Ossifying lipoma of the parapharyngeal space: CT and MRI findings

Ossifying lipomas independent of bone tissue are very rare. A literature review revealed that only few cases of ossifying lipoma independent of bone tissue have been reported. None of the cases have been reported in the international radiology literature. In addition, there are no reports concerning the MRI features of this entity. We describe CT and MRI findings in a case of ossifying lipoma of the parapharyngeal space.

MR white lung sign: incidence and significance in pulmonary consolidations

PURPOSE

The presence of a pulmonary consolidation with a signal intensity comparable with that of the static fluid on heavily T2-weighted MR images has been named the "MR white lung sign." This sign has been described in mucinous bronchioloalveolar carcinoma (BAC). Our purpose was to establish the frequency and significance of this sign in pulmonary consolidations of varied causes.

METHOD

In this prospective study, 83 patients with pulmonary consolidation underwent MR examination between January and December 1999. Segmental or lobar consolidations were due to pneumonia without central obstruction (n = 22), pneumonitis with central obstruction (n = 21), cicatricial atelectasis (n = 8), passive atelectasis (n = 10), radiation pneumonitis (n = 8), mucinous BAC (n = 5), infarction (n = 3), bronchiolitis obliterans organizing pneumonia (n = 3), nonmucinous BAC (n = 2), and lymphoma (n = 1). The MR white lung sign was considered present when the signal intensity of a pulmonary consolidation was comparable with that of the static fluid on heavily T2-weighted images obtained with MR hydrography sequences. Interobserver agreement, sensitivity, and specificity of the white lung sign in diagnosing mucinous BAC were calculated.

RESULTS

The MR white lung sign was present in 7 (8%) of 83 consolidations, including 5 (100%) of 5 cases of mucinous BAC and 2 (10%) of 21 cases of obstructive pneumonitis. The frequency of the white lung sign was 100% in mucinous BAC and 2.6% in consolidations due to other causes. The difference was statistically significant (p < 0.05).

CONCLUSION

The white lung sign is an uncommon finding in pulmonary consolidations evaluated with heavily T2-weighted sequences. However, the sign is characteristic of mucinous BAC and adds specificity to the radiologic diagnosis.

Usefulness of power Doppler and contrast-enhanced sonography in the differentiation of hyperechoic renal masses

BACKGROUND

In a prospective study, we compared power Doppler with and without contrast medium in the depiction of vascularity for the characterization of hyperechoic renal lesions.

METHODS

Forty-one hyperechoic renal expansive lesions (29 benign, 12 malignant) in 32 patients were studied with power-Doppler ultrasonography before and after administration of an echo-enhancing agent (Levovist Schering AG, Berlin, Germany). Vascular architecture of the lesions was categorized into five different patterns.

RESULTS

Power Doppler ultrasonography showed vascular structures in 25 lesions. The study enhanced with Levovist showed vascularity in eight of 16 lesions not seen on the unenhanced study. The characterization of vascular patterns with unenhanced power Doppler ultrasonography improved diagnostic accuracy compared with gray-scale ultrasonography (59% vs. 32%). The combination of B mode and power Doppler produced even greater diagnostic accuracy (78%), independent of the administration of echo-enhancing agent. Levovist administration was useful in the differential diagnosis between pseudotumor and neoplasm.

CONCLUSION

The use of sonographic contrast agent did not increase the diagnostic accuracy of power Doppler in the differential diagnosis of hyperechoic renal lesions but was advantageous for the characterization of suspected pseudomasses.

Intrahepatic portal vein aneurysm: three-dimensional power Doppler demonstration in four cases

We describe four cases of portal vein aneurysm that were studied with ultrasonography, color Doppler, computed tomography, and magnetic resonance imaging as well as three-dimensional power Doppler. Three-dimensional ultrasonography showed the portal aneurysm and its relationship to its portal branches in all patients and showed the portosystemic communication in three. In all cases, computed tomography or magnetic resonance imaging confirmed the three-dimensional ultrasonographic findings.

