Traumatic diaphragmatic injury: a review of CT signs and the difference between blunt and penetrating injury

PURPOSE

We aimed to present the frequency of computed tomography (CT) signs of diaphragmatic rupture and the differences between blunt and penetrating trauma.

MATERIALS AND METHODS

The CT scans of 23 patients with surgically proven diaphragmatic tears (both blunt and penetrating) were retrospectively reviewed for previously described CT signs of diaphragmatic injuries. The overall frequency of CT signs was reported; frequency of signs in right- and left-sided injuries and blunt and penetrating trauma were separately tabulated and statistically compared.

RESULTS

The discontinuous diaphragm sign was the most common sign, observed in 95.7% of patients, followed by diaphragmatic thickening (69.6%). While the dependent viscera sign and collar sign were exclusively observed in blunt-trauma patients, organ herniation (P = 0.05) and dangling diaphragm (P = 0.0086) signs were observed significantly more often in blunt trauma than in penetrating trauma. Contiguous injury on either side of the diaphragm was observed more often in penetrating trauma (83.3%) than in blunt trauma (17.7%).

CONCLUSION

Knowledge of the mechanism of injury and familiarity with all CT signs of diaphragmatic injury are necessary to avoid a missed diagnosis because there is variability in the overall occurrence of these signs, with significant differences between blunt and penetrating trauma.Traumatic diaphragmatic injury has been found in 3%–8% of patients undergoing surgical exploration after blunt trauma and in 10% of patients with penetrating trauma (1, 2). The rate of initially missed diagnoses on computed tomography (CT) ranges from 12% to 63%. A missed diagnosis can later present as intrathoracic visceral herniation and strangulation with a mortality rate of 30%–60% (2, 3). In this era of increasing nonoperative management for most cases of blunt abdominal trauma, it becomes essential to diagnose diaphragmatic rupture on imaging to ensure early and timely operative repair of the rupture. The reasons for missed early diagnoses include potentially distracting and more severe thoracic and abdominal visceral injuries and lack of familiarity with all the imaging appearances and signs of diaphragmatic rupture (2, 4).Various imaging modalities including chest radiographs, ultrasonography, CT, and magnetic resonance imaging have been used in the diagnosis of diaphragmatic rupture (1). Currently, multidetector CT (MDCT) is the modality of choice for the detection of diaphragmatic injury. MDCT has increased the accuracy of diagnosis of diaphragmatic rupture. MDCT has inherent technical advantages, such as rapid, volumetric data acquisition for the chest and abdomen within a single breath hold, minimization of motion artifacts, thin-section reconstruction and sagittal and coronal reformat-reducing partial-volume effects that assist in diagnosing subtle defects (1). MDCT also aids in detecting the associated chest, abdomen, ribs, and bony injuries in these polytrauma patients. Various studies have revealed CT to have a variable sensitivity and specificity of 61%–87% and 72%–100%, respectively, for the diagnosis of diaphragmatic rupture (1, 5–7). Killeen et al. (6) demonstrated that the sensitivity for detecting left-sided ruptures (78%) is higher than for right-sided ruptures (50%). This finding has been attributed to the better soft tissue-fat contrast on the left side and the difficulty in diagnosing subtle liver herniation on the right side.Various signs of diaphragmatic rupture have been described on CT. These signs have been divided into direct and indirect signs and signs of uncertain/controversial origin, according to Desir and Ghaye (8), and have been tabulated in 2, 3).

Table 1.

CT signs of diaphragmatic injury^a

An innovative modification of the retrograde approach to angioplasty and recanalization of the superficial femoral artery

Endovascular therapy has been performed for chronic limb ischemia for nearly 50 years. Superficial femoral artery occlusions can be managed by the retrograde contralateral (“crossover”), antegrade ipsilateral, or retrograde popliteal (“facedown”) approaches. The retrograde approach was initially fraught with limitations and served as a backup option. Refinements to this technique have made it an enticing option and possibly the first choice in selected patients. We herein describe an innovative modification of this method.Endovascular therapy has been performed for chronic limb ischemia since 1964, with intraluminal and subintimal angioplasty of the superficial femoral artery (SFA) gaining popularity in the last decade (1). SFA occlusions can be managed by retrograde contralateral or antegrade ipsilateral approaches (2, 3); when these approaches fail, some practitioners resort to using a re-entry device (4, 5). The retrograde popliteal approach was initially fraught with limitations and served as a backup option (1, 4, 6). However, refinements to this technique have made this an enticing option (2–7), and it has been advocated as a first-line treatment in select patients (3). We herein describe another modification of this method.     

CT mapping of the vertebral level of right adrenal vein

PURPOSE

We aimed to evaluate the accuracy of multidetector computed tomography (MDCT) venous mapping for the localization of the right adrenal veins (RAV) in patients suffering from primary aldosteronism.

METHODS

MDCT scans of 75 patients with primary aldosteronism between March 2008 and November 2011 were evaluated by two readers (a junior [R1] and a senior [R2] radiologist) according to the following criteria: quality of RAV depiction (scale, 1–5), localization of the RAV confluence with regard to the inferior vena cava, and depiction of anatomical variants. Results were compared with RAV venograms obtained during adrenal vein sampling and corroborated by laboratory testing of cortisol in selective RAV blood samples. Kappa statistics were calculated for interobserver agreement and for concordance of MDCT mapping with the gold standard.

RESULTS

Successful RAV sampling was achieved in 69 of 75 patients (92%). Using MDCT mapping, adrenal veins could be visualized in 78% (R1, 54/69) and 77% (R2, 53/69) of patients. MDCT mapping led to correct identification of RAV in 70% (R1, 48/69) and 88% (R2, 61/69) of patients. Venograms revealed five cases of anatomical variants, which were correctly identified in 60% (R1, R2). MDCT-based localizations were false or misleading in 16% (R1, 11/69) and 7% (R2, 5/69) of cases.

