation of the substance from two different x-ray energy levels. Results revealed the presence of monosodium urate crystals in the intervertebral discs. This technique is proposed as a noninvasive way to evaluate for gout in atypical locations or those difficult to sample and may replace an invasive intervertebral disc/endplate aspiration and/or biopsy. Dual energy CT should be considered in patients with elevated serum uric acid and concern for spinal involvement of gout.     

Abdominal imaging dose in radiology and radiotherapy – Phantom point dose measurements,effective dose and secondary cancer risk

PurposeTo compare abdominal imaging dose from 3D imaging in radiology (standard/low-dose/dual-energy CT) and radiotherapy (planning CT, kV cone-beam CT (CBCT)).MethodsDose was measured by thermoluminescent dosimeters (TLD’s) placed at 86 positions in an anthropomorphic phantom. Point, organ and effective dose were assessed, and secondary cancer risk from imaging was estimated.ResultsOverall dose and mean organ dose comparisons yield significantly lower dose for the optimized radiology protocols (dual-source and care kV), with an average dose of 0.34±0.01 mGy and 0.54±0.01 mGy (average ± standard deviation), respectively. Standard abdominal CT and planning CT involve considerably higher dose (13.58 ± 0.18 mGy and 18.78±0.27 mGy, respectively). The CBCT dose show a dose fall-off near the field edges. On average, dose is reduced as compared with the planning or standard CT (3.79 ± 0.21 mGy for 220° rotation and 7.76 ± 0.37 mGy for 360°), unless the high-quality setting is chosen (20.30 ± 0.96 mGy). The mean organ doses show a similar behavior, which translates to the estimated secondary cancer risk. The modelled risk is in the range between 0.4 cases per million patient years (PY) for the radiological scans dual-energy and care kV, and 300 cases per million PY for the high-quality CBCT setting.ConclusionsModern radiotherapy imaging techniques (while much lower in dose than radiotherapy), involve considerably more dose to the patient than modern radiology techniques. Given the frequency of radiotherapy imaging, a further reduction in radiotherapy imaging dose appears to be both desirable and technically feasible.     

肺结核合并下呼吸道感染患者CT影像特点及IL-23R水平表达的临床意义

摘要 目的：探讨肺结核合并下呼吸道感染患者CT影像特点及IL-23R水平表达的临床意义。方法：选取2015年1月-2018年8月于我院就诊的123例肺结核患者,将所选取的患者按是否合并下呼吸道感染分为单纯肺结核组73例和肺结核合并下呼吸道感染组50例。分析两组组患者临床表现、CT影像学图片、CT影像学表现、血清IL-23R的表达水平的差异。结果：单纯肺结核组患者出现14例低热、11例胸闷、17例消瘦、14例气短、18例痰中带血、14例颈部淋巴结肿大、23例咳嗽、21例胸痛。肺结核合并下呼吸道感染组患者出现16例低热、13例胸闷、21例消瘦、19例气短、20例痰中带血、15例颈部淋巴结肿大、26例咳嗽、23例胸痛,两组患者临床表现差异均无统计学意义（P＞0.05）。单纯肺结核组CT影像学图片显示可见结节影或包块影,呈明显分叶征、短毛刺征、空泡征并发肺不张、棘状突起,边缘较清晰,增强扫描后明显强化。肺结核合并下呼吸道感染组CT影像学图片显示有分叶、毛刺,同时肺内肿物周边存在晕征、血管聚集征、卫星灶征、胸膜凹陷等表现,此外伴纵膈及肺门淋巴结明显肿大,胸壁侵犯。肺结核合并下呼吸道感染组CT影像中毛刺状结节、胸膜凹陷、空洞、分叶征、肿块、条索影比例均高于单纯肺结核组,差异有统计学意义（P＜0.05）。肺结核合并下呼吸道感染组患者IL-23R水平明显高于单纯肺结核组,差异有统计学意义（P＜0.05）。结论：与单纯肺结核患者相比较,肺结核合并下呼吸道感染患者临床表现更为严重,CT影像学特点更为明显,患者血清中IL-23R表达水平明显升高,临床可通过CT影像学结合血清IL-23R检测,以提高肺结核合并下呼吸道感染患者的临床诊断。     

Positron emission tomography (18FDG-PET) in the detection of medullary thyroid carcinoma metastases