Perineural spread in a case of sinonasal sarcoidosis: case report

We report a case of sinonasal sarcoidosis with perineural spread along the trigeminal and vidian nerves in which primarily MR imaging but also CT allowed excellent visualization of this infiltration.

Gallbladder duplication: MR cholangiography demonstration

Gallbladder duplication is a rare anatomic malformation. We present a case of gallbladder duplication in a patient who underwent laparoscopic cholecystectomy in which breath-hold magnetic resonance cholangiography showed the biliary anomaly, allowing a correct preoperative differentiation of the specific type of duplication.

Hepatobronchial fistula due to transphrenic migration of hepatic echinococcosis: MR demonstration

We present an uncommon case of hepatic hydatidosis, complicated by transphrenic migration of the cyst, in which the use of magnetic resonance performed with ultrafast, breath-hold, heavily T2-weighted sequences (HASTE) demonstrated a bronchial fistula.

CT and MR findings in neoplastic perineural spread along the vidian nerve

The aims of this article are to describe the findings of perividian tumor spread and to compare the accuracy of MRI and CT in diagnosing perineural metastasis along the vidian nerve. Moreover, the frequency of perividian metastasis in patients with head and neck cancer was evaluated. The CT and MR examinations of 98 consecutive untreated patients with histologically proven head and neck cancer were retrospectively reviewed. We considered as criteria for perineural tumor spread along the vidian nerve the following CT and MR findings: For CT (a) enlargement of the pterygoid canal, (b) erosion of its bony wall, and (c) obliteration of its normal fatty content; and for MR (a) enlargement of the vidian nerve, (b) enhancement of the nerve, and (c) obliteration of fat, particularly in the anterior part of the pterygoid canal. Ten patients met the selected criteria for perineural metastasis, which was bilateral in 3 patients, with a total of 13 vidian metastases. The CT scans demonstrated unilateral involvement of the vidian nerve in 9 patients. The MRI scans showed 13 perineural metastases. In 3 patients MR scans demonstrated involvement of four vidian nerves that appeared normal on CT examinations. The diagnostic difference between CT and MRI was statistically significant (Fisher's exact test; p = 0.04). Perineural spread along the vidian nerve is an event more frequent than previously reported and must be investigated with a careful imaging technique. Although a major limitation of our study is the lack of histological proof, the MR finding of a significant enhancement of the nerve, whether enlarged or normal in size, could be considered very suggestive of this kind of metastatic spreading, particularly if associated with simultaneous involvement of the neighboring structures (pterygopalatine fossa, foramen lacerum, trigeminal branches, etc.).

Chronic infiltrative lung diseases: value of gadolinium-enhanced MRI in the evaluation of disease activity--early report

STUDY OBJECTIVE

To determine the value of gadolinium-enhanced MRI in the assessment of disease activity in chronic infiltrative lung diseases (CILDs).

DESIGN

Retrospective study.

SETTING

University hospital.

MATERIALS AND METHODS

Twenty-five consecutive patients with CILD were studied. The following diseases were diagnosed: sarcoidosis (n = 10), bronchiolitis obliterans organizing pneumonia (n = 3), usual interstitial pneumonia (n = 4), radiation pneumonia (n = 2), desquamative interstitial pneumonia (n = 1), rheumatoid lung (n = 1), vasculitis (n = 1), alveolar proteinosis (n = 1), bronchioloalveolar carcinoma (n = 1), and chronic eosinophilic pneumonia (n = 1). In each patient, the disease activity was assessed by one or more of the following studies: BAL (n = 18), gallium-radioisotope lung scanning (n = 6), serum angiotensin-converting enzyme assay (n = 10), and open lung biopsy (n = 4). T1-weighted breath-hold MRI studies were obtained before and after IV injection of gadolinium. The MRI examinations were analyzed to assess the presence or absence of lesional enhancement.

RESULTS

The presence of enhanced pulmonary lesions was seen in 14 patients. All of these patients had active disease. Of the 17 patients with active disease, 14 had enhanced lesions, and 3 had unenhanced lesions. Pulmonary lesions were not enhanced in any patients with inactive disease. The difference was statistically significant (Fisher Exact Test, p < 0.05).