CONCLUSION

Preinterventional MDCT mapping may facilitate successful catheterization in adrenal vein sampling.Primary aldosteronism (PA) has lately been claimed to be one of the most common causes of secondary hypertension, with reports indicating a prevalence of more than 10% (1, 2), especially in patients with resistant hypertension (3). While PA is more common than previously thought, the majority of cases is not accompanied by the full clinical picture of Conn’s syndrome (triad of hypertension, hypokalemia, and metabolic alkalosis), and many patients are in fact normokalemic. In addition to its role in causing hypertension, PA may also be an independent cardiovascular risk factor, as demonstrated by higher cardiovascular and renal morbidity in patients suffering from PA in comparison to matched controls with essential hypertension (2, 4, 5). PA is caused either by an aldosterone-producing adenoma (65%–70% of cases) or bilateral adrenal hyperplasia (30%–35% of cases), whereas unilateral adrenal hyperplasia, aldosterone-producing carcinomas, or an ectopic secretion of aldosterone are rare (6). Differentiation of the underlying condition is crucial for the treatment of patients with PA: while unilateral disease can be cured by laparoscopic adrenalectomy, cases of bilateral aldosterone secretion will be medically treated with mineralocorticoid receptor antagonists.The 2008 Endocrine Society Clinical Practice Guidelines recommend computed tomography (CT) of the adrenal region in all patients with biochemically confirmed PA, to rule out malignancy (2). The primary indication does not involve the subtype differentiation of PA, because multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) have both been proven to be scarcely sensitive and specific in the detection of aldosterone-producing adenomas (7). Hence, adrenal vein sampling (AVS) continues to represent the gold standard in the subtype differentiation of PA. However, AVS is a technically demanding interventional procedure even in experienced institutions. While the catheterization of the left adrenal vein is usually uncomplicated, sampling of the right adrenal vein (RAV) is often more challenging. Therefore, in the majority of cases successful bilateral AVS fails because of the missing catheterization on the right side (8–10). Published success rates for this procedure range from 42% up to 98% in experienced hands (11).Few authors have mentioned the possible advantage of reading CT-scans prior to AVS to identify the RAV (8, 12). To our knowledge, this is the first report on venous MDCT mapping for AVS. The purpose of this study was to evaluate the usefulness of newly introduced MDCT venous mapping for the localization of the RAV prior to selective catheterization in patients suffering from PA.     

Optimal reconstruction interval in dual source CT coronary angiography: a single-center experience in 285 patients

PURPOSE

We aimed to evaluate the visibility of coronary arteries and bypass-grafts in patients who underwent dual source computed tomography (DSCT) angiography without heart rate (HR) control and to determine optimal intervals for image reconstruction.

MATERIALS AND METHODS

A total of 285 consecutive cases who underwent coronary (n=255) and bypass-graft (n=30) DSCT angiography at our institution were identified retrospectively. Patients with atrial fibrillation were excluded. Ten datasets in 10% increments were reconstructed in all patients. On each dataset, the visibility of coronary arteries was evaluated using the 15-segment American Heart Association classification by two radiologists in consensus.

RESULTS

Mean HR was 76±16.3 bpm, (range, 46–127 bpm). All coronary segments could be visualized in 277 patients (97.19%). On a segment-basis, 4265 of 4275 (99.77%) coronary artery segments were visible. All segments of 56 bypass-grafts in 30 patients were visible (100%). Total mean segment visibility scores of all coronary arteries were highest at 70%, 40%, and 30% intervals for all HRs. The optimal reconstruction intervals to visualize the segments of all three coronary arteries in descending order were 70%, 60%, 80%, and 30% intervals in patients with a mean HR <70 bpm; 40%, 70%, and 30% intervals in patients with a mean HR 70–100 bpm; and 40%, 50%, and 30% in patients with a mean HR >100 bpm.

CONCLUSION

Without beta-blocker administration, DSCT coronary angiography offers excellent visibility of vascular segments using both end-systolic and mid-late diastolic reconstructions at HRs up to 100 bpm, and only end-systolic reconstructions at HRs over 100 bpm.Improvements in computed tomography (CT) scanning technology throughout the last decade have resulted in widespread acceptance of contrast-enhanced multidetector CT (MDCT) coronary angiography as a reliable modality for noninvasive evaluation of the coronary arteries (1). Having a high negative predictive value, MDCT coronary angiography is considered particularly beneficial in patients with low to intermediate pretest probability for coronary artery disease (CAD) by reliably excluding coronary artery stenosis and therefore, preventing unnecessary invasive angiography (2, 3).Small dimensions and continuous rapid motions of coronary arteries make their visualization by CT challenging. Thus, excellent spatial and temporal resolution is required for adequate imaging of coronary arteries. Initial reports using a 4-detector row MDCT were promising in selected patients with low heart rates (HRs) (4–6); however, image quality was not sufficient for assessment in up to 29% of the coronary segments. With the introduction of 16- and 64-row MDCT, major improvements of image quality were achieved, with adequate visualization of up to 97% of coronary segments (7–9). Since, image quality deteriorates with increasing HRs even with 64-slice MDCT scanners (10, 11), it has been common in clinical practice to use HR-modulating beta-blockers to achieve better diagnostic quality. In 2005, dual source CT (DSCT) system equipped with two sets of X-ray tubes and corresponding detectors mounted onto the gantry with an angular offset of 90° was introduced (12). Using half-scan reconstruction algorithms, this system provides high temporal resolution (83 milliseconds [ms]) that corresponds to a quarter gantry rotation time. Preliminary studies without use of beta-blocker premedication have shown that DSCT coronary angiography provides good image quality of coronary arteries even at a relatively high HR (13, 14). Subsequent studies with relatively small patient populations confirmed these findings with diagnostic image quality in 97.8% of coronary artery segments (15, 16).Achievement of good image quality with DSCT coronary angiography is highly dependent upon selecting the optimal reconstruction interval for evaluation. Previous publications indicate a relationship between optimal reconstruction window and HR with mid- to end-diastolic reconstructions providing better image quality at low HRs, whereas at faster HRs, end-systolic reconstructions will often provide the dataset with the least motion artifact (17–19). However, some of these prior studies were based on relatively small patient samples, and in some, the entire R-R interval was not evaluated. Detection of optimal reconstruction interval is also important for the purpose of radiation dose reduction. Since DSCT scanners are equipped with electrocardiogram (ECG)-based tube current modulation, the width and timing of the ECG pulsing window, during which the full tube current is given, can be manually selected by the operator with the tube current outside the pulsing window decreased to 20% or 4% of the nominal tube current and thus, significantly reducing the radiation dose up to 40% (20).We aimed to evaluate the visibility of coronary arteries and bypass-grafts in patients who underwent DSCT angiography without HR control and to determine optimal intervals for image reconstruction.     

The role of multidetector CT in local staging and evaluation of retroperitoneal surgical margin involvement in colon cancer

PURPOSE

We aimed to evaluate preoperative T and N staging and retroperitoneal surgical margin (RSM) involvement in colon cancer using multidetector computed tomography (MDCT).

METHODS

In this retrospective study, preoperative MDCTs of 141 patients with colon adenocarcinoma were evaluated in terms of T and N staging and retroperitoneal surgical margin involvement by two observers. Results were compared with histopathology.

RESULTS

In determining extramural invasion, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MDCT were 81%, 50%, 95%, 26%, and 81% for observer 1 and 87%, 75%, 97%, 27%, and 84% for observer 2, respectively. Moderate interobserver agreement was observed (κ=0.425). In determining T stage of the tumor, accuracy of MDCT was 55% for observer 1 and 51% for observer 2. In the detection of lymph node metastasis, sensitivity, specificity, PPV, NPV, and accuracy of MDCT were 84%, 46%, 60%, 74% and 64% for observer 1 and 84%, 56%, 65%, 78%, and 70% for observer 2, respectively. Interobserver agreement was substantial (κ=0.650). RSM was involved in six cases (4.7%). When only retroperitoneal colon segments were considered, 1.6% of subjects demonstrated RSM involvement. Four of the six RSM-positive tumors were located on sigmoid colon and one tumor was on transverse colon and caecum. Considering all colon tumors, in the detection of RSM involvement, sensitivity and specificity of MDCT were 33% and 81% for observer 1 and 50% and 80% for observer 2. Interobserver agreement was moderate (κ=0.518).

