Real-time contrast enhanced ultrasound imaging of focal splenic lesions

Objective

To investigate the imaging features of focal splenic lesions (FSLs) on contrast-enhanced ultrasound (CEUS).

Methods

Thirty two patients with FSLs proved by pathology were retrospectively analyzed. CEUS was performed using intravenous bolus injection of 2.4 ml sulfur hexafluoride-filled microbubble contrast agent and real time scanning. There were hemangioma (n = 7), lymphoma (n = 8), true cyst (n = 3), infarction (n = 4), hematolymphangioma (n = 2), metastasis tumor (n = 2), and one for each of the following entities extramedullary hemopoiesis, hamartoma, tuberculosis, Langerhans’ cell histiocytosis, inflammatory pseudotumor and myxofibrosarcoma.

Results

Among 21 benign lesions, 4 infarctions and 3 cysts presented non-enhancement throughout CEUS scanning, and the other 14 lesions displayed various enhancement levels with 6 (42.9%) hyper-enhancement, 2 (14.3%) iso-enhancement and 6 (42.9%) hypo-enhancement in arterial phase and 11 (78.6%) hypo-enhancement, 1 (7.1%) iso-enhancement and 2 (14.3%) hyper-enhancement in late phase, respectively. The enhancement pattern included 9 (64.3%) homogeneous, 4 (28.6%) heterogeneous and 1 (7.1%) rim-like enhancement. As for the malignant FSLs, all the lesions became completely or extensively hypo-enhancement during the late phase no matter their vascularity during arterial phase.

Conclusions

The CEUS features reported in this series may enrich the knowledge for CEUS characterization of FSLs.     

Gadoxetic acid-enhanced 3.0 T MRI for the evaluation of hepatic metastasis from colorectal cancer: Metastasis is not always seen as a “defect” on the hepatobiliary phase

Purpose

To determine specific imaging features of hepatic metastasis from colorectal cancer, focusing on the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI.

Materials and methods

Over a 2-year period, 79 hepatic metastatic lesions were identified from 32 patients (22 men and 10 women) who proven colorectal cancer and underwent gadoxetic acid-enhanced 3.0 T MRI. Hepatic metastases were proven pathologically in 16 patients: by surgical liver resection (n = 14) and by US-guided biopsy (n = 2). The remaining 16 patients were considered to have hepatic metastasis based on imaging studies and clinical information. Two radiologists evaluated the imaging features of each MRI sequence, including high resolution T2WI, dynamic contrast enhancement study with hepatobiliary phase, and diffusion weighted image. We also compared SI of the lesions on T2WI and HBP.

Results

T2WI showed homogeneous high SI (n = 25; 31.7%), target appearance (n = 3; 3.8%), reversed target appearance (n = 2; 2.6%), and heterogeneously high SI (n = 49; 62%). On HBP, homogeneous defect were seen in 22 lesions (27.9%), target appearance in five lesions (6.4%), reversed target appearance in two lesions (2.5%), and heterogeneous defect in 50 lesions (63.3%); including reticular (70%), partially globular (26%), and diffuse GGO-like (4%) patterns. According to the imaging features on HBP, the homogeneous defect and heterogeneous defect groups had a mean ADC value of 0.99 × 10⁻³ and 1.07 × 10⁻³ mm²/s, respectively, without statistically significant difference.

Conclusion

Hepatic metastasis from colorectal cancer usually showed as a heterogeneous defect on HBP and a heterogeneous high SI on T2WI. The generally accepted “true defect” was not a common finding in hepatic metastasis from colorectal cancer.     

Differentiating benign from malignant solid breast lesions: Combined utility of conventional ultrasound and contrast-enhanced ultrasound in comparison with magnetic resonance imaging

Objective

To prospectively evaluate the diagnostic efficacy of conventional ultrasound (US), contrast-enhanced US (CEUS), the combined use of two modalities, and magnetic resonance imaging (MRI) in the differentiation of focal solid breast lesions.

