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Biomedical subjects

M Lemmerling

Publications and source records attributed to M Lemmerling.

At least 37 records · Page 2Linked to original sources
PubMed1999

Non-invasive diagnostic assessment of extensive vertebral artery tortuosity with enlargement of the intervertebral foramen.

Two cases with an incidental finding of a widened intervertebral foramen due to extensive tortuosity of the vertebral artery are presented. Computed tomography angiography and magnetic resonance imaging/magnetic resonance angiography (MRA) both proved to be useful as non-invasive techniques to provide the diagnosis. In-plane saturation is a disadvantage seen with the two-dimensional time-of-flight MRA technique.

Adult↗
PubMed1999

[Methyl-11C]thymidine positron emission tomography in tumoral and non-tumoral cerebral lesions.

BACKGROUND: No ideal radiopharmaceutical exists for positron emission tomography (PET) that fulfills all clinical requirements for the study of brain tumors. PURPOSE: The usefulness of a recently developed PET tracer, [methyl-11C]thymidine ([methyl-11C]TdR) is explored in brain tumors. PATIENTS AND METHODS: Twenty patients with confirmed tumoral and non-tumoral brain lesions were investigated with [methyl-11C] TdR PET. The 11C activity was visually and quantitatively assessed. In two patients, dynamic scans were performed. The PET findings were compared to those of magnetic resonance imaging (MRI) or computed tomography (CT) of the brain and to the final diagnosis. RESULTS: Eight out of ten patients with confirmed tumoral lesions or tumor recurrence had increased 11C activity within the lesion. In ten non-tumoral lesions no increased 11C uptake was found. The dynamic PET studies showed that [methyl-11C] TdR first acts as a blood flow tracer, but that later on the uptake of 11C activity is due to labeled metabolites, crossing the blood-brain barrier. Increased tracer activity was only observed in tumoral and not in non-tumoral contrast-enhanced lesions on MRI or CT. CONCLUSIONS: [Methyl-11C] TdR is not a selective PET radiopharmaceutical for brain tumors, but can be used as a tracer for tumoral blood-brain barrier disruption.

Adolescent↗
PubMed1999

MRI prior to major tumor surgery in the head and neck.

MRI plays an important and specific role prior to tumor surgery in the head and neck region. It is especially interesting in providing a detailed description of the exact tumor extent close to the skull base and to investigate perineural and perivascular tumor spread. In selected cases this technique can give a presumed histopathological diagnosis for a mass that is clinically detected. This is especially true for some benign masses, such as hemangiomas, cysts and lipomas. The role of MRI with regard to a lymph node imaging survey in the neck is rather limited. MRI is moreover not routinely performed in neck regions where many motion artifacts can be expected, such as in the larynx.

Head and Neck Neoplasms↗
PubMed1999

Posttraumatic subdural hygroma: CT findings and differential diagnosis.

Subdural hygroma is a cerebrospinal fluid accumulation in the subdural space. It is an epiphenomenon of head injury. CT is the preferred diagnostic imaging modality. Differential diagnosis has to be made with chronic subdural hematoma, and atrophy with enlargement of the subarachnoid space. As time goes by, subdural hygroma either resolves, or it becomes a chronic subdural hematoma. Neurosurgical evacuation is only required when mass effect creates neurologic symptoms.

Aged↗
PubMed1999

Imaging of the parapharyngeal space.

The parapharyngeal space is a deep space of the neck, always well visible on CT and MR imaging of the head and neck; in normal circumstances, this space should look symmetrical. The parapharyngeal space is often subdivided in compartments; such subdivision is helpful when considering the site of origin of a parapharyngeal space mass. Several concepts of compartmentalization of this space exist, sometimes leading to confusion; not the names but the anatomy is important to know. This manuscript reviews shortly the anatomy of the parapharyngeal space, the use of modern cross-sectional imaging methods in the evaluation of this region, and focuses somewhat more on imaging of primary parapharyngeal lesions.

Adipose Tissue↗
PubMed1999

Postoperative radiotherapy of paranasal sinus tumours: a challenge for intensity modulated radiotherapy.

BACKGROUND AND PURPOSE: Intensity modulated radiotherapy (IMRT) is used in our department for treatment of paranasal sinuses. We describe the methodology that was developed together with the clinical implementation, illustrated by a case report. MATERIAL AND METHODS: Patient history, treatment and short follow-up are described. An IMRT, obtained by superposition of static beam segments was implemented. Electronic portal images, compared to digitally reconstructed radiographs (DRR) were used to evaluate and adjust patient positioning. RESULTS, DISCUSSION AND CONCLUSION: IMRT is an appropriate and feasible treatment technique for head and neck cancer in anatomical regions that are difficult to treat. A high tumour dose can be combined with a good sparing of the surrounding organs at risk (OAR's).