CONCLUSION

MDCT is a promising technique with moderate interobserver agreement in detection of extramural invasion, lymph node metastases, and RSM involvement in colon carcinomas.With the advent of technological improvements, computed tomography (CT) became one of the important diagnostic tools in the evaluation of local characteristics, preoperative staging, and prognostic factors of colon cancers (1). CT is recommended by EURECCA consensus group for staging of colon cancers (2). Extramural invasion (EMI) is an important factor affecting the prognosis in patients with colon cancer (3). Preoperative CT can detect EMI in colon cancers with high sensitivity (4). In addition, CT-based T staging can be used to stratify patients into good and poor prognosis (4, 5).Correlation between local recurrence and circumferential resection margin involvement in rectal cancer suggests the importance of retroperitoneal surgical margin (RSM) involvement in retroperitoneal ascending and descending colon tumors. RSM involvement is defined as less than 1 mm distance between RSM and primary adenocarcinoma or metastatic retroperitoneal lymph node in descending and ascending colon cancers (6). Studies suggest that RSM positivity may be a predictor and an independent prognostic indicator showing local recurrence in colon cancers (7).Classical colon cancer treatment is based on histopathologic prognostic factors in the resected specimen (1). However, at the present time, with the development of more effective chemotherapeutic agents and higher accuracy in preoperative staging, neoadjuvant treatments are preferred in patients with high-risk colon cancer (2, 8). Preoperative radiologic assessment of EMI and RSM positivity can decrease the local recurrence risk through timely recommendation of neoadjuvant chemotherapy which would lead to regression of metastatic lymph nodes, retroperitoneal extension, and tumor burden (6–8). Since severe adverse effects can be observed, neoadjuvant treatment should be administered to patients who would benefit the most from it. The aim of this study was to evaluate preoperative T and N staging and RSM involvement in colon cancer using multidetector CT (MDCT) and compare them with histopathology results.     

Development,growth, propagation,and angiographic utilization of the rabbit VX2 model of liver cancer: a pictorial primer and “how to” guide

The VX2 tumor is a leporine anaplastic squamous cell carcinoma characterized by rapid growth, hypervascularity, and facile propagation in the skeletal muscle. Since its introduction over 70 years ago, it has been used to model a variety of malignancies, and is commonly employed by interventional radiologists in preclinical investigations of hepatocellular carcinoma. However, despite the widespread and lasting popularity of the model, there are few technical resources detailing its use. Herein, we present a comprehensive pictorial outline of the technical methodology for development, growth, propagation, and angiographic utilization of the rabbit VX2 liver tumor model.The rabbit VX2 tumor model has played a longstanding role in experimental oncology. Developed in 1930–1940 by Rous et al. (1, 2), the VX2 tumor is a virus-induced anaplastic squamous cell carcinoma characterized by hypervascularity, rapid growth, and easy propagation in the skeletal muscle (3, 4). Since its introduction, the tumor has been used to model cancers of the head and neck (5), kidney (6), brain (7), lung (8), urinary bladder (9), uterus (10), liver (11, 12), bone (13), and pancreas (14). The high growth rate and the relatively large size of rabbit vasculature render the model particularly well suited for use by interventional radiologists, and in recent years the model has been employed in numerous studies pertaining to the imaging and locoregional treatment of hepatocellular carcinoma (15–19). However, despite the widespread and lasting popularity of the model, there are few, if any, comprehensive technical resources detailing its use, leaving many key procedural details to be conveyed anecdotally. Lack of a technical guide may also represent a barrier to entry of interventional radiologists into translational research. With that in mind, this review is intended to provide a complete pictorial overview of the development, growth, propagation, and angiographic utilization of the rabbit VX2 tumor model based on the experience of a single operator in order to serve as a reference for novice and experienced investigators alike.     

Diagnosis and management of hemoptysis

Hemoptysis is the expectoration of blood that originates from the lower respiratory tract. It is usually a self-limiting event but in fewer than 5% of cases it may be massive, representing a life-threatening condition that warrants urgent investigations and treatment. This article aims to provide a comprehensive literature review on hemoptysis, analyzing its causes and pathophysiologic mechanisms, and providing details about anatomy and imaging of systemic bronchial and nonbronchial arteries responsible for hemoptysis. Strengths and limits of chest radiography, bronchoscopy, multidetector computed tomography (MDCT), MDCT angiography and digital subtraction angiography to assess the cause and lead the treatment of hemoptysis were reported, with particular emphasis on MDCT angiography. Treatment options for recurrent or massive hemoptysis were summarized, highlighting the predominant role of bronchial artery embolization. Finally, a guide was proposed for managing massive and non-massive hemoptysis, according to the most recent medical literature.In clinical practice hemoptysis is a common symptom, which may require further investigation. It is defined as the expectoration of blood that originates from the lower respiratory tract (1). Bleeding from the upper airways is excluded from this definition.In most cases hemoptysis is a self-limiting event but in fewer than 5% it may be severe or massive, representing a life-threatening condition that warrants urgent investigations and treatment (2). Massive hemoptysis usually refers to the expectoration of a large amount of blood and/or to a rapid rate of bleeding. The blood volume expectorated over 24 hours is generally used for distinguishing massive and nonmassive hemoptysis, although the choice of a cutoff value is controversial (3). Volumes of 100 to 1000 mL of blood (4–9) have been described as indicative of massive hemoptysis, but no specific volume has been universally accepted. Furthermore, a large volume of expectorated blood alone should not define massive hemoptysis, but rather an amount of blood sufficient to cause a condition that threatens the patient’s life can be a more correct and functional definition of severe hemoptysis (4, 5).Asphyxia due to the flooding of the airways rather than exsanguination is usually the cause of death, and it is commonly accompanied by cardiovascular collapse. The mortality rate from untreated massive hemoptysis is more than 50% (6). Therefore, prompt recognition of severe hemoptysis and identification of its causes are mandatory to initiate an adequate treatment and to avoid fatal complications (6). Imaging plays a relevant role in managing this clinical condition.This article aims to provide a comprehensive review on massive and nonmassive hemoptysis, with particular emphasis on the pathophysiologic mechanisms, the anatomy of systemic and pulmonary arteries responsible for hemoptysis, and the role of imaging modalities in diagnosing causes and helping treatment. Strengths and limitations of the various diagnostic modalities will be analyzed and a guide for managing hemoptysis, according to the most recent medical literature, will be proposed.     