Materials and methods

61 patients with BI-RADS category 3–5 breast lesions detected at conventional US underwent CEUS and MRI. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of conventional US, CEUS, combination of two modalities and MRI for discrimination between benign and malignant breast lesions.

Results

Tissue specimens of 61 breast lesions were obtained either from surgical resection (n = 46) or from needle biopsy (n = 15). Histopathologic diagnosis revealed 28 benign and 33 malignant lesions. The diagnostic performance of conventional US and CEUS in differentiating benign from malignant breast lesions showed no significant difference (P = 0.741). The combination of two modalities significantly improved the diagnostic accuracy compared with either conventional US or CEUS alone (P = 0.031 and P = 0.012, respectively). The area under the ROC curve (A_z) value for the combined use of two modalities for discrimination between benign and malignant breast lesions was 0.94, and that for MRI was 0.91, whereas no statistical difference was found between them (P = 0.296).

Conclusion

The combined use of conventional US and CEUS has a better diagnostic performance than either method alone and displays good agreement with MRI in the differentiation capability for benign and malignant breast lesions.     

Brain MR imaging abnormalities in pediatric patients after allogeneic bone marrow transplantation

Objective

Our aim was to analyze brain MRI findings in pediatric patients who developed neurologic complications after allogeneic bone marrow transplantation.

Materials and methods

This prospective study included 33 consecutive patients (age range from 3 to 18 years, mean 11.8 ± 5.1 years). They were referred to the MRI unit because of the neurological symptoms in the post transplant period. The underlying disorders included: non malignant hematological disorders (n = 20, 60.6%) and hematological malignancies (n = 13, 39.4%). Onset of the presentation of the complication in relation to the chronology of the transplant was identified in each patient (phase1: from days 0 to 30, phase 2: from days 30 to 100, and late phase after day 100).

Results

According to the MRI findings 6 patients (18.2%) showed normal examinations. Twenty-seven patients (81.8%) with positive MRI findings, are grouped into 7 main categories: posterior reversible encephalopathy syndrome (n = 16, 48.48%), intracranial hemorrhage (n = 2, 6.06%), cerebral venous sinus thrombosis (n = 1, 3.03%), CNS infection (n = 2, 6.06%), leukoencephalopathy (n = 5, 15.15%), mild atrophy (n = 11, 33.33%), CNS relapse (n = 1, 3.03%), with 9 patients having more than one diagnosis. Ten cases of PRES and 1 case of sinus thrombosis were detected in phase 1. Two cases of PRES and 2 cases of intracranial hemorrhage were detected in phase 2. Four cases of leukoencephalopathy, 4 cases of PRES, 2 cases of CNS infection, and 1 case of CNS relapse were detected in phase 3.

Conclusion

CNS complications after allogenic BMT in pediatric patients could cause a significant clinical problem. MRI can provide early diagnosis and follow-up to monitor treatment changes. Knowing the onset of the presentation of the complication in relation to the chronology of the transplant is important as it provides significant guidance on which causes to consider.     

Indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography: Assessment of the additional diagnostic value of contrast-enhanced ultrasound in the non-cirrhotic liver

Objective

To assess the additional diagnostic value of contrast-enhanced ultrasound (CEUS) in the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography (CT).

Methods

Fifty-five solid hepatic lesions (1–4 cm in diameter) in 46 non-cirrhotic patients (26 female, 20 male; age ± SD, 55 ± 10 years) underwent CEUS after being detected on contrast-enhanced CT which was considered as non-diagnostic after on-site analysis. Two blinded independent readers assessed CT and CEUS scans and were asked to classify retrospectively each lesion as a malignant or benign based on reference diagnostic criteria for the different hepatic lesion histotypes. Diagnostic accuracy and confidence (area – A_z – under ROC curve) were assessed by using gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (n = 30 lesions), histology (n = 7 lesions), or US follow-up (n = 18 lesions) as the reference standards.