Adenocarcinoma↗
PubMed1999

An undescribed coexistence of a subserosal exophytic gastric leiomyoma with a serous microcystic pancreatic adenoma.

We present the case of a 66-year-old woman with complaints of odynophagia but normal gastro-oesophagoscopic findings. On computed tomographic examination, a presumptive diagnosis of a cystic liver tumor and a microcystic pancreatic adenoma was made. Histopathological examination of the hepatic mass, however, revealed a subserosal exophytic gastric leiomyoma. Considerations to avoid the potential pitfall of diagnosing an exogastric leiomyoma as a liver tumor are emphasized. Moreover, the unique association of an exogastric leiomyoma and a serous microcystic pancreatic adenoma is discussed.

Adenoma↗
PubMed1999

Leptomeningeal metastases from ethmoid sinus adenocarcinoma: clinico-radiological correlation.

A patient with sinonasal adenocarcinoma is presented with leptomeningeal metastases affecting multiple cranial nerves and spinal nerve roots. Head and neck cancer is known to be an extremely rare source for leptomeningeal metastatic spread. The cranial nerves, the spinal cord and roots and the cerebral hemispheres can be affected in case of leptomeningeal metastatic spread. Examination of the CSF is the hallmark of the diagnosis if leptomeningeal metastatic spread is suspected, but this case illustrates that the combination of specific clinical features on one hand and specific lesions on the Gd-enhanced T1-weighted MRI study on the other hand is reliable enough to make a presumed diagnosis if the CSF analysis remains negative. We suggest that in our patient direct leptomeningeal spread occurred through the cribriform plate to the CSF, followed by further spread in a gravity dependent way.

Adenocarcinoma↗
PubMed1998

Ossified retroperitoneal malignant Schwannoma with spinal leptomeningeal metastases.

A malignant retroperitoneal schwannoma in a patient without von Recklinghausen's disease is reported. Ossification in the tumour, shown on CT and MRI in this previously untreated patient is exceptional. MRI demonstration of spinal leptomeningeal metastases supports the hypothesis of haematogenous metastatic spread of systemic malignant tumours to the leptomeningeal spaces.

Female↗
PubMed1998

Schwannoma of the tip of the nose: MRI.

We report a schwannoma with a rare location at the tip of the nose in a 20-year-old woman with an otherwise unremarkable medical history. The imaging findings underline the usefulness of MRI in narrowing down the differential diagnosis of masses in this region. Once the diagnosis was focussed on a neural origin of the mass, the exact nature of the tumour could not be predicted from the MRI, although the presence of a capsule on imaging studies as well as at operation suggested it was probably a schwannoma. A schwannoma must be considered when one encounters a sharply delineated mass at the tip of the nose, showing high signal on T2-weighted images and strongly contrast enhancement.

Adult↗
PubMed1998

Secondary superficial siderosis of the central nervous system in a patient presenting with sensorineural hearing loss.

We present a 50-year-old man who was investigated for sensorineural hearing loss. On MRI of the brain superficial siderosis of the central nervous system was seen, while MRI of the spine revealed an ependymoma of the cauda equina. This case illustrates the importance of performing T2-weighted imaging of the brain and posterior fossa when sensorineural hearing loss is present. Spine imaging is mandatory when superficial siderosis of the brain is diagnosed without identification of a bleeding source in the brain.

Brain↗
PubMed1998

CT of the temporal bone in the CHARGE association.

We reviewed the CT examinations of the temporal bone, performed with 1-mm-thick contiguous sections, of seven patients with the CHARGE association. We found abnormalities of the incus and stapes, with ossicular chain fixation, absence of the stapedius muscle and oval window, hypoplasia or dysplasia of the vestibule and absence of the semicircular canals in all ears. The pyramidal eminence and tympanic sinus were absent and there were anomalies of the cochlea in 13 of 14 ears. Absence of the semicircular canals is the most specific change in patients with the CHARGE association.

Abnormalities, Multiple↗
PubMed1998

Laryngeal embryonal rhabdomyosarcoma in a child: MRI appearance.

We report a rare case of a young girl with an embryonal rhabdomyosarcoma of the right aryepiglottic fold. Local disease recurrence, occurring 7 years after subtotal resection and adjuvant chemotherapy, was studied with plain radiography, CT and MRI. To the best of our knowledge, this is the first report illustrating the MRI characteristics of a laryngeal embryonal rhabdomyosarcoma in a child.

Child↗
PubMed1998

Primary sinonasal mucosal melanoma: three different therapeutic approaches to inoperable local disease or recurrence and a review of the literature.