The potential role of modern US in the follow-up of patients with retroperitoneal fibrosis

PURPOSE

We aimed to evaluate a standardized ultrasonography (US) algorithm for the visualization of pathologic para-aortic tissue in retroperitoneal fibrosis (RPF).

MATERIALS AND METHODS

Thirty-five patients with lumbar RPF of typical extent, as determined by abdominal magnetic resonance imaging, were included. Examinations were conducted using standardized abdominal US with axial sections obtained at the levels of the renal arteries, aortic bifurcation, and both common iliac arteries. Imaging of each section was acquired with fundamental B-mode (US) and tissue harmonic imaging, respectively. In addition, we examined RPF visualized using extended field-of-view US.

RESULTS

Tissue harmonic imaging adequately visualized RPF of typical extent in 33 patients (94.2%). Excellent and good visualization with mild artifacts were achieved in 25 (71.4%) and six (17.1%) patients, respectively. When RPF spread along the iliac arteries, excellent visualization was achieved in 38.7% for the left side and 34.5% for the right side. There were significantly fewer diagnostic examinations for the right iliac (27.6%) than for the left one (9.7%) (P = 0.016). Overall, harmonic imaging achieved significantly better visualization than fundamental B-Mode (P < 0.001).

CONCLUSION

We described the first systematic evaluation of RPF visualization by modern US techniques. The best imaging quality was found in the typical RPF location, at the level of the aortic bifurcation. These results advocate for the presented US algorithm as an efficient follow-up alternative to cross-sectional imaging in RPF patients.Chronic periaortitis or retroperitoneal fibrosis (RPF) is a rare fibrosing disease that affects para-aortic tissues (1–3). It typically presents as a proliferating lumbar process surrounding the ureters and retroperitoneal vascular structures (Fig. 1) (2, 4). Sporadic, atypical manifestations in pelvic and mesenteric regions are also possible (5).Open in a separate windowFigure 1. a–c.Typical extent of the retroperitoneal fibrosis surrounding the infrarenal aorta (a). Spreading of the fibrosis to the renal arteries and along the common iliac arteries (b). Standardized US examination with four transverse sections (c). AO, aorta; AIC, common iliac artery; RA, renal artery; RPF, retroperitoneal fibrosis.Magnetic resonance imaging (MRI) allows precise evaluation of the extent and complications (6). RPF presents as hypointense (often isointense to striated muscle) plaques in native T1-weighted magnetic resonance (MR) images with significant gadolinium contrast enhancement of active and untreated retroperitoneal fibrosis (7–9).Ultrasonography (US) is primarily used in patients with RPF for a rapid and practical diagnosis of consecutive hydronephrosis (6). RPF presents as a smooth-bordered mass with either an echo-poor or echo-free signal (10, 11). Two studies in the 1980s indicated that US revealed only a poor overall sensitivity in the detection of RPF (12, 13). Feinstein et al. (14) reported that only 25% of affected patients with computed tomography (CT)-mediated diagnosis of RPF showed corresponding ultrasonographic abnormalities. Since that time the quality of US scanners has improved dramatically, and modern techniques, such as tissue harmonic imaging (THI) and extended field-of-view US, have significant advantages for routine clinical diagnosis (15–17). Today, US has established itself as an effective and cost-efficient imaging method for the screening and follow-up of infrarenal aortic aneurysms (18, 19). US, however, is not used routinely for RPF follow-up, nor has a systematic evaluation of modern ultrasonographic methods been available to date.The aim of the present study was to evaluate the potential role of modern ultrasonographic techniques for the visualization of fibrous tissue in patients with prediagnosed RPF.     

Volumetric thin-section CT: evaluation of pulmonary interlobar fissures

PURPOSE

We aimed to perform an imaging analysis of interlobar fissures and their variations using thin-section computed tomography (CT).

METHODS

Volumetric thin-section CT scanning was performed in 208 subjects. Interlobar fissures were observed on axial images, and reconstructed coronal and sagittal images were observed by multi-planar reformatting (MPR). The vessel distributions were verified by maximal intensity projection (MIP). On the axial images, the interlobar fissures were characterized by lines of hyperattenuation, bands of hyperattenuation, avascular zones, and mixed imaging. The interlobar fissures were divided into seven grades according to the percentage of defects over the entire fissure.

RESULTS

On the axial images, of all interlobar fissures without avascular zones, 70.2% of the right oblique fissures (ROFs) and 94.2% of the left oblique fissures (LOFs) appeared as lines, and 83.2% of the horizontal fissures (HFs) appeared as bands. All of the interlobar fissures appeared as lines on the coronal and sagittal images. Of all cases, 17.8% showed fully complete interlobar fissures for all three fissures. Incomplete fissures included 41.3% of ROFs, 58.2% of HFs, and 45.2% of LOFs. In ROFs and LOFs, discontinuity was most frequently below 20%, while in HFs discontinuity was most frequently 41%–60%. The most common classification of incomplete interlobar fissures was a discontinuous avascular zone.

CONCLUSION

Incomplete interlobar fissures are common variations of interlobar fissures. Techniques including volumetric thin-section CT, MPR, and MIP can assist in the diagnosis of incomplete interlobar fissures.The pulmonary interlobar fissures are important landmarks for pulmonary anatomy. They adopt a double membrane structure formed by invagination of the visceral pleura. The interlobar fissures are 1–3 mm thick and consist of the right oblique fissure (ROF), horizontal fissure (HF), and left oblique fissure (LOF) (1, 2). The recognition of pulmonary interlobar fissures and their variations is beneficial for identifying pulmonary lesion locations, evaluating disease progression, selecting surgical operations, and applying endoscopic therapy (3–5). With the constant development of imaging techniques, thin-section computed tomography (CT) can provide more detailed information regarding lung structure with respect to the anatomy (5–7). Multiplanar reformatting (MPR) (8) and maximal intensity projection (MIP) are reconstruction techniques based on a noninvasive methodology that detect pulmonary interlobar fissure variations. The results generated by these techniques highly resemble the results of an autopsy (8). In this study, the pulmonary interlobar fissures and their variations were investigated and analyzed by volumetric thin-section MPR and MIP images.     

Efficacy of CT in diagnosis of transudates and exudates in patients with pleural effusion

PURPOSE

We aimed to evaluate the efficacy of multidetector computed tomography (CT) imaging in diagnosis of pleural exudates and transudates using attenuation values.

MATERIALS AND METHODS

This retrospective study included 106 patients who were diagnosed with pleural effusion between January 2010 and June 2012. After the patients underwent chest CT, thoracentesis was performed in the first week. The attenuation values of the pleural effusions were measured in all patients.

