Transient severe motion during arterial phase in patients with Gadoxetic acid administration: Can a five hepatic arterial subphases technique mitigate the artifact?

Gadoxetic acid (Gd-EOB-DTPA) is a hepatocyte-specific magnetic resonance (MR) contrast agent, which has been increasingly used in recent years. However, it has been reported that Gd-EOB-DTPA related transient severe motion (TSM) is sometimes observed during the hepatic arterial phase of MR imaging, which may influence image quality. Since the hepatic arterial phase of contrast enhancement is used for the diagnosis of hepatocellular carcinoma, it is crucial to obtain a decent arterial phase imaging. The present study analyzed motion in patients receiving Gd-EOB-DTPA, comparing a single arterial phase acquisition to a five arterial phase acquisition to determine whether the multiphase acquisition was able to alleviate the TSM-related hepatic arterial MR imaging artifact. It was demonstrated that the single-phase acquisition failed to provide adequate diagnostic image quality in patients with TSM, whereas the multiphase arterial acquisition provided acceptable image quality in 20/22 (90.9%) patients with TSM. In conclusion, the results of the present study demonstrated that multiphase arterial acquisition is superior to single-phase arterial acquisition, mitigating arterial MR imaging artifacts caused by TSM after the administration of Gd-EOB-DTPA.

Y-configuration stent combined with iodine-125 seeds strand for the treatment of hepatocellular carcinoma with tumor thrombosis in portal vein branches: A case report.

RATIONALE: Currently, the treatment of hepatocellular carcinoma (HCC) associated with portal vein tumor thrombosis (PVTT) is a challenge. Percutaneous puncture endovascular placement of iodine-125 (I) seeds strand and stent is reported to treat HCC with tumor thrombus effectively. However, it is proved to be only suitable for the main portal vein (MPV) thrombus. PATIENT CONCERNS: A 42-year-old male patient was referred to our institution after experiencing right upper abdominal distention without abdominal pain, nausea, or vomiting for 2 weeks. The patient had a history of hepatitis B virus infection over a 20 year period. DIAGNOSIS: After a full evaluation, the patient was diagnosed with primary HCC with a tumor thrombus in both main and branch portal veins. INTERVENTIONS: We used a Y-configuration stent combined with I seeds strand to treat the tumor thrombus in both main and branch portal veins. OUTCOMES: The patient's liver function and the stent patency period were improved. More importantly, the patient had an acceptable survival time. LESSONS: A Y-configuration stent makes it possible to treat tumor thrombosis in portal vein branches (PVBs). However, the long-term curative effects of Y-configuration stents need to be verified.

Serum cystatin c is not superior to serum creatinine for early diagnosis of contrast-induced nephropathy in patients who underwent angiography.

BACKGROUND: Iodiated contrast-induced nephropathy (CIN) is a serious complication of contrast-enhanced imaging. The aim of this study was to evaluate the diagnostic sensitivities and specificities of serum cystatin C (sCys C) and serum creatinine (sCr) for CIN and to further investigate difference of the incidence, risk factors, and in-hospital and 3-month prognosis of CIN according to sCys C criteria and sCr criteria. METHODS: We prospectively evaluated 213 patients who underwent angiography. The sCr and sCys C concentrations were detected before and at 48 hours, 72 hours after the procedure. The incidence, risk factors, and in-hospital and 3-month prognosis of CIN were analyzed. Receiver operating characteristic curve (ROC) analysis was performed for sCr and sCys C 48 hours after procedure. RESULTS: The incidence of CIN was 24.4% (sCys C criteria) and 8% (sCr criteria). Diabetes mellitus, dehydration, and hypoalbuminemia were independent risk factors for CIN. Area under the ROC of sCys C 48 hours after procedure was not superior to sCr (0.715 vs 0.790, P=.178). The mortality of patients with CIN in sCr criteria increased significantly (P<.05). CONCLUSION: In this study, the incidence and risk factors of CIN were related to diagnostic criteria. The sCys C was not superior to sCr for predicting CIN in the patients who underwent angiography.

MRI contrast agents: Classification and application (Review).

