Laurence A. Mack

Repairs of the rotator cuff. Correlation of functional results with integrity of the cuff.

We evaluated the results of 105 operative repairs of tears of the rotator cuff of the shoulder in eighty-nine patients at an average of five years postoperatively. We correlated the functional result with the integrity of the cuff, as determined by ultrasonography. Eighty per cent of the repairs of a tear involving only the supraspinatus tendon were intact at the time of the most recent follow-up, while more than 50 per cent of the repairs of a tear involving more than the supraspinatus tendon had a recurrent defect. Older patients and patients in whom a larger tear had been repaired had a greater prevalence of recurrent defects. At the time of the most recent follow-up, most of the patients were more comfortable and were satisfied with the result of the repair, even when they had sonographic evidence of a recurrent defect. The shoulders in which the repaired cuff was intact at the time of follow-up had better function during activities of daily living and a better range of active flexion (129 +/- 20 degrees compared with 71 +/- 41 degrees) compared with the shoulders that had a large recurrent defect. Similar correlations were noted for the range of active external and internal rotation and for strength of flexion, abduction, and internal rotation. In the shoulders in which the cuff was not intact, the degree of functional loss was related to the size of the recurrent defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Distinguishing normal from abnormal gestational sac growth in early pregnancy.

In order to evaluate normal and abnormal gestational sac development, serial sonograms were performed in 83 women whose initial sonogram demonstrated a gestational sac lacking a detectable embryo. Of 53 normal gestations, the mean sac growth was 1.13 mm/day (range, 0.71‐1.75). In comparison, of 30 abnormal gestations, 24 demonstrated sac growth, and of these, the mean growth was 0.70 mm/day (range, 0.14‐1.71). Based on these observations, we suggest that gestational sac growth of less than or equal to 0.6 mm/day is evidence for abnormal development. Analysis of the initial and follow‐up scans for the 53 normal gestations showed that a living embryo was always detected when the mean gestational sac was greater than 25 mm in average diameter, and a yolk sac was always seen when the mean sac diameter was greater than 20 mm. In comparison, of 30 abnormal gestations, six were greater than 25 mm without a detectable embryo, and four were greater than 20 mm without a yolk sac. Recommendations for the optimal time of a follow‐up sonogram are presented based on the initial sac size.

Chromosomal abnormalities in fetuses with omphalocele. Significance of omphalocele contents.

Twenty‐six consecutive fetuses with a sonographically detectable omphalocele and known karyotype were reviewed to identify risk factors that might be associated with chromosomal abnormalities. Risk factors that were analyzed included contents of the omphalocele sac, maternal age, fetal sex, sonographically detectable concurrent anomalies, and any major concurrent anomaly. Chromosomal abnormalities were found in 10 cases (38%) from trisomy 18 (n = 4), trisomy 13 (n = 4), trisomy 21 (n = 1), or 45, X (n = 1). The absence of liver from the omphalocele sac (intracorporeal liver) was strongly associated with an abnormal karyotype; chromosomal abnormalities were present in all 8 fetuses with an intracorporeal liver compared to 2 of 18 fetuses with an extracorporeal liver (p less than .0001, two‐tailed Fisher exact test). Other risk factors that were statistically associated with chromosomal abnormalities included advanced maternal age (greater than or equal to 33 years, p = .03) and sonographically detectable concurrent malformations (p = .05). We conclude that sonographic findings can help determine the relative risk of chromosomal abnormalities in fetuses with omphalocele; abnormal karyotypes were significantly associated with the absence of liver from the omphalocele sac and sonographically detectable concurrent malformations in this series. Sonographers should also be aware that omphaloceles that contain bowel alone tend to be small and can be missed or mistaken for other abdominal wall defects (gastroschisis or umbilical hernia).

Three-dimensional ultrasonic angiography using power-mode Doppler

To visualize the vascular anatomy of parenchymal organs, we have developed a system for producing three-dimensional ultrasonic angiograms (3D USA) from a series of two-dimensional power-mode Doppler ultrasound (PDU) scans. PDU scans were acquired using a commercial scanner and image-registration hardware. Two-dimensional images were digitized, and specially designed software reconstructed 3D volumes and displayed volume-rendered images. The geometric accuracy of our system was assessed by scanning a flow phantom constructed from tubing. The system was tested on patients by scanning native and transplanted kidneys, and placentas. Three-dimensional images of the phantoms depicted the spatial relationships between flow within the tubing segments and contained less than 1 mm of geometric distortion. Three-dimensional images of the kidney and placenta demonstrated that spatial relationships between vasculature structures could be visualized with 3D USA. Applications of this new technique include analysis of vascular anatomy and the potential assessment of organ perfusion.

Long-bone growth in fetuses with Down syndrome

Short stature is a well-recognized component of Down syndrome. The femur lengths of affected fetuses have been observed to be shorter than normal, with a ratio of actual to expected femur length of less than 0.91 indicating a high risk of trisomy. To further evaluate this finding we have determined the relationship between limb lengths and gestational age in 37 postmortem fetal specimens with trisomy 21. Control values were obtained from 174 normal fetuses. Measurements of the femur, tibia, fibula, humerus, radius, and ulna were made from roentgenograms or by direct measurement of the bone. Most measurements for each bone of the affected fetuses fell below the normal regression line for that bone, but only 3/37 femurs, 4/32 tibias, 5/32 fibulas, 9/32 humeri, 10/32 radii, and 7/32 ulnas fell more than 2 SDs below the mean. The ratios of actual to expected femur lengths were computed and six fetuses with Down syndrome (16.2%) had ratios less than 0.91. The bones of the extremities of fetuses with trisomy 21 are shorter than normal, but the differences are relatively small. The ratio of actual/expected femur lengths was a less efficient predictor of Down syndrome than were either maternal age or maternal serum alpha-fetoprotein tests. The upper extremity bones were shorter than normal more often than were the bones of the lower extremity, and this finding should be explored further in a prospective study.

