F-18 fluorodeoxyglucose chest uptake in lung inflammation and infection.

PURPOSE: F-18 fluorodeoxyglucose (FDG) may accumulate at sites of inflammation or infection, making interpretation of whole-body scans difficult in patients with cancer. METHODS: More than 650 whole-body positron emission tomographic (PET) scans performed to examine patients with cancer were reviewed to identify uptake in pulmonary infection or inflammation based on the appearance of F-18 FDG chest uptake, chest radiographs, computed tomography, or all of these. RESULTS: Ten patients had uptake in benign lung disease. Eight patients had head and neck tumors and two patients had breast cancer. Intense focal or multifocal F-18 FDG chest uptake was seen in 6 of 10 scans. This was difficult to distinguish from pulmonary metastases based on the scan appearance. However, in the remaining patients, the uptake was atypical for malignancy and displayed an apical, segmental, or lobar pattern. In all patients, the F-18 FDG lung uptake corresponded to benign radiologic changes (infiltration, consolidation, or atelectasis), and the final diagnosis was pulmonary inflammation or infection. Nine patients were asymptomatic and one patient had clinical aspiration pneumonia. Follow-up PET scans were performed in five patients to evaluate their conditions. Chest uptake disappeared completely in three patients and partially in two patients, and there were no new findings. Variable degrees of F-18 FDG chest uptake have been reported with more than 40 different benign causes. They can be classified based on the underlying mechanism into four major categories: 1) Inflammation or infection, 2) benign tumor, 3) physiologic activity, and 4) iatrogenic. Most of these false-positive cases are included in the first category. CONCLUSIONS: Pulmonary infection or inflammation might predispose patients to localized F-18 FDG chest uptake mimicking pulmonary metastases and limiting the specificity of whole-body scans performed in patients with cancer.

Ultrasound-guided 1.2-mm cutting-needle biopsies of head and neck tumours.

PURPOSE: To establish the role of ultrasound-guided cutting-needle biopsy in the diagnostic-work-up of tumours in the head and neck region. MATERIAL AND METHODS: Seventy-two patients (74 biopsies) with tumours in the head and neck were biopsied by means of a biopsy gun fitted with a 1.2-mm biopsy needle (midsized-needle biopsy, MNB). Twenty-four biopsies were taken from salivary glands, 29 from lymph nodes, and 21 from miscellaneous locations. Thirty-three of the patients were biopsied by MNB under ultrasound guidance after a blinded fine-needle aspiration biopsy (FNAB) was considered non-diagnostic or non-representative. RESULTS: In 91% of the cases, the MNB diagnosis was identical to the final diagnosis (surgical or radiological/clinical follow-up: at least 6 months), 9% were false-negative/ non-representative. In 17/33 patients MNB was considered to provide more diagnostic information than FNAB, the methods had equal accuracy in 12 patients, and in 4 patients the information already gained with FNAB was superior to that provided by MNB. The non-diagnostic sampling rate for FNAB was 25% versus 3% for MNB. In 26 patients with malignant lymphoma, MNB results were diagnostically correct in all but 2 cases. FNAB was correct in 2 of 9 cases. There were no biopsy-related complications. CONCLUSION: MNB was found to be safe and to possess a high degree of diagnostic accuracy, and could therefore, particularly in patients with lymphoma, be considered a diagnostic alternative to FNAB.

Unusual anterior course of the sigmoid sinus: report of a case and review of the literature.

The position and dimensions of the jugular bulb and the venous dural sinuses vary considerably. While the anatomical variations of the jugular bulb have been extensively reported in the literature, that of the sigmoid sinus have been reported only rarely. We report a case of unusual anterior course of the vertical segment of the sigmoid sinus which was encountered during an attempted myringoplasty. Anomalies of the jugular bulb in general are also described.

Imaging of tuberculosis--experience from 503 patients. I. Tuberculosis of the chest.