CONCLUSION

Gadolinium-enhanced MRI may prove to be a useful tool in assessing disease activity in CILDs.

US power Doppler of hepatic angiomyolipoma with low fat content

Hepatic angiomyolipoma (AML) is a rare tumor containing a variable amount of fat. Angiomyolipoma prevalently constituted by vessels can be difficult to differentiate from other hypervascular hepatic tumors containing a small amount of fat. We describe US power Doppler findings in a case of hepatic AML with minimal fat content.

What is the best position of the arms in mantle field for Hodgkin's disease?

PURPOSE

To evaluate the best position of the arms in mantle field for Hodgkin's disease.

METHODS AND MATERIALS

In 12 patients, with surgical clips placed at the time of an axillary dissection for breast cancer, the radiological projection of the clips according to three arm positions was prospectively evaluated: akimbo (A), extended (E), and up over the head (U). The surgical clips were arbitrarily separated into two groups: lower and upper. In each patient, the distance between the surgical clips and chest wall was measured, and the possibility of shielding the lungs and humeral heads was evaluated.

RESULTS

The mean displacement of the lower clips away from the chest wall when the patients were in A, E, and U positions was 2.5, 3.0, and 4.6 cm, respectively. The upper group clips showed a lower difference in distance from chest wall. In the U position, there was always a clip of the lower group that projected over the humeral head, making it impossible to block this structure.

CONCLUSION

In the A position, there is the possibility of blocking the humeral head, but it is necessary to irradiate more lung parenchyma. Type E treatment setup allows the shielding of both lung and humeral head, while maintaining adequate margins around the axillary nodes. In the U position, there is a greater possibility of shielding the lung parenchyma, but it is impossible to block the humeral heads.

Magnetic resonance imaging of bronchioloalveolar carcinoma

The purpose of this study is to describe the magnetic resonance (MR) features of bronchioloalveolar carcinoma. MR examinations of 18 patients with proven bronchioloalveolar carcinoma were reviewed. Detection at computed tomography (CT) and pathologic confirmation were the entry criteria. Nine patients had a solitary nodule, three patients a lobar consolidation, and six patients had diffuse disease. For each patient, both breath-hold T2-weighted fast spin-echo, and breath-hold T1-weighted gradient-echo images, before and after injection of gadolinium, were available. Nine patients with pulmonary consolidation or diffuse disease had also heavily T2-weighted MR imaging (Haste or TSE 240; Siemens, Erlangen, Germany). MR imaging showed pulmonary abnormalities in 17 of 18 patients. Unenhanced T1-weighted and T2-weighted images depicted tumor in 16 of 18 patients. Contrast-enhanced T1-weighted images showed tumor in 17 of 18 patients. In no case did MR imaging depict abnormalities corresponding to the ground-glass opacities seen on CT scans. In three patients with mucinous bronchioloalveolar carcinoma, heavily T2-weighted images showed lesions isointense with respect to static fluid of the human body. In conclusion, the ability of MR imaging in detecting small nodules and ground-glass opacities is limited. However, heavily T2-weighted sequences are able to show the presence of mucin. This is useful information because mucinous bronchioloalveolar carcinoma carries a poor prognosis.

Diagnostic pitfalls of breath-hold MR urography in obstructive uropathy

Breath-hold MR urography (MRU) is being used with increasing frequency to evaluate urinary tract pathology. Although multiple studies have documented the accuracy of breath-hold MRU in the evaluation of obstructive uropathy, pitfalls associated with this technique may result in diagnostic errors. This essay illustrates both technical and interpretive pitfalls of MRU and suggests strategies for their recognition and avoidance.

Sudden unilateral deafness with endolymphatic sac adenocarcinoma: MRI

A 30-year-old man presented with sudden left deafness and vertigo. CT showed an osteolytic retrolabyrinthine tumour of the left temporal bone. High signal from the tumour and labyrinth was seen on fat-suppressed T 1-weighted images. At surgery, a haemorrhagic papillary-cystic adenocarcinoma of the endolymphatic sac was found.

