[Endocranial complications in otitis media: what you need to remember]

Thanks to the potency of antibiotics, life-threatening complications of otitis media are rare. In many cases, however, the symptomatology is veiled, and the course of the disease tends to be protracted. Secondary symptoms may preponderate and often mask those associated with the ear itself. If a case of otitis media fails to clear up, or mastoiditis develops, or sensorineural deafness, vertigo, headaches, seizures, or meningism occur, the possibility of an otogenous complication must immediately be considered and the patient submitted to diagnostic imaging without delay, so as to ensure early surgical treatment of a possible lesion in the ear.

MR perfusion measurements on pharyngeal tumors: comparison of quantification strategies

For the case of pharyngeal carcinomas, the clinical value as well as the stability of several evaluation methods of MR tomographic perfusion measurement are compared. Eighteen patients suffering from histologically proven squamous cell carcinomas were investigated by MR tomography (1.5 T, 0.2 mmol/kg Gd‐DTPA) prior to and during radiation therapy. Perfusion measurements were performed using a double‐echo FLASH sequence. Parameters describing regional blood flow, blood volume, mean transit time, and interstitial concentration of contrast medium (CM) were calculated, applying seven different combinations of correction approaches (separating the shortening of T1 and T2∗, arterial input function (AIF), and tumor shunts). Their correlations to MR independent tumor physiological parameters were analyzed (metabolic activity measurements using ¹⁸F‐FDG‐PET, polarographical pO2 measurement, tumor volume). Significant improvements of the correlation between perfusion‐dependent and other tumor physiological parameters could be achieved by decoupling the shortening of T1 and T2∗ and by applying of the tumor shunt model. Deconvolution from the AIF deteriorated the correlation. Therefore, the elimination of the T1 shortening due to interstitial CM proves to be essential for MR perfusion measurements on contrast medium uptaking lesions. Depending on the measurement conditions (temporal resolution, signal‐to‐noise ratio), the consideration of the AIF can even make the results significantly worse by introducing additional measuring errors.

PACS numbers: 87.61.‐c

Pelvic magnetic resonance imaging after bone marrow harvest – a retrospective study in 50 unrelated marrow donors

A total of 50 unrelated marrow donors were examined by pelvic magnetic resonance imaging (MRI) to investigate the morphological sequelae of bone marrow harvesting (BMH). Signal increase in T2-weighted sequences and contrast media enhancement in T1 sequences at the operative sites were found as typical MRI morphology 4 weeks after harvest (group A, n=16), corresponding to edema, hyperemia and proliferative activity. Although tissue repair was completed in the majority of donors 1 year after BMH, about 36% of donors in group B (n=16) had abnormal findings. These included a persistence of the 'acute injury' signal pattern (2/16, 12%), and signal alterations due to fatty marrow conversion (4/16, 24%). The proportion of MRI abnormalities increased to over 70% in two-time donors (group C, n=11), which might indicate a cumulation of tissue damage after repetitive harvests. If donors had experienced prolonged discomfort after BMH (group D, n=7), MRI revealed pathological signals in 86%. In conclusion, the MRI morphology reflects the pathophysiological reactions after BMH, including inflammation and tissue repair. A further prospective evaluation in a larger number of donors is necessary to confirm these results and to identify the factors which influence the extent and duration of tissue damage.

Intraluminal tumour thrombus of a mixed non-seminomatous germ cell tumour of testis within the inferior vena cava

BACKGROUND

Intracaval tumour thrombus developed per continuitatem from a primary testicular tumour is rare.

CASE REPORT

A patient with metastatic mixed non-seminomatous germ cell tumour of the testis extending into the inferior vena cava (IVC) is presented. He belonged to the intermediate-risk group according to the IGCCCG (International Germ Cell Cancer Collaborative Group) classification. The 26-year-old man underwent right inguinal orchiectomy. Computed tomography revealed the tumour thrombus as filling defect in the IVC extending nearly to the right renal vein. Duplex sonography detected a partial thrombosis of the IVC. Combination chemotherapy led to regression of pulmonal metastases and the intraluminal tumour thrombus. 5 months later, retroperitoneal lymphadenectomy was performed and the intraluminal thrombus was extracted by cavotomy. The thrombus originated from the ostium of the right testicularis vein in the IVC. Histological examination revealed no vital tumour tissue.