PURPOSE: To give an overview of 503 patients with tuberculosis (TB) and to describe the radiologic findings of chest TB. MATERIAL AND METHODS: A total of 503 patients with proven TB were reviewed; 266 had chest involvement. RESULTS: Lung lesions were demonstrated in 214 patients. Infiltrates in the basal parts of the lungs or pleural effusion were often primarily mistaken for viral or bacterial infections. Consolidations within the lungs and pleural thickening were sometimes indistinguishable from malignancy. Positive culture of the sputum without lung lesions was encountered in 12 cases. Enlarged mediastinal lymph nodes were demonstrated in 67 cases, 35 without lesions in the lungs. The lymphadenopathy could be extensive, and both clinically and radiologically indistinguishable from lymphoma. CONCLUSION: Due to the present increase in incidence of TB and the fact that TB can mimic many other conditions, it is important that both clinicians and radiologists have TB high on the list for differential diagnoses.

Imaging of tuberculosis. III. Tuberculosis as a mimicker of brain tumour.

PURPOSE: To show that intracranial tuberculosis (TB) often masquerades as brain tumour. MATERIAL AND METHODS: Forty-six patients with intracranial TB, who after CT at the local hospital were referred for surgery or radiotherapy of brain tumour, are presented. Sometimes the correct diagnosis was first established during surgery for brain tumour. RESULTS: The differentiation between TB and gliomas, meningiomas, metastases, or lymphomas may be impossible from the clinical history and CT findings. Angiography, done in 25 of our cases, often helped by not showing the expected tumour vasculature. MR, performed in 9 patients, helped by demonstrating a layered capsule on T2-weighted images in 4 of the lesions (hypointense rim outside hyperintense rim); the centres of the lesions were of decreased, usually very mixed T2 signal intensity. CONCLUSION: Even in patients with findings typical of brain tumour, TB remains an important differential diagnosis.

Imaging of tuberculosis. V. Peripheral osteoarticular and soft-tissue tuberculosis.

PURPOSE: To assess frequency, location, and appearance of peripheral osteoarticular and soft-tissue tuberculosis (TB). MATERIAL AND METHODS: Twenty-five of 503 patients with TB had peripheral osteoarticular TB and 5 had soft-tissue TB. Chest radiography, CT, and MR imaging were applied. RESULTS: The location of the osteoarticular lesion was articular/epiphyseal in 14 patients, articular/metaphyseal in 3, and metaphyseal without joint involvement in 3. Involvement of flat bone was found in 4 patients (5 lesions). The morphologic appearance was similar to that of a lytic tumour in 9 patients (10 lesions) and that of a destructive joint lesion in 16 patients. The soft-tissue TB in all 5 patients presented as an abscess. Twelve patients had a total of 20 additional sites of involvement: chest in 9, abdomen in 4, spine in 4, the neck in 3, and the central nervous system in one patient. CONCLUSION: On the basis of radiologic appearance, it can be difficult to differentiate peripheral osteoarticular and soft-tissue TB from other degenerative, inflammatory, or neoplastic disorders, and the importance of a high awareness is stressed in order to reach an early diagnosis.

Pre- and postoperative CT and MR in pseudoaneurysms of the heart.

Pseudoaneurysms of the heart have a propensity to rupture and surgery is indicated. Usually in these cases diagnostic imaging is based on angiographic and/or echocardiographic studies. We have attempted to determine in pre- and postoperative studies the value of CT and ECG-gated MRI in patients with pseudoaneurysm. Seven patients with a pseudoaneurysm and/or dyskinesia of the posterolateral or diaphragmatic wall of the left ventricle were investigated with CT and/or ECG-gated MR studies, in addition to angiography, echocardiography, and radionuclide studies, prior to cardiac surgery. Postoperative follow-up studies with CT in six and MR in five patients were also carried out. Both CT and ECG-gated MRI allowed us to visualize the neck and CT also confirmed the communication between the cavities with or without demonstrating the conduit. In addition, disruption of the epicardial fat layer by the pseudoaneurysm was seen on both CT and MR, and the presence of intrapericardial adhesions was visualized on MR. Finally, CT and MRI, in postoperative follow-up studies, may indicate a myocardial discontinuity adjacent to the surgical patch.

Epicardial fat causing pitfalls in CT and MR imaging of the pericardium.