INTRODUCTION: Medullary thyroid carcinoma (MTC) is usually more advanced at presentation than differentiated thyroid cancers and often has distant metastases. The primary treatment of MTC is total thyroidectomy and regional lymph node dissection. The efficacy of these procedures has been limited by the aggressiveness of the disease and metastatic spread at the time of surgery. Persistently elevated levels of calcitonin (CT) and carcinoembryonic antigen (CEA) or their increase postoperatively are indicative for residual or recurrent disease. Conventional imaging methods such as ultrasonography, computed tomography, magnetic resonance imaging and MIBI scintigraphy usually fail to find the source of calcitonin. Better imaging properties have been shown by DMSA scintigraphy, somatostatin receptor scintigraphy or by positron emission tomography (PET). The aim of the study was to evaluate the diagnostic accuracy of PET for the localisation of occult MTC in patients after surgery with increased concentrations of CT, in whom conventional imaging procedures have not been successful. MATERIAL AND METHODS: The PET investigation using (18)F-fluoro- 2-deoxy-D-glucose combined with computed tomography ((18)FDG-PET/CT) was performed at the Department of Nuclear Medicine (Oncology Centre in Bydgoszcz) between January and October 2004. In five patients with postoperative calcitonin ranging from 164 to > 2000 ng/l (normal < 10 ng/l) no tumour lesions were found using other imaging methods. RESULTS: In four of five cases, responsible lesions with a higher metabolism of FDG, indicating MTC tissue (remnants or metastases), were localised. In one patient no focus of FDG accumulation was found despite high CT concentration. PET detected tumour manifestations in the neck and the mediastinum in two patients, in the lung and the left adrenal gland in one case and in the neck and the liver in another patient. As a result of surgery for the removal of a residual tumour or metastases the accuracy of diagnosis was confirmed by histopathology in all four cases and a decrease in CT and CEA levels was observed in 3/4 cases. The metabolic imaging findings by PET/CT ensured that the surgery on these patients was successful. CONCLUSIONS: For the detection of occult residual or metastatic MTC lesions, (18)FDG-PET is a valuable procedure in imaging diagnostics.     

CT检查中造影剂不良反应的预防、处理及对影像学检查的影响分析

目的：在CT等医学影像检查过程中,常需要应用造影剂。在造影剂的使用常常发生不良反应,掌握不良反应的发生率,减少或减轻患者的不良反应,能够使CT增强扫描顺利进行,提高检查安全性。方法：搜集我院2011年10月至2012年9月间的1500例CT造影增强检查患者,包括冠状动脉CT血管成像（冠脉CTA）、头部CT血管成像（头CTA）、肝脏增强、泌尿系三维成像（CTU）以及双下肢血管成像（双下肢CTA）,进行造影剂的不良反应类型、造影剂药物剂量、注射速度等统计分析,总结造成不良反应发生的因素及处理方法。结果：不良反应的类型包括发热、呕吐、荨麻疹、面色潮红、局部疼痛、流泪、血压下降、喉头水肿、休克等。使用非离子型造影剂出现不良反应者85例,占5．67％。其中轻度反应65例,占4．33％;中度反应16例,占1．06％;重度4例,占0．27％。结论：在CT增强扫描过程中,造影剂的用量及注射速度与不良反应的发生有相关性。cT检查过程总应该认真执行操作流程,密切观察病人情况,积极防治,正确处理,将造影剂不良反应降低到最低程度,使患者更加安全。     

Zero echo time MRI-only treatment planning for radiation therapy of brain tumors after resection

Using magnetic resonance imaging (MRI) as the sole imaging modality for patient modeling in radiation therapy (RT) is a challenging task due to the need to derive electron density information from MRI and construct a so-called pseudo-computed tomography (pCT) image. We have previously published a new method to derive pCT images from head T1-weighted (T1-w) MR images using a single-atlas propagation scheme followed by a post hoc correction of the mapped CT numbers using local intensity information. The purpose of this study was to investigate the performance of our method with head zero echo time (ZTE) MR images. To evaluate results, the mean absolute error in bins of 20 HU was calculated with respect to the true planning CT scan of the patient. We demonstrated that applying our method using ZTE MR images instead of T1-w improved the correctness of the pCT in case of bone resection surgery prior to RT (that is, an example of large anatomical difference between the atlas and the patient).     