CONCLUSION

In patients with testicular cancer information about pathological processes of the IVC is important for therapeutic management. Testicular tumours seldom extend up the IVC.

[Paraneoplastic hyperthyroidism in a patient with metastasizing teratocarcinoma and excessively high HCG]

Clinically manifest hyperthyroidism is a rare paraneoplastic syndrome in patients with excessive HCG production due to testicular cancer. A 40-year-old patient with right testicular cancer (teratoma, embryonal cell carcinoma), diffuse pulmonary metastases and high serum HCG levels presented with symptomatic hyperthyroidism. The patient received immediately thyrostatic therapy and 4 cycles of PEI chemotherapy (Cisplatin, Etoposide, Ifosfamide). Thyroid function had returned to normal by the beginning of the second course of chemotherapy. After right orchiectomy and resection of residual pulmonary masses which revealed vital tumor cells, two additional courses of chemotherapy were performed. The patient is well and without evidence of disease 11 months after therapy. All patients with testicular cancer and excessive HCG production should be evaluated for biochemical and clinical signs of hyperthyroidism and treated accordingly with antithyroidal medication and immediate cytoreductive chemotherapy.

Diffusion-weighted MR imaging of cholesteatoma in pediatric and adult patients who have undergone middle ear surgery

OBJECTIVE

The aim of this prospective study was to determine the role of diffusion-weighted MR imaging combined with conventional MR imaging for the detection of residual or recurrent cholesteatoma in patients who have undergone middle ear surgery.

SUBJECTS AND METHODS

Twenty-two patients who had undergone resection of cholesteatoma were referred for MR imaging. MR imaging (1.5 T) was performed using a diffusion-weighted single-shot spin-echo echoplanar sequence, a proton density and T2-weighted double-echo turbo spin-echo sequence, and T1-weighted spin-echo sequences before and after IV injection of gadopentetate dimeglumine (0.1 mmol/kg of body weight). An experienced reviewer evaluated the diffusion-weighted MR images for the presence of a high-signal-intensity cholesteatoma. Imaging findings were correlated with findings from surgery in 17 patients and with findings from clinical follow-up examination in five patients.

RESULTS

Diffusion-weighted MR imaging combined with conventional MR imaging depicted 10 of 13 cholesteatomas (sensitivity, 77%). The three lesions that were missed were smaller than 5 mm. All the MR images of patients without cholesteatoma were correctly interpreted as showing negative findings for cholesteatoma (specificity, 100%). The positive predictive value and negative predictive value were 100% and 75%, respectively.

CONCLUSION

Diffusion-weighted MR imaging combined with conventional MR imaging can confirm residual or recurrent cholesteatoma in patients who have undergone middle ear surgery by showing a high-signal-intensity lesion. Because tumors smaller than 5 mm may be missed, a diffusion-weighted MR imaging study with negative findings does not exclude small residual or recurrent cholesteatoma.

MRI of the coronary arteries: flip angle train optimization for 3D sequences

Application of contrast agents in MRI of coronary arteries improves contrast-to-noise ratio (CNR), but widens the range of T1 relaxation times of the tissues to be imaged. The flip angle train, generated for the measurement of all phase-encoding steps in the 3rd spatial dimension of the navigator echo FLASH sequence used, is optimal only for one T1. Computer simulations show that it is not advisable to optimize the sequence on the basis of an extremely short T1 relaxation time (such as in the case of contrast-enhanced vessels) because the imaging of the surrounding tissue would be negatively influenced. A sequence optimization to a T1 of approximately 200 ms seems to allow a CNR improvement of > or = 50%.