To study the complex anatomy of the pericardium and the pericardial recesses, notably the transverse sinus and the recess behind and under the common pulmonary artery, cryomicrotomy sections of 4 frozen cadaver specimens were correlated with CT and MR imaging in multiple planes. In addition, CT chest studies of 254 patients and MR chest studies from 78 patients were reviewed. Epicardial fat interposed between the transverse sinus of the pericardium and the ascending aorta was a normal finding confirmed by cryomicrotomy studies and seen by CT in 23 of 245 patients and in MR imaging in 3 of 78 patients. Epicardial fat indenting the pericardial sac below the common pulmonary artery caused an inhomogeneous signal, mimicking lymphadenopathy on coronal T1 weighted MR images in 4 patients.

CT and MR evaluation of pericardial and retrosternal adhesions after cardiac surgery.

The visibility of the pericardium as well as of the space between the dorsal aspect of the sternal surface and the pericardial surface after cardiac surgery was determined by CT and/or MR with electrocardiographic (ECG)-gated spin-echo (SE) and gradient-echo sequences. Seventeen patients who had undergone cardiac operations and who were admitted for cardiac reoperation were investigated with CT and/or MR prior to sternal reentry. Five patients were investigated with CT alone, ten with both CT and MR, and two with MR only. At reoperation, retrosternal adhesions were classified as present or absent, and intrapericardial adhesions were classified as absent, minimal, moderate, or severe. A similar classification was applied to the CT and MR findings. In 14 of 15 patients, the CT findings were in agreement with those found at operation regarding postoperative retrosternal extrapericardial adhesions in the cranial retrosternal space and in 12 of 15 in the caudal retrosternal space. Computed tomography could not detect intrapericardial adhesions. Magnetic resonance was sensitive to metal artifacts from sternal sutures in both sequences and could therefore not be used to detect postoperative retrosternal extrapericardial adhesions. On the other hand, MR with ECG-gated SE sequences confirmed intrapericardial adhesions in 44 of 57 locations.

Comparison of methods of imaging the salivary glands.

Surgery on the salivary glands can be a considerable surgical challenge because of their complex and delicate structure. To avoid damage to the facial nerve, and because pleomorphic adenomas are the most common space-occupying lesions of the parotid glands, a formal parotidectomy is often undertaken. To plan the surgical approach better and to avoid unnecessary surgery in some patients, the search for the ultimate imaging technique for the salivary glands continues. A few recent reports comparing various imaging techniques for the salivary glands are discussed in this review.

Long-term radiographic follow-up of the sella turcica in hyperprolactinaemic women.

Seventy-three hyperprolactinaemic women were followed up with radiographic examinations (lateral and posteroanterior coned down views) of the sella turcica for 5 to 13 years during which time all but one had received treatment with bromocriptine. Progression of the sellar asymmetry occurred in 25 women (7 during pregnancy), 14 had regression of their changes in the pituitary fossa while 34 did not show any changes in the configuration of the sella turcica. Prolactin levels in serum, duration of bromocriptine therapy or sellar configuration could not predict later radiographic progressive or regressive changes of the sella turcica. The clinical course was benign in the majority of the women with signs of prolactin-producing adenomas. The risk of serious tumour enlargement seems to be very small. We were not able to demonstrate any parameter which could predict the growth or shrinkage of the tumour. Routinely repeated radiographic sellar examinations are unnecessary in the vast majority of hyperprolactinaemic women.

The occurrence of macroscopical pituitary calcifications in prolactinomas.

Radiographs of the sella turcica from 73 hyperprolactinaemic women, were followed-up for 5 to 13 years. Six women (8%) were found to harbour granular calcific deposits in the anterior part of the sella turcica visible on the plain radiographs. In three women the calcification increased in size during follow-up. This was accompanied by signs of regression of other features of pituitary tumour on the radiographs in two women. Pituitary calcifications associated with hyperprolactinaemia seem to represent a benign and regressive process.

Pericardial effusion and pericardial compartments after open heart surgery. An analysis by computed tomography and echocardiography.