RESULTS

According to Light’s criteria, 30 of 106 patients with pleural effusions had transudates, and the remaining patients had exudates. The Hounsfield unit (HU) value of the exudates (median, 12.5; range, 4–33) was significantly higher than that of the transudates (median, 5; range, 2–15) (P = 0.001). Additionally, when evaluated by disease subgroups, congestive heart failure and empyema were predictable in terms of median HU values of the pleural effusions with high and moderate sensitivity and specificity values (84.6% and 81.2%, respectively; 76.9% and 66.7%, respectively). Compared with other patients, the empyema patients had significantly more loculation and pleural thickening.

CONCLUSION

CT attenuation values may be useful in differentiating exu-dates from transudates. Although there is an overlap in most effusions, exudate can be considered when the CT attenuation values are >15 HU. Because of overlapping HU values, close correlation with clinical findings is essential. Additional signs, such as fluid loculation and pleural thickness, should be considered and may provide further information for the differentiation.Pleural effusion is a common clinical problem; indeed, it can arise from many diseases (1, 2). The first step in assessing a pleural effusion is to decide whether the pleural fluid is a transudate or an exudate (3). Transudate is caused by imbalances in hydrostatic and oncotic forces. It results from diseases such as heart failure, kidney failure, and cirrhosis. However, an exudate occurs when local factors influencing the accumulation of pleural fluid are altered. Exudates can be caused by clinical conditions such as pneumonia, malignancy, and thromboembolism (4).Although clinical and radiological findings may provide significant evidence about the cause(s) of pleural effusion(s), it may still be necessary to evaluate some cases with diagnostic thoracentesis (4, 5). Clinically, exudative effusion can be successfully separated from transudative effusion using Light’s criteria. The nature of the pleural effusion is based on diagnostic thoracentesis (1, 2). However, computed tomography (CT) can be used to evaluate the nature of pleural effusions to avoid the complications of thoracentesis (6, 7). Features such as pleural nodules, pleural thickening, loculation, extrapleural fat tissue thickness, and effusion density can be evaluated by CT to discriminate between exudates and transudates (8). Only two reported studies have examined CT attenuation values in patients with pleural effusions (9, 10); these showed different attenuation values for evaluation of pleural effusions.The aim of the present study was to evaluate the efficacy of multidetector CT (MDCT) images in diagnosing pleural exudates and transudates using attenuation values.     

Diffusion-weighted MRI findings of treated and untreated retroperitoneal fibrosis

PURPOSE

We aimed to evaluate diffusion-weighted imaging (DWI) findings in patients with treated and untreated retroperitoneal fibrosis (RPF).

METHODS

We analyzed magnetic resonance imaging examinations of 44 RPF patients (36 male, 8 female), of which 15 were untreated and 29 were under therapy. Qualitative DWI and T1 postcontrast signal intensities and the largest perivascular extent of RPF were compared between treated and untreated groups and correlated to erythrocyte sedimentation rate and C-reactive protein values. Quantitative DWI signal intensities and apparent-diffusion-coefficients were calculated in regions-of-interest, together with a relative index between signal intensities of RPF and psoas muscle in 15 untreated patients and 14 patients under treatment with remaining perivascular fibrosis of more than 5 mm.

RESULTS

The extent of RPF in untreated patients was significantly larger compared with the extent of RPF in treated patients (P < 0.0001). DWI signal intensities were significantly higher in untreated patients than in patients under therapy (mean, 27 s/mm² vs. 20 s/mm²; P = 0.009). The calculated DWI-index was significantly higher in untreated patients than in patients under therapy (P = 0.003).

CONCLUSION

Our data show significant differences in the DWI findings (b800 signal intensities and relative DWI-index) of patients with treated and untreated RPF. DWI is a promising technique in the assessment of disease activity and the selection of patients suitable for medical therapy.Retroperitoneal fibrosis (RPF) is a rare disease affecting the retroperitoneal space (1–3). It presents as retroperitoneal proliferation of fibrous tissue surrounding the retroperitoneal vascular structures and abutting the medial aspect of the ureters. Clinical findings of RPF are non-specific; the most common symptom is chronic back pain. Further symptoms include lower extremity edema, deep vein thrombosis, oliguria, and urinary tract infection (3). Computed tomography (CT) and magnetic resonance imaging (MRI) are the preferred imaging modalities for the diagnosis of RPF (3). Retroperitoneal fibrosis shows contrast enhancement of gadolinium containing contrast media in MRI (4). Medical treatment is classically based on steroids like prednisone (3). Recent studies suggested tamoxifen as another safe and effective treatment alternative (5).The assessment of disease activity is relevant for planning of further medical or surgical therapy (6, 7). Nowadays the disease activity is assessable by positron emission tomography tracer uptake (3), with a relatively low resolution and the need of ionized radiation. As an alternative, dynamic contrast-enhanced MRI was suggested for the evaluation of disease activity (7, 8). However, gadolinium may be contraindicated in patients with impaired renal function due to the potential development of nephrogenic systemic fibrosis (NSF) (9). This is especially relevant in RPF patients with postrenal failure due to ureteral compression. For those cases a supplemental method for the determination of disease activity would be helpful.Diffusion-weighted imaging (DWI) is a radiation-free unenhanced MRI modality that has been applied for the detection of bowel inflammation in patients with chronic inflammatory bowel diseases (10, 11), as well as for oncological retroperitoneal and abdominal applications (12–14). Therefore, we aimed to evaluate the application and findings of DWI in patients with treated and untreated RPF disease.     

Clinical,pathological, and imaging characteristics of primitive neuroectodermal tumors of the spine

Primitive neuroectodermal tumors (PNETs) located in the spine are extremely rare, and information concerning these tumors in the medical literature is limited to single case reports. This pictorial essay presents the clinical, pathological, and imaging characteristics of PNET of the spine.Primitive neuroectodermal tumors (PNETs) are malignant tumors thought to arise from the neural ectoderm and comprise undifferentiated small round cells (1–3). PNETs located in the spine are extremely rare, and information concerning these tumors in the medical literature is limited to single case reports (4–5). This pictorial essay presents the clinical, pathological, and imaging characteristics of PNET of the spine.     

CT-guided percutaneous cryoablation of central lung tumors

PURPOSE

Cryoablation has been successfully used to treat lung tumors. However, the safety and effectiveness of treating tumors adjacent to critical structures has not been fully established. We describe our experience with computed tomography (CT)-guided percutaneous cryoablation of central lung tumors and the role of ice ball monitoring.

MATERIALS AND METHODS

Eight patients with 11 malignant central lung tumors (nine metastatic, two primary; mean, 2.6 cm; range, 1.0–4.5 cm) located adjacent to mediastinal or hilar structures were treated using CT-guided cryoablation in 10 procedures. Technical success and effectiveness rates were calculated, complications were tabulated and intraprocedural imaging features of ice balls were described.

