Slow Washout Pattern Research Articles

Comparison of Contrast-Enhanced Ultrasonography to Color Doppler Ultrasound in Evaluation of Carotid Body Tumors.

ObjectiveThe objectives of this study were to prospectively 1) explore the characteristics and enhanced patterns of carotid body tumors (CBTs) at color Doppler ultrasound (CDU) and contrast-enhanced ultrasonography (CEUS) qualitatively and quantitatively and 2) compare CDU and CEUS for their morphology and vascularity signature.MethodsCDU and CEUS with Sonovue® were used to evaluate 25 CBT lesions. The comparison between these ultrasonic modalities included the size, Shamblin type, vascularity, and feeding vessels of the lesion areas. The time–intensity curve (TIC) analysis was used to obtain the dynamics of the contrast-enhancement features of CBTs.ResultsThe TIC analysis presented a fast wash-in [wash-in time: 3.00 ± 1.10 s, mean ± SD] and slow wash-out [wash-out time: 58.79 ± 24.21 s, mean ± SD] pattern in the CBT lesions, with a high area under the curve (AUC) of 669.68 ± 143.46 mm2 (mean ± SD). In comparison with CDU, CEUS was superior in identifying Shamblin type I or III CBT lesions (χ2 = 17.389, p=0.002). It detected a significant difference in the AUC between moderate and marked vascularity groups (563.33 ± 102.63 vs. 707.22 ± 138.81, t=-2.311, p=0.031.), while CDU observed no significant difference between these two groups. Although CDU was more sensitive than CEUS in detecting feeding vessels (100% vs. 88%), CEUS better visualized the origins of feeding vessels (χ2 = 9.162, p=0.010).ConclusionCEUS can better investigate the Shamblin type and vascularity of CBT lesions than CDU. CBTs displayed a fast wash-in, slow wash-out pattern with high AUC in the TIC analysis in the CEUS mode. CDU is more sensitive in detecting feeding vessels than CEUS, while CEUS can better visualize the origins of feeding vessels.

Quantitative analysis in parathyroid adenoma scintigraphy.

Surgery is the only curative treatment for primary hyperparathyroidism. Parathyroid scintigraphy is one method used to preoperatively localize the lesion. We examined time-related changes in radiopharmaceutical uptake in parathyroid adenomas (PTAs) and thyroid gland by quantitative single-photon-emission computed tomography (SPECT) imaging to assess differences between rapid and delayed washout patterns. The study group consisted of 35 histologically verified PTAs after radio-guided surgery extirpation in 33 patients with primary hyperparathyroidism. Patients underwent a three-phase SPECT/CT study of the neck and upper thorax post 99mTc-methoxyisobutylisonitrile (MIBI) injection. Images were reconstructed using a proprietary ordered-subset-conjugate-gradient-maximization algorithm (Siemens xSPECT Quant). PTAs were divided into those with a rapid (group A) and those with a slow (group B) washout pattern. SUVmax values of PTAs and thyroid gland tissue at 10, 90 and 180 min post 99mTc-MIBI injection were recorded and statistically assessed. Retention indexes related to the early examination were calculated for PTA and thyroid gland (RI-PTA and RI-TG). There were 11 PTAs in group A and 24 in group B. Significant between-group differences in PTA SUVmax and PTA/thyroid gland ratios were observed only at 180 min postinjection (P = 0.0297, P = 0.0222, respectively). RI-PTAs differed significantly at 90 and 180 min postinjection (P = 0.0298, P = 0.0431). No differences in PTA volumes, thyroid gland SUVmax values or RI-TG were observed between the groups. PTAs with rapid and slow washout patterns have different characteristics on quantitative analysis in later phases. No significant differences in directly measurable quantitative values (SUVmax, PTA/thyroid gland ratio) at the early stages of multi-phase examination were observed.