Simultaneous occurrence of Hodgkin's lymphoma and eosinophilic granuloma: a potential pitfall in positron emission tomography imaging

Positron emission tomography (PET) with [18F]fluorodeoxyglucose [18F]FDG has evolved as a method of increasingly clinical importance in the management of patients with malignant lymphoma. However, inflammatory lesions also accumulate [18F]FDG and may cause difficulties with interpretation. This report deals with 2 patients with simultaneous occurrence of Hodgkin's lymphoma and eosinophilic granuloma, a rare but known coincidence of diseases. In the first case, Hodgkin's disease could not be differentiated from eosinophilic granuloma. Positron emission tomography showed increased [18F]FDG uptake both in lymphoma manifestations and in the granuloma. In the second case with proven Hodgkin's disease, post-treatment examination showed a positive PET lesion in the mediastinal residual mass, which was interpreted as viable lymphoma. However, histologic examination revealed that it was an eosinophilic granuloma.

MR perfusion measurement of contrast uptaking lesions: consideration of T2* shortening due to interstitial contrast agent

AIM

In MR perfusion measurements of contrast uptaking lesions, time intensity curves are hampered by T 1 shortening as well as by the change of T 2 * due to interstitial contrast material (CM). Using double echo sequences, the influence of T 1 can be mathematically eliminated. For correction of the T 2 * influence an empirical algorithm using time-intensity-curves exclusively measured in the suspected lesion is proposed.

METHODS

The interstitial CM concentration is assumed to be proportional to the change of the intensity for T E = 0 or to the change of the relaxation rate DeltaR 1 respectively. The intravascular CM concentration is estimated from DeltaR 2 *. It is adjusted to zero for a time point sufficiently late after the bolus injection by subtraction of the interstitial concentration. This method was applied to double echo FLASH measurements on 15 pharyngeal tumors.

RESULTS

The proposed correction transforms the time dependence of the estimated intravascular CM concentration into a plausible course.

CONCLUSION

Double echo perfusion measurements can be corrected for the interstitial CM induced T 2 * shortening without additional measurements with proneness to errors. This does not necessarily improve the diagnostic value, since possibly "implied multivariate aspects" of uncorrected parameters (here: contrast uptake of the lesion is related to tumor neoangiogenesis as well) are eliminated.

Prognostic value of positron emission tomography in the evaluation of post-treatment residual mass in patients with Hodgkin's disease and non-Hodgkin's lymphoma

The prognostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the assessment of post-treatment residual masses in patients with Hodgkin's disease (HD) or non-Hodgkin's lymphomas (NHL) was evaluated. We prospectively studied 58 patients with HD (n = 43) or NHL (n = 15) who had post-therapeutic complete remission with residual masses (CRu) indicated by computerized tomography. Analysis of 62 residual locations by FDG-PET was performed separately for HD and NHL. Patients with a PET-positive residual mass [standardized uptake value (SUV) > 3] had a recurrence rate of 62.5% (5/8 patients), whereas patients with PET-negative residual mass (SUV < or =3.0) showed a recurrence rate of 4% (2/50 patients, P = 0.004). A positive FDG-PET study correlated with a significantly poorer progression-free survival (P < 0.00001). No recurrence occurred in any of the 39 HD patients with a negative PET scan (negative predictive value, 100%). Four out of four NHL patients with a positive PET study relapsed (positive predictive value, 100%). In conclusion, FDG-PET is a suitable non-invasive method with a high degree of accuracy in the prediction of early recurrence in lymphoma patients with CRu.

[Secondary high-grade MALT lymphoma of the stomach in a 69-year-old patient with gastrocolic fistula]

A 69-year-old man was referred to our department with an exorbitant foetor ex ore, dysphagia and dyspepsia. Upper endoscopy had been performed prior by an outpatient gastroenterologist and the patient had received an eradication therapy for a Helicobacter pylori-induced gastritis. At admission upper endoscopy showed a gastric ulcer which drained a stinking fluid. Endosonography, computed tomography and an upper gastrointestinal series with water soluble media revealed a gastrocolic fistula. Multiple biopsies showed a low-grade gastric MALT lymphoma. Therefore, a surgical reconstruction with Roux-en-Y esophagojejunostomy and transverso-descendostomy was performed. The histology of the completely removed stomach revealed a high-grade Non Hodgkin Lymphoma (NHL) with parts of a low-grade NHL. 3 weeks after surgery chemotherapy was started with the CHOP-regime which was well-tolerated by the patient.