Liposomes and Micelles to Target the Blood Pool for Imaging Purposes

Abstract

The blood pool is among body compartments of a special interest for imaging using magnetic resonance (MR) and computed tomography (CT), since with the help of selective blood-pool contrast agents blood perfusion and various cardiac parameters as well as a status of the blood flow and vascular system in any organ can be evaluated. Blood pool-specific imaging agents can also provide minimally invasive angiography, image guidance of minimally invasive procedures, oncologic imaging of angiogenesis, ascertaining organ blood volume, and identifying hemorrhage. Particulate contrast agents (such as liposomes and micelles) whose distribution is limited to the blood pool, should have a size larger than fenestrated capillaries (> 10 nm), contain the reporter (paramagnetic or radiopaque) moiety structurally incorporated within the particulate, and be able to stay in the blood long enough to obtain clinically useful images. We describe here a new generation of long-circulating Gd-loaded liposomes and iodine-loaded micelles to provide an efficient blood pool MR and CT imaging, respectively. In this study, we developed the optimized protocol to prepare a liposomal MR contrast agent with high relaxivity and narrow size distribution. Liposomes were loaded with Gadolinium (Gd) via so called polychelating amphiphilic polymer (PAP) that represents a low-molecular-weight DTPA-polylysine linked via its N-terminus to a lipid anchor, NGPE-PE. Gd-containing liposomes were additionally modified with PEG to provide the longevity in vivo. We demonstrated also that upon the intravenous administration in rabbits and dogs, a new preparation causes prolonged decrease in the blood Tl value, permits to obtain sharp and clear MR images of the vasculature, and may be considered as a potential contrast agent for MRI of the blood pool. In addition, to prepare micellar contrast agents for CT blood-pool imaging, we synthesized an iodine-containing amphiphilic block-copolymer consisting of methoxypoly(ethyleneglycol) and polyl?,N-(triiodobenzoyl)]-L-lysine. In aqueous solutions, it forms stable micelles with an average diameter of 80 nm and an iodine content of 35–40% wt. Iodine-containing micelles were intravenously injected into rats and rabbits at a dose of 170 mg I/kg and produced significant and sustained enhancement of the blood pool (aorta and heart), liver and spleen for a period of at least 3 hours providing clear and informative CT images.     

Scintigraphie des parathyroïdes double isotope Tc-MIBI/I dans l’hyperparathyroïdisme primaire : comparaison entre un protocole d’acquisition planaire et une TEMP de soustraction couplée à la TDM

In patient with primary hyperparathyroidism, preoperative imaging first objective is to determine accurately and reliably position and anatomic localization of enlarged parathyroid gland in order to guide surgeon for gland removal and to permit minimally invasive surgery. Although subtraction planar scintigraphy is an efficient imaging to diagnose hyperfunctioning parathyroid, the lack of anatomical reference for this single imaging technique could be obviated by hybrid imaging. We compared, in 23 patients with primary hyperparathyroidism, a planar scan of neck and mediastinum associated with a cervical anterior pinhole scan to a subtraction (¹²³I/^99mTc-MIBI) SPECT scan of neck and mediastinum fused with CT. Surgical and histopathologic findings were used as the standard of truth. Subtraction SPECT/CT appeared to be more sensitive and specific than planar protocol to diagnose and to accurately localize pathologic parathyroid. Sensitivity was 76 and 56 %, specificity was 100 and 80 % for hybrid SPECT/CT and planar protocol respectively. SPECT protocol was typically more efficient to diagnose pathologic parathyroid derived from upper gland and for patient with concomitant nodular goiter.     

Metabolic and Receptor Imaging in Patients with Neuroendocrine Tumors: Comparison of Fludeoxyglucose-Positron Emission Tomography and Computed Tomography with Indium in 111 Pentetreotide

ObjectiveTo determine whether positron emission tomography/computed tomography (PET/CT) and indium In 111 pentetreotide, individually or collectively, predict the outcome of patients with neuroendocrine tumors (NETs).MethodsBetween July 31, 2002, and May 4, 2007, 29 patients with previously diagnosed NETs underwent both PET/CT and indium In 111 pentetreotide imaging at our institution. The images were evaluated for the presence of abnormalities. Clinical outcomes were classified as survival without major morbidities, survival with severe complications of disease, or death. Time to outcome was measured in months from the imaging date to outcome. Kaplan-Meier survival curves were calculated in which patient outcome was compared with results on PET/CT and indium In 111 pentetreotide imaging.ResultsOf the 29 patients, 9 had abnormalities on both PET/CT and indium In 111 pentetreotide imaging. Two patients had abnormal findings on PET/CT but normal findings on pentetreotide imaging. In 5 patients, findings were normal on PET/CT but abnormal on pentetreotide imaging. In 13 patients, normal findings were noted on both PET/CT and pentetreotide imaging. Kaplan-Meier analysis demonstrated a significant survival advantage for patients who had normal findings on PET/CT in comparison with abnormal PET/CT findings (P = .01). Patients with normal findings on indium In 111 pentetreotide imaging had a higher but insignificant survival advantage over those with abnormal results on pentetreotide imaging (P = .08).ConclusionFor evaluation of NETs, PET/CT and indium In 111 pentetreotide are complementary. Increased metabolic activity in tumor cells is reflected by abnormalities on PET/CT. Patients who had abnormal PET/CT findings had a generally poorer prognosis and a more rapid clinical deterioration than those with normal PET/CT findings. (Endocr Pract. 2009;15:521-527)     