Testicular Carcinoma in a Patient with Previously Demonstrated Testicular Microlithiasis

A 21-year-old man initially presented with a history of bilateral testicular pain and hematospermia. Ultrasound revealed a normal right testis and multiple echogenic foci throughout the left testis consistent with testicular microlithiasis (part A of figure). No focal masses were identified sonographically. Symptoms resolved after treatment for epididymitis. Three years later the patient presented to the emergency department because of increasing back pain. Computerized tomography of the retroperitoneum revealed multiple pulmonary nodules and lymphadenopathy. Ultrasound demonstrated multifocal solid left testicular masses i n addition to testicular microlithiasis (part B of figure). The right testis was sonographically normal. Testicular microlithiasis, and mixed embryonal cell carcinoma and seminoma of the left testis were noted on pathological examination.

Low grade gliomas: comparison of intraoperative ultrasound characteristics with preoperative imaging studies

Thirty-three patients with low grade gliomas were evaluated with preoperative computed tomography (CT), magnetic resonance (MR) and intraoperative ultrasound (IOUS). Six patients had undergone previous surgical exploration. Tumor borders were marked with cortical letters and corresponding depths calculated. Resection of tumor corresponded to these ultrasound dimensions. The histology of biopsy specimens from tumor and ultrasound determined margins was studied on formalin fixed permanent sections using hematoxylin and eosin (H&E) and immunocytochemistry (GFAP).Tumors were all seen on preoperative MR studies and most commonly showed a decreased T1 and increased T2 signal. Seven tumors showed variable enhancement with gadolinium. On CT two tumors were not seen, twenty-three tumors were hypodense and eight hyperdense. Three tumors showed variable CT contrast enhancement. All tumors were hyperechoic on ultrasound. Twenty-five (75%) tumors were well defined with distinct margins compared to adjacent brain. Eight tumors had poorly defined borders on ultrasound; five (62%) of these lesions had previously undergone surgeery. Eight tumors invaded functional brain identified by stimulation mapping techniques (e.g., speech cortex), thus limiting the resection. Five resections were limited because of involvement of important anatomical structures (e.g., corpus callosum). Of the remaining 20 tumors, seventeen (85%) had ultrasound defined margins that were histologically free of solid tumor (normal brain or sparse atypical cells only).Low grade gliomas are readily identified and their margins well defined by intraoperative ultrasound regardless of preoperative imaging patterns. The results suggest that IOUS may enhance intraoperative delineation and extent of resection for low grade gliomas.

Fetal bowel. Normal sonographic findings.

The normal sonographic appearance of fetal colon and small bowel is reported in a prospective study of 130 fetuses. The colon, which appeared as a continuous tubular structure located around the perimeter of the abdominal cavity, was seen in some fetuses as early as 22 menstrual weeks and in all fetuses examined after 28 weeks. Colon diameter demonstrated a linear relation (r = 0.82) with menstrual age, reaching a maximum of 18 mm at term. In comparison, small bowel was located centrally and individual segments never exceeded 7 mm in diameter or 15 mm in length. Small bowel loops were seen in only 30% of fetuses examined after 34 weeks. Peristalsis was routinely demonstrated of the small bowel, but was not observed in the colon.

Diagnosis of Inflammatory Bowel Disease with Ultrasound: An In Vitro Study

Transabdominal ultrasound is frequently used to detect complications of inflammatory bowel disease. It has been proposed that ultrasound can distinguish between ulcerative colitis and Crohns disease based on the degree of thickening and changes in the layered structure of the intestine. The authors evaluated the ability of ultrasound to distinguish between ulcerative colitis, Crohns colitis, and normal colon by blindly comparing images made of resected colon specimens. The histologic interpretation of precisely the same area of tissue that was imaged was compared with the blinded image interpretation. Images from all 18 colitis specimens were correctly interpreted as being abnormal because of increased submucosal and overall wall thickness. Published ultrasound criteria for distinguishing between Crohns disease and ulcerative colitis based on overall wall thickness and indistinctness of layers were inaccurate in 4 of 15 specimens and indeterminate in 3 cases. Ultrasound appears to be accurate in distinguishing normal from inflamed colon, but ultrasound findings alone should not be used to determine the cause of bowel inflammation.

The Dandy-Walker malformation prenatal sonographic diagnosis and its clinical significance.

To determine the usual sonographic findings and clinical significance of the Dandy‐Walker malformation (DWM) identified in utero, we reviewed seven proven cases diagnosed by prenatal ultrasound during a 6‐year period. All patients demonstrated complete or partial absence of the cerebellar vermis and a posterior fossa cyst. Other central nervous system (CNS) findings included hydrocephalus (five cases) and agenesis of the corpus callosum (one case). Extra‐CNS abnormalities were prospectively identified in 3 of 4 fetuses with multiple anomalies. Chromosomal analysis was performed on all four fetuses with multiple extra‐CNS anomalies, yielding 2 abnormal karyotypes (trisomy 18 and mosaic trisomy 13). Fetal mortality was directly dependent on the presence of extra‐CNS anomalies. Five fetuses ultimately died, including all four with multiple extra‐CNS anomalies. The remaining two patients are alive at 1.5 and 6 years of age. We conclude that DWM has a distinctive sonographic appearance that can be identified by prenatal ultrasound and that identification of DWM should initiate a careful search for concurrent anomalies as well as consideration of chromosomal analysis.