Results

Final diagnoses included 29 hemangiomas, 3 focal nodular hyperplasias, 1 hepatocellular adenoma, and 22 metastases. The additional review of CEUS after CT images improved significantly (P < .05) the diagnostic accuracy (before vs after CEUS review = 49% [20/55] vs 89% [49/55] – reader 1 and 43% [24/55] vs 92% [51/55] – reader 2) and confidence (A_z, 95% Confidence Intervals before vs after CEUS review = .773 [.652–.895] vs .997 [.987–1] – reader 1 and .831 [.724–.938] vs .998 [.992–1] – reader 2).

Conclusions

CEUS improved the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced CT by identifying some specific contrast enhancement patterns.     

Potential impact of PET/CT on the initial staging of lymphoma

Purpose

The aim of this study was to investigate the potential impact of PET/CT on the initial staging of lymphoma with comparison to each of the PET and CT components alone.

Materials and methods

PET/CTs from 37 patients with lymphoma undergoing initial staging were studied. Review of PET, CT and PET/CT images were done and staging of each patient by each modality was assigned and compared together. Clinical follow-up, additional imaging and histology served as the standard of reference.

Results

PET/CT correctly diagnosed 83 nodal regions as positive for lymphomatous involvement versus 61 and 57 detected by PET and CT respectively. The respective sensitivities, specificities, and accuracies for the detection of nodal involvement were: PET: 88.4%, 65%, 94%, CT 89.1%, 60.1%, 96.1%, PET/CT 96.3%, 88.3%, 98.2%. PET/CT also correctly identified more extra-nodal lesions (n = 24) than CT (n = 16) and PET (n = 15). Correct staging was more accurate at PET/CT (n = 31) in comparison to PET alone (n = 23) and CT alone (n = 21).

Conclusions

PET/CT was superior to PET and CT in the initial staging of lymphoma with significant better performance compared to PET and CT to clarify nodal and extra-nodal involved sites. The application of PET/CT rather than CT or PET is likely to be more beneficial.     

CT and MR features of xanthogranulomatous cholecystitis: An analysis of consecutive 49 cases

Objective

To study the CT and MR features of xanthogranulomatous cholecystitis (XGC).

Materials and methods

49 patients had pathologically confirmed XGC. All patients underwent contrast enhanced CT, and 10 patients had additional plain MRI. The CT and MRI results were retrospectively analyzed.

Results

On CT, all patients had thickening of gallbladder wall, with 87.8% cases showed diffuse thickening. 85.7% cases had intramural hypo-attenuated nodules in the thickened wall. Continuous mucosal line and luminal surface enhancement were noted in 79.6% and 85.7% cases, respectively. Gallbladder stones were seen in 69.4% patients. The coexistence of the above 5 CT features was seen in 40% cases, and 80% cases had the coexistence of ≥4 features. Diffused gallbladder wall thickening in XGC is more likely to have disrupted mucosal line, and XGC with disrupted mucosal line is more likely to be associated with liver infiltration. In 60% patients the inflammatory process extended beyond gallbladder, with the interface between gallbladder and liver and/or the surrounding fat blurred. 40% cases had an early enhancement of liver parenchyma. Infiltration to other surrounding tissues included bowel (n = 3), stomach (n = 2), and abdominal wall (n = 1). On MR images, 7 of 9 intramural nodules in 7 subjects with T1-weighted dual echo MR images showed higher signal intensity on in-phase images than out-of-phase images.

Conclusion

Coexisting of diffuse gallbladder wall thickening, hypo-attenuated intramural nodules, continuous mucosal line, luminal surface enhancement, and gallbladder stone highly suggest XGC. XGC frequently infiltrate liver and surrounding fat. Chemical-shift MRI helps classifying intramural nodules in the gallbladder wall.     

