Browsing by Author "Hameed, Tariq A."

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    Nephrocalcinosis in Calcium Stone Formers Who Do Not Have Systemic Disease
    (Elsevier, 2015-11) Bhojani, Naeem; Paonessa, Jessica E.; Hameed, Tariq A.; Worcester, Elaine M.; Evan, Andrew P.; Coe, Fredric L.; Borofsky, Michael S.; Lingeman, James E.; Department of Urology, IU School of Medicine
    Purpose Nephrocalcinosis is commonly present in primary hyperparathyroidism, distal renal tubular acidosis and medullary sponge kidney disease. To our knowledge it has not been studied in patients with calcium phosphate stones who do not have systemic disease. Materials and Methods We studied patients undergoing percutaneous nephrolithotomy who had calcium phosphate or calcium oxalate stones and did not have hyperparathyroidism, distal renal tubular acidosis or medullary sponge kidney disease. On postoperative day 1 all patients underwent noncontrast computerized tomography. If there were no residual calcifications, the patient was categorized as not having nephrocalcinosis. If there were residual calcifications, the patient underwent secondary percutaneous nephrolithotomy. If the calcifications were found to be stones, the patient was categorized as not having nephrocalcinosis. If the calcifications were not stones, the patient was categorized as having nephrocalcinosis. Patients were grouped based on the type of stones that formed, including hydroxyapatite, brushite and idiopathic calcium oxalate. The extent of nephrocalcinosis was quantified as 0—absent nephrocalcinosis to 3—extensive nephrocalcinosis. Patients with residual calcifications on postoperative day 1 noncontrast computerized tomography who did not undergo secondary percutaneous nephrolithotomy were excluded from analysis. The presence or absence of nephrocalcinosis was correlated with metabolic studies. Results A total of 67 patients were studied, including 14 with hydroxyapatite, 19 with brushite and 34 with idiopathic calcium oxalate calculi. Nephrocalcinosis was present in 10 of 14 (71.4%), 11 of 19 (57.9%) and 6 of 34 patients (17.6%) in the hydroxyapatite, brushite and idiopathic calcium oxalate groups, respectively (chi-square p = 0.01). The mean extent of nephrocalcinosis per group was 1.98, 1.32 and 0.18 for hydroxyapatite, brushite and idiopathic calcium oxalate, respectively (p ≤0.001). The presence of nephrocalcinosis positively correlated with urine calcium excretion (mean ± SD 287.39 ± 112.49 vs 223.68 ± 100.67 mg per day, p = 0.03). Conclusions Patients without systemic disease who form hydroxyapatite and brushite stones commonly have coexistent nephrocalcinosis. Nephrocalcinosis can occur in calcium oxalate stone formers but the quantity and frequency of nephrocalcinosis in this group are dramatically less.
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    Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse
    (Massachusetts Medical Society, 2022) Sorensen, Mathew D.; Harper, Jonathan D.; Borofsky, Michael S.; Hameed, Tariq A.; Smoot, Kimberly J.; Burke, Barbara H.; Levchak, Branda J.; Williams, James C., Jr.; Bailey, Michael R.; Liu, Ziyue; Lingeman, James E.; Radiology and Imaging Sciences, School of Medicine
    Background: The benefits of removing small (≤6 mm), asymptomatic kidney stones endoscopically is unknown. Current guidelines leave such decisions to the urologist and the patient. A prospective study involving older, nonendoscopic technology and some retrospective studies favor observation. However, published data indicate that about half of small renal stones left in place at the time that larger stones were removed caused other symptomatic events within 5 years after surgery. Methods: We conducted a multicenter, randomized, controlled trial in which, during the endoscopic removal of ureteral or contralateral kidney stones, remaining small, asymptomatic stones were removed in 38 patients (treatment group) and were not removed in 35 patients (control group). The primary outcome was relapse as measured by future emergency department visits, surgeries, or growth of secondary stones. Results: After a mean follow-up of 4.2 years, the treatment group had a longer time to relapse than the control group (P<0.001 by log-rank test). The restricted mean (±SE) time to relapse was 75% longer in the treatment group than in the control group (1631.6±72.8 days vs. 934.2±121.8 days). The risk of relapse was 82% lower in the treatment group than the control group (hazard ratio, 0.18; 95% confidence interval, 0.07 to 0.44), with 16% of patients in the treatment group having a relapse as compared with 63% of those in the control group. Treatment added a median of 25.6 minutes (interquartile range, 18.5 to 35.2) to the surgery time. Five patients in the treatment group and four in the control group had emergency department visits within 2 weeks after surgery. Eight patients in the treatment group and 10 in the control group reported passing kidney stones. Conclusions: The removal of small, asymptomatic kidney stones during surgery to remove ureteral or contralateral kidney stones resulted in a lower incidence of relapse than nonremoval and in a similar number of emergency department visits related to the surgery.