Magnetic resonance imaging (MRI) contrast agents are categorised according to the following specific features: chemical composition including the presence or absence of metal atoms, route of administration, magnetic properties, effect on the magnetic resonance image, biodistribution and imaging applications. The majority of these agents are either paramagnetic ion complexes or superparamagnetic magnetite particles and contain lanthanide elements such as gadolinium (Gd3+) or transition metal manganese (Mn2+). These elements shorten the T1 or T2 relaxation time, thereby causing increased signal intensity on T1-weighted images or reduced signal intensity on T2-weighted images. Most paramagnetic contrast agents are positive agents. These agents shorten the T1, so the enhanced parts appear bright on T1-weighted images. Dysprosium, superparamagnetic agents and ferromagnetic agents are negative contrast agents. The enhanced parts appear darker on T2-weighted images. MRI contrast agents incorporating chelating agents reduces storage in the human body, enhances excretion and reduces toxicity. MRI contrast agents may be administered orally or intravenously. According to biodistribution and applications, MRI contrast agents may be categorised into three types: extracellular fluid, blood pool and target/organ-specific agents. A number of contrast agents have been developed to selectively distinguish liver pathologies. Some agents are also capable of targeting other organs, inflammation as well as specific tumors.

Pulsed arterial spin labeling effectively and dynamically observes changes in cerebral blood flow after mild traumatic brain injury.

Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient's condition and judging prognosis after traumatic brain injury.

Pituitary metastasis of choriocarcinoma: A case report.

Choriocarcinoma is an aggressive obstetric or gynecological neoplasm with a high malignant potential. It is a form of gestational trophoblastic disease and often secondary to hydatidiform mole, and intrauterine or ectopic pregnancy. Choriocarcinoma has a proclivity to metastasize to the lung, vagina, pelvis or liver in over 50% of patients, which always occurs in the early stage of the disease. With an appropriate amount of chemotherapy, the tumor may be treated effectively. However, pituitary metastasis of choriocarcinoma is extremely rare. To the best of our knowledge, no cases of choriocarcinoma metastasizing to the pituitary have been cited previously. Here, we report a case of choriocarcinoma that presented with pituitary metastasis.

Evaluation of hypointense liver lesions during hepatobiliary phase MR imaging in normal and cirrhotic livers: is increasing flip angle reliable?

Gd-EOB-DTPA is a newly developed liver specific magnetic resonance contrast agent, which is widely used for focal liver lesion (FLL) detection and liver function evaluation. However, it has been demonstrated that hepatocytes uptake of Gd-EOB-DTPA obviously decreased in cirrhotic liver, and cirrhotic liver parenchyma may show reduced enhancement in hepatobiliary phase, which would result in decreased liver-to-lesion contrast (LLC) and liver to lesion signal intensity ratio (LLSIR). Therefore, it is important to improve the image quality in cirrhotic liver, as it may alter therapeutic strategy. In this paper, we have shown adjustments of the flip angle (FA) provides a simple step to achieve better image quality for evaluation of FLLs, especially to those patients with severe liver cirrhosis. On the basis of our quantitative analysis, both of the LLC and the LLSIR with high FA protocol were always higher than those of low FA protocol. Additionally, on high FA images, more FLLs were detected, peritumoral invasion was found, boundary of the tumor was more remarkably, and better visualization of bile duct was observed. In conclusion, for the patient with severe liver cirrhosis, increasing FA can obviously improve the image quality, which is helpful for FLLs depiction.

Susceptibility Weighted Imaging and Mapping of Micro-Hemorrhages and Major Deep Veins after Traumatic Brain Injury.