[Comparative study of sagittal and coronal MRI of histological disk and temporomandibular joint specimen for examining an identity of anterior disk dislocation and anterior capsular connective tissue]

PROBLEM

Anterior dislocation of the articular disk of the temporomandibular joint (TMJ) found by MRI tomography often presents a problem. It may persist in MRI despite improvement of articular symptoms and even be found in healthy persons free of any symptoms. Can this be explained by the similarity in structure of the anterior connective tissue of the disk and capsule and their pathological changes? Is a second coronal plane required for MRI investigation?

MATERIAL AND METHODS

The preauricular regions of 72 patients of the TMJ clinic were examined by oblique-sagittal and oblique-coronal MRI. A Siemens-Vision MRI was used. It was also possible to prepare 10 articular disks of the TMJ with anterior capsular tissue as well as 20 complete TMJs of adults from autopsy material. Sagittal, transversal, and horizontal serial sections were examined histologically.

RESULTS

In 49 of the 72 cases examined, an anterior dislocation without reduction found in the sagittal MRI was not confirmed in the oblique-coronal MRI. In the sagittal MRI it was possible to differentiate three, in the coronal MRI six typical forms of magnetic resonance signals, which are represented in figures. They are compared with anatomical and histological connective tissue findings adjacent to the TMJ. The structural similarity of the disk and anterior capsular tissue of the TMJ is demonstrated. The close connection of the disk and connective tissue surrounding the TMJ makes differentiation of MRI findings difficult especially following regressive and adaptive reactions.

CONCLUSIONS

In MRI, anterior capsular tissue is able to simulate dislocation of the disk. Pathological tissue reactions may alter the MRI signal and lead to the wrong diagnosis of dislocation of the disk. Diagnosis of an anterior disk dislocation cannot be established solely on the basis of oblique-sagittal MRI findings.

Diabetes insipidus in a patient with a highly malignant B-cell lymphoma and stomatitis

A 37-year-old male patient with a diffuse pleomorphic B-cell-lymphoma, which has been diagnosed two month earlier with the primary site at the pterygopalatine fossa on both sides with infiltration of the clivus and cavernous sinus was referred to our hospital for continuation of the third course of CHOP chemotherapy. At admission he reported about a recent history of painful swallowing and intermittent substernal chest pain. Alleviation of the pain on swallowing and the chest pain was apparently only possible by drinking 10 to 15 l of cold coca cola throughout the day and night, a regimen that resulted in polyuria. Physical examination revealed extensive thrush stomatitis and soor esophagitis. Despite successful treatment with fluconazole, polydipsia continued unabated. The classic osmotic test of dehydration and exogenous vasopressin revealed hypothalamic diabetes insipidus (DI). Basal hormones and stimulated endocrine function tests of the adenohypophysis were found to be normal. MRI-scan revealed lymphoma infiltration of the neurohypophysis. After the third course of CHOP chemotherapy the patient surprisingly recovered completely from his excessive thirst. The present report shows that clinical disorders such as thrush stomatitis can mask diabetes insipidus caused by an early relapsing lymphoma.

The value of coronal computer tomograms in fractures of the mandibular condylar process

OBJECTIVE

A prospective investigation designed to compare the diagnostic accuracy of conventional panoramic and posteroanterior mandibular radiographs with that of coronal computed tomography scans in cases of fracture of the mandibular condylar process was conducted.

STUDY DESIGN

In all, 182 patients with a total of 249 fractures (some unilateral and some bilateral) of the mandibular condyle received conventional radiographs and coronal computed tomography scans as diagnostic procedures. The ability of these procedures to detect and correctly classify these fractures was determined, and their importance for therapeutic decision-making is described.

RESULTS

All clinically identified fractures were detected by means of both conventional and computed tomography imaging. However, only computed tomography scanning could correctly classify high condylar neck fractures.

CONCLUSIONS

Especially in cases of high condylar neck fracture, coronal computed tomography scans were more useful than conventional radiographs in the determination of type of condylar fracture so that a correct treatment decision could be made.