Organizing pneumonia due to actinomycosis: an undescribed association.

Organizing pneumonia is a pathologic entity characterized by intra-alveolar buds of granulation tissue that can extend to the bronchiolar lumen. It is a non-specific finding reflecting a pattern of pulmonary response to aggression that can be cryptogenic or associated with several causes. Pulmonary actinomycosis is a rare infectious disease, of bacterial aetiology, and of difficult diagnosis. This disease usually causes non-specific respiratory symptoms and radiological findings, and the treatment is based on the use of antibiotics. The authors describe a clinical case of a 53-year-old male smoker (50 pack years), initially seen for complaints of right-sided chest pain and sub-febrile temperature. Imaging studies revealed a mass in the inferior right lobe and enlarged mediastinal lymph nodes. Empirical treatment with antibiotics caused partial and temporary improvement. Transthoracic biopsy revealed a pattern of organizing pneumonia with giant multinucleated cell granulomas. Repeat imaging studies revealed an enlargement of the pulmonary mass and therefore a right inferior lobectomy was performed. The pathologic study revealed a histological pattern of organizing pneumonia surrounding inflammatory bronchiectasis with a large number of Actinomyces colonies. To our knowledge there is presently no report in the literature of organizing pneumonia associated with Actinomyces infection.

US-guided interventional joint procedures in patients with rheumatic diseases--when and how we do it?

OBJECTIVE: To describe the main indications and the technical steps to perform ultrasound guided procedures in patients with rheumatic diseases. To access procedures accuracy, safety and effectiveness. MATERIALS AND METHODS: 27 patients with pain related to articular complications of rheumatic diseases and according to previous radiographic or US exam were submitted to several US-guided procedures. 42% of patients (n=11) had rheumatoid arthritis, 11% (n=3) spondyloarthropathies, 18% (n=5) psoriatic arthritis, 15% (n=4) undifferentiated arthritis, 3% (n=1) Sjögren syndrome and 11% (n=3) had gout. Described procedures are synovial biopsies, intra-articular injections of corticosteroids, radiation synovectomy and synovial cysts drainage procedures. When a therapeutical procedure was made, patients were evaluated by 2 rheumatologists. Corticosteroids used were Prednisolone and Triamcinolone. Yttrium-90 was used for synovectomy. RESULTS: In all cases success was achieved with correct needle placement inside the joint. After injection/aspiration symptoms successfully solved with all patients improving their health status. No complications were recorded during follow-up period. CONCLUSIONS: US-guidance is very reliable to afford a safety procedure always checking the injection, biopsy or aspiration. Guided-biopsy has high success rates obtaining several samples. Thus is also possible to use more powerful/long acting therapeutic drugs aggressive to extra-articular structures avoiding complications.

Unexpected MR-T1 enhancement of endocrine liver metastases with mangafodipir.

With the use of available liver magnetic resonance contrast agents, such as mangafodipir (Mn-DPDP), liver metastases do not exhibit enhancement on T1-weighted images. This absence of enhancement is due to the lack of hepatocytes within these tumors. The purpose of this report is to demonstrate an unexpected enhancement on T1-weighted images 30 minutes after injection of mangafodipir, in the case of endocrine liver metastases from a non-hyperfunctioning neuroendocrine pancreatic tumor. Different hypotheses could explain this unexpected enhancement, such as increased arterial tumoral flow or high metabolic activity. Contrary to liver metastases of other origins, Mn-DPDP enhancement can be present in neuroendocrine metastases. J. Magn. Reson. Imaging 1999;10:193-195.

Benign and malignant hepatocellular tumors: evaluation of tumoral enhancement after mangafodipir trisodium injection on MR imaging.

The aim of this work was to study the ability of mangafodipir trisodium (Mn-DPDP)-enhanced MR imaging in differentiating malignant from benign hepatocellular tumors. Eleven patients with pathologically proved hepatocellular carcinomas, six with focal nodular hyperplasias, and one with a single hepatocellular adenoma were examined by spin-echo and gradient-echo T1-weighted sequences before, 1 h after, and 24 h after intravenous injection of Mn-DPDP (5 micromol/kg). Quantitative analysis including enhancement and lesion-to-liver contrast-to-noise ratio, and qualitative analysis including the presence of a central area and a capsule were done on pre- and post-Mn-DPDP-enhanced images. Enhancement was observed in all the tumors with significant improvement (p < 0.05) in contrast-to-noise ratio 1 h after, and 24 h after intravenous injection of Mn-DPDP. There were no significant differences in the mean enhancement and the mean contrast-to-noise ratio (CNR) between benign and malignant tumors. No enhancement was seen within internal areas observed in 7 hepatocellular carcinomas, and in 5 focal nodular hyperplasias, and within capsules which were observed in 9 hepatocellular carcinomas. In our study, Mn-DPDP increased CNR of both benign and malignant tumors but did not enable differentiation between benign and malignant tumors of hepatocellular nature.

Water enema computed tomography (WE-CT) in the local staging of low colorectal neoplasms: comparison with transrectal ultrasound.