Micro-hemorrhages are a common result of traumatic brain injury (TBI), which can be quantified with susceptibility weighted imaging and mapping (SWIM), a quantitative susceptibility mapping approach. A total of 23 TBI patients (five women, 18 men; median age, 41.25 years old; range, 21.69-67.75 years) with an average Glasgow Coma Scale score of 7 (range, 3-15) at admission were recruited at mean 149 d (range, 57-366) after injury. Susceptibility-weighted imaging data were collected and post-processed to create SWIM images. The susceptibility value of small hemorrhages (diameter ≤10 mm) and major deep veins (right septal, left septal, central septal, right thalamostriate, left thalamostriate, internal cerebral, right basal vein of Rosenthal, left basal vein of Rosenthal, and pial veins) were evaluated. Different susceptibility thresholds were tested to determine SWIM's sensitivity and specificity for differentiating hemorrhages from the veins. A total of 253 deep veins and 173 small hemorrhages were identified and evaluated. The mean susceptibility of hemorrhages was 435±206 parts per billion (ppb) and the mean susceptibility of deep veins was 108±56 ppb. Hemorrhages showed a significantly higher susceptibility than all deep veins (p<0.001). With different thresholds (250, 227 and 200 ppb), the specificity was 97%, 95%, and 92%, and the sensitivity was 84%, 90%, and 92%, respectively. These results show that SWIM could be used to differentiate hemorrhages from veins in TBI patients in a semi-automated manner with reasonable sensitivity and specificity. A larger cohort will be needed to validate these findings.

Functional characteristics of the brain in college students with internet gaming disorder.

Internet gaming disorder (IGD) is a subtype of internet addiction disorder (IAD), but its pathogenesis remains unclear. This study investigated brain function in IGD individuals using task-state functional magnetic resonance imaging (fMRI). It is a prospective study in 19 IGD individuals and 19 matched healthy controls. They all received internet videogame stimuli while a 3.0 T fMRI was used to assess echo planar imaging. Brain activity was analyzed using the Brain Voyager software package. Functional data were spatially smoothed using Gaussian kernel. The threshold level was positioned at 10 pixels, and the activation range threshold was set to 10 voxels. Activated brain regions were compared between the two groups, as well as the amount of activated voxels. The internet videogame stimuli activated brain regions in both groups. Compared with controls, the IGD group showed increased activation in the right superior parietal lobule, right insular lobe, right precuneus, right cingulated gyrus, right superior temporal gyrus, and left brainstem. There was a significant difference in the number of activated voxels between the two groups. An average of 1078 voxels was activated in the IGD group compared with only 232 in the control group. Internet videogame play activates the vision, space, attention, and execution centers located in the occipital, temporal, parietal, and frontal gyri. Abnormal brain function was noted in IGD subjects, with hypofunction of the frontal cortex. IGD subjects showed laterality activation of the right cerebral hemisphere.

Thalidomide Effects in Patients with Hereditary Hemorrhagic Telangiectasia During Therapeutic Treatment and in Fli-EGFP Transgenic Zebrafish Model.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by recurrent epistaxis, mucocutaneous telangiectasia, and arteriovenous malformations. The efficacy of traditional treatments for HHT is very limited. The aim of this study was to investigate the therapeutic role of thalidomide in HHT patients and the effect in FLI-EGFP transgenic zebrafish model. METHODS: HHT was diagnosed according to Shovlin criteria. Five HHT patients were treated with thalidomide (100 mg/d). The Epistaxis Severity Score (ESS), telangiectasia spots, and hepatic computed tomography angiography (CTA) were used to assess the clinical efficacy of thalidomide. The Fli-EGFP zebrafish model was investigated for the effect of thalidomide on angiogenesis. Dynamic real-time polymerase chain reaction assay, ELISA and Western blotting from patient's peripheral blood mononuclear cells and plasma were used to detect the expression of transforming growth factor beta 3 (TGF-ß3) messenger RNA (mRNA) and vascular endothelial growth factor (VEGF) protein before and after 6 months of thalidomide treatment. RESULTS: The average ESS before and after thalidomide were 6.966 ± 3.093 and 1.799 ± 0.627, respectively (P = 0.009). The "telangiectatic spot" on the tongue almost vanished; CTA examination of case 2 indicated a smaller proximal hepatic artery and decreased or ceased hepatic artery collateral circulation. The Fli-EGFP zebrafish model manifested discontinuous vessel development and vascular occlusion (7 of 10 fishes), and the TGF-ß3 mRNA expression of five patients was lower after thalidomide therapy. The plasma VEGF protein expression was down-regulated in HHT patients. CONCLUSIONS: Thalidomide reverses telangiectasia and controls nosebleeds by down-regulating the expression of TGF-ß3 and VEGF in HHT patients. It also leads to vascular remodeling in the zebrafish model.

