Swallowing patterns in human subjects with and without temporomandibular dysfunction.

Recent clinical impressions have suggested that tongue-thrust swallowing may often occur in patients with internal derangement of the temporomandibular joint(s) and may represent an unconscious effort to avoid temporomandibular joint (TMJ) dysfunction by minimizing noxious stimuli from the joints. The purpose of this study, therefore, was to determine the swallowing patterns in human subjects with and without TMJ dysfunction. The swallowing patterns of 25 adult orthodontic patients already known to have TMJ dysfunction and 25 adult control subjects without such dysfunction were examined with the aid of kinesiographic and electromyographic recordings taken while the subjects were sipping water. Analysis of the data revealed that 19 patients with TMJ dysfunction used a tongue-thrust open-jaw swallowing pattern, while only nine control subjects used such a swallowing pattern. Furthermore, six of the patients with TMJ dysfunction had an anterior open bite, while none of the control subjects had an anterior open bite. The results suggest that patients with aberrant swallowing patterns should be examined for temporomandibular joint dysfunction.

Variable patterns of technetium-99m MAA perfusion in the therapeutically embolized liver.

Hepatic perfusion studies using 99mTc macroaggregate albumin (MAA) particles have been utilized to document arterial catheter position and flow distribution in patients who are to undergo hepatic arterial chemotherapy infusion (HAI). We have recently been treating nonresectable hepatic neoplasms with transcatheter hepatic arterial chemoembolization (HAE) followed by HAI. The MAA perfusion studies in these patients show variable patterns. For this reason, we have reviewed our recent experience with 15 patients who underwent 21 HAEs and HAIs. The arteriograms and the MAA perfusion studies were reviewed and correlated. Early (within 4 hr of embolization) perfusion studies revealed flow reversal, or MAA reflux into an undesirable location in 11 cases. Two selected follow-up scans in 24 hr revealed restoration of flow to the embolized lobe, confirming the proper position of the catheter for HAI. Knowledge of both the hepatic arterial anatomy, and of the specific embolization procedure will allow accurate interpretation of the MAA perfusion study. Initial flow reversal, or MAA reflux, should not be interpretated as a malpositioned catheter, but prompt reevaluation after a period of 24 hr to document restoration of antegrade flow is suggested.

Gastrointestinal and pancreatic endocrine tumours.

The radiological diagnosis and interventional management of neuroendocrine tumours of the gastrointestinal tract and pancreas are challenging, demanding the complete gamut of available resources. Carcinoid tumours are most commonly found in the appendix and small bowel. Barium studies usually disclose a small solitary mucosal or submucosal mass in the distal ileum at times associated with smooth muscle hypertrophy and thickening of the mucosal folds. Intussusception and bowel obstruction may be the presenting finding. Mesenteric involvement may evoke a desmoplastic reaction with rigidity, fixation, angulation and tethering of small bowel loops. Angiography may demonstrate a hypervascular primary neoplasm but more frequently reveals vascular encasement and distortion from the mesenteric desmoplastic reaction. Pancreatic islet cell tumour is best defined radiologically by angiography and computed tomography as a well circumscribed hypervascular mass which enhances with contrast material. Portal venous sampling is of considerable assistance in localizing insulinoma. Metastases from neuroendocrine tumours to lymph nodes and to the liver are usually hypervascular. In the evaluation of the liver by CT scanning prior to contrast as well as dynamic scanning during the bolus intravenous injection of contrast material are necessary. At times the precontrast scan is more revealing. Computed tomography with the catheter in the superior mesenteric artery followed by selective hepatic arteriography is the most accurate combination for the detection of hepatic metastases. Interventional radiological management by sequential hepatic arterial embolization is the treatment of choice for multiple hepatic metastases from neuroendocrine tumours. Thus far, the maximum number of embolic episodes in a single patient has been 13. The carcinoid syndrome has been controlled in 87% while 79% of islet cell tumour hepatic metastases have responded. Contraindications to HAE includes a combination of all of the following: (i) replacement of more than 50% of the liver by tumour, (ii) serum lactic dehydrogenase above 425 mU/ml, (iii) serum glutamic oxaloacetic transaminase above 100 mU/ml, and (iv) bilirubin above 2 mg/dl. In the face of occlusion of the portal vein by intravascular neoplasm, HAE is contraindicated only if portal flow through collateral vein is away from the liver.

Metastatic adnexal trophoblastic neoplasm: contribution of MR imaging.

We report a case of pathologically proven metastatic trophoblastic neoplasm involving the adnexa which occurred after dilatation and curettage and chemotherapy. Duplex doppler ultrasound demonstrated increased vascularity in the adnexa. Angiography was sensitive but did not decisively distinguish between tumor in the adnexa and arteriovenous fistula in the uterus. In addition to abnormal vascularity, magnetic resonance also showed foci of abnormal signal in the adnexa not seen in the uterus and correctly suggested the presence of tumor.

MR imaging of traumatic spinal arachnoid cyst.

We report a case of post-traumatic lumbar arachnoid cyst, which enlarged the spinal canal and eroded the posterior elements. Computed tomographic myelography and magnetic resonance (MR) were complementary, and both correctly characterized the cystic nature of the lesion. Communication between the cyst and the subarachnoid space was demonstrated on CT myelography, which also clearly showed bone changes in the spinal canal. Continuity of the cyst with the spinal subarachnoid space was seen clearly on sagittal MR, and the MR signal characteristics of the cyst were identical with CSF.