MRI for characterization of primary tumors in the non-cirrhotic liver: Added value of Gd-EOB-DTPA enhanced hepatospecific phase

Purpose

To evaluate the added value of hepatospecific phase in Gd-EOB-DTPA enhanced magnetic resonance imaging (MRI) in patients with primary tumors in non-cirrhotic liver.

Methods

Twenty-nine patients (median, 39 years; range, 18–81 years; 11 male) underwent preoperative Gd-EOB-DTPA enhanced MRI including hepatospecific phase after 10 and 20 min of contrast injection at four institutions in Europe, North America and New Zealand. Images were evaluated by three different readers (R1–R3) who characterized liver tumors with and without consultation of the hepatospecific phase images. Confidence in diagnosis was scored on a visual analog scale from 1 to 10. Histopathology (adenoma, n = 5; focal nodular hyperplasia, n = 11 and hepatocellular carcinoma, n = 13) in all patients served as the standard of reference. Differences were evaluated using the McNemar and Wilcoxon signed rank test.

Results

Without hepatospecific phase images available, 22 (76%), 19 (66%) and 19 (66%) of 29 tumors were characterized correctly by the three readers respectively. Mean confidence in diagnosis was 6.1, 5.7 and 5.8. With the hepatospecific phase included, characterization of liver tumors did not change significantly with 21 (72%), 23 (79%) and 19 (66%) of 29 tumors diagnosed correctly (p > 0.05). According confidence ratings increased to 6.3, 6.5 and 7.7, respectively. Increase in diagnostic confidence was significant for R2 and R3 (p < 0.05) and independent of reader's experience.

Conclusion

The additional hepatospecific phase in Gd-EOB-DTPA enhanced MRI did not significantly increase diagnostic accuracy in characterization of primary tumors in the non-cirrhotic liver. However, 2/3 readers showed a significant increase in diagnostic confidence after consultation of the hepatospecific phase.     

Role of magnetic resonance spectroscopy in differentiation between recurrence of glioma and post radiation injury

Purpose

This study aims to evaluate the role of MR spectroscopy in the detection of recurrent glioma and differentiation from post radiation injury.

Patients and methods

32 patients (20 males and 12 females) complaining of different neurological symptoms were enrolled prospectively in this study between September 2011 and December 2013. These patients were selected on the basis that they were known patients with pathologically proved glioma who underwent radiotherapy. All patients underwent standard MRI examination and MR spectroscopy.

Results

This study included 32 patients, twenty four patients (75%) proved histologically to be of recurrent glioma (group I) and 8 cases (25%) diagnosed as post radiation injury (group II). Peri-tumoral infiltration was present in 18 cases (56.25%) of recurrent glioma. Significantly increased Cho/Cr and Cho/NAA ratios were observed in neoplastic (n = 24) compared with non-neoplastic lesions (n = 8). Presence of lactate and lipid yielded correct classification as neoplastic and non-neoplastic lesions.

Conclusion

Magnetic resonance spectroscopy is a useful tool for the detection of recurrent glioma and differentiation from post radiation injury.     

Detecting subarachnoid hemorrhage: Comparison of combined FLAIR/SWI versus CT

Objectives

Aim of this study was to compare the utility of susceptibility weighted imaging (SWI) with the established diagnostic techniques CT and fluid attenuated inversion recovery (FLAIR) in their detecting capacity of subarachnoid hemorrhage (SAH), and further to compare the combined SWI/FLAIR MRI data with CT to evaluate whether MRI is more accurate than CT.

Methods

Twenty-five patients with acute SAH underwent CT and MRI within 6 days after symptom onset. Underlying pathology for SAH was head trauma (n = 9), ruptured aneurysm (n = 6), ruptured arteriovenous malformation (n = 2), and spontaneous bleeding (n = 8). SWI, FLAIR, and CT data were analyzed. The anatomical distribution of SAH was subdivided into 8 subarachnoid regions with three peripheral cisterns (frontal-parietal, temporal-occipital, sylvian), two central cisterns and spaces (interhemispheric, intraventricular), and the perimesencephalic, posterior fossa, superior cerebellar cisterns.