RESULTS

All procedures were technically successful; imaging after 24 hours demonstrated no residual tumor. Five tumors recurred, three of which were re-ablated successfully. A hypodense ice ball with well-defined margin was visible during the first (n=6, 55%) or second (n=11, 100%) freeze, encompassing the entire tumor in all patients, and abutting (n=7) or minimally involving (n=4) adjacent mediastinal and hilar structures. Pneumothorax developed following six procedures (60%); percutaneous treatment was applied in three of them. All patients developed pleural effusions, with one patient requiring percutaneous drainage. Transient hemoptysis occurred after six procedures (60%), but all cases improved within a week. No injury occurred to mediastinal or hilar structures.

CONCLUSION

CT-guided percutaneous cryoablation can be used to treat central lung tumors successfully. Although complications were common, they were self-limited, treatable, and not related to tumor location. Ice ball monitoring helped maximize the amount of tumor treated, while avoiding critical mediastinal and hilar structures.Malignant lung tumors represent a major cause of morbidity and mortality in developed nations (1). While surgical resection remains the treatment of choice for the local control of both non-small cell lung cancer and metastases to the lung, percutaneous image-guided ablative therapies, particularly heat-based ablation techniques such as radiofrequency (RF) ablation, have emerged as safe and effective alternatives in patients who are not surgical candidates (2–7). However, treatment of lung tumors using RF ablation presents technical challenges, including high electrical resistance of alveolar air, poor thermal conductivity of aerated lung, and the heat-sink effect of blood and air flow in well-perfused and aerated lung tissue (8, 9). In addition, RF ablation has a limited role in the treatment of tumors that are close to mediastinal and hilar structures (2–9). Since intraprocedural visualization of ablation zone margins is not possible during heat-based ablation procedures, treatment of central tumors could harm mediastinal and hilar structures, including the tracheobronchial tree. As a result, tumors close to central structures are generally not amenable to treatment using percutaneous heat-based ablation techniques (2–10). Also, RF ablation may interfere with conduction system of the heart and function of the pacemakers (11).A growing body of literature describes the successful use of cryoablation in the treatment of malignancies in the liver, kidneys, and soft tissues (12–14). The ability to deploy multiple, individually-controlled cryoablation applicators facilitates the creation of ablation zones of desired shapes and sizes that can be tailored to the morphology of the tumor being ablated (15, 16). Cryoablation is also monitorable; ice balls can be visualized by computed tomography (CT) as a distinct ovoid area of low attenuation during the procedure. As a result, the treatment can be optimized while minimizing the risk of harming nearby critical structures (12–16). Also, cryoablation may be less painful than RF ablation (17). Finally, it has been suggested that cryoablation may be better suited for the treatment of thoracic tumors adjacent to the mediastinum because it spares the architecture of collagen-containing structures relative to RF ablation and enables preservation of the integrity of the tracheobroncheal tree (18). Heat-based ablation methods may not be safe in the treatment of central lung tumors because of a possibility of bronchial disruption or perforation, which may result in bronchopleural fistula formation (19). Although cryoablation has been used to treat lung malignancies (19–31), there are limited data on the safety and effectiveness of percutaneous cryoablation of central lung tumors. In this study, we describe our experience with CT-guided percutaneous cryoablation of central lung tumors and the role of ice ball monitoring.     

Targeted endovenous treatment of Giacomini vein insufficiency-associated varicose disease: considering the reflux patterns

PURPOSE

We aimed to assess the technical feasibility of targeted endovenous treatment of Giacomini vein insufficiency (GVI)-associated varicose disease and report our early results.

METHODS

We retrospectively screened 335 patients with varicose disease who underwent endovenous laser ablation from September 2011 to January 2013, and determined 17 patients who underwent Giacomini vein ablation. Using a targeted endovenous treatment approach considering the reflux pattern, all healthy great saphenous veins (GSV) or vein segments were preserved while all insufficient veins (Giacomini vein, perforator veins, small saphenous vein, anterior accessory GSV, major tributary veins, or incompetent segments of the GSV) were ablated. Treatment success was analysed using Doppler findings and clinical assessment scores before and after treatment.

RESULTS

Targeted endovenous treatment was technically successful in all cases. Seven GSVs were preserved totally and three GSVs were preserved partially (10/17, 58%), with no major complications. Clinical assessment scores and Doppler findings were improved in all cases.

CONCLUSION

Targeted endovenous treatment of GVI-associated varicose disease is safe and effective. In majority of GVI cases saphenous vein can be preserved using this approach.The Giacomini vein (GV) is defined as a branch of cranial extension of the small saphenous vein (SSV) that connects the SSV with the posterior thigh circumflex vein (PTCV) (1). In 14% of the population, SSV continues directly as the GV (2). Although most varices are caused by reflux originating from the great saphenous vein (GSV), SSV, or accessory saphenous branches, varicose disease caused by a Giacomini vein insufficiency (GVI) is not a rare condition (3, 4). GVI is commonly seen with varices that arise on the posterior thigh or calf and accounts for 4%–6% of cases treated by endovenous laser ablation (ELA) (5–8). There is no defined standard treatment for GVI-associated varicose disease. Performing a phlebectomy as the only treatment may result in recurrent varicose disease for some patients. Classical saphenous vein-focused surgical therapies may result in overtreatment or undertreatment. Targeted endovenous treatment (TET) differs from surgical treatments by focusing on the reflux sources and preserving healthy GSV, either totally or partially, while ablating insufficient segments of the vein. The ablation may be applied to any vein including the GV, perforator vein, SSV, and anterior accessory GSV, except the deep veins.ELA has recently evolved into an accepted option for eliminating truncal reflux for an incompetent GSV or SSV, with successful saphenous vein ablation rates ranging from 88% to 100% (9–12). However, reports of ELA treatment of the GVI are rare (3, 4, 7, 13). Some authors recommend only GSV ablation (4), while others ablate the insufficient GV (3). To the best of our knowledge, there is only one study on treatment of GVI considering the reflux pattern, which used both ELA and sclerotherapy (13). The present study focuses on the saphenous vein sparing effect of TET while treating the GVI by ELA and sclerotherapy.Today, reflux sources other than the saphenous veins, such as the perforator veins or GVs, are also accessible and can be treated selectively with the help of new endovenous techniques. TET considering the various reflux patterns is a minimally invasive and selective treatment method for GVI that may prevent unnecessary saphenous ablations in some cases. The purpose of this study was to evaluate the technical feasibility of TET and report early treatment results of 17 patients who had GVI with various reflux sources.     

Paratracheal air cysts: prevalence and relevance to pulmonary emphysema and bronchiectasis using thoracic multidetector CT

PURPOSE

We aimed to determine the prevalence of paratracheal air cysts (PTACs) and the relationship of PTACs with emphysema and bronchiectasis through retrospective analysis of multidetector computed tomography (MDCT) findings.

