ADJUNC11VE MEDICAL KNOWLEDGE RadionuclideScrotalImaging:FurtherExperiencewith 210 NewPatients Part2: ResultsandDiscussion DavidC. P. Chen, Lawrence E. Holder,and Moshe Melloul TheUnionMemorialHospital,arkiTheJohnsHopkinsMedicallnstitutions,Baltimore,Maryland J Nuci Med 24: 841—853,1983 RESULTS Clinically these patients had less severe pain, less Acutescrotalpain.The finaldiagnosesof 109patients swelling, and more focal tenderness. The diagnosis is presenting with acute scrotal pain are shown in Table 1. confirmed by the scan findings. In the RNAs of a ma Those who had acute pain but whose complaints were jority of these patients (n 12), there was not enough directly related to trauma are listed separately in Table blood flow through spermatic cord or extra-cord vessels 5. Sixty-nine patients had acute scrotal inflammation to define them. Mild, increased perfusion was noted in that responded to antibiotic treatment. Despite imaging seven patients (four only in the cord vessels and three in diagnosis of inflammation, three patients were operated both cord and extra-cord vessels). Scrotal perfusion in on because the clinician strongly suspected torsion. The 17 patients showed a small area of increased focal ac pathologic results confirmed acute inflammation in the tivity that corresponded to the inflamed portion of the epididymis, with torsion absent. Forty-five patients had epididymis. In two patients the RNAs showed no in acute epididymitis. In 32 of these the RNA pattern creased scrotal perfusion. The scrotal image was ab consisted of increased perfusion through the vessels of normal in all 19 patients, demonstrating a focal area of the spermatic cord and to the lateral aspect of the hem tracer accumulation corresponding to the anatomical iscrotum, corresponding to the usual location of the ep location of the head (n 9), body (n 6), or tail (n ididymis. The scrotal study revealed linear or curvilinear 4) of the epididymis (Fig. 13). increased tracer activity to the head, body, and tail of the Thirty-five patients had acute torsion. Surgical ex epididymis (Fig. 1 1, upper). Displacement ofthe epidi ploration was performed on all but four, with torsion dymis centrally or even medially was noted in 13 of these confirmed. Two patients refused surgical exploration; 45 patients (Fig. 1 1, lower). Five patients had acute one was not operated on because the clinician judged the epididymo-orchitis. Their RNAs showed increased testicle to be nonviable; and another was treated with perfusion through the cord vessels, and not only to the antibiotics because of the primary physician's unsha epididymis but also extending medially to the inflamed kable conviction of infection. Each of these four patients testicle. The scrotal image revealed asymmetric in had testicular atrophy in their long-term follow-up. creased activity extending from the epididymis to the Table 2 summarizes the scintigraphic characteristics testicle (Fig. 12). of different phases of testicular torsion (Figs. 14—17). Nineteen patients had acute focal epididymitis. These characteristics relate to the changes described in the section on pathophysiology. In nine cases a “nubbin sign―was noted in the RNA. We have suggested this Received Nov. 8, 1982; revision accepted Mar. 10, 1983. term to describe a “nubbin―or bump of activity cx For reprints contact: Dr. David C. P. Chen, Division of Nuclear tending medially from the iliac artery (Figs. 15, 16). It Medicine, The Johns Hopkins Medical Institutions, 615 North Wolfe Street, Baltimore, MD, 21205. may be due to the reactive increased blood flow in the C Present address: The Department of Nuclear Medicine, Beilinson spermatic cord vessels, terminating abruptly at the site Hospital Hospital, Petah-Tikva, Israel. of the twist (3). Volume 24, Number 9 841 CHEN, HOLDER, AND MELLOUL TABLE1. FINALDIAGNOSISOF PATIENTSWiTh ACUTESCROTALPAIN imageFinal No.PathologicCorrect diagnosis patientsconfirmationdiagnosis Acute inflammation 69 Acute epididymitis 45 2 45 Acute epididymo-orchitis 5 0 5 Focal epididymitis 19 1 19 Acute testicular torsion 35 Resolved torsion 1 1 1 Early phase (0—7hr) 13 13 13 Middle phase (7—24hr) 5 5 5 Late phase (more than 24 hr)t 16 12 16 Torsion of appendix testis 1 0 Normal 4 1 4 Total 109 35 108 * Patients whose complaints were directly related to trauma are not included in this group. t Three of these patients were imaged more than 5 dayS after initial symptoms of acute pain. They were included here for completenessindescribingthe spectrumoftesticulartorsion. When the radionuclide examination demonstrated an is a case of a false-positive diagnosis of acute testicular early (n = 13) or middle (n 5) phase of testicular torsion. torsion (Figs. 14, 15), surgery was performed