Results

SAH was detected in a total of 146 subarachnoid regions. CT identified 110 (75.3%), FLAIR 127 (87%), and SWI 129 (88.4%) involved regions. Combined FLAIR and SWI identified all 146 detectable regions (100%). FLAIR was sensitive for frontal-parietal, temporal-occipital and Sylvian cistern SAH, while SWI was particularly sensitive for interhemispheric and intraventricular hemorrhage.

Conclusions

By combining SWI and FLAIR, MRI yields a distinctly higher detection rate for SAH than CT alone, particularly due to their complementary detection characteristics in different anatomical regions. Detection strength of SWI is high in central areas, whereas FLAIR shows a better detection rate in peripheral areas.     

Role of computed tomography and magnetic resonance imaging in diagnosing pericardial lesions

Objective

In this research, patients who had pericardial lesions are imaged by either CT or MRI and the purpose of this paper is to discuss which imaging modality should be used in the assessment of patients with different pericardial diseases.

Patients and methods

Thirty patients ranging in age between 3 months and 46 years diagnosed as having pericardial lesions by transthoracic echocardiography were prospectively studied. All patients were examined by history taking, chest X-ray, clinical examination, transthoracic echocardiography, Multidetector CT and/or magnetic resonance imaging.

Result

Several types of lesions were identified including constrictive pericarditis (n = 10), pericardial simple effusion (n = 9), pericardial tumors (n = 5), pericardial abscess (n = 4), pericardial hemorrhage (n = 4) and one case of pericardial cyst. Three patients had combined lesions.

Conclusion

CT and MR imaging should be used when findings at echocardiography are difficult to interpret, inconclusive or conflict with clinical findings. CT is better used for the assessment of postoperative cases while MRI is superior in detecting and diagnosing pericardiac masses and constrictive pericarditis.Also, because of radiation involving CT scan should be avoided in children if possible but has the advantage of fast imaging speed and often no need for sedation of patients and children.     

Breast MRI of pure ductal carcinoma in situ: Sensitivity of diagnosis and influence of lesion characteristics

Objectives

The purpose of the study was to evaluate the sensitivity of breast MRI in the detection of pure DCIS and to analyze the influence of lesion type and nuclear grade.

Methods

58 consecutive patients with pathologically proven pure DCIS and preoperatively performed breast MRI were retrospectively reviewed and analyzed. Sensitivities in the detection of DCIS were calculated for MRI and mammography (Mx). Influence of MRI lesion type and nuclear grading on DCIS diagnosis was evaluated.

Results

MRI detected pure DCIS with a sensitivity of 79.3%. The sensitivity of Mx was lower (69%), but the difference was not statistically significant (p = 0.345). 46.2% of the DCIS presented as enhancing mass and 53.8% as non-mass-like enhancement (NMLE). None of the masses but 21.4% (n = 6) of the NMLE were underestimated as probably benign (BI-RADS^® 3). MRI measured lesion sizes showed a moderate correlation (r = 0.74) with histopathologically measured lesion sizes. MRI detection rate of DCIS decreased significantly (p = 0.0458) with increasing nuclear grade. Calculated sensitivities were 100% for low-grade DCIS, 84.6% for intermediate-grade DCIS, and 66.7% for high-grade DCIS.

Conclusions

In this study MRI could detect pure DCIS more sensitively than Mx. Despite of missing statistically significance preoperative MRI seems to be helpful in patients with DCIS who are eligible for breast conservation. This applies in particular to patients with non-high-grade DCIS because those were significantly more often positive on MRI and significantly more often negative on Mx. Misinterpretation occurs especially in cases of NMLE and high-grade DCIS and therefore a correlation with Mx is also recommended.     