METHODS

MDCT findings of 1027 consecutive patients who underwent routine thorax examination between January 2012 and January 2013 were evaluated retrospectively for the presence of PTACs. Localization of the PTACs, as well as their size, shape, and relationship with the trachea were examined. Presence of emphysema and bronchiectasis was recorded, and bronchiectasis severity index was calculated when present. We randomly selected 80 patients who had no visible PTACs as the control group. The findings of patients with and without PTACs were compared.

RESULTS

PTACs were determined in 82 of 1027 patients (8%), in 8.8% of females and 7.3% of males. The presence of PTACs was determined to be independent of gender (P = 0.361). Eighty-one PTACs (98.8%) were located in the right side of the trachea and 56.1% had a tracheal connection. The presence of PTACs significantly correlated with the presence and severity of bronchiectasis (P = 0.001 and P = 0.005 respectively). There was no significant relationship between the presence of PTACs and the presence of emphysema on CT images (P = 0.125).

CONCLUSION

The prevalence of PTACs was determined as 8% in this study. There was significant association between PTACs and bronchiectasis.Paratracheal air cysts (PTACs) are small collections of air adjacent to the trachea at the level of the thoracic inlet (1). Pathological diagnosis of PTACs in surgically confirmed cases includes tracheal diverticulum, lymphoepithelial cyst, and bronchogenic cyst (1–3). These cysts are covered with ciliary columnar epithelium and connected with the trachea (4). The majority of PTACs are reported as tracheal diverticula in the literature, due to their connection with the trachea (2). The thoracic inlet between the cartilage and muscle layers in right posterolateral wall of the trachea is the most common location for PTACs. A relationship may be seen between an isolated PTAC and the trachea l lumen (5). These lesions may cause recurrent infections by acting as a reservoir for secretions.Occasionally, PTACs can be confused with other causes of extraluminal air collections as laryngocele, pharyngocele, Zenker’s diverticulum, apical hernia of the lung, mediastinal air, apical paraseptal blebs, or bullae. To distinguish PTACs from other pathologies, its typical location in the right posterior paratracheal region at the thoracic inlet can be helpful: PTACs locate away from the lung pleura, communicate with the trachea and have rounded margins that can be differentiated from emphysematous changes (6).PTACs are usually discovered incidentally on thorax computed tomography (CT). They may be associated with a chronic cough or chronic obstructive pulmonary diseases (COPD). The reported prevalence of PTACs ranges from 0.75% to 8.1% (4, 6–8). There have been a limited number of studies reporting the incidence of PTACs related to COPD or emphysema as detected by CT, and the reported results are variable (4, 6, 8–11). The relationship between PTACs and pulmonary emphysema or bronchiectasis is still unclear. To our knowledge, no published study has evaluated the relationship between PTACs and bronchiectasis, using a bronchiectasis severity index and objective measures to determine the extent of bronchiectasis on CT images.The purpose of our study was to evaluate the prevalence and characteristics of PTACs, as well as their relationship with bronchiectasis and emphysema, on thorax CT scans.     

Effect of the time to intervention on the outcome of thrombosed dialysis access grafts managed percutaneously

PURPOSE

We aimed to investigate the effect of the time interval from the clinical presentation of a thrombosed dialysis access graft to intervention on procedure success.

MATERIALS AND METHODS

Records from two academic institutions for patients who underwent percutaneous thrombectomy of occluded surgical hemodialysis graft access sites in interventional radiology from 2006 to 2011 were reviewed retrospectively. The following data were recorded: gender, age, time and date of the initial request for a thrombectomy and the procedure, age of the surgical access, angiographic outcome, and clinical outcome (successful or unsuccessful postinterventional dialysis). Univariate and multivariate logistic regression were used to evaluate whether the time to intervention significantly affected the study endpoint.

RESULTS

In total, 268 percutaneous thrombectomies were performed in 139 patients. Of these 224 (83.5%) were categorized as successful and 44 (16.4%) as unsuccessful. The time to intervention was 19.9±30.1 vs. 22±35 hours for successful and unsuccessful procedures, respectively. The difference between the two was not significant, and there were also no significant differences in covariate distributions between successful and unsuccessful outcomes.

CONCLUSION

During the first 72 hours following clinical presentation of a thrombosed dialysis access graft, time to intervention may be considered independent of procedure outcome.Patent vascular access is critical for patients with kidney failure who rely on regularly scheduled hemodialysis. Detailed evidence-supported guidelines have been developed regarding vascular access placement (1–4), and much has been written about the surveillance, maintenance, biology, cost, and interventional techniques for these accesses (5–15). Similarly, predictors of success following radiological intervention of these access sites have been evaluated, including pressure, the degree of stenosis, and procedure type (16, 17). Patient age, access site, underlying comorbidities, the serum albumin level, and systemic systolic pressure over time have been evaluated as potential predictors of graft patency following intervention (16, 18). Nevertheless, the optimal timing of intervention for thrombosed dialysis access remains unknown. This study investigated the relationship between the time elapsed from clinical thrombosis presentation and intervention on the procedural success as defined by anatomic (angiographic) and clinical (subsequent dialysis) outcome variables (19).     

Adrenal venous sampling for stratifying patients for surgery of adrenal nodules detected using dynamic contrast enhanced CT

PURPOSE

We aimed to assess the value of adrenal venous sampling (AVS) for diagnosing primary aldosteronism (PA) subtypes in patients with a unilateral nodule detected on adrenal computed tomography (CT) and scheduled for adrenalectomy.

MATERIALS AND METHODS

This retrospective study included 80 consecutive patients with PA undergoing CT and AVS. Different lateralization indices were assessed, and a cutoff established using receiver operating characteristic curve analysis. The value of CT alone versus CT with AVS for differentiating PA subtypes was compared. The adrenalectomy outcome was assessed, and predictors of cure were determined using univariate analysis.

RESULTS

AVS was successful in 68 patients. A cortisol-corrected aldosterone affected-to-unaffected ratio cutoff of 2.0 and affected-to-inferior vena cava ratio cutoff of 1.4 were the best lateralization indices, with accuracies of 82.5% and 80.4%, respectively. CT and AVS diagnosed 38 patients with aldosterone-producing adenomas, five patients with unilateral adrenal hyperplasia, and 25 patients with bilateral adrenal hyperplasia. Of the 52 patients with a nodule detected on CT, subsequent AVS diagnosed bilateral adrenal hyperplasia in 14 patients (27%). Compared to the results of combining CT with AVS, the accuracy of CT alone for diagnosing aldosterone-producing adenomas was 71.1% (P < 0.001). The cure rate for hypertension after adrenalectomy was 39.2%, with improvement in 53.5% of patients. On univariate analysis, predictors of persistent hypertension were male gender and preoperative systolic blood pressure.

