Three-dimensional intravascular ultrasound imaging of normal and diseased canine and human arteries.

This study reports three-dimensional reconstruction of two-dimensional intravascular ultrasound images obtained along 5 cm vessel segments. Each three-dimensional image was produced by computerized "stacking" of a set of consecutive two-dimensional images (mode 90 images per set; range 32 to 256). Three-dimensional images (n = 26) were obtained from 11 human normal and atherosclerotic arteries (three in vitro and eight in vivo) and five in vivo canine studies. In vivo human examinations included three iliac, one deep, and three superficial femoral arteries and one aortic dissection. Five in vivo canine vessels (three iliac stenoses and two aortic dissections) were imaged before and after intraluminal stent deployment. Images were displayed on a gray-scale monitor, allowing examination of vessel images as complete cylinders or longitudinal hemisections in any user-defined plane. This enabled global examination of vascular segments and identified luminal shape, wall thickness, and distribution and morphology of plaques. Reconstructions of aortic dissections illustrated the extent of the dissection and produced an anatomic picture of the false lumen. Three-dimensional imaging enhanced stent deployment by identifying the site for deployment, dimensions of the vessel lumen, and changes in morphology after stent insertion. There was good correlation in vessel dimensions measured by angiography, two-dimensional intravascular ultrasonography and longitudinal gray-scale reconstructions (r = 0.74 to 0.95; p = 0.34 to 0.001) but poor correlation with measurements from three-dimensional surface-rendered images (r = 0.13 to 0.48; p = 0.42 to 0.87). We conclude that three-dimensional intravascular ultrasound imaging is an innovative new method for identifying the type, extent, and spatial configuration of arterial disease, with promising diagnostic and therapeutic applications.

Sequential intraluminal ultrasound evaluation of balloon angioplasty of an iliac artery lesion.

This report describes intravascular ultrasound imaging of a localized 81% stenosis in the left common iliac artery of a 52-year-old woman. The lesion was dilated using an 8 mm balloon and was imaged pre- and post-dilation using arteriography and a 5F, 30 Mhz intravascular ultrasound catheter. The same site was imaged again intraoperatively at two months following the initial procedure using an 8F, 20 Mhz intravascular ultrasound catheter when the patient had a femoropopliteal bypass for continuing ischemia. Intravascular ultrasound imaging allowed accurate, sequential, on-line calculation of the cross-sectional area and volume of the lesion both, acutely and following healing of the site. The morphology of the fractured arterial plaque was clearly defined, demonstrating distribution of calcification, and intraluminal flaps not apparent on arteriography. The case demonstrates the unique potential of intravascular ultrasound in assessing the immediate effect of interventions and evaluating the long-term healing.

Hyperparathyroid crisis. Successful treatment of ten comatose patients.

Hyperparathyroid crisis is a rare disease manifested by elevated serum calcium, weakness, nausea and vomiting, altered states of consciousness, and elevated circulating parathormone. This hypercalcemic state is noted for a frequently acute presentation and associated high mortality rate, approaching 60% in some series. Ten patients in parathyroid crisis were observed in a consecutive personal series of 325 cases of operatively proved hyperparthyroidism. All 10 patients were successfully treated. Each patient remained or lapsed into persistent coma despite extensive medical management and normalization of serum calcium in some instances. An emergency parathyroidectomy was performed in all cases. Reversal of the comatose state was noted in all patients within 24 hours, followed by gradual normalization of serum calcium. Serum calcium ranged from 15 to 19.6 mg/dl. The blood urea nitrogen level was elevated in six patients. A single adenoma was found in nine patients and multiglandular disease involving the neck and the mediastinum in one. All patients survived. The successful treatment of this disease demands prompt and accurate diagnosis coupled with vigorous medical therapy and emergency parathyroidectomy if the patient's status continues to deteriorate.