BACKGROUND: To determine the accuracy of computed tomography performed with a water enema application (WE-CT) in the local staging of low colorectal neoplasms and to compare the results with those of transrectal ultrasonography (TRUS). METHODS: Forty patients with low colorectal tumors were evaluated prospectively by CT with the simultaneous administration of a lukewarm rectal enema (0.5-1.5 L). Thin slices (5 mm) and intravenous application of iodinated contrast media were routinely used. TRUS was performed in 18 patients. Tumor size, location, and staging according to the TNM classification of the UICC were registered. Tumors were classified as < T3 (T1 or T2) or as T3 or T4. For staging peritumoral lymph node metastases on WE-CT, two criteria of positivity were tested: N+ if at least one peritumoral node > or 5 mm in diameter was seen (reading A); N+ if at least one peritumoral node > or = 5 mm or three peritumoral nodes < 5 mm were identified (reading B). RESULTS: For the tumor staging, WE-CT showed a sensitivity of 90%, a specificity of 73%, a positive predictive value (PPV) of 90%, a negative predictive value (NPV) of 73%, and an accuracy of 85%. For TRUS, the results were sensitivity of 73%, specificity of 29%, PPV of 62%, NPV of 40%, and an accuracy of 39%. Concerning nodal staging with WE-CT, results were superior when reading A was used: sensitivity = 84%, specificity = 83%, PPV = 73%, NPV = 91%, and accuracy = 84%. TRUS showed a sensitivity of 29%, specificity of 100%, PPV of 100%, NPV of 67%, and an accuracy of 71%. CONCLUSION: WE-CT is a reliable technique for the local staging of low colorectal tumors that can be superior to TRUS. For diagnosis of peritumoral metastatic lymph nodes on WE-CT, the 5-mm diameter cutoff value is the most appropriate size criterion.

Hyperintense benign liver lesions on spin-echo T1-weighted MR images: pathologic correlations.

BACKGROUND: To determine the incidence of hyperintensity on T1-weighted spin echo (SE) images in benign liver lesions, value of fat-suppressed magnetic resonance (MR) imaging for the detection of fat within these lesions, and the causes of hyperintensity by correlation to pathologic examinations. METHODS: Five hundred forty-nine patients with 805 benign liver lesions including 585 hemangiomas, 188 focal nodular hyperplasias (FNHs), 14 hepatic adenomas (HAs), 14 focal fatty infiltrations (FFIs), two biliary cystadenomas, and two hemorrhagic cysts were examined by T2-weighted and T1-weighted SE MR imaging. For hyperintense lesions on T1-weighted SE images, fat-suppressed images were obtained by selective presaturation of fat. RESULTS: Thirty-two lesions (four FNHs, 10 HAs, 14 FFIs, two biliary cystadenomas, and two hemorrhagic cysts) appeared hyperintense on T1-weighted SE images; 21 of these became hypointense on the fat-suppressed T1 weighted SE images (one FNH, six HAs, and 14 FFIs) and contained fat at pathological examination. The other 11 lesions remained hyperintense on fat-suppressed T1-weighted SE images and had no fat deposition. Causes of hyperintensity in these cases were sinusoidal dilatation, copper deposition, hemorrhage, and high protein content. CONCLUSION: Among benign liver lesions, hyperintensity on T1-weighted SE images is rare (3.9%). Causes of this hyperintensity are fat deposition, copper accumulation, sinusoidal dilatation, bemorrhage, and high protein content. Fat-suppressed imaging can distinguish fat deposition from other causes of hyperintensity.

Calcification in focal nodular hyperplasia: a new problem for differentiation from fibrolamellar hepatocellular carcinoma.

PURPOSE: To describe calcification in focal nodular hyperplasia (FNH) of the liver, which poses a new problem for the differentiation of FNH from fibrolamellar hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Ultrasound, computed tomography, and magnetic resonance imaging findings of 357 FNH lesions diagnosed in the past 5 years in 295 patients (274 female, 21 male; aged 14-72 years) were retrospectively reviewed with emphasis on intralesional calcification. RESULTS: Calcifications were seen in five FNH lesions (1.4%) as small, solitary spots located centrally or peripherally within the lesions. Morphologic features of these calcifications were similar to those of calcifications in two of six fibrolamellar HCCs in the same period. CONCLUSION: Calcification in FNH is a rare and atypical finding that poses further difficulty for differentiation from fibrolamellar HCC.

Induced pneumoperitoneum in CT evaluation of peritoneal carcinomatosis.

BACKGROUND: Imaging of peritoneal carcinomatosis is a well-known problem even for technologies as recent as computed tomography (CT). The purpose of this study was to evaluate whether CT performed after induced pneumoperitoneum (CT-PP) could have a higher sensitivity in the detection of peritoneal implants over conventional CT. METHODS: Five patients with known ovarian malignancies underwent standard CT and CT-PP. Exploratory laparotomy was performed with a maximum interval of 7 days from the last imaging procedure. Results were prospectively compared with surgical findings on a compartment to compartment basis. RESULTS: CT-PP was well-tolerated with no serious adverse reactions registered. The anterior and visceral peritoneum, the paracolic gutters and subphrenic areas were particularly well depicted but not the pelvis which was poorly evaluated in all cases. CT-PP detected all the three cases where peritoneal carcinomatosis was present even when metastatic nodules were smaller than 2 mm; it also showed intraabdominal adhesions in two patients, an important finding that precludes the use of intraperitoneal chemotherapy. CONCLUSIONS: With CT-PP there seems to be a reduction in the threshold of detectability of peritoneal implants. The direct demonstration of intraperitoneal adhesions is an important secondary finding. Disadvantages of CT-PP are (1) it is a time-consuming method and (2) it does not evaluate all the peritoneal recesses potentially involved in peritoneal carcinomatosis.