Computed tomography and magnetic resonance imaging of adenoid cystic carcinoma in the maxillary sinus: a retrospective study with radiologic-histopathologic correlations

The aim of this study was to investigate computed tomography (CT) and magnetic resonance imaging (MRI) findings in adenoid cystic carcinoma (ACC) in the maxillary sinus and their correlations with the tubular, cribriform, and solid histopathologic types of ACC. Twenty cases of histopathologically proven ACC in the maxillary sinus were retrospectively reviewed. CT and MRI findings were correlated with histopathologic results. On CT, significant differences were discovered among the 3 histopathologic ACC types in range, size, shape, margins, type of bone destruction, and time intensity curve (TIC) (P ≤ .018). Tubular lesions were limited in range, were smaller than the other types, produced small cystic patterns with well-defined margins, and caused a cribriform pattern of bone destruction. All tumors demonstrated heterogeneous intensity signal on T1- and T2-weighted images (T1WI and T2WI) and appeared as hypo- or isointense small cystic lesions on T1WI and hyperintense on T2WI (n=6). Postcontrast MRI revealed marked heterogeneous enhancement for all lesions. The TIC showed a rapidly enhancing and slow washout pattern in all tubular lesions and a rapidly enhancing and rapid washout pattern in solid tumors. Different histologic patterns of ACCs have distinctive radiologic features, which can facilitate accurate preoperative diagnosis.

Early gadolinium enhancement in hypertrophic cardiomyopathy: a potential premature marker of myocardial damage.

Early gadolinium enhancement (EGE), one CMR diagnostic criteria in acute myocarditis, has been related with hyperemia and capillary leakage. The value of EGE in hypertrophic cardiomyopathy (HCM) remains unknown. Our aim was to determine the prevalence of EGE in patients with HCM, and its relation with late gadolinium enhancement (LGE). The association of EGE with morphological and clinical parameters was also evaluated. Sixty consecutive patients with HCM and CMR from our center were included. All the clinical and complementary test information was collected prospectively in our HCM clinic. Left ventricular (LV) measurements were calculated from cine sequences. EGE and LGE were quantified with a dedicated software. Clinical events were collected from medical records. A slow wash-out pattern on EGE was detected in up to 68 % of the patients, being an isolated finding without LGE in 10 (16 %). This cohort showed a greater maximal LV wall thickness (20.1 ± 4 vs. 18.1 ± 3.5mm, p = 0.010) and asymmetry ratio (1.86 ± 0.42 vs. 1.62 ± 0.46; p = 0.039). The percentage of EGE/slice and the difference with the percentage LGE/slice demonstrated a significant positive correlation with the maximal LV wall thickness (Rho 0.450 and 0.386 respectively). EGE also correlated with number of segments with LVH (LV hypertrophy) and the asymmetry ratio. Neither EGE nor LGE were associated with classical risk factors, the risk score for sudden cardiac death, or with major clinical events. EGE was a frequent finding in HCM, even in absence of LGE. This phenomenon showed a positive correlation with morphological markers of disease burden.

Ultrasound features of hepatocellular adenoma and the additional value of contrast-enhanced ultrasound

Hepatocellular adenoma (HCA) is a rare benign tumor of the liver. It is of clinical importance to differentiate HCA from other liver tumors, especially hepatocellular carcinoma (HCC). This study aimed to evaluate the characteristic features of HCA by conventional ultrasound and contrast-enhanced ultrasound (CEUS) findings. Twenty-six patients (10 males and 16 females; mean age 36.2+/-5.0 years) with 26 histopathologically proven HCAs were retrospectively identified. According to the maximum diameter of HCAs, they were divided into three groups: <30 mm, 30-50 mm, and >50 mm. Ultrasound examinations were performed with C5-2 broadband curved transducer of Philips iU22 unit (Philips Bothell, WA, USA). For each lesion, a dose of 2.4 mL SonoVue® (Bracco Imaging Spa, Milan, Italy) was injected as a quick bolus into the cubital vein. Lesions' echogenicity, color-Doppler flow imaging and contrast enhancement patterns were recorded. Grayscale ultrasound revealed that most of HCAs were hypoechoic (73.1%, 19/26). Spotty calcifications were detected in 26.9% (7/26) of the lesions. Color-Doppler flow imaging detected centripetal bulky color flow in 46.2% (12/26) of the HCAs. CEUS showed that 73.1% (19/26) of the HCAs displayed as rapid, complete and homogenous enhancement, and 53.8% (14/26) showed decreased contrast enhancement in the late phase. There was no significant difference in enhancement patterns among different sizes of HCAs (P>0.05). Centripetal enhancement with subcapsular tortuous arteries was common in larger HCAs. CEUS combined with grayscale and color-Doppler flow imaging helped to improve preoperative diagnosis of HCAs. The characteristic imaging features of HCAs included: rapid homogeneous enhancement and slow wash-out pattern on CEUS; heterogeneous echogenicity on grayscale ultrasound; and centripetal enhancement with subcapsular tortuous arteries in large HCAs.