High-resolution computed tomographic findings of Aspergillus infection in lung transplant patients

Objective

The aim of this study was to assess high-resolution computed tomographic (HRCT) findings at presentation in lung transplant patients diagnosed with pulmonary Aspergillus infection.

Materials and methods

We retrospectively reviewed HRCT findings from 23 patients diagnosed with pulmonary aspergillosis. Imaging studies were performed 2–5 days after the onset of symptoms. The patient sample comprised 12 men and 11 women aged 22–59 years (mean age, 43.6 years). All patients had dyspnea, tachypnea, and cough. Diagnoses were established with Platelia Aspergillus enzyme immunoassays for galactomannan antigen detection in bronchoalveolar lavage and recovery of symptoms, and HRCT findings after voriconazole treatment. The HRCT scans were reviewed independently by two observers who reached a consensus decision.

Results

The main HRCT pattern, found in 65% (n = 15) of patients, was centrilobular tree-in-bud nodules associated with bronchial thickening. This pattern was described in association with areas of consolidation and ground-glass opacities in 13% (n = 3) of patients. Consolidation and ground-glass opacities were the main pattern in 22% (n = 5) of patients. The pattern of large nodules with and without the halo sign was observed in 13% (n = 3) of patients, and were associated with consolidation and ground-glass opacities in one case.

Conclusion

The predominant HRCT findings in lung transplant patients with pulmonary aspergillosis were bilateral bronchial wall thickening and centrilobular opacities with the tree-in-bud pattern. Ground-glass opacities and/or bilateral areas of consolidation were also common findings. Pulmonary nodules with the halo sign were found in only 13% of patients.     

Nasopharyngeal tuberculosis: CT and MRI findings in thirty-six patients

Purpose

Tuberculosis is uncommon in the nasopharynx. The purpose of this study was to investigate the CT and MRI features of 36 cases of tuberculosis in this area.

Materials and methods

CT (n = 15) and MRI (n = 21) scans from 36 patients with histologically proved tuberculosis of the nasopharynx were reviewed by two experienced radiologists, paying particular attention to the lesions’ distribution, location, extent, size, internal architecture, pattern, and degree of enhancement, and cervical lymphadenopathy.

Results

Twenty-nine patients exhibited a polypoid mass pattern and seven had diffuse mucosal thickening. The roof of the nasopharynx was involved in all cases. The mean size of the lesions was 11.4 mm. Striped pattern was detected in 19 cases. Adjacent muscle invasion or bone destruction was not detected. Heterogeneous enhancement was detected in all patients, and necrosis in the nasopharyngeal lesions was detected in 16 cases. Poor, moderate, and marked enhancement was detected in one, 27, and eight cases, respectively. Thirty-four patients had involvement of the cervical lymph nodes. Twenty-two and 28 cases were associated with bilateral lymphadenopathy or necrosis, respectively. The retropharyngeal lymph node was the most commonly involved site (94.1%).

Conclusion

The presence of necrosis and striped pattern in nasopharyngeal lesions, site predilection, no invasion of regional structures, and central necrosis with peripheral rim enhancement of cervical lymphadenopathy may suggest the diagnosis of nasopharyngeal tuberculosis.     

Abdominal ultrasonography in preterm necrotizing enterocolitis. Is it superior to plain radiography?

Purpose

To explore whether abdominal ultrasound (AUS) provide additional information over plain radiography in cases of necrotizing enterocolitis (NEC).

Methods

This study is a prospective study of 30 premature neonates with NEC in our neonatal intensive care unit between August 2010 and November 2011. Fifteen premature control neonates were also included in the study.