Correlation of radionuclide and ultrasound studies with biopsy findings for diagnosis of renal transplant rejection.

The diagnosis of early renal transplant rejection is of the utmost importance to the transplant recipient. Unfortunately, such a diagnosis is often extremely difficult to make. In an attempt to clarify this issue we retrospectively evaluated 35 patients with the presenting diagnosis of rejection for the correlation of comparable radionuclide (RN) and ultrasound (US) examinations with biopsy findings. In 21 patients with heavy interstitial mononuclear cell infiltration, 22 of 23 serial RN studies within forty-eight hours of biopsy were positive for rejection. Only 3 of 14 comparable US studies were positive for rejection. When examinations performed within approximately fourteen days were evaluated, 7 of 11 RN studies were positive for rejection, while 2 of 9 comparable US studies were positive for rejection. However, in 14 patients with mild or no interstitial cellular infiltration, only 6 of 13 RN studies were positive, while all 4 US examinations were negative. In the group evaluated at approximately two weeks, 2 of 6 RN studies were positive, while 0 of 5 US studies were positive. We conclude that the serial RN study is more sensitive than US examination for the diagnosis of acute rejection. US, however, proved valuable in the identification of transplant complications (i.e., fluid collections, ascites, and hydronephrosis).

Real-time ultrasonic scanning in sheep: the results of the first year of its application on farms in south-west Scotland.

After a two-day period of instruction in the use of a linear real-time ultrasonic scanning machine the results obtained by three operators scanning a variety of types of ewe under different conditions were recorded and compared with the actual lambing results. In the first season an overall accuracy of 95 per cent was achieved for the diagnosis of barren ewes and ewes carrying either one or two or more lambs. However, monitoring the accuracy achieved for the diagnosis of zero, one, two, three or four lambs demonstrated an improvement in expertise with time, the accuracy increasing from below 70 per cent to over 90 per cent. A particular improvement was observed after a comparative session with an experienced operator. Analysis of the figures of accuracy for zero, one, two, three and four lambs highlighted the differences between operators which were less evident if only the results for zero, one or two or more lambs were analysed. These analyses showed that 'newly trained' operators were not at first able to scan successfully. However, after a period of acquaintance with the technique (approximately 500 ewes) and an 'appraisal session' with an expert the accuracy of the operators improved sufficiently to be of commercial value to hill flocks and possibly to low-ground flocks with limited housing.

Guided cyst puncture and aspiration.

With the widespread acceptance of ultrasonography and computed tomography for the evaluation of renal masses, the role of guided renal cyst puncture in the evaluation of a suspected renal cyst has undergone revision in recent years. In this article, the authors review the technique, interpretation, and complications of diagnostic cyst puncture and attempt to define its current diagnostic and therapeutic indications.

Bladder injury in blunt pelvic trauma.

Clinical and radiologic findings in 97 patients with bladder injury secondary to blunt pelvic trauma were reviewed. Fifty-five patients had extraperitoneal bladder rupture; 35, intraperitoneal rupture; two, interstitial bladder injury; and five, combined intraperitoneal and extraperitoneal bladder rupture. Of the 61 of 97 patients with film studies available for review, two patients with surgically proved intraperitoneal rupture had false-negative cystograms. In two other cases of intraperitoneal rupture, the diagnosis was established with cystography but was not demonstrated with urography. All cases of extraperitoneal rupture were demonstrated cystographically; in 15 cases in this group, the injury was complex, with extravasation of contrast material beyond the confines of the perivesical space. In two additional patients, incomplete bladder injury termed "interstitial bladder rupture" was identified. A classification of bladder injury based on cystographic patterns of extravasation is proposed.

Retroaortic left renal vein: an interpretive pitfall on computed tomography.

In a patient with retroaortic left renal vein, the anomalous vessel is demonstrated by computed tomography to take a caudal course of several centimeters before crossing in a retroaortic fashion to join with the inferior vena cava. This case differs from previously published reports. Computed tomography provided excellent anatomic details of the vascular anomaly and highlighted the value of postcontrast dynamic computed tomography scanning.

CT diagnosis of fluid in lesser sac mimicking thrombosis of inferior vena cava.

A patient with ascites and fluid in the lesser sac mimicking the appearance of a clot in the inferior vena cava is described. A knowledge of liver anatomy, particularly the lesser sac in the region of porta hepatis, aids in avoiding this CT pitfall.

Attenuation of millimeter wavelength radiation by gaseous water.

A theoretical computation and absorption by water vapor of radiation within the millimeter and submillimeter region of the electromagnetic spectrum permits the determination of attenuation coefficients for given vapor densities, pressures, and temperatures. The rigid asymmetrical top rotor approximation for all angular momentum quantum numbers J

Focal properties of a plane grating in a convergent beam.

Focusing from a plane grating can be accomplished by using convergent radiation incident on the grating in such a manner that any incident angle alpha(n), the resulting diffraction angle beta(n), will be on the same side of the grating normal. The theory for the focal properties is developed by applying Fermat's principle of least time to selected terms resulting from a finite series expansion of the system's distance function. Derivations are given for finding the focal curve equation, astigmatism, and coma, of the most usable configuration of the optical components. Discussions of the aberrations disclose methods for eliminating the astigmatism and reducing the coma.