Solitary fibrous tumours in the extracranial head and neck region: correlation of CT and MR features with pathologic findings.

Solitary fibrous tumours (SFTs) are rare, mesenchymal neoplasms. The purpose of this study was to analyse the radiological and clinicopathological features of SFTs in the extracranial head and neck region. We retrospectively reviewed the clinical, computed tomography (CT), magnetic resonance imaging (MRI), and pathological features in 18 patients (12 men and 6 women), aged 18-75years, with histologically proven SFTs in the extracranial head and neck region. Fourteen patients underwent CT scanning and nine underwent MRI. The histological techniques included routine haematoxylin-eosin staining and immunohistochemical analysis. Clinical data were retrieved from the medical records. Most tumours presented as a slow-growing painless mass. Eighteen SFTs arose in the orbit, cheek, masticator space, the parapharyngeal space, infratemporal fossa, maxillary, submandibular space and the parotid gland, respectively. All 18 lesions were found as a solitary mass, ranging in size from 1.2 to 6.8cm (mean 3.57cm). They mostly presented with an ovoid shape, with well-defined margin, and isodensity on plain CT, isointensity on T1-weighted imaging, mild hyperintensity on T2-weighted imaging and diffusion-weighted imaging, and marked heterogeneous enhancement on contrast-enhanced CT and MRI. The time-intensity curves (TICs) exhibited a rapidly enhancing and slow washout pattern on dynamic contrast-enhanced MRI and dual-phase CT. Imaging findings of the SFTs depended on the histopathological components. SFTs most commonly present with an asymptomatic mass in adults. A solitary, ovoid and well-defined mass with strong enhancement after contrast agent injection is suggestive of this diagnosis. Rapidly enhancing and slow washout pattern TICs may be additional valuable features.

MRI findings of solitary fibrous tumours in the head and neck region

To analyse the MRI findings of solitary fibrous tumours in the head and neck region. We retrospectively reviewed MR images in eight patients with solitary fibrous tumours proven on histological examination. All the patients underwent conventional MRI, and four patients also underwent dynamic contrast-enhanced MRI and diffusion-weighted imaging in five cases. Image characteristics were analysed. All lesions were found as solitary well-defined masses ranging in size from 1.9 to 6.8 cm (mean, 4.1 cm). They were mostly homogeneous and isointense to the muscle on T1 weighted images and heterogeneous and mildly hyperintense on T2 weighted images. After gadolinium administration, areas that were mildly hyperintense on T2 weighted images were strongly enhanced. They were mildly hyperintense on diffusion-weighted imaging. The average tumour-apparent diffusion coefficient values were 0.001 157 ± 0.000 304 9 mm s(-2) compared with the muscle 0.000 760 ± 0.000 265 0 mm s(-2), and there was a statistical difference of p = 0.002. The time-intensity curves exhibited a rapidly enhancing and a slow washout pattern on dynamic contrast-enhanced MRI. Solitary fibrous tumours should be considered in cases of heterogeneous hypervascular tumours in the head and neck region. Areas of mild hyperintense intensity on T2 weighted images that are strongly enhanced after gadolinium injection are suggestive of this diagnosis. Non-restricted diffusion and rapidly enhancing and slow washout pattern time-intensity curves may be additional valuable features.