Results

Patients were classified into two groups: the first group with suspected NEC (stage I) (n = 14) and the second with definite NEC (stage II or III) (n = 16). In group I abdominal ultrasound (AUS) revealed intramural air (n = 9) and portal venous gas (PVG) (n = 1) while plain radiography showed only gaseous distension. In group II, intramural air (n = 10), PVG (n = 2), free fluid (n = 6) focal fluid (n = 1) and free air (n = 6) detected by AUS compared to pneumatosis intestinalis (PI) (n = 2) PVG (n = 1) and free air (n = 5) by plain radiography. Additionally bowel wall thinning was detected in 2 neonates of group I and 3 of group II.

Conclusion

Our results suggest AUS to be superior to plain radiography in early detection of complication as intestinal perforation by eliciting PVG and fluid collection and so early surgical management. Therefore this may decrease morbidity and mortality rates.     

Volume perfusion CT (VPCT) for the differential diagnosis of patients with suspected cerebral vasospasm: Qualitative and quantitative analysis of 3D parameter maps

Object

Cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH) implies high risk for secondary ischemia. It requires early diagnosis to start treatment on time. We aimed to assess the utility of “whole brain” VPCT for detecting localization and characteristics of arterial vasospasm.

Methods

23 patients received a non-enhanced CT, VPCT and CTA of the brain. The distribution of ischemic lesions was analyzed on 3D-perfusion-parameter-maps of CBF, CBV, MTT, TTS, TTP, and TTD. CT-angiographic axial and coronal maximum-intensity-projections were reconstructed to determine arterial vasospasm. CT-data was compared to DSA, if performed additionally. Volume-of-interest placement was used to obtain quantitative mean VPCT values.

Results

82% patients (n = 19) had focal cerebral hypoperfusion. 100% sensitivity and 100% specificity was found for TTS (median 1.9 s), MTT (median 5.9 s) and TTD (median 7.6 s). CBV showed no significant differences. In 78% (n = 18) focal vessel aberrations could be detected either on CTA or DSA or on both.

Conclusion

VPCT is a non-invasive method with the ability to detect focal perfusion deficits almost in the whole brain. While DSA remains to be the gold standard for detection of CV, VPCT has the potential to improve noninvasive diagnosis and treatment decisions.     

Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

Purpose

The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer.

Materials and methods

We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon.

Results

Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1).Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively).

Conclusion

Dynamic contrast-enhanced magnetic resonance imaging had a high sensitivity, negative predictive value for the prediction of breast cancer but a low specificity due to features of foreign body-related lesions that mimicked malignant lesions. The significant predictive factors for malignancy were margins, kinetic curve pattern and final assessment category. Overall inter-observer agreement for the kinetic curve pattern was good.     

Quantification of coronary artery stenosis with high-resolution CT in comparison with histopathology in an ex vivo study

Purpose

To investigate the ex vivo performance of high-resolution computed tomography (CT) for quantitative assessment of percentage diameter stenosis in coronary arteries compared to histopathology.

Materials and methods

High-resolution CT was performed in 26 human heart specimens after the injection of iodinated contrast media into the coronary arteries. Coronary artery plaques were visually identified on CT images and the grade of stenosis for each plaque was measured with electronic calipers. All coronary plaques were characterized by histopathology according to the Stary classification, and the percentage of stenosis was measured.

Results

CT depicted 84% (274/326) of all coronary plaques identified by histology. Missed plaques by CT were of Stary type I (n = 31), type II (n = 16), and type III (n = 5). The stenosis degree significantly correlated between CT and histology (r = 0.81, p < 0.001). CT systematically overestimated the stenosis of calcified plaques (mean difference - 11.0 ± 9.5%, p < 0.01) and systematically underestimated the stenosis of non-calcified plaques (mean difference −6.8 ± 10.4%, p < 0.05), while there was no significant difference for mixed-type plaques (mean difference −0.4 ± 11.7%, p = 0.85). There was a significant underestimation of stenosis degree as measured by CT for Stary II plaques (mean difference −14 ± 9%, p < 0.01) and a significant overestimation for Stary VII plaques (mean difference 9 ± 10%, p < 0.05), but there was no significant difference in stenosis degree between both modalities for other plaque types.