[CT imaging features for 2 cases of retroperitoneal solitary fibrous tumor].

OBJECTIVE: To determine the CT imaging features for retroperitoneal solitary fibrous tumor (SFT).
 METHODS: The imaging features of CT for 2 SFT cases, confirmed by pathological examination, were retrospectively analyzed and compared with pathological results.
 RESULTS: The results of CT showed that retroperitoneal SFTs were large, well-defined and consisted of solid components with different density (equal or low). In the scan of contrast enhancement, tumors were strongly enhanced, and the multiple vascular shadows were seen in the tumor at arterial phase. There was progressive enhancement from the arterial to venous phase, and capsule of tumor was displayed. Histologically, the tumors were composed of spindle cells within a background of collagen stroma, and showed a wide range of growth patterns, alternating hypercellular (tumor cell-rich) and hypocellular (collagen-rich) areas. The diagnosis was confirmed by positive immunohistochemical staining for CD34 and bcl-2.
 CONCLUSION: The retroperitoneal SFT possesses a definite characteristic in CT imaging features, and the diagnosis can be confirmed by histopathology and immunohistochemistry.

[Advances in clinical application of quantitative susceptibility mapping in central nervous system].

Susceptibility weighted imaging (SWI) is a magnetic resonance technology with a high resolution, three-dimensional gradient echo and fully velocity compensated sequence. It is also sensitive to substance with different magnetisability. Based on the quantitative reconstruction of SWI, quantitative susceptibility mapping (QSM) has been used in monitoring the change of intravenous iron, calcium, microbleeds and oxygen content. This article summarizes principle of QSM and the latest progress of QSM application in the diseases of central nervous system.

MRI manifestation of xanthomatous hypophysitis: a case report and review of the literature.

The inflammatory lesion of the pituitary gland is unusual. A 33-year-old woman with headache, visual impairment, and menelipsis was admitted to the Second Xiangya Hospital, Central South University. The results of magnetic resonance imaging (MRI) for pituitary gland showed a sellar mass with iso-intensity on T1 weighted imaging and high signal on T2 weighted imaging. The homogeneous lesion was enhanced on contrast MRI. The pituitary stalk was thickened accompanied by the cavernous sinus invasion, which showed a "triangle" saddle occupation on the MRI coronal plane. An endocrinological examination revealed mild hypocortisolism. Th e patient was diagnosed as pituitary adenoma based on the MRI findings and endocrinological examination. Trans-sphenoidal surgery was performed. The intra-operative histological examination also suggested a pituitary adenoma. Th e histopathological examination showed accumulation of foamy cells and xanthomatous epithelioid cells, supporting the diagnosis of xanthomatous hypophysitis. Xanthomatous hypophysitis possesses certain MRI features. Th e most typical imaging features are the thickening of the pituitary stalk and the sign of "triangle" occupation on MRI coronal plane, which are very helpful to the correct diagnosis and optimal management.

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging: A potential utility for the evaluation of regional liver function impairment following transcatheter arterial chemoembolization.

The present study aimed to evaluate regional liver function impairment following transcatheter arterial chemoembolization (TACE), assessed by magnetic resonance imaging (MRI) enhanced by gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). Additionally, this study evaluated the associations between signal intensity and various clinical factors. A prospective study was conducted between March 2012 and May 2013 with a total of 35 patients. Gd-EOB-DTPA-enhanced MRI was performed 3-5 days after TACE therapy. The signal to noise ratio (SNR) was subsequently calculated for healthy liver tissue regions and peritumoral regions, prior to and 20 min after Gd-EOB-DTPA administration. The correlation between clinical factors and relative SNR was assessed using Pearson's correlation coefficient or Spearman's rank correlation coefficient. Prior to Gd-EOB-DTPA administration, the SNR values showed no significant difference (t=1.341, P=0.191) in healthy liver tissue regions (50.53±15.99; range, 11.25-83.46) compared with peritumoral regions (49.81±15.85; range, 12.34-81.53). On measuring at 20 min following Gd-EOB-DTPA administration, the SNR in healthy liver tissue regions (82.55±33.33; range, 31.45-153.02) was significantly higher (t=3.732, P<0.001) compared with that in peritumoral regions (75.77±27.41; range, 31.42-144.49). The relative SNR in peritumoral regions correlated only with the quantity of iodized oil used during TACE therapy (r=0.528, P=0.003); the age, gender, diameter and blood supply of the tumor, or Child-Pugh class of the patient did not correlate with relative SNR. Gd-EOB-DTPA-enhanced MRI may be an effective way to evaluate regional liver function impairment following TACE therapy.