MR Evaluation of Sinonasal Angiomatous Polyp

SAP is a rare lesion of the sinonasal cavity, which may be misdiagnosed as a benign or malignant neoplasm. The purpose of our study was to comprehensively evaluate the MR imaging features of SAP. Forty patients with SAP confirmed pathologically were retrospectively reviewed. Of the 40 patients undergoing MR imaging, 39 had postcontrast T1WI; 30, DCE MR imaging; and 17, DWI. The image features assessed included the location, shape, margin, size, signal intensity, and enhancement pattern on DCE MR imaging and ADC maps. All 40 SAPs originated from the maxillary sinus, but the lesions frequently extended into the ipsilateral nasal cavity (38/40), toward the choana (19/40), and into the nasopharynx (8/40). The lesions demonstrated hypointensity on T1WI and heterogenous hyperintensity on T2WI. All 40 lesions showed a peripheral hypointense rim on T2WI. Postcontrast MR imaging revealed marked heterogeneous nodular and patchy enhancement. Progressive enhancement was found on DCE MR imaging in 30 cases. The TIC showed a steady enhancement pattern in 3 cases, a rapidly enhancing and slow washout pattern in 6 cases, and a rapidly enhancing and rapid washout pattern in 21 cases. On DWI, the mean ADC value was (1.40 ± 0.20) × 10(-3) mm(2)/s. Distinctive features of SAP on conventional MR imaging include internal heterogeneous hyperintensity and a peripheral hypointense rim on T2WI, as well as strong nodular and patchy enhancement on postcontrast MR images. The progressive enhancement on DCE MR imaging can also suggest the diagnosis.

Nasal Cavity Eosinophilic Angiocentric Fibrosis: CT and MR Imaging Findings

EAF consists of exceedingly rare lesions and presently lacks specific imaging reports. The purpose of this study was to determine the CT and MR imaging features of nasal cavity EAF. We retrospectively reviewed 6 patients with histology-proven EAF in the nasal cavity. All 6 patients underwent CT and 3 patients also underwent MR imaging. The following imaging features were reviewed: 1) location, 2) shape, 3) margin, 4) CT attenuation, and 5) MR imaging signal intensity. In addition, the accompanying changes and the TIC of the DCE MR imaging were analyzed. All occurrences of EAF were located at the anterior nasal cavity, arising from the nasal septum in 4 patients, with irregular shape, and the lateral nasal wall in 2, with oval configuration. The mean size was 29.8 mm (range 12-52 mm). On nonenhanced CT, EAF lesions appeared isoattenuated relative to gray matter. On the T1-weighted image, the lesions were isointense in 3 (100%) patients. On the T2-weighted image, the lesions were isointense in 1 (33.3%) patient and hypointense in 2 (66.7%) patients. Occurrences of EAF revealed moderate inhomogeneous contrast enhancement. Three patients underwent DCE MR imaging and the TICs exhibited a rapidly enhancing and slow washout pattern. One patient had bilateral lacrimal gland enlargement, which displayed low signal intensity on the T2-weighted image. A familiarity with imaging findings, including lesion location, isoattenuation and bony changes, and hypointensity on T2-weighted images may help to accurately diagnose this rare entity.