CONCLUSION

To avoid inappropriate surgery, AVS is necessary for diagnosing unilateral nodules with aldosterone hypersecretion detected by CT.Primary aldosteronism (PA) is the most common form of secondary hypertension, with a prevalence of 5%–11% (1–3). PA is due primarily to the hypersecretion of aldosterone by an aldosterone-producing adenoma (APA) or unilateral (primary) adrenal hyperplasia (UAH), which constitute 30%–40% of cases; the remainder are presumed to be secondary to idiopathic bilateral adrenal hyperplasia (BAH) (1, 4, 5). APA and UAH are two forms of unilateral aldosterone hypersecretion, and both are curable with adrenalectomy. BAH induces bilateral aldosterone hypersecretion, and anti-aldosterone drugs are used in its medical management (5–7).The plasma aldosterone-to-renin ratio is used to screen for PA in patients at high risk for PA (8). Recent guidelines recommend using computed tomography (CT) of the adrenal gland to categorize the subtype after confirming PA. However, CT cannot reliably visualize a microadenoma or distinguish between an incidentaloma or BAH and APA. It has been suggested that adrenal venous sampling (AVS) be performed to determine the subtype of PA and to differentiate between unilateral and bilateral production of aldosterone preoperatively (9). AVS to measure the adrenal vein aldosterone and cortisol is the gold standard for lateralizing aldosterone secretion (10). Lateralization is defined using several ratios. In patients with APA or UAH, a unilateral adrenalectomy results in a complete cure or improved hypertension and potassium normalization in approximately 30% of patients, with reported rates up to 86% (11–15).This study assessed several lateralization ratios to establish the most predictive of unilateral disease. We also compared the CT results with those of bilateral AVS for differentiating the PA subtype, with the assumption that AVS is necessary before surgery, even in patients with nodules <10 mm detected with CT. Finally, we assessed the outcomes of adrenalectomy in our patients to identify preoperative predictors of a good outcome.     

Reliability of semiquantitative assessment of osteophytes and subchondral cysts on tomosynthesis images by radiologists with different levels of expertise

PURPOSE

We aimed to assess reliability of the evaluation of osteophytes and subchondral cysts on tomosynthesis images when read by radiologists with different levels of expertise.

MATERIALS AND METHODS

Forty subjects aged >40 years had both knees evaluated using tomosynthesis. Images were read by an “experienced” reader (musculoskeletal radiologist with prior experience) and an “inexperienced” reader (radiology resident with no prior experience). Readers graded osteophytes from 0 to 3 and noted the presence/absence of subchondral cysts in four locations of the tibiofemoral joint. Twenty knees were randomly selected and re-read. Inter- and intrareader reliabilities were calculated using overall exact percent agreement and weighted κ statistics. Diagnostic performance of the two readers was compared against magnetic resonance imaging readings by an expert reader (professor of musculoskeletal radiology).

RESULTS

The experienced reader showed substantial intrareader reliability for graded reading of osteophytes (90%, κ=0.93), osteophyte detection (95%, κ=0.86) and cyst detection (95%, κ=0.83). The inexperienced reader showed perfect intrareader reliability for cyst detection (100%, κ=1.00) but intrareader reliability for graded reading (75%, κ=0.79) and detection (80%, κ=0.61) of osteophytes was lower than the experienced reader. Inter-reader reliability was 61% (κ=0.72) for graded osteophyte reading, 91% (κ=0.82) for osteophyte detection, and 88% (κ=0.66) for cyst detection. Diagnostic performance of the experienced reader was higher than the inexperienced reader regarding osteophyte detection (sensitivity range 0.74–0.95 vs. 0.54–0.75 for all locations) but diagnostic performance was similar for subchondral cysts.

CONCLUSION

Tomosynthesis offers excellent intrareader reliability regardless of the reader experience, but experience is important for detection of osteophytes.Tomosynthesis is a digital X-ray imaging technique that allows acquisition of tomographic information (1). In the literature, its use has been reported for imaging of lungs (1–4), breast (5–7), and head and neck region (8–10); for visualization of kidneys through intravenous pyelogram (11); for localization of an endorectal balloon for prostate image-guided radiation therapy (12); and for evaluation of aortic arch calcification (13), and bone and joint pathologies (14–21). While its clinical use has become common in chest and breast imaging, its clinical application in arthritis imaging is scarcely documented in the literature (14, 15, 22).In a recent study, we reported that tomosynthesis had higher sensitivity for detection of osteophytes and subchondral cysts compared to conventional radiography, using magnetic resonance imaging (MRI) findings as the reference standard (15). In that study, the readings were performed by a single expert musculoskeletal radiologist, and the intrareader reliability for this reader was reported as excellent (weighted κ=1.00 for osteophytes and 0.86 for subchondral cysts). Although it is known that reader experience is important for high reliability in radiographic assessment of knee osteoarthritis (23), it is not known whether excellent reliability can be achieved when tomosynthesis images are read by radiologists with different levels of experience.Tomosynthesis is a potentially useful tool in osteoarthritis research and might be used more frequently in the future because of its advantages over radiography. For its use to become more widespread, however, we need to understand whether reader experience affects the reliability of scoring osteoarthritis features on tomosynthesis, as it does with conventional radiography. It is possible that tomosynthesis can provide high reliability even with inexperienced readers because of the tomographic nature of the acquired images.The aim of this study was to determine the intrareader and inter-reader reliability for semiquantitative scoring of osteophytes and subchondral cyst detection using tomosynthesis, when read by radiologists with different levels of experience.     

Genotype-phenotype correlations in hepatocellular adenoma: an update of MRI findings

Hepatocellular adenoma (HCA) is a generally benign liver tumor with the potential for malignancy and bleeding. HCAs are categorized into four subtypes on the basis of genetic and pathological features: hepatocyte nuclear factor 1α-mutated HCA, β-catenin-mutated HCA, inflammatory HCA, and unclassified HCA. Magnetic resonance imaging (MRI) plays an important role in the diagnosis, subtype characterization, and detection of HCA complications; it is also used to differentiate HCA from focal nodular hyperplasia. In this review, we present an overview of the genetic abnormalities, oncogenesis, and typical and atypical MRI findings of specific subtypes of HCA using contrast-enhanced MRI with or without hepatobiliary contrast agents (gadobenate dimeglumine and gadoxetate disodium). We also discuss their different management implications after diagnosis.Hepatocellular adenoma (HCA) is a rare, benign tumor of the liver that occurs predominantly in young and middle-aged women (1). In contrast to focal nodular hyperplasia (FNH), HCA may involve complications, such as a life-threatening bleeding and malignant degeneration (1–3). The strong association between the occurrence of HCA and the use of oral contraceptives was first acknowledged in 1970s (4), and the incidence of HCA is now thought to be 30 times greater in oral contraceptive users compared to nonusers (5, 6). A dose-dependent association and spontaneous regression following the withdrawal of estrogens have also been described (4, 7). However, the exact role of estrogen in HCA is still poorly understood.In this review, we present an overview of the typical and atypical magnetic resonance imaging (MRI) findings of different HCAs compared to FNH, and discuss various pitfalls that may be encountered with MRI.