Sinonasal melanoma is an uncommon disease with a bad prognosis and a high local recurrence rate. The use of radiotherapy in such conditions remains controversial. A review of the literature is presented in an attempt to answer some of the questions regarding therapeutic options. Data on incidence, aetiology, pathology and prognosis are also provided. Case studies are reported of three patients with sinonasal melanoma referred to our department in a relatively short time period and needing radiotherapy as a single treatment modality, using a conformal three-dimensional treatment technique. One patient was also treated with temporary 1251 seeds, while another was treated using intensity modulation. Both intensity modulation and temporary 1251 seeds are feasible techniques, providing satisfactory dose distributions encompassing the tumour volume while sparing critical structures. Surgery remains the treatment of choice for sinonasal melanoma. Radiotherapy should be used postoperatively and is a good alternative in cases of inoperable disease. Adjacent critical structures limit the radiation dose to the tumour area, especially when high fraction doses are used. Therefore, beam intensity modulation and 1251 seeds can be used to increase the tumour dose without exceeding the radiation tolerance of the surrounding structures.

Adult↗
PubMed1998

Otological manifestations of CHARGE association.

The combined findings of abnormalities of the incus and stapes, absence of the oval window, absence of the stapedius muscle (with absent pyramidal eminence and tympanic sinus in most cases), and abnormalities of different parts of the inner ear (dysplastic cochlea, hypoplastic or dysplastic vestibule, and absent semicircular canals) are characteristic of the CHARGE association. Computed tomography and magnetic resonance imaging using 1-mm-thick contiguous slices proved useful in demonstrating the broad spectrum of temporal bone abnormalities in patients with the CHARGE association.

Adolescent↗
PubMed1998

Value of computed tomography of the temporal bone in acute otomastoiditis.

In this study we report our experience with 24 patients with acute mastoiditis treated at the University Hospital in Ghent, Belgium. The most common presenting signs and symptoms of acute mastoiditis were an abnormal tympanic membrane (21/24), otorrhea (17/24) and earache (13/24). Postauricular edema and erythema with protrusion of the ear, often used as a diagnostic criterion, was present in only 3 patients. Demineralisation of the trabeculae was the most frequent radiological finding (13/24). Based on CT findings a distinction was made between two groups: acute incipient mastoiditis (13/24) and acute coalescent mastoiditis (5/24). Thirteen patients recovered with conservative therapy consisting of IV antibiotics and early myringotomy with or without placement of a ventilation tube. Mastoidectomy was required in 11 patients. Nine patients presented with a complication of infection extending beyond the mastoid compartment. The results are discussed and the value of CT scanning as a diagnostic tool and decisive element in the choice of therapy is analysed.

Acute Disease↗
PubMed1997

55Co-PET in stroke: relation to bloodflow, oxygen metabolism and gadolinium-MRI.

BACKGROUND: Several studies have shown the feasibility of Co-isotopes (55Co and 57Co) in imaging of neuronal damage in stroke, multiple sclerosis, cerebral tumors and trauma. These studies indicate that Co-isotopes allow visualization of brain pathology related to inflammatory processes, reactive gliosis and cell death. Until now, it is not clear if 55Co accumulation occurs in the core of infarction or in the penumbra. Therefore, in the present study, we compared 55Co-PET with functional parameters such as cerebral bloodflow (rCBF) using C15O2, oxygen metabolism (rCMRO2) using 15O2 and cerebral bloodvolume (CBV) using C15O in PET and with the anatomical parameter Gd-MRI. PATIENTS AND METHODS: Seventeen patients (11 male; 6 female) age 43 to 84 (mean 69) with middle cerebral artery (mca) stroke, as proven by CT or MRI, were examined with 55Co-PET (0.5-1.0 mCi 55CoCl2), C15O2-, 15O2- and C15O-PET in one session 0-30 days after stroke-onset. Regions of infarction were defined by rCMRO2 being smaller than 65% or rCBF below 45% of the contralateral value and were subsequently superimposed on the cobalt scan. To compare the Cobalt uptake with the Gd-MRI, a realignment program was used that matches the MRI with the bloodflow images. Clinical status was established using the Orgogozo stroke scale at admission and at discharge (at least 6 weeks after admission) and the Barthel index. RESULTS: Eight patients showed a positive Co-PET scan and were used for further analysis. It appeared that Co accumulates in areas with a diminished oxygen metabolism and with a preserved bloodflow. We found Co-uptake in only a part of the Gd enhanced brain tissue with a tendency to be located peripherally or outside the Gd demarcated brain tissue. CONCLUSION: The results of the present study suggest that Co accumulates into infarcted brain tissue with a rather preserved flow independently of blood-brain barrier breakdown.

Adult↗