Leiomyoma of the sinonasal cavity: CT and MRI findings

Aim To determine the computed tomography (CT) and magnetic resonance imaging (MRI) features of leiomyoma of the sinonasal cavity. Materials and methods Six patients with histology-proven leiomyomas in the sinonasal cavity were retrospectively reviewed. All six patients underwent CT and three patients also underwent MRI. The following imaging features were reviewed: size, margin, CT attenuation, MRI signal intensity, and lesion extent. In addition, the time–intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) were analysed in two patients. Results All leiomyomas had well-defined margins. The mean size was 36 mm (range 20–51 mm). On unenhanced CT, the lesions appeared isodense to cerebral grey matter in four (67%) and slightly hypodense in two (33%) patients. Leiomyomas appeared isointense On T1-weighted imaging (WI) and slightly hyperintense on T2WI in three patients. The lesions showed moderate contrast enhancement. Two patients underwent DCE MRI, and the TIC showed a rapidly enhancing and slow washout pattern. The mean apparent diffusion coefficient (ADC) value were 1.66 × 10 −3 mm 2/s and 1.78 × 10 −3 mm 2/s for the two lesions, respectively. Conclusions Well-defined, homogeneous, expansile masses without bony erosion are typical features of leiomyoma. Althrough rare, this entity should be included in the differential diagnosis of benign tumours in this region.

CT and MRI appearance of osteolytic intraosseous meningioma of the orbit

Objective To study CT and MRI findings of osteolytie intmosseons meningioma of the orbit and evaluate their clinical significance. Methods Eight cases of osteolytic meningioma arising from the orbital bone were confirmed by histopathology. CT and MRI findings of these meningiomas were analyzed retrospectively. Results Among the 8 cases of benign intransseous meningioma of the orbit, 5 were meningotheliomatous, 2 fibrotic and 1 transitional in histopathology. Their locations included 4 in the lateral and superior walls, 3 in the lateral wall, and only one in the lesser wing of sphenoid bone neighboring the orbital apex. The maximum diameter of the lesions ranged from 18 to 47 mm (mean,29 ram). All lesions showed a relatively well-defined margin with 6 cases having an oval shape, and 2 cases having an irregular contour. On CT, 6 lesions demonstrated bony destruction with coarse margin and 2 lesions showed bony cystic dilatation with a well-defined margin. On non-contrast CT, 7 lesions showed isodensity to gray matter and 1 lesion revealed a slight hypodensity. Three lesions showed moderate enhancement on postcontrast CT.On MR T, WI, 6 lesions of osteolytic intaosseous meningioma of the orbit demonstrated isointensity compared to gray mater and 2 lesions slight hypointyensity. On T2WI, 6 lesions showed isointensity and 2 lesions slight hyperintensity. On contrast-enhanced MRI, 6 lesions showed moderate enhancement and 2 lesions exhibited marked enhancement. Heterogeneous signal intensity with inhomogeneous enhancement was seen in 3 lesions on MR images. The time-intensity curve (TIC) of dynamic contrast enhancement of 3 tumors on MRI appeared as rapid enhancing and slow wash-out pattern in 2 cases, rapid enhancing and rapid wash-out pattern in the third one. In comparison to CT, MRI appeared to show the secondary and complicated changes of the lesions more clearly. Conclusions Isointensity with moderate contrast enhancement appears to be the typical manifestation of intraosseous osteolytic meningioma of the orbit on MR. CT is useful for judging the original site of these lesions. MRI is superior to CT in depicting the extent of these lesions. Combined imaging findings of CT and MRI can provide more comprehensive information for diagnosis and therapy of these tumors. Key words: Meningioma; Orbital neoplasms; Tomography; X-ray computed; Magnetic resonance imaging

