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Biomedical subjects

J Diehl

Publications and source records attributed to J Diehl.

At least 55 records · Page 3Linked to original sources
PubMed1984

Progressive multifocal leukoencephalopathy in a renal transplant recipient. Increased diagnostic sensitivity of computed tomographic scanning by double-dose contrast with delayed films.

A progressive, deteriorating neurologic disorder developed in a 28-year-old white man 10 years after he successfully received a living related donor kidney transplant. An extensive neurologic evaluation was unrevealing, including normal results of computed tomographic scanning of the brain with and without contrast medium. Repeated computed tomographic scanning after a double dose of radiocontrast medium in conjunction with delayed imaging revealed multiple areas of abnormal enhancement. This technique helped to direct brain biopsy, which led to the early diagnosis of progressive multifocal leukoencephalopathy and the institution of specific therapy.

Adult↗
PubMed1984

Digital tomosynthesis: technique modifications and clinical applications for neurovascular anatomy.

Digital tomosynthesis studies (DTS) using a linear tomographic motion can provide good quality clinical images when combined with subtraction angiotomography. By modifying our hardware system and the computer software algorithms, we were able to reconstruct tomosynthesis images using an isocentric rotation (IR) motion. Since this is the motion used by C-arm and U-arm angiographic units, these modifications allow for the use of DTS studies in most modern angiographic suites at a reasonable cost. Applying a combination of linear tomographic and IR techniques in clinical cases, we performed DTS studies in six patients, five with aneurysms and one with a hypervascular tumor. The results showed detailed definitions of the pathologic entities and the regional neurovascular anatomy. Based on this early experience, DTS would seem to be a useful technique for the preoperative surgical planning of vascular abnormalities.

Brain Neoplasms↗
PubMed1983

Subtemporal decompressions for shunt-dependent ventricles: mechanism of action.

The literature suggests that subtemporal decompression is an effective treatment for the syndrome of shunt-dependent ventricles because it allows the ventricle to enlarge around the shunt catheter tip. Pre- and post craniectomy ventricular areas were measured from computed tomography scans with a computer digitizing technique in three patients with this syndrome who had undergone four surgical procedures. All patients improved symptomatically following craniectomy. A significant decrease in total ventricular area was noted in all instances. The results suggest that subtemporal craniectomy causes the ventricles to become smaller, not larger. Other possible explanations for the effectiveness of the procedure are discussed.

Cerebrospinal Fluid Shunts↗
PubMed1983

Successful treatment of primary central nervous system lymphomas with chemotherapy after osmotic blood-brain barrier opening.

Three patients with primary central nervous system (CNS) lymphoma have had major tumor regression with multiagent chemotherapy given in association with reversible blood-brain barrier opening used to enhance drug delivery to the tumor. In addition, in one patient barrier modification was carried out in the posterior fossa by mannitol infusion into the vertebral artery without untoward effects, an approach not heretofore accomplished. Computed tomographic (CT) studies documented that discontinuation of steroids rapidly effected an increase in the delivery of contrast agent to the tumor. CT monitoring of the degree of barrier modification showed tumor nodules and tumor size not apparent on the control scans, thereby providing additional evidence of the existence of a blood-brain barrier in CNS tumors. These studies further show that drug (contrast) delivery to the tumor, as well as to the surrounding barrier, is enhanced after reversible blood-brain barrier modification. Finally, chemotherapy administered by this approach resulted in defined, objective tumor responses in these three patients.

Adult↗
PubMed1982

Computed tomographic assessment of squamous cell carcinoma of oral and pharyngeal cavities.

Computed tomographic (CT) scans were prospectively obtained on 68 patients with previously untreated stages III and IV squamous cell carcinoma of the oral and pharyngeal cavity. We report herein the results of CT evaluation of primary disease arising in these sites, improvements in contrast-enhancement techniques, and CT assessment of the patient's condition after radiation or chemotherapy treatment.

Biopsy↗
PubMed1981

Computerized axial tomography with air contrast of the cerebellopontine angle and internal auditory canal.