Evaluation of a no-reference image quality metric for projection X-ray imaging using a 3D printed patient-specific phantom

PurposeFeasability of a no-reference image quality metric was assessed on patient-like images using a patient-specific phantom simulating a frame of a coronary angiogram.MethodsOne background and one contrast-filled frame of a coronary angiogram, acquired using a clinical imaging protocol, were selected from a Philips Integris Allura FD (Philips Healthcare, Best, The Netherlands). The background frame’s pixels were extruded to a thickness proportional to their grey value. One phantom was 3D printed using composite 80% bronze filament (max. thickness of 5.1 mm), the other was a custom PMMA cast (max thickness of 8.5 cm). A vessel mold was created from the contrast-filled frame and injected with a solution of 320 mg I/ml contrast fluid (75%), water and gelatin. Still X-ray frames of the vessel mold + background phantom + 16 cm PMMA were acquired at manually selected different exposure settings using a Philips Azurion (Philips Healthcare, Best, The Netherlands) in User Quality Control Mode and were exported as RAW images. The signal-difference-to-noise-ratio-squared (SDNR²) and a spatial-domain-equivalent of the noise equivalent quanta (NEQ_SDE) were calculated. The Spearman’s correlation of the latter parameters with a no-reference perceptual image quality metric (NIQE) was investigated.ResultsThe bronze phantom showed better resemblance to the original patient frame selected from a coronary angiogram of an actual patient, with better contrast and less blur than the PMMA phantom. Both phantoms were imaged using a comparable imaging protocol to the one used to acquire the original frame. The bronze phantom was hence used together with the vessel mold for image quality measurements on the 165 still phantom frames. A strong correlation was noted between NEQ_SDE and NIQE (SROCC = –0.99, p < 0.0005) and between SDNR² and NIQE (SROCC = –0.97, p < 0.0005).ConclusionUsing a cost-effective and easy to realize patient-specific phantom we were able to generate patient-like X-ray frames. NIQE as a no-reference image quality model has the potential to predict physical image quality from patient images.     

运用CT三维重建测量重度先天性脊柱侧凸Cobb角的临床应用

目的:评价在CT三维重建上测量重度先天性脊柱侧凸Cobb角度的可重复性和可靠性。方法:收集在我院诊治的重度先天性脊柱侧凸病人的CT三维重建和脊柱全长X线片,共计67例。由五名不同测量者对CT三维重建脊柱畸形冠状面主弯Cobb角测量两次,两次间隔在三周以上,并测量脊柱全长X线片脊柱畸形冠状面主弯Cobb角一次,运用组内相关系数分析测量结果之间的可重复性和可靠性。结果:同一测量者两次测量结果之间的差值平均为4.5°。同一测量者两次测量结果之间的组内相关系数为0.969,不同测量者之间测量结果的组内相关系数为0.913。取五名测量者在CT三维重建上第一次测量的Cobb角度,其平均值为(110.5±23.5)°,五名测量者在X线片上测量结果的平均值为(103.1±22.0)°,对两组数据进行Mann-Whitney非参数检验差异有统计学意义(Z=-2.86,P=0.004)。结论:在CT三维重建上测量重度先天性脊柱侧凸的Cobb角,可以减小测量的误差,提高测量的可重复性和可靠性,是一种相对准确的测量方法。     

CT fractional flow reserve: the next level in non-invasive cardiac imaging

The haemodynamic effect of a coronary artery stenosis is a better predictor of prognosis than anatomical lumen obstruction. Until recently, no individual non-invasive test could provide both accurate coronary anatomy and lesion-specific myocardial ischaemia. However, computer tomography (CT) fractional flow reserve, which can be calculated from a standard CT coronary angiogram, was recently demonstrated to accurately detect and rule out the haemodynamic significance of individual coronary artery stenoses.