Mucinous cystadenocarcinoma of the lung: CT-pathologic correlation in three cases

Mucinous cystadenocarcinoma (MCA) is a rare tumor that is considered to be a cystic variant of mucin-producing lung adenocarcinoma. MCA expands grossly by storing mucus and contains few neoplastic cells. We present the CT images of three patients with MCA and correlate them with pathologic specimens. The CT findings of MCA include a uniform low-attenuation, focal thickening of the cystic wall and enhancing septa.

Computed tomography halo sign in pulmonary nodules: frequency and diagnostic value

On computed tomography (CT) scanning, a ground-glass opacity zone surrounding a pulmonary nodule has been named the computed tomography (CT) halo sign. To investigate the frequency and diagnostic value of the CT halo sign, the authors reviewed the CT examinations of 305 patients with proven diseases producing solitary or multiple nodules. The CT halo sign was seen in 22 patients (7%). Eleven patients had a solitary nodule; five patients had multiple nodules; and six patients had nodules associated with areas of pulmonary consolidation, or ground-glass opacity, or both. Solitary nodules were the result of bronchioloalveolar carcinoma (n = 5), tuberculoma (n = 2), squamous cell carcinoma, non-Hodgkin lymphoma, myxovirus infection, and metastasis (n = 1 each). Multiple nodules were the result of metastasis (n = 2), Kaposi sarcoma (n = 2), and Wegener granulomatosis (n = 1). Nodules associated with areas of consolidation or ground-glass opacity were the result of metastasis (n = 2), bronchioloalveolar carcinoma, bronchiolitis obliterans organizing pneumonia, eosinophilic pneumonia, and invasive pulmonary aspergillosis (n = 1 each). The data showed that the CT halo sign is a nonspecific finding. It is known that in immunocompromised patients the CT halo sign should suggest invasive pulmonary aspergillosis, Kaposi sarcoma, and lymphoproliferative pulmonary disorders. However, in immunocompetent patients, the authors found that a solitary nodule with the CT halo sign and pseudocavitations has a high likelihood of being a bronchioloalveolar carcinoma.

Radiolucencies and cavitation in bronchioloalveolar carcinoma: CT-pathologic correlation

Bronchioloalveolar carcinoma (BAC) is a polymorphic lung cancer the incidence of which is rising. The presence of intratumoral radiolucencies is an important feature of bronchioloalveolar carcinoma. The aim of this study was to present pictorially the spectrum of intratumoral radiolucencies visible in BAC. In 57 BACs studied with thin-slice CT, we identified six types of radiolucencies: (a) patent intratumoral bronchioles (air bronchiologram); (b) pseudocavitations; (c) cavitation; (d) serpentine radiolucencies; (e) internal alveologram; and (f) multiple cystic lesions.

[Magnetic resonance pyelography: clinical use of ultrafast breath-hold sequences in obstructive uropathy. Personal experience]

INTRODUCTION

We investigated the diagnostic yield of MR pyelography (MRP) performed with two ultrafast breath-hold sequences in obstructive uropathy patients.

MATERIAL AND METHODS

Thirty-four patients with US demonstration of urinary tract dilation were examined with MRP at 1.5 T and with a standard body coil. HASTE sequences (TE 66, ETL 128, FA 180 degrees, 1 NEX, MA 240 x 256, slice thickness 4 mm, TA 13 s) were always performed and 26/34 patients were also examined with single-shot TSE sequences (TE 1100, ETL 240, FA 150 degrees, 1 NEX, slice thickness 7 cm, MA 240 x 256, FS, TA 7 s); 20/34 patients were given 500 mL superparamagnetic contrast agent (Lumirem). MRP findings were interpreted independently by two radiologists and analyzed for image quality, the presence/absence of dilation, the obstruction grade (mild, moderate, severe), site (intrarenal; ureteropelvic junction; proximal, mid-, distal ureter; indeterminate) and cause (intrinsic obstruction from a stone or other conditions; stenosis; indeterminate cause). The sensitivity, specificity, positive and negative predictive values for the detection of urinary tract dilation were calculated for each reviewer and interobserver agreement was calculated with the k analysis relative to the presence, grade, site and cause of urinary tract dilation.