Crazy paving pattern caused by pulmonary alveolar proteinosis: CT findings and the pathologic basis.

OBJECTIVE: To explore CT findings and pathologic basis of crazy paving pattern caused by pulmonary alveolar proteinosis. METHODS: Twenty-four patients who were diagnosed pathologically as pulmonary alveolar proteinosis by transbronchial lung biopsy and bronchoalveolar lavage fluid from June 2006 to May 2012 were included in this retrospective study. All patients underwent a 64-slice CT of the lungs. RESULTS: CT findings: crazy paving pattern was observed on CT imaging of all 24 patients. In 23 patients, crazy paving pattern displayed strip-shaped opacities with smooth edges, and there was a clear boundary between the pathological and normal lung tissues. The reticular opacities were connected with peripheral blood vessels and the branches were formed, and their diameters decreased slightly. Microscopically, hemangiectasis were seen in 17 patients. CONCLUSION: Crazy paving pattern caused by pulmonary alveolar proteinosis displayed clear edges, and smooth reticular opacities, most of which were due to hemangiectasis of interlobular, interacinar and interalveolar septa. These findings of CT are helpful for the specific diagnosis of pulmonary alveolar proteinosis.

[Lung MRI at 3T: comparison of CT and MRI in initial evaluation of pulmonary alveolar proteinosis].

OBJECTIVE: To explore whether the phospholipidoproteinaceous material deposit within the alveoli by a high-field 3T MRI has signal characters and its application for diagnosing pulmonary alveolar proteinosis. METHODS: A total of 11 patients with pulmonary alveolar proteinosis previously diagnosed by fiberoptic bronchoscope lung biopsy underwent 64-slice helical CT scans and 3T MRI scans, and the CT scans and the MRI scans were compared. RESULTS: The phospholipidoproteinaceous material deposit within the alveoli presented longer or equal T1 relaxation time and longer T2 relaxation time, without characters of fatty or deposits of protein-like substance signals and enhancement. The distribution, form, number and size of the lesions at T2WI were almost the same as those at CT, the lesions were irregular in morphology, and there was a clear boundary between the lesions and the adjacent normal lung tissues. Dynamic contrast-enhanced MRI showed thickened pulmonary arteriolae and venulae in the lesions with more obviously thickened pulmonary venulae, which were in conformity with the pulmonary artery and venule enhancement. CT scan in 1 out of the 11 cases showed lesions in both lungs mainly consisted of stripe-shaped and reticular structures, and no obvious sign of pulmonary alveolar proteinosis residue was found. MRI scan detected alveolar proteinosis that failed to be shown by CT scan. CONCLUSION: 3T MRI T2WI can easily detect the lesions of long T2 signals formed by the lipoproteinaceous material deposit within the alveoli. In the lesions, geographic appearance was presented, and the crazy paving pattern was dimly visualized. MRI can reflect the morphological characters of PAP like CT and it is slightly better compared with CT in such aspects as evaluating the theraputic effect of lung lavage. As supplement to CT, high-field 3T MRI can serve as an important examination for lung diseases.

[Magnetic resonance imaging for active ankylosing spondylitis].