Sphenoid sinus ectopic pituitary adenomas: CT and MRI findings

Ectopic pituitary adenomas (EPAs) are rare lesions. The purpose of this study was to describe the CT and MRI features of sphenoid sinus EPAs. Eight patients with histology-proven EPAs in the sphenoid sinus, all of whom underwent CT and MRI, were reviewed retrospectively. The following imaging features were analysed: (i) size, (ii) margin, (iii) CT attenuation characteristics and (iv) MRI signal intensity. In addition, the involvement of adjacent structures and the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI were analysed. All EPAs had well-defined margins and showed no relationship to the intrasellar pituitary gland. The mean size was 28 mm (range, 20-46 mm). On non-enhanced CT, the lesions appeared isodense to grey matter in 7 (88%) patients and hypodense in 1 (12%) patient. Only two patients underwent post-contrast CT, and they showed moderate enhancement. On T1 weighted images, EPAs appeared isointense in 6 (75%) patients and hypointense in 2 (25%). On T2 weighted images, the lesions appeared hyperintense in 2 (25%) patients and isointense in 6 (75%). EPAs showed mild to moderate heterogeneous contrast enhancement and exhibited a cribriform-like appearance. Two patients underwent DCE MRI; the TIC showed a rapidly enhancing and slow washout pattern. The following features were also seen: an empty sella, bone changes and involvement of the cavernous sinus (5 patients; 62.5%). In conclusion, a high index of suspicion for EPA and a familiarity with the imaging findings may help to diagnose this rare entity accurately.

Correlation of Contrast-Enhanced MR Findings and Tumor Microvessel Density of Breast Masses

Purpose: To compare the contrast-enhanced dynamic MR findings of solid breast masses with their histopathologic tumor angiogenesis. Materials and Methods: Thirty-two cases of pathologically proved breast lesions (8 benign and 24 malignant lesions) examined with contrast-enhanced MRI were retrospectively reviewed, focusing on the tumor size, the maximum amount of contrast enhancement (% Signal Intensity Change, SIC), the time to peak (early or late peak) and the type of time-signal intensity curve (TSC). We compared the characteristic MR findings of breast cancer with the microscopic maximum microvessel density (MVD). Results: Among the total of 11 small lesions ( 2 cm, 9 malignant and 2 benign), 8 cases of malignant lesions showed high MVD ( 20). On the other hand, among the 21 large lesions (> 2 cm, 15 malignant and 6 benign), only two cases of malignant and five cases of benign lesions showed high MVD. More than 100% SIC was observed in a total of 11 malignant and two benign lesions, but 8 of these 11 malignant lesions showed low MVD ( 3 min) was observed in 18 (17 malignant and 1 benign) lesions, and 11 of these 17 malignant lesions showed low MVD. An early high peak and early or slow wash-out pattern, which is typical of the malignant type, was seen in 18 (17 malignant and 1 benign) lesions, but 12 of these 17 malignant lesions showed low MVD. There is no statistically significant correlation between the characteristic MR findings of breast cancer and the MVD. Conclusion: Although high MVD indicated malignancy in the case of the small lesions, the histopathologic MVD was not significantly correlated with either the increased amount of enhancement, early time-to peak or the malignant pattern of the TSC.

Diffuse slow washout of myocardial thallium-201: A new scintigraphic indicator of extensive coronary artery disease

When coronary artery disease is extensive and of relatively uniform severity, regional myocardial hypoperfusion may be balanced during stress, precluding development of spatially relative perfusion defects. Assessment of the washout of thallium-201 from myocardial regions may provide diagnostic assistance in these cases because washout analysis is spatially nonrelative and hypoperfused myocardial regions manifest a slow thallium-201 washout rate. In 1,265 consecutive patients having quantitatively analyzed stress-redistribution scintigraphy, 46 had a diffuse slow washout pattern with no or a maximum of one regional perfusion defect. Thirty-two underwent clinically indicated coronary angiography, and 23 (72%) of these were found to have three vessel or left main disease. Of 30 similar patients without a diffuse slow washout pattern and with no or a maximum of one perfusion defect, only 5 (17%) had extensive coronary disease. An independent relation between diffuse slow washout and extensive coronary disease was demonstrated by a Mantel- Haentzel chi-square analysis of a wide variety of other indexes of extensive disease. A diffuse washout abnormality, even in the absence of other scintigraphic, clinical or electrocardiographic indicators, carries a high predictive value for three vessel or left main coronary artery disease. The predictive value is maintained when the exercise level achieved is submaximal. Although an infrequent occurrence (3.6% of tested patients), a diffuse slow washout pattern without other scintigraphic indications of extensive coronary disease should lead to further diagnostic testing.