RESULTS

MRP examinations were considered technically adequate in all cases by both observers. As for the presence of urinary tract dilation, the values were 100% for the first observer and 97%, 100%, 100%, and 95%, respectively, for the second observer. Interobserver agreement was .98 for dilation presence (excellent), .80 for dilation degree (excellent), .62 for dilation site (good) and finally .69 for dilation cause (good).

DISCUSSION AND CONCLUSIONS

MRP performed with the ultrafast breath-hold technique provides very good results in diagnosing urinary tract dilation, as well as the obstruction grade, site and cause, with results equal or even superior to those of non-breath-hold sequences. Ultrafast MRP lasts only 10 minutes, meaning it occupies the magnet shortly and costs less: it can be thus considered a routine alternative to conventional diagnostic imaging, especially ivp, in the evaluation of obstructive uropathy.

[Use of oral superparamagnetic contrast media in cholangiopancreatography with TSE single-shot magnetic resonance]

PURPOSE

To investigate the yield of an oral superparamagnetic contrast agent (Lumirem) in turbo spin echo (TSE) single-shot MR cholangiopancreatography (MRCP) in patients candidate to laparoscopic cholecystectomy.

MATERIAL AND METHODS

Thirty patients (mean age: 52.2 years) scheduled for laparoscopic cholecystectomy underwent MRCP with TSE single-shot sequences. To cover the biliary tree, thick-section TSE images were acquired according to the cross-sectional location of the biliary tract. Six 50-mm images progressively rotated by 30 degrees each were acquired during breath-holds. The precontrast images were obtained before the negative oral contrast agent was administered. The postcontrast images were acquired 10 minutes after oral contrast agent administration. Two observers made a qualitative evaluation on all images: the contrast enhancement was assessed comparing the pre- and postcontrast images of each examination on the basis of signal intensity in the stomach and duodenum, giving a score on a graduate scale. The greater yield of postcontrast images was validated by statistical analysis. The actual diagnostic improvement obtained with postcontrast images was validated for every single case.

RESULTS AND CONCLUSIONS

The greater yield of postcontrast images was statistically significant in the common bile and cystic ducts, but not in the gallbladder and Wirsung duct. Better images were obtained in 22/30 patients. The actual diagnostic improvement in the visualization of the common bile and cystic ducts was statistically significant in 7/30 patients. To conclude, administering an oral negative contrast agent improved image quality and the diagnostic yield. The agent was well tolerated and safe and we suggest its use in TSE single-shot MRCP of the patients candidate to laparoscopic cholecystectomy.

Ground-glass attenuation in nodular bronchioloalveolar carcinoma: CT patterns and prognostic value

PURPOSE

The purpose of our study was to assess the CT patterns and prognostic value of ground-glass attenuation in nodular bronchioloalveolar carcinoma (BAC).

METHOD

We retrospectively reviewed CT examinations of 22 patients with 24 nodular BACs who underwent surgery. CT and pathologic findings were analyzed and correlated with postoperative course of disease.

RESULTS

We detected five patterns of ground-glass attenuation associated with nodular BAC: pure ground-glass nodule (n = 1), ground-glass nodule with superimposed lymphangitis (n = 1), nodule with mixed areas of ground-glass attenuation and consolidation (n = 2), ground-glass halo around nodule (halo sign) (n = 3), and nodule associated with a plurisegmental area of ground-glass attenuation (n = 1). Two patients with the halo sign and a third patient with a plurisegmental area of ground-glass attenuation rapidly developed diffuse pulmonary disease by bronchogenic spread and died a few months after surgery.

CONCLUSION

Our series demonstrates that focal BAC may progress to diffuse pulmonary involvement by bronchogenic spread. The presence of a large area of ground-glass attenuation associated with a nodular BAC might be the CT sign of an aggressive biologic behavior. In these cases there is a high likelihood for diffuse disease to develop from bronchogenic spread.