OBJECTIVE: To diagnoze active ankylosing spondylitis (AAS) by magnetic resonance imaging (MRI). METHODS: MRI of the sacroiliac joint (SIJ) was performed on 48 patients who were clinically diagnosed as probable AS without radiologic evidence of sacroiliitis. Among them 21 were diagnozed as active sacroiliitis with MRI, whose examination was terminated; 27 whose MRI of SIJ did not diagnoze as active sacroiliitis were performed MRI in the thoracic spine. The diagnostic criteria of MRI for AAS of SIJ and/or the thoracic spine were fomulated by consulting documents. The definite diagnosis of AAS was finally made after follow-up for half a year. The sensitivity and specificity of the MRI of SIJ and/or MRI of thoracic spine were assessed. RESULTS: In the 48 patients without radiologic evidence of sacroiliitis, 38 were finally diagnosed as AAS, with established consensus criteria as reference standard. The sensitivity and specificity of the MRI of SIJ were 52.6% and 90.0%, and for the MRI of SIJ and/or the MRI of the thoracic spine 76.3% and 90.0%, respectively. CONCLUSION: Clinically probable AS without MRI evidence of sacroiliitis, MRI of the thoracic spine can increase the sensitivity of AAS diagnosis.

Decreased frontal lobe function in people with Internet addiction disorder.

In our previous studies, we showed that frontal lobe and brainstem functions were abnormal in on-line game addicts. In this study, 14 students with Internet addiction disorder and 14 matched healthy controls underwent proton-magnetic resonance spectroscopy to measure cerebral function. Results demonstrated that the ratio of N-acetylaspartate to creatine decreased, but the ratio of cho-line-containing compounds to creatine increased in the bilateral frontal lobe white matter in people with Internet addiction disorder. However, these ratios were mostly unaltered in the brainstem, suggesting that frontal lobe function decreases in people with Internet addiction disorder.

[Multislice spiral computer tomography imaging characteristics of urachus lesions].

OBJECTIVE: To analyze the multislice spiral computer tomography (MSCT) manifestations and its value in the diagnosis of urachus lesions. METHODS: A total of 26 patients with urachus disease diagnosed by pathological examination in our hospital between October 2007 and May 2011 were included in this study. We retrospectively analyzed MSCT images on the size, location, and shape character of the foci, and the image features of Retzius space. RESULTS: In the group, 12 patients had simple urachal cyst with homogeneous fluid filling the cavity with thin wall in CT scanning; five had infected urachal cyst with thickened and enhanced wall, some patch and strip appearing in Retzius space surrounding the lesion; two had infected urachal sinus, and another 3 had urachus leakage. Four had urachal tumor showing irregular cysticsolid mass over the apex of the bladder with apparent enhancement in contrast imaging, and 2 had calcification. Invasion of the bladder wall was found in 4 patients, extensive invasion of the ileum, rectum, uterus and retroperitoneal lymph nodes was found in 1. CONCLUSION: MSCT scan can demonstrate the location, shape, extent of the lesion as well as the relation with adjacent structures, thereby providing valuable information for the diagnosis and differential diagnosis of urachus lesions.

[Characteristic CT findings and pathologic basis of ground glass opacity caused by pulmonary alveolar proteinosis].

OBJECTIVE: To explore characteristic CT findings and pathologic basis of ground glass opacity caused by pulmonary alveolar proteinosis (PAP). METHODS: Retrospective analysis of CT and pathological findings of 24 patients with PAP who were pathologically diagnosed from June 2006 to August 2011. RESULTS: Findings with CT: the lesions of the 24 patients mainly presented ground glass opacities. Local consolidations were seen in 8 patients. In 23 patients part of ground glass opacities bordered strip-shaped opacities with smooth edges, and there was a clear boundary between them and the bordering normal lung tissues, presenting a geographic appearance. Lesions in the 5 cases were mixed with alveoli or lobule aerocele, which made ground glass opacities present curved edges. Crazy paving pattern was detected in the 24 patients. Microscopically, the alveoli were seen to be filled with floccules proteinaceous material in various quantities in the 24 patients; hemangiectasis and congestion were seen in 17 patients, and enlarged alveolar cavities were seen in 5 patients. CONCLUSION: PAP usually causes ground glass opacities with clear edges, and different from ground glass opacities with obscure edges caused by other pulmonary diseases. They are relatively specific to the imagining diagnosis to PAP.