Thirty-three patients with pericardial effusion after open heart surgery were investigated with computed tomography (CT). Twelve of the 33 patients also underwent echocardiography prior to pericardiocentesis. The effusions were typed according to the results of the CT investigation. Because of postoperative adhesions, typical patterns of localized pericardial effusions were found in 16 patients. The localized compartments were seen on the right and left side of the heart and around the aorta and the pulmonary artery. CT was therefore shown to be of value for selecting the approach for drainage with catheter pericardiocentesis.

Computed tomography of the oropharynx in obstructive sleep apnea.

Uvulopalatopharyngoplasty (UPPP) is currently the preferred method for treatment of the obstructive sleep apnea syndrome (OSAS). However, only 50 per cent of the patients operated upon are cured by this surgical procedure, and there is a demand for better and more objective selection criteria. Computed tomography (CT) of the oropharynx was obtained in 32 consecutive adult patients with proven OSAS. An additional 15 patients with the same complaints, but without objective evidence of OSAS, were used as a control group, together with 20 normal subjects. The axial widths of the tongue and the genioglossus and hyoglossus muscles were measured by CT. Both the tongue and genioglossus widths were significantly larger in the OSAS patients than in the two control groups (p less than 0.001). The increased tongue width will cause encroachment of the oropharyngeal airway below the level of the soft palate. Thus, CT can be used to measure the tongue size in order to evaluate its predictive value for the outcome of the UPPP procedure.

Uvulopalatopharyngoplasty in the sleep apnea syndrome. Predictors of results.

A prospective study of 34 consecutive patients with the sleep apnea syndrome was undertaken to evaluate the effectiveness and complications of, and predictors of, results in a conservative type of uvulopalatopharyngoplasty (UPPP). At six months, 65% of the patients had a 50% or greater reduction in the number of apneas and hypopneas per hour (responders). The responders to UPPP were less severely affected preoperatively regarding apneas and hypopneas, the mean number of which (+/- SD) were 32.7 +/- 20.8 compared with 64.6 +/- 26.0. They also had a lower body mass index before UPPP (31.3 +/- 4.1 vs 36.0 +/- 7.0 kg/m2). Preoperative computed tomography and cephalometry indicated that the nonresponders had narrower upper airways. It is concluded that UPPP is the treatment of choice for mild to moderate sleep apnea syndrome, but not for severely affected, heavily overweight patients with an increased tongue width.

Computed tomography of the submandibular salivary glands.

Computed tomography offers a convenient method for the evaluation of the submandibular salivary glands and their surroundings. Normal measurements were established based on 38 normal subjects. The visualization of the ductal system in the gland and the relationship of the gland to the platysma muscle were recorded. The CT scans of 12 patients with a tongue base carcinoma and 4 patients with a verified obstruction of the submandibular duct were also reviewed to establish how the glands are affected by extrinsic lesions. The normal glands measured 28 x 18 mm (+/- 5 mm) in the axial plane. Two patients with unilateral hypoplasia of the gland were found in the normal group. Visualization of the intraglandular duct is not a specific finding since it was observed in more than 25 per cent of the normal group. Displacement and bulging of the platysma muscle by the submandibular gland can be a sign of glandular enlargement. It was also seen in 9 out of 12 patients with carcinoma of the base of the tongue.

Anomalies of digastric muscles: CT and MR demonstration.

Anomalies of the anterior bellies of the digastric muscles were described during the 19th century and have been of little clinical significance. However, new imaging modalities, such as ultrasound, CT, and magnetic resonance (MR) imaging, can easily depict muscle anatomy without having to rely on dissection studies. The anterior bellies of the digastric muscles were evaluated in 40 patients having CT and 35 patients having MR imaging of the oropharynx. An accessory muscle crossing the midline between two normal digastric muscles was found in a patient in the MR imaging group. In the CT group, one patient showed absence of one anterior belly; in its place a small muscle was seen passing from the hyoid bone to the midline raphe of the mylohyoid muscle. It is necessary to recognize that muscle variants of the digastric muscle occur, to avoid confusion with abnormal lesions of the floor of the mouth and the submental space.