immediatly Subacute scrotal pain. Table 3 lists the final diagnoses and all the patients' twisted testicles were salvaged. A of 25 patients with subacute scrotal pain. In ten of them, “missedtorsion―(late phase of torsion) pattern was the diagnosis was nonacute epididymitis. Two of these observed in 16 patients (Fig. 16), and here only two had pathologic diagnosis. This group included two pa testicles were salvaged. One was in a 29-yr-old man who tients who were previously treated for acute epididymitis presented with acute scrotal pain, beginning three days with incomplete or slow resolution, and eight patients before examination. At the time of operation, his left who had mild focal epididymitis and did not seek treat cord was twisted three complete turns and the testicle ment when symptoms originally began. In seven of these was black. The surgeon relieved the twist and put warm ten, their RNAs showed no increased flow in either the gauze on the testicle. About 5 mm later this testicle testicular or pudendal arteries. Three of them did have turned pink, orchiopexy was performed, and follow-up mild increased perfusion in the testicular arteries. Mildly RSI demonstrated a well-perfused testicle. The second increased scrotal perfusion was noted in all patients cx salvaged testicle was in a 27-yr-old who presented with cept one, whose scrotal perfusion was normal. In the a 28-hr history of sudden scrotal pain and an enlarged scrotal study, mildly or moderately increased activity was left testicle. At surgery the testicle was purplish blue, but noted in the entire epididymis (n 3), head (n 1), not hemorrhagic or necrotic. The spermatic cord had body (n = 4), or tail (n = 2). The scrotal imaging pattern twisted only 180°. Bilateral orchiopexy was then per of nonacute epididymitis is indistinguishable from acute formed. focal epididymitis. Manual untwisting was performed on one patient Four patients had scrotal abscess. All originally pre before radionuclide imaging, which proved normal. sented with symptoms of acute epididymitis and were Orchiopexy was performed the same day, and at surgery treated with antibiotics. When their symptoms did not his right testis was slightly bluish. The spermatic cord improve, however, they were referred for RSI to separate was long but not twisted. slowly resolving epididymitis or scrotal abscess from Four patients with acute scrotal pain had normal missed torsion. In their RNAs, profoundly increased studies. Surgery on one of these patients revealed a tracer activity was noted, not only in the vessels passing normal testicle with no evidence of testicular torsion. The through the spermatic cord but also in the pudendal ar other three were followed clinically and did well without tery. Scrotal perfusion was also markedly increased, with subsequent genital problems. One patient had torsion of activity present in the dartos and the hemiscrotum (Fig. an appendix testis. RSI showed a poorly perfused right 18). In the scrotal study, markedly increased tracer ac testicle. Under the impression of early torsion, surgery tivity was seen throughout the hemiscrotum, with an area was performed; a small hydrocele and torsion of a cyst of decreased activity representing the abscess. These four of Morgagni were found; the testicle was normal. This patients were explored and the abscesses were drained. 842 THE JOURNAL OF NUCLEAR MEDICINE ADJUNCTIVE MEDICAL KNOWLEDGE p. 1 2 3 J• 2 3 FIG. 11. Acute epidIdymltls. RNA(upper left): Note actlvfty In testicular and deferentIal vessels (T)and gently curved scrotal perfusion located in expected lateral positIon of epididymis (arrows). (1) 0—5sac, (2) 6—10,(3) 11—15,(4) 16—20,(5) 21—25,(6) 26—30.Scrotal image (upper right): Laterally placed, curvilInear densfty(arrow). RNA(lower left: Activity Inthe testicular and deferential vessels (T)and curvilinear scrotal perfusion to medially displaced epididymis (arrow). lime Intervals as In upper left. Scrotal image (lower ri@t): Medially located epididymis (arrow) that is slightly broader than the average; right (R)and left (L)testIcles are normal. @ @‘<•:@ f:-T 1 2 3 4 5 6 FIG. 12. Epldldymo-orchftis. RNA (left): Increased perfusion through testIcular and deferential vessels (T). Scrotal perfusIon, directed laterally, but curved less obviously In this case, broadens to Include ri@t testicle (R). liming as in Fig 11. Scrotal Image (rI@it): Increased activityInvolvingrighttesticle(R).NormallefttestIcle(L). Volume 24, Number 9 843 @ @, CHEN, HOLDER, AND MELLOUL 2 3 4 5 6 @ ,,@ •, .. ‘ - . R L FIG. 13. Focal epididymitis. RNA (left): No Increased perfusion of testicular or deferential vessels. Area of focal increased scrotal perfusion is seen (arrow). Timing as in Fig. 11. Scrotal scan (ri@t): Focal area