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    Sensitivity of Non-Contrast Computed Tomography for Small Renal Calculi with Endoscopy as the Gold Standard
    (Elsevier, 2018) Bhojani, Naeem; Paonessa, Jessica E.; El Tayeb, Marawan M.; Williams, James C.; Hameed, Tariq A.; Lingeman, James E.; Urology, School of Medicine
    Objectives To compare the sensitivity of non-contrast CT to endoscopy for detection of renal calculi. Imaging modalities for detection of nephrolithiasis have centered on abdominal x-ray (KUB), ultrasound (US), and non-contrast computed tomography (CT). Sensitivities of 58-62% (KUB), 45% (US), and 95-100% (CT) have been previously reported. However, these results have never been correlated with endoscopic findings. Methods Idiopathic calcium oxalate stone formers with symptomatic calculi requiring ureteroscopy (URS) were studied. At the time of surgery, the number and location of all calculi within the kidney were recorded followed by basket retrieval. Each calculus was measured and sent for micro CT and infrared spectrophotometry. All CT scans were reviewed by the same genitourinary radiologist who was blinded to the endoscopic findings. The radiologist reported on the number, location, and size of each calculus. Results 18 renal units were studied in 11 patients. Average time from CT scan to URS was 28.6 days. The mean number of calculi identified per kidney was 9.2±6.1 for endoscopy and 5.9±4.1 for CT (p<0.004). The mean size of total renal calculi (sum of longest stone diameters) per kidney was 22.4±17.1 mm and 18.2±13.2 mm for endoscopy and CT, respectively (p=0.06). Conclusions CT scan underreports the number of renal calculi, probably missing some small stones and unable to distinguish those lying in close proximity to one another. However, the total stone burden seen by CT is, on average, accurate when compared to that found on endoscopic examination.
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    Use of a Knowledge-based Iterative Reconstruction Technique, IMR, to Improve Image Quality and Lower Radiation Dose
    (Anderson, 2019) Hameed, Tariq A.; Radiology and Imaging Sciences, School of Medicine
    Use of IMR in Clinical Practice IMR is used in a variety of ways in our practice. Since our department has already reduced radiation dose as part of standard practice, we use IMR to improve the image quality at a given radiation dose. [...]we use IMR for CT angiography (CTA) examinations that require high contrast and high spatial resolution; in these cases, IMR is useful to reduce section thickness and lower noise (Case 5). Because IMR images are virtually noise free, they appear different from iDose4 images. [...]in the initial stages, reviewing images side-by-side with both reconstruction techniques may help to achieve familiarity with the new technique. The dissection flap (red arrow) is also more sharply delineated from the surrounding true and false lumen on the IMR image (C). [...]using the same CT examination, but 2 different processing techniques, it is apparent that with IMR, there is better contrast resolution between the lesion and the surrounding parenchyma, improving the sensitivity for lesion detection and providing better visualization of the abnormality, compared to iDose4.