The introduction of computerized axial tomography (C.T.) in 1973 completely changed the diagnostic evaluation of acoustic neuromas. Seventy to eighty percent of all acoustic neuromas can be diagnosed with intravenous enhanced C.T. scan. Acoustic tumors with a diameter of less than 1.5 cm, however, are not consistently seen on C.T. scan. Twenty-six consecutive patients were evaluated by C.T. scan with air contrast posterior fossa myelography (C.T. air cisternography). Nineteen studies were normal, with complete air filling of the internal auditory canal. Surgically verified acoustic neuromas were demonstrated in four patients. Two studies were inconclusive and there was one false positive. Other than headaches, there is no morbidity associated with this technique. C.T. air cisternography should be considered as the definitive study for evaluating patients for acoustic neuromas who have normal intravenous contrast enhanced C.T. scans. This study reports the first intracanalicular tumor diagnosed with this technique.

Adult↗
PubMed1981

Osmotic blood-brain barrier disruption in the posterior fossa of the dog.

Transient reversible osmotic blood-brain barrier disruption was produced in the posterior fossa of 33 dogs. A percutaneous catheter technique was used for the infusion of hypertonic mannitol into the vertebral artery. Neither the catheter technique nor the osmotic barrier modification resulted in interference with brain-stem function in most animals. The degree of barrier modification achieved by osmotic disruption in the posterior fossa is similar to that previously described for barrier modification of the supratentorial parenchyma. Methotrexate delivered to the brain via the vertebral artery resulted in a drug concentration of 100 to 300 ng/gm brain tissue. When the same amount of drug was given following osmotic blood-brain barrier disruption, brain tissue contained 1100 to 5000 ng of methotrexate/gm of brain tissue. Finally, the adequacy of the blood-brain barrier modification in the posterior fossa was shown to be quantifiable by the amount of enhancement on computerized tomographic scans.

Animals↗
PubMed1980

Unruptured cerebral aneurysms presenting as recurrent transient neurologic deficits.

Recurrent transient neurologic deficits were evaluated clinically in four patients. In three patients, the symptoms included recurrent transient homonymous hemianopia, episodic weakness and numbness of the left arm and leg, and recurrent sudden loss of speech and of strength in the right arm. In these three patients, the episodes were first thought to be transient ischemic attacks (TIAs). A fourth patient had repeated confusional spells, in which a recurrent musical theme excluded other thoughts. This was associated with dizziness and difficulty in naming. A partial complex seizure was thought responsible. In each of the cases the symptoms lasted less than 30 minutes and were not associated with loss of consciousness, headache, or stiff neck. Electroencephalogram (EEG), brain scan, lumbar puncture, and computed tomography (CT) scan were normal. In all patients, cerebral arteriography unexpectedly revealed an unruptured cerebral aneurysm. The locations of the aneurysms were appropriate to the symptoms, which remitted in the three patients treated surgically for the aneurysm. Although the pathophysiology is uncertain, an ischemic process may be implicated.

Adult↗
PubMed1980

Reversible osmotic blood-brain barrier disruption in humans: implications for the chemotherapy of malignant brain tumors.

The blood-brain barrier seems to be an important factor in drug access to malignant brain tumors. Successful experimental reversible disruption of the blood-brain barrier in animals provided the basis for a clinical evaluation of osmotic disruption in five patients with primary and metastatic malignant brain tumors. Good to excellent blood-brain barrier disruption was achieved in four patients with a single nontransient complication, a superficial wound infection at the burr hole site in the first patient. Reversible, transient osmotic barrier disruption was achieved 15 times in five patients without additional toxicity. Computed tomography and radionuclide brain imaging were shown to be useful noninvasive monitors of the adequacy and extent of barrier disruption. These studies also provide further evidence that the barrier is at least partially intact in human tumors because in one patient a metastsis was seen only after barrier disruption.

Adenocarcinoma↗
PubMed1975

Investigation of ureteric function with simultaneous intraureteric pressure recordings and ureteropyelography.

Ureteric function was investigated by simultaneous intraureteric pressure recording (ureterometry) and retrograde ureteropyelography. With a multichannel catheter, intraluminal pressures can be recorded simultaneously at three levels in the ureter. The catheter can also be used to inject contrast medium. In normal antegrade peristalsis, an interval of 0.5-1.5 sec. was observed from the disappearance of the urine bolus to the recording of the maximal contraction pressure. In cases of long-lasting retroperistalsis, the urinary flow was impaired. Combined ureterometry and ureteropyelography appears to be a valuable method for detailed studies of ureteric function.

Adult↗