Conclusions

High-resolution CT reliably depicts advanced stage coronary plaques with an overall good correlation of stenosis degree compared to histology, however, the degree of stenosis is systematically overestimated in calcified and underestimated in non-calcified plaques.     

Can conventional magnetic resonance imaging predict survival in pediatric diffuse intrinsic pontine glioma? A single institution experience

Background

Pediatric diffuse intrinsic pontine glioma (DIPG) remains dismal regardless the new therapeutic and technical advances.

Objective

To investigate the value of magnetic resonance imaging (MRI) in predicting DIPG prognosis.

Patients and methods

Twenty-five DIPG patients with 95 (initial and post radiotherapy) MR examinations were studied. Hydrocephalus was detected in 6 cases (24%), basilar artery encasement in 20 (80%), ill defined border in 16 (64%), perilesional edema in 2 cases (8%) and none showed leptomeningeal spread. Conformal 3-dimensional radiotherapy (39 Gy/13 fractions or 54 Gy/30 fractions) was applied.

Results

The median overall survival (MOS) was 9.3 months (95% CI: 7.9–10.8) and the one year overall survival was 18 ± 8.9%. Post radiation MRI performed 3–6 months after treatment showed regression in 8 cases (32%), stationary course in 5 (20%) and progression in 12 cases (48%). The MOS was higher in children whose MRI showed regression (10.0, CI: 6.3–13.7) than those with radiological progression (8.0, CI: 5.9–10.1 months) or stationary course (7.0, CI: 4.9–9.1). However; these differences did not rank to the level of significance. There was no statistical association of tumor size (p = 0.907), presence of hemorrhage (p = 0.314), or surrounding edema (p = 0.263); entrapment of the basilar artery (p = 0.782); pattern of enhancement (p = 0.851); and hydrocephalus (p = 0.354) with the length of the overall survival.

Conclusions

Though MRI is the mainstay for the diagnosis of DIPG, yet its prognostic value is limited. New MR techniques as MR spectroscopy and diffusion tensor imaging should be evaluated as additional tools for prognostic evaluation of DIPG.     

Lung nodule detection in a high-risk population: Comparison of magnetic resonance imaging and low-dose computed tomography

Objective

To investigate the potential of MRI for lung nodule detection in a high-risk population in comparison to low-dose CT.

Methods

49 participants (31 men, 18 women, 51–71 years) of the German Lung Cancer Screening and Intervention Trial (LUSI) with a cancer-suspicious lung lesion in CT were examined with non-contrast-enhanced MRI of the lung at 1.5 T. Data were pseudonymized and presented at random order together with 30 datasets (23 in men, 7 in women, 18–64 years) from healthy volunteers. Two radiologists read the data for the presence of nodules. Sensitivity and specificity were calculated. Gold standard was either histology or long-term follow-up. Contrast-to-Noise-Ratio (CNR) was measured for all detected lesions in all MRI sequences.

Results

Average maximum diameter of the lesions was 15 mm. Overall sensitivity and specificity of MRI were 48% (26/54) and 88% (29/33) compared to low-dose CT. Sensitivity of MRI was significantly higher for malignant nodules (78% (12.5/16)) than for benign ones (36% (13.5/38); P = 0.007). There was no statistically significant difference in sensitivity between nodules (benign and malignant) larger or smaller than 10 mm (P = 0.7). Inter observer agreement was 84% (κ = 0.65). Lesion-to-background CNR of T2-weighted single-shot turbo-spin-echo was significantly higher for malignant nodules (89 ± 27) than for benign ones (56 ± 23; P = 0.002).

Conclusion

The sensitivity of MRI for detection of malignant pulmonary nodules in a high-risk population is 78%. Due to its inherent soft tissue contrast, MRI is more sensitive to malignant nodules than to benign ones. MRI may therefore represent